Background and Summary of the invention

The invention concerns, in an aspect, a planetary climate adaptation measure that comprises the dispersal of titanium oxide-containing aerosols to produce bright white fog and cooling clouds, and to brighten dark patches on icefields and any other ground surface that could benefit from whitening, such as open cast coal mines or ice fields. The present invention is linked in many aspects to former publication WO 2023/051858 A1 assigned to the same applicants. As this application is a follow-up application to WO 2010/075856 A1 and in particular WO 2023/051858 A1 , and as it concerns improvements and further developments thereof as well as new aspects thereto, and further in order not to repeat each and every line of text as published, the disclosure of former application WO 2023/051858 A1 is incorporated by reference in its entirety into the present application.

A lot of effort is put in the investigation of climate change and how to influence or amend it. With unprecedented heat waves, droughts and wildfires occurring around the world and the melting of ice, such as Greenland’s ice, accelerating at an alarming rate, it's clear that global policies to curb climate change have failed. In the following, examples are given that are loosely related to the present work, but that also show some downsides that have a negatively affecting potential.

In “Benefits, risks, and costs of stratospheric geoengineering”, Geophys. Res. Lett., 36, L19703, by Robock et Al., 2009, the injection of a stratospheric aerosol is discussed. Sulphur dioxide or carbonate particles should be injected into the stratosphere, to mimic the ‘global dimming’ effect of large volcanic eruptions. For example, the 1991 Pinatubo eruption temporarily lowered average global temperature by around 1°C for two years. However, any particle content in the stratosphere catalyses release of halogen radicals from the dormant halogenated compounds that exist there, thus eventually destroying the ozone layer. Stratospheric aerosols also attenuate UV and the shorter light wavelengths, reducing the natural tropospheric aerosol photolysis that drives depletion of atmospheric methane and other oxidable greenhouse gases. UV index would be expected to decrease by 19% to 20% at 30°N, and 23% to 26% at 70°N. The effect of each aerosol injection into the stratosphere could last up to two years, which is a dangerously long time to wait if unwanted side effects occur, such as unseasonal or extreme droughts.

In “Marine cloud brightening: regional applications”, Phil. Trans. R. Soc. A.3722014005320140053, from Latham et AL, 2014, a proposal to restore climatic conditions by reflecting an additional half percent of the sun's energy is discussed by brightening marine clouds with an aerosol produced from seawater. This, it is claimed, would recover polar ice loss, weaken developing hurricanes and eliminate or reduce coral bleaching. However, no proven technology yet exists to create the required -100 nm, monodisperse droplets from seawater.

Leslie Field discussed in U.S. Patent US 10 980 192 B2 to refreeze the Arctic by floating a blanket of white ceramic microbeads over large Arctic Ocean areas. However, if the beads become bio-fouled, they would reduce rather than increase Arctic net albedo. This would then accelerate Arctic warming, a process that would be difficult to stop and the beads are difficult to remove.

Kholod et Al. describes in “Global methane emissions from coal mining to continue growing even with declining coal production”, Journal of Cleaner Production, Volume 256, 2020, 120489, projections of global methane emissions from coal mining under different coal extraction scenarios and with increasing mining depth through 2100. The paper proposes an updated methodology for calculating fugitive emissions from coal mining, which accounts for coal extraction method, coal rank, and mining depth and uses evidence-based emissions factors. A detailed assessment shows that coal mining-related methane emissions in 2010 were higher than previous studies show. This study also uses a novel methodology for calculating methane emissions from abandoned coal mines and represents the first estimate of future global methane emissions from those mines. The results show that emissions from the growing population of abandoned mines increase faster than those from active ones. Using coal production data from six integrated assessment models, this study shows that by 2100 methane emissions from active underground mines increase by a factor of 4, while emissions from abandoned mines increase by a factor of 8. Abandoned mine methane emissions continue through the century even with aggressive mitigation actions.

In one aspect of this invention, the inventors were confronted with the different requirements that arise when atmospheric methane concentration should be lowered, but at the same time other environmental influences should be kept as low as possible. In addition, the inventors became aware of a problem that is not linked to the former work, and that is an actual net increase in insolation and a decrease in outwardly (out of the atmosphere) directed radiation that takes energy from the heating atmosphere. As a result, more and more energy provided by the sun is kept in the earth’s atmosphere that contributes to global warming. In other words, earth’s albedo is decreasing, where albedo is the fraction of sunlight that is diffusely reflected and thus does not increase the earth’s temperature.

The decrease of the earth’s albedo is particularly relevant at the Arctic and Antarctic surfaces, because a lower albedo leads to an increase in an amount of ice that is melted, where the decrease of ice mass itself leads to a decrease of albedo of this area and in the end to a potentially irreversible loss of ice. For example, albedo decrease that was measured recently involves e.g. the albedo of Greenland’s ice surface that decreased by about 20% over the last decade, from “Changing Greenland - Melt Zone”, Mark Jenkins in National Geographic, June 2010.

Therefore, and to summarize, it is an object of the invention to provide improvements to the state of the art regarding possibilities to reduce climate warming and maybe even to influence or decrease ice melting rates on a local scale regarding a specific glacier or even on a global scale.

The object of the invention is achieved by subject matter of the independent claims. Preferred embodiments of the invention are the subject of dependent claims.

To give a brief example as an outline, as the inventors discovered, by shielding melting icefields from direct sunlight with white fog and clouds, the Tropospheric Oxidation Aerosol (TOA) can be used to help protect and even refreeze polar and mountain ice. In addition, it can reduce open cast coalmine emissions, deplete atmospheric methane and other powerful greenhouse gases, and reduce the intensity of wildfires. These are just some of the ways TOA may be used to postpone or perhaps even avoid dangerous planetary tipping points for the foreseeable future. TOA could be used as an adaptation measure to maintain survivable conditions for the decades needed for greenhouse gas emissions to be significantly reduced, and drawdown technologies developed to restore Earth’s atmospheric greenhouse gas climate forcing to preindustrial conditions.

Herein, a cloud and/or surface brightening Aerosol, that is designed to self-activate when irradiated with electromagnetic radiation, such as sunlight is presented. The Aerosol according to one aspect is photoactive in that incoming irradiation activates the Aerosol, that is understood as “self-activating”, because no manmade input or further means are necessary for the Aerosol to activate. In a cumulative or alternative design the Aerosol may be activated by means of Aerosol droplets in the Aerosol comprising a diameter of 2 m or less. The brightening Aerosol comprises an amount of chlorine, in other words it is chlorine-containing. Chlorine-containing means that Cl is present in the Aerosol, such as hydrochloride or such as atomic chlorine. Hereinafter it will be referred to “chlorine-containing” when the presence of Cl is addressed, and it will be distinguished, for example, in between “atomic chlorine” when the form is preferred, and “chloride” when it is preferred. So the Aerosol preferably comprises such as a chlorine-containing shell and/or a chlorine-containing solution, such as hydrochloride, and comprises a pH value of 3 or lower. The Aerosol further comprises Aerosol-borne particles designed to develop a brightening of a volume unit of the atmosphere and/or to increase an albedo of at least a part of a surface of our planet, wherein the Aerosol, when activated, is also designed to release atomic chlorine into an air volume where the Aerosol is released or emitted to.

Advantageously the Aerosol may be designed such that resulting Aerosol-water-droplets that eventually fall down as rain and/or settle on the ground fulfil any normative regulation in terms of drinkable fresh rainwater. Additionally or alternatively, the Aerosol may be designed to generate potable water.

The Aerosol-borne particles of the Aerosol may be comprising metal, such as at least one of titanium, such as TiO2, or titanium dihydroxy peroxide, or an amount of titanium (I VJchloride that is used as precursor, silicon, such as silicon(l VJchloride (from precursor), or aluminum, such as aluminum(ll IJchloride (from precursor), or a mixture thereof.

The Aerosol may further be comprising at least one of the following substances:

- Si(OH)4, for example including polymeric condensates such as SiO2 and/or SiO2-TiO2 copolymers,

- Ti(OH)4, for example including polymeric condensates such as TiO2, TiO2-SiO2 copolymers and/or TiR4, wherein R = -O-Si(R3), -O-Ti(R3) and/or OH,

- TiO2(OH)2, for example including polymeric condensates such as TO2O, TiO2O-SiO2, and/or TO2R2, wherein R = -O-Si(R ₃ ),-O-Ti(R ₃ ), -O-TO2R and/or OH,

- Fe2O3,

- FeOOH,

- Fe(OH) ₃ ,

- H2O,

- AICI3, for example as an aqueous liquid and/or (solid) shell of a core-shell composition,

- FeCh, for example as an aqueous liquid and/or (solid) shell of a core-shell composition, - AI(NC>3)3, for example as an aqueous liquid and/or (solid) shell of a core-shell composition,

- Fe(NO3)3, for example as an aqueous liquid and/or (solid) shell of a core-shell composition.

Addition of at least one of the additional substances as mentioned in the list above, particularly such as AICI3, may provide for the additional step converting said particles slowly into clay mineral compounds, for example by reaction with seawater.

Additionally or alternatively, the at least one additional substance may be provided as a micropowder, such as nanoparticles. As in the meanwhile there are good availabilities of Fe20s and TiC»2 nano-powders on the market, these powders may be used directly as precursors for aerosol production, for example by turbulent mixing the powder into the carrier gas. By use of such a powder precursor e.g. in the form of a micropowder or nanoparticles, the provision of the chlorine-containing component (such as chloride) to produce the photocatalytic activity of the aerosol can be provided by means of an injection of at least one vaporous chlorine-containing compound from the group HCI, AICI3, TiC I4 or SiCk. The contact of the vaporous chlorine-containing compound with the nano-powder aerosol is done preferably by mixing the aerosol with the vaporous chlorine-containing precursor before emission into the atmosphere, for example within a static mixer or a rotating mixer.

Mixing of the two phases powder aerosol and chlorine-containing vapour may also be provided by contacting aerosol and vapour by help of a propelling rotor, e.g. arranged above their emission stacks. Preferably in this case the emission stacks of the chlorine-containing and powder precursor components, and possibly a third precursor constituted e.g. as hydrogen peroxide as a third vaporous component, may be provided in arranging two (or three) concentric pipes assembled concentrically into each other. The mixture of the two or three components emitting from the concentric arranged stack pipes may be arranged by a propelling rotor.

The addition of at least one of the additional substances as mentioned in the list above, particularly such as AICI3, may further provide the aerosol particles with a relatively high hygroscopicity as to act as cloud condensation nuclei. It may reduce the sublimation temperature of ferric chloride. It may act as chlorine-containing depot in oxic Ti and Si particle aerosols. It may act as gelatinous flocculant for Ti, Fe and Si oxide/hydroxide micro particles as soon as it reaches or sediments into the ocean. It may change Ti, Fe and Si oxide/hydroxide particles slowly into clay mineral compounds by reaction with seawater. And it may provide the aerosol particles with a white color in glacial areas like Greenland so as to avoid coloring by iron and to avoid having iron act as micronutrient for cyanobacteria and other coloring life on the glacier. AICI3 as a component of the Aerosol may also be helpful to fix chlorine-containing to nano-powder TiC»2 particles. While ferric oxide may be covered with a mono- or multiatom chlorine-containing layer shell by addition of HCI and/or SiCk this is not possible for TiC>2 nano-powder: for this purpose AICI3 or FeCh is advantageous as Cl source.

The atomic chlorine may be released in the solid, liquid or gaseous phase. Additionally or alternatively, the atomic chlorine may be released by means of inbound irradiation, e.g. by means of insolation of sunlight, to effectively remove a quantity of atmospheric methane.

The Aerosol may advantageously be designed to perform at least one of the following: to help induce (provoke) cloud formation, preferably low cloud formation such as fog or low stratus, i.e. as a stratiform low cloud, or haze, when the Aerosol is emitted into the atmosphere, and wherein the Aerosol further increases the cloud’s albedo; and/or: to brighten existing clouds by increasing a droplet concentration of cloud droplets per unit volume; and/or: to brighten existing clouds by decreasing a droplet diameter of cloud droplets; and/or: to brighten an earth’s surface when it is spread over said surface, like Arctic or Antarctic ice areas; and/or: to brighten gas-borne soot particles, for example when released into a soot-containing exhaust gas, and/or smoke e.g. from wildfires or slash and burn practices.

The before-mentioned compound may additionally be comprising the chlorine-containing solution and the Aerosol-borne particles as a composition. In a particularly preferred further development, the composition may be provided as a core-shell composition, where the core comprises said brightening particle or particles and/or wherein said shell comprises said chlorine-containing solution, that is preferably also a nitrate-containing solution. Additionally or alternatively, said shell may form a coat on said particle or particles.

The majority of the particles may preferably comprise a diameter of less than 1 pm. Additionally or alternatively, the Aerosol may be provided in a monodisperse form. Monodisperse may be understood in that the diameter of the particles has a small spread, so that the individual particle diameter is close to the mean diameter. Additionally or alternatively, the particles may comprise 5 % or less than 5 % of an impurity material.

The composition may be comprised as a core-shell composition of droplets, wherein for example each droplet comprises a mean diameter of 1 pirn or more. Said core of said core-shell composition may comprise silicon, for example as Si(OH)4. Further, said shell may comprise said particles, such as titanium, for example as TiC»2 or, particularly preferred, titanium dihydroxy peroxide. The titanium dihydroxy peroxide may be obtained by addition of H2O2 to produce TiO2(OH)2.

Said chlorine-containing solution may additionally comprise chlorine or chloride in an amount of at least 1 weight %. Alternatively or additionally it may comprise nitrate in an amount of at least 1 weight %. Alternatively or additionally the pH of the Aerosol may be conditioned by means of an acidification of the chlorine-containing solution. Further alternatively or additionally the conditioning of the pH value of the Aerosol may be performed by means of adding a gaseous or vaporous acidifier to the Aerosol, wherein, for example, the acidifier is elected from a group of components that generate hydrochloric acid by means of hydrolysis and/or from the group of components containing one or more N-0 and/or N-O- H bonds.

Said particles may further be provided as a solid hydrolysate. Alternatively or additionally the Aerosol may further comprise ferric iron as an ion in liquid solution or in solid state. Additionally or alternatively, the chlorine-containing solution may comprise nitrate and/or nitric acid in solution.

As a further aspect of the present disclosure there is shown a precursor for use in the composition of an Aerosol as mentioned above, the precursor comprising at least one of the following:

- SiCk gaseous or liquid,

- TiCk gaseous or liquid,

- AlCh gaseous or solid,

- FeCh gaseous or solid,

- FeCh x nH2O as a solid or liquid hydrous solution,

- Fe(NOs)3 x nH2O as a solid or liquid hydrous solution,

- AlCh x nH2O as a solid or liquid hydrous solution,

- AI(NC>3)3 x nH2O as a solid or liquid hydrous solution,

- HNO3 as a liquid or a liquid hydrous solution,

- NO2 gaseous,

- HONO gaseous,

- NO gaseous,

- N2O4 gaseous,

- N2O3 gaseous,

- N2O5 gaseous and/or liquid,

- CINO gaseous,

- CINO2 gaseous,

- H2O2 as a liquid or a liquid hydrous solution,

- TO2 as a solid powder or a hydrous liquid suspension,

- TiO2(OH)2 as a solid powder or a hydrous liquid suspension,

- H2O as a liquid or vapour, e.g. from a power station cooling tower.

In the present specification there is further described an Aerosol generator for generating the Aerosol as defined above, the generator comprising a first precursor device for providing a first Aerosol precursor containing brightening particles, a second precursor device for providing a second Aerosol precursor, wherein the second precursor is provided as a rapid gas-flow and the first precursor is injected or mixed into said second precursor. The Aerosol generator may be further developed in that it comprises concentric nested pipes for emission of said first and second precursors.

An apparatus for the generation of a brightening Aerosol may also be constituted with a greenhouse area covered by means of a greenhouse cover and a top opening arranged at a top side of said greenhouse cover. The apparatus may further comprise that the top opening is closable by closing means. Such closing means may be designed iris-like. Additionally or alternatively, such closing means may be a multipart closing means comprising several movable parts that can slide into each other.

Further, herein an apparatus is sketched for the generation and/or release of a brightening Aerosol, such as defined above. The apparatus comprises a greenhouse arrangement for warming up a gas inside the greenhouse arrangement, a buildup chamber that is connected to or arranged in the greenhouse arrangement designed such that a pressure differential to an outside and/or with respect to said greenhouse arrangement can be established. It further comprises a monodirectional valve arrangement between the greenhouse arrangement and the buildup chamber that is designed to let pass said gas from the greenhouse arrangement into the buildup chamber, it is thus an inflow valve for the buildup chamber. The warmed gas can be provided from the greenhouse arrangement to the buildup chamber for loading the buildup chamber with an Aerosol. Further an outlet for release of the Aerosol into an outside is provided as well as an adjustable pressure modulator for adjusting a gas pressure in the buildup chamber.

Said adjustable pressure modulator may further comprise an outlet cover for at least partly covering the outlet of said buildup chamber. Additionally or alternatively, said adjustable pressure modulator may provide means for compressing an inner volume of said buildup chamber. These means may preferably be designed to provide a pressure pulse in the buildup chamber. Additionally or alternatively, the apparatuses may further be designed to eject a parcel of Aerosol through the outlet upon pressure buildup in the buildup chamber.

The adjustable pressure modulator may further comprise an outflow stabilizer, by means of which an ejected Aerosol packet is able to be emitted further away. For example the outflow stabilizer induces a rotational movement on the Aerosol packet in order to promote or alter an intrinsic movement that stabilizes the Aerosol packet, such as a vortex.

The apparatus may further comprise an extendable bellow to seal portions of the buildup chamber against undesired outflow of Aerosol and to improve pressure buildup in the buildup chamber. Additionally or alternatively, further at least one camshaft and a motor for moving said camshaft may be comprised. The camshaft may be designed to lower and/or raise the outlet cover (16) such as for pressure buildup.

For example any of the apparatuses as mentioned before as well as the apparatuses that will be described hereinafter can be designed as a vertical axis rotating vortex generator, for example following the Louat-Michaud principle. Then it would be preferred to arrange the aerosol emitter within the lower end of the vertical vortex. In other words, the installation might be used in principle as a classic vortex engine according to the Louat-Michaud principle, for example if the cover is kept fixed and unmoved. To optimize this device for generation of the Louat-Michaud vortex generation 3 or more large openings could be provided in between the greenhouse arrangement and the buildup chamber to increase the open area and reduce the pressure difference between inside and outside the buildup chamber to a minimum.

Further, an apparatus for the generation and/or release of a brightening Aerosol is described comprising an exhaust chimney for releasing the Aerosol into the atmosphere, a reservoir designed to provide storage for microparticles, such as nanosized particles, a particle inlet to allow said microparticles to enter the exhaust chimney, and a second transport line to deliver a transport fluid, such as compressed air, where the exhaust chimney is designed such that by means of providing said transport fluid the microparticles are carried through the exhaust chimney and out into the atmosphere to form an Aerosol plume.

That apparatus may further comprise a venturi nozzle in the exhaust chimney to further increase a pressure gradient. Additionally or alternatively the microparticles may be provided in a solid state, e.g. as a powder.

Further in this specification the use of the Aerosol as defined above is defined, e.g. in order to decrease hydroxyl radical depletion induced by wildfire carbon monoxide (CO) emission and/or to decrease a lifetime of a flue gas component emitted by said wildfire. Said flue gas component is particularly black carbon or soot. Such a use process contains the steps emission of the Aerosol in a proximity to a wildfire, such as upwind thereof, so that said CO, in the presence of atomic chlorine as provided by said Aerosol, reacts with water vapor and oxygen in a catalytic or quasi catalytic, self-replenishing process.

In yet another use of the Aerosol dotation of an exhaust gas that comprises soot particles is defined, so that said soot particles are disabled and/or self-induced convection or photophoresis is prevented and/or become reduced in their lifetime in the atmosphere in that they become hydrophilized by catalytic and/or photocatalytic oxidation. In disabling it is understood to stop or significantly shorten flying motion of the soot particle(s) so that they return to ground. In an example the weight of the soot particles can be increased. But interestingly, the soot particles are carried in the air partly due to their ability to heat up the air parcel directly surrounding the respective soot particle, and by convective movement they are carried higher up in the atmosphere, until eventually even reaching the tropopause, or even the stratosphere. By “deactivating” the soot particles they’re either washed out of the sky or are brightened sufficiently that they lose the ability to sufficiently warm up the air parcel they are floating in, thus stopping the convective process.

By means of an apparatus or an aerosol an ice cover is producible. Therefore, an ice cover generated by means of emission of the Aerosol as defined above is defined that comprises titanium dioxide as a bright or white hydrolysate gel. Such an ice cover may further comprise silicon dioxide as a bright or white hydrolysate gel. Additionally or alternatively the ice cover may be a binder-free cover. It is particularly preferred to utilize binder-free material, where e.g. the cover (gel) is not fixed to the ice, but adheres by friction.

First selected embodiments

When dust and smoke from human activities and smoke from forest fires gets deposited on icefields it darkens them. This dark material also provides nutrients for the growth of biofilms, and other sessile life, further lowering the ice albedo. But when ice is melting this also exhibits a

The large-particle formation process happens as follows: The nebulised silicon tetrachloride droplets quickly react with moisture in the airstream to form silica (SiO2) particles, possibly with an alumina content. As titanium tetrachloride vapour is added to the airstream these silica/alum ina particles gather a TiC k / AICI3 coat in the air. This coat then reacts in-situ with remaining moisture in the air, becoming an oxide coat on the original particle. The use of SiCk / AICI3 as feedstock for particle cores and the addition of AICI3 for the coat reduces the overall cost and enables titanium-based feedstock supplies to go further.

Each tonne of TiCk is expected to measurably whiten several square kilometres of ground or ice with settled TOA particles. The degree of whitening depends on the concentration of settled particles. The effect of bright white clouds passing over sunlit icefields during the melting season will be to slow their rate of melting. In winter-time and at night-time when ice naturally forms, TOA applications should be paused to allow heat to radiate out to space through unmodified skies. This asymmetric pattern of application may enable the refreezing of ice fields.

TOA seeded clouds may also induce snowfall that might otherwise have landed as rain, as has begun happening even at high elevations in Greenland.

A small component of ferric chloride in the TOA feedstock is included mainly to add into the resulting clouds a more efficient mechanism for photocatalytic production of Cl radicals. Such a component might be added when it is not intended to generate deposits on icefields. No meaningful or useful interaction is expected between the other TOA particles and ferric chloride particles. Instead, since ferric chloride remains solid below around 250°C, ferric chloride particles are expected to coexist separately in the same cloud, operating independently. The ferric chloride particles’ photolysis process will benefit from the abundance of the HCI educt of the reaction of the other chlorine-containing feedstocks, enabling efficient methane depletion in the cloud while it remains airborne in sunlight.

However, TOA clouds with a ferric chloride component passing over sunlit wildfires will convert carbon monoxide (CO) produced by them to CO2, deplete the wildfire methane emissions, add additional °OH radicals and render the smoke particles more easily washable out by rain.

Titanium oxide, the white highly reflective property of TOA may be formed in the atmosphere (air) from hydrolysis of titanium tetrachloride (TiCk) by moisture. When vaporised to air SiCk, AICI3 and TiCk immediately react with the water vapour content of the air, producing HCI gas and respectively solid SiO2, Si(OH)4, AI2O3, TO2 and/or Ti(OH)4 particles, by e.g. the following reactions:

SiCk + 2H ₂ O — > SiO ₂ + 4HCI

SiCk + 4H ₂ O — > Si(OH) ₄ + 4HCI

TiCk + 2H ₂ O — > TiO ₂ + 4HCI

TiCk + 4H ₂ O — > Ti(OH) ₄ + 4HCI

2AICI ₃ + 3H ₂ O - AI2O3 + 6HCI

HCI gas occurs naturally in the atmosphere, and TOA particles pose no threat to the environment at the concentrations needed to refreeze polar and mountain ice. The troposphere naturally contains aerosol particles of pH between 0.5 and 2.0. TOA-seeded clouds that rain out over forests would cause minimal harm, if any.

TiCk and SiCk are liquids at room temperature. TiCk boils at 130°C. SiCk boils at 58°C. Since each liquid readily dissolves into the other, they could be dispersed together as a mixed solution. AICI3 sublimates at -180°C. FeCh sublimates at ~250°C. Mixing these two anhydrous powders together enables a sublimation temperature closer to that of AICI3.

Where particles are formed with a silica core and titanium oxide coat or shell (core-shell particles), it is preferred to create a silica/alumina aerosol first, and then apply the Ti/AI oxide coat immediately after further downstream in the airstream. This necessitates storing and dispersing the chlorine-containing feedstocks separately. FeCh and AlCh do not readily dissolve in the liquid chlorides, and so may need to be vaporised separately in separate sublimation chambers. The TiCk feedstock may contain only up to 2.9% by weight FeCh content dissolved into it. AICI3 solubility in the liquid chlorine-containing feedstocks is similarly low. Conversely the content of ferric chloride and aluminium chloride in a mix of vapours of TiCk and/or SiCk does not depend on any liquid solubility limitations, they can therefore be mixed in any combination of concentrations.

Whether mixed or stored and emitted separately, the whole chlorine-containing feedstock taken together always contains at least 1% TiCk by weight. TOA particles are hygroscopic and so become coated by water. The HCI educt of the reaction readily dissolves in the water coat of each particle. When a TOA particle coat freezes, the HCI content naturally evaporates out from it.

HCI on TiO ₂ is mainly attracted by the weak H2O base surrounding the TiO ₂ particle. Water holds the HCI by changing from the neutral H2O water molecule into the hydronium cation H3O+ by capturing the proton from HCI, producing a chlorine anion. Since water is a weak base any dryness, for example caused by freezing, changes the chlorine-containing hydronium back into water molecules and HCI. Hence the HCI leaves ice by simple evaporation.

Aerosol production processes and devices

Three different processes are proposed at this point. All involve introducing a chlorine-containing feedstock into a fast-flowing gas stream containing at least 90% air, which could be:

- air flowing past an aircraft in flight,

- air flowing down from a helicopter, driven by its rotor, - exhaust gases from a jet engine

- air driven by an air pump or fan

- a strong wind, etc.

For example it is proposed to continuously introduce the entire chlorine-containing feedstock into the gas stream as a vapour.

Alternatively, it is proposed to continuously introduce a mainly silicon tetrachloride feedstock into the gas stream as a nebulised droplet aerosol. These droplets immediately hydrolyse with moisture in the gas stream to silica (SiC»2) and Silica acid Si(OH)4. A vapourised mainly titanium-tetrachloride feedstock is then continuously added at a point downstream where the silica particles are forming, such that the silica particles become coated either by titanium oxide or titanium-tetrachloride (or both) and the TiCk reacts with remaining moisture in the gas stream so that the silica particles end up with at least a partial TiC»2 coat.

In yet another embodiment it is proposed to continuously nebulize a single mixture (solution) of any combination of chlorine-containing precursors into the gas stream as a droplet aerosol. These droplets become hydrolyzed by moisture in the air, becoming a hydrolyzed particle comprising at least TiC»2 but preferably at least 10% TiC»2 (and/or Ti(OH)4) or more.

The three before-mentioned processes produce oxide particles hydrolyzed by moisture in the air, and the HCI educt of the reaction. They thus end up containing and/or being coated with hydrochloric acid.

In the following, three types of device are proposed for the production of the aerosol. The first type produces mainly <1 pm diameter TiC»2 aerosol particles, most of which do not sediment until removed from the air by precipitation (snow or rain).

The second and third types produce mainly >1 pm diameter TiC>2 / Ti(OH)4 aerosol particles. These larger particles are heavy enough to fall immediately out of the air.

The two modes of TOA dispersal are hereinafter termed small-particle mode TOA, and large-particle mode TOA. The weight fraction of particles having a diameter of 1 pm or less in the small-particle mode TOA resulting aerosol is -80%. The weight fraction of particles in the large- particle mode TOA having a diameter of 1 pm or less in this aerosol is -30%.

Since both methods produce a fraction of TOA particles that have a diameter of 1 pm or less it is possible to make white clouds with both of them. For this purpose, the TOA from vaporous origin needs less chlorine-containing precursor feedstock than TOA from nebulized origin for the same number of resulting oxide particles.

The afore-mentioned devices store their feedstock of liquids in preferably a plastic tank. Each liquid is pumped to the outlet by a pump. Where FeCh and AlCh are included as solid feedstock these must be sublimated separately, and their vapour(s) mixed with vapour produced by boiling SiCk / TiCk liquid(s).

All devices must disperse their vapour or droplet aerosol into the air away from the object hosting the device, and away from any other material vulnerable to corrosion by acid or the chlorine-containing precursor feedstock.

Small-particle mode TOA is preferably produced from a vapour produced by pumping chlorine-containing precursor vapour into a pipe heated preferably to ~200°C that moves the mixed vapours to an emission point that emits the mix to an airstream as vapour.

Large-particle mode TOA is produced by initially pumping mainly SiCk into a nebuliser, such as a spray nozzle or spinning disc that sprays the liquid chlorine-containing feedstock droplets into an airstream. The oxide coating is applied by emitting the appropriate chlorine- containing vapour into the airstream containing mainly SiCk droplets hydrolysing in the air from its water vapour content.

Alternatively or additionally, as the case may be, a fixed wing aircraft-based device could be used in order to disperse the aerosol from an aircraft. It may consist of a simple heated pipe outlet mounted on the back of the fuselage, and/or one or more pipes at the trailing edge of each wing. For heat sources, the hot flue gas jet produced by the (jet) engines or piston engines may be used. The air flow during flight keeps the emitted TiCk away from the craft itself.

Ships, boats, hovercraft and ground-based devices could also be used. They need a strong fan or jet engine to create an airstream as preferred for the aerosol particle formation process, to thrust the aerosol several hundred metres up in the air, to ensure sufficient spreading of the aerosol.

A preferred area of application is modern wind turbines to produce the energy for heating the chlorine-containing feedstock, and at the same time due to their size, as a platform for dispersal. The rotor blades of these devices are ideal for the emission of the Aerosol plumes that are described herein. Suitable for this purpose are, vaporous TiCk alone or a mixture of vaporous titanium tetrachloride with one or more vapors of silicon tetrachloride and/or titanium tetrachloride and/or ferric chloride and/or aluminium chloride.

TOA dispersal should be from the leeward side of one or more turbine blades. Each chlorine-containing feedstock must be boiled or sublimated separately, then mixed with the other vapour(s) and moved along pipe(s) heated preferably to ~200°C fitted behind one or more turbine blades to an outlet on each blade. Emissions to the air of the vapour mix will immediately create a dense fog that will blow over the melting ice and down to the coast.

These chlorine-containing vapors are emitted from pipe openings situated on the rotor blade sides which are facing away from the wind. According to the blade position the relative velocity of the pipe openings is large enough to develop a pressure drop inside the pipes which will suck out the chlorine-containing vapor. The vapor arrives at the blade outlets from boilers which boil the chlorine-containing liquid (SiCk and TiC k) for production of chlorine-containing vapors or sublimate the chlorine-containing solid (FeCh and AlCh) for production of chlorine-containing vapors. The chlorine-containing vapor becomes conducted by pipe connection from every boiler and or sublimator into a heated chlorine-containing vapor collector to prevent the vapors from condensation. This vapor collector is connected with every rotating blade of the wind turbines by a heated rotating pipe.

The chlorine-containing vapors of Ti, Si and Al emitted by the rotor blades produce a white hydrolysate fog which contains nanometric primary oxide particles containing O-bridges between the metallic elements and hydroxyl groups at the particle surfaces. Given the high relative humidity level these primary particles are coated by hydrochloric acid. Given its high refractive index the vapour of TiCk produces the most reflective fog.

Particles up to 10% by weight Ti-hydrolysate produced by mixed vapors of Ti-, Si- and Al-chlorides are nearly of the same reflectivity as the fog produced by pure TiC k.

Only the fogs produced by Fe-containing chlorine-containing vapors have significantly less reflectivity even at an amount of only 10 weight% of Fe hydrolysate, because Fe does not completely hydrolyze at these conditions. Even the mixed hydrolysate does not contain hydrolyzed ferric chloride in solution or even solid substance.

For remote locations, for example, aircraft may be used for refilling the chlorine-containing storage containers and potentially would not be needed for TOA dispersal.

TOA may provide for example for the following three cooling mechanisms:

First, in order to form clouds, that increase albedo, by means of the TOA aerosol droplets may be nucleated that form white clouds in air that is super-saturated with water vapour (100% relative humidity). Low lying clouds are known to have an overall cooling effect. That is because over a 24-hour period they typically reflect more of the sun's energy away than the energy they trap beneath them. If any deleterious cloud cooling effect is detected the TOA intervention can be stopped immediately, with the effect then lasting a maximum of a few weeks.

Second, increasingly icefields around the world are developing dark patches from deposited smoke and dust particles. TOA may be designed to settle onto polar areas inside snowflakes that are whitened by its presence. These whitened snowflakes will more readily reflect away sunlight than ordinary snowflakes, and thus may whiten these surfaces. The deposition area of the aerosol may be elected by means of the place of release of the aerosol and the particle size, that influences the distance the particles are borne over air.

Third, icebound sessile life growth, such as microbial biofilms, algae, plants and fungi may be suppressed by the oxidative effect of OH and CL radicals. These radicals are produced by the photocatalytic action of sunlight on the settled aerosol particles. Airborne TOA particles also photo-catalyse production of OH and Cl radicals. These radicals already occur naturally, and it is their oxidative power that drives the main mechanism by which methane is naturally removed from the atmosphere. So, the presence of TOA in sunshine will speed up natural atmospheric methane depletion, curbing the warming acceleration globally. Since wetland methane emissions are already rising, and soil CO2 emissions are projected to rise as the planet warms, curbing global warming acceleration will slow these self-reinforcing feedback loops and numerous others.

The Aerosol may further provide protection of °OH radicals from depletion by wildfires. Any ferric chloride particles or ferric chloride content of the TOA particles may be hydrolyzed and contained within a nitrate and/or chlorine-containing coat. This is an advantageous state for effective photolysis of chlorine atoms. Chlorine atoms have a strong affinity for the gaseous phase and so move out of the particles into the air. In the air over wildfires Cl atoms oxidise carbon monoxide (CO), producing HCI:

CO + °CI + H2O + 72O2 - CO2 + HCI + °OH

HCI has a strong affinity for the liquid phase. Thus, HCI moves back into particle coats, resupplying the particles with the chlorine needed for the process to continue repeatedly in the presence of sunshine. This means there is no limit to the amount of CO that can be depleted, because the process is essentially catalytic.

However, a major amount of the aerosol will eventually find sooner or later its way into the ocean. Most of the open ocean exhibits a quite low primary productivity because of extremely low concentrations of iron micronutrient. Where small-particle mode TOA is used to create ocean cooling clouds a ferric chloride component is recommended, to first deplete atmospheric methane and then, when it is rained out into oligotrophic HNLC ocean regions, diffusely fertilise the ocean areas where the aerosol is rained out.

Usage of the aerosol, in particular the embodiment that is called TOA herein, addresses the following near-term global threats to the climate: A first threat includes the Arctic warming at around four times the global average, in part due to its loss of albedo (reflectivity). Areas of open Arctic Ocean during the summer months are absorbing heat from the sun instead of reflecting heat away, as they did only a few decades ago when the Arctic was mainly covered by ice. In order to address this threat, wind turbine-mounted dispersal units may be placed on the Northern Canadian, Greenland and other Arctic Island or coastal glacial surfaces further inland than the location of the fast-melting margins of the ice caps. For example, continuously blowing katabatic winds will then drive the fine fraction of the white fog to the adjacent sea surface which will warm up and produce clouds, which then will become a bright white color and highly reflective. In the Arctic these winds will blow a long column of cloud over large parts of the Arctic Ocean, slowing its rate of ice melting during the mid-summer months.

Fortunately, winds continually blow over the North Pole and all around the Arctic Ocean during summer months. Therefore, shipmounted units could additionally disperse TOA to form cooling clouds at suitable times and locations determined by weather forecasting.

The settling of fine TiO2 particles onto surface waters would increase their albedo for several days or weeks until they are advected several metres below. They could be applied to areas of blue water (as seen from space) where little or no phytoplankton is currently growing. Such high albedo (turquoise coloured) seas already exist where coccolithophora naturally grow in abundance in locations such as the Caribbean Isles. Therefore, little or no harm to ocean ecosystems is expected.

A second threat that currently seems to be the biggest threat is of sea level rise caused from loss of Greenland and Antarctic glaciers. The most unstable of these exist at the edges of these ice sheets. The extent of unstable glaciers / ice sheets on Greenland and the Antarctic today is reaching the order of 100 km inland. It may therefore be too costly to cover such large areas with large particle TOA, other than the most severely melting dark patches.

Fortunately, katabatic winds blow continuously from the centre of these land masses towards their coastlines. This presents an opportunity to place bright white fog dispersing wind turbines inland beyond the extent of the melting ice for operation during summer months. Such fog blows over the melting ice down towards the coast and out to sea, curbing its melting rate. The warmer calmer more humid air coming off the sea will lift the fog up, seeding cloud formation, and providing sun screening to coastal waters, curbing their warming too, and helping to protect the underside of ice shelves and overhanging glaciers from melting.

Any aerosol particles settling on the ice before reaching the coast will provide longer term shielding. When the ice these particles settle on eventually melts and flows to the coast down through moulins it discharges into coastal waters and will cover them with a milky white TOA particle-rich layer, further protecting them from sun warming. Since the discharged glacial waters are fresh (not salty) they float on the surface above the denser salty water, providing further protection from sun warming for several weeks or months after discharge, further curbing the warming of these coastal waters during summer months.

A third threat concerns “permafrost methane bombs”. Since permafrost is already melting in high latitudes and releasing microb ially generated methane, the prospect of a near-term ‘microbial methane bomb’ seems to become real in near future. In addition, large areas of permafrost protect frozen methane hydrates beneath them, which are beginning to release methane as the protective permafrost layer above them melts away. Therefore, curbing summer warming of these large areas with cooling clouds will curb this additional dangerous feedback loop. Again, the Aerosol particles, when settled will curb methanogenic microbial growth by the oxidative action of the OH and Cl radicals generated by sunshine.

A fourth threat concerns loss of urban water supplies. Mountain glaciers such as those on the Himalayas, Andes, and Rockies provide a year-round water source to huge rivers that are the main water source to over a billion people around the world. Many of these mountain glaciers are expected to disappear over the coming decades due to climate change and could at least in part be preserved by TOA interventions. Bright white clouds formed from small-particle mode TOA will help protect numerous glaciers from excessive summer melting. Large-particle mode TOA deposited on dark patches, for example by aircraft, will help protect individual glaciers.

A fifth threat concerns increasing amounts of extreme weather events. Meteorological data can be used to determine the optimal time and location to create and/or brighten marine clouds to restore clement, predictable weather patterns such as monsoon rains, and to reduce the intensity of hurricanes. Detailed planning of this type has already been proposed for Marine Cloud Brightening interventions and could be leveraged for TOA interventions similarly intended to modify weather patterns. In these cases, small-particle mode TOA is recommended for application over the ocean.

A sixth mode of use includes wildfire suppression. TOA aerosol fog and clouds released over areas vulnerable to wildfires will cool them and help prevent them from becoming dangerously dry. If a fire still breaks out, inclusion of ferric chloride will deplete some of the methane coming

AICI3 can also be produced by the carbo-chlorination route, for example from bauxite, which produces AICI3 plus impurities such as FeCh, TiCk and SiCk. However, since these impurities are constituents of other TOA chlorine-containing feedstock, they can remain in the AICI3 feedstock.

But where TOA is intended for inhabited locations such as ski resorts AICI3 impurities should be removed. This can be done by adding SiCk to TiCk during its manufacture, which produces a harmless clay mineral educt. This AICI3 removal process increases the cost but is recommended for applications to areas close to human habitation.

If supply of titanium ores (mainly Ilmenite and Anatas) runs short, a mixture of TiCk, SiCk and AICI3 can still produce TOA. Even if the mixture contains only 10% TiCk in SiCk the resulting aerosol ice cover can still be highly reflective. The main drawback is that the lower TO2 content will reduce the aerosol’s °OH and °CI radical production in the presence of sunlight and therefore methane depletion capacity. However, FeCh aerosol is much more effective at producing °OH and °CI radicals. The addition of FeCh to the chlorine-containing feedstock mix will therefore enhance the TOA’s °OH and °CI radical production in the presence of sunlight.

To summarize, in these first embodiments, the focus lies on an Aerosol of white TiC»2-containing particles, covered with a coat of, or contained within a droplet of mainly hydrochloric acid, which provides a cooling effect by at least one of: producing white cooling clouds in the troposphere, whitening existing tropospheric clouds, increasing the albedo of surfaces it settles on by whitening them, preserving ice albedo by suppressing growth of terrestrial icebound sessile life that it settles on (microbial, biofilm, algal and plant growth) by shielding them from sunshine, and/or in the presence of sunshine producing °OH and °CI radicals, thereby providing further potential cooling by: further suppressing growth of terrestrial icebound sessile life that it settles on, which further increases the albedo of the icefield, reducing its temperature, and/or depleting atmospheric methane and other greenhouse warming agents, which reduces wetland, permafrost, and soil temperature, reducing their microbial methane and CO2 emissions.

Further, the Aerosol can develop a ground or ice surface covering produced by this aerosol wherein it either settles directly or is precipitated out in snow or rain. Such a surface cover preferably contains by weight: between 1 % and 100% TiO2, between 0% and 99% SiO2, between 0% and 99% AI2O3, and/or between 0% and 90% FeCI3.

The Aerosol and ground and/or ice surface covering produced by the aerosol that is dispersed into the troposphere may be used for cooling at least one of the following areas: Arctic, Antarctic, Greenland, and Patagonian ice, mountain and coastal glaciers, areas of permafrost, areas of low albedo land, abandoned or in-use open cast coal mines, areas of open ocean.

In these first embodiments, a process by which the aerosol and/or surface covering is produced, may be described wherein: a vapour of TiCk (that is preferred, and it may contain impurities), or a pre-mixed vapour of TiCk and SiCk, or a pre-mixed vapour of any combination of TiCk, SiCk, AlCh and FeCh, is directed into a fast-flowing gas stream containing at least 90% air. Herein, the vapour reacts with water vapour present in the gas flow and the atmosphere it mixes with, to produce particles: of TiC>2, or containing TiC>2 and SiC>2, or containing any combination of TiC»2, SiC>2, AlCh and Fe2O3. Most of the particles produced herewith comprise a diameter of less than 1 pm. The vapour and particles may contain up to 5% impurities. The particles contain water and HCI by hydrolysis and moisture absorption. Water vapour becomes adsorbed onto the particles, forming an aqueous coat, and HCI dissolves into the particles’ aqueous coats by hydrolysis.

The process for production of the Aerosol and/or the covering may alternatively or cumulatively comprise steps in order to generate droplets mainly greater than 1 pm in diameter. It is laid down by forming in a first step a silica particle aerosol from vaporous or liquid droplets of SiCk in a fast-flowing gas stream containing at least 90% air, by that SiCk reacting with water vapour in the airstream, and the silica particles of which then in a second step are coated downstream in the airflow with, by weight of coating, between 90% and 100% TiC>2, and between 0% and 10% Fe2Os Herein, the silica (SiC>2) particle is coated with TiC»2 and AI2O3 or just TiC»2 produced by reaction of moisture in the airstream and the vapour produced by boiling a solution mixture of TiCk with AlCh or just liquid TiCk. These large-size aerosol particles fall out of the air quicker or more readily than the aerosol particles produced by the process as mentioned directly before. The feedstock and particles may contain up to 5% impurities.

The process by which the aerosol is produced may alternatively or cumulatively comprise, wherein a droplet aerosol, that is comprising: liquid TiCk, or a pre-mixed liquid of TiCk and SiCk, or a pre-mixed liquid of any combination of TiC»2, SiC>2, AlCh and FeCh, is produced with droplets mainly greater than 1 pm in diameter in a first step, which are then directed into a fast-flowing air and / or flue gas stream that is flowing into the troposphere, whereby water vapour in the gas flow and/or troposphere reacts with the droplets thereby precipitating solid, coagulating particles comprising the oxide educts, until the chlorine-containing compound(s) is/are fully reacted, whereupon each primary particle/droplet: becomes hydrolyzed by the adsorption of further water vapour in the surrounding air, the HCI educt from the reaction dissolves at least in part into the water content of each particle, these larger aerosol particles fall out of the air quicker or more readily than the aerosol particles, and may contain up to 5% impurities.

The process may alternatively or additionally comprise nucleating new cloud droplets in the troposphere, resulting in white clouds, owing to: the increased number of smaller cloud aerosol particles, the white colour of the Aerosol particles.

A device as discussed before and that produces the aerosol and covering as described before with the process as described before may comprise a composition of: a liquid of TiCk, (that is preferred, and may contain impurities), or a pre-mixed liquid of TiCk and SiCk, or a pre-mixed liquid of TiCk, SiCk and FeCh. The composition is held in a tank and is pumped into a heated metal pipe or chamber that boils the liquid, causing it to be vaporised, wherein the pipe emits the vapourised liquid into the fast-flowing gas stream specified before, and the vapour outlet is constructed of an adequately alloyed stainless steel or other material able to withstand corrosion by the hot vapour and/or acid corrosion.

Such a device that produces the aerosol may alternatively or cumulatively comprise: either a hot chamber or pipe vapourises the SiCk liquid; or a nebuliser such as a spray nozzle or spinning disc nebulises the SiCk liquid; into a fast-flowing gas stream containing at least 90% air, and a hot chamber or pipe vaporizes the TiCk or TiCk / AlCh mixture into the resulting silica particle aerosol, resulting in the silica aerosol particles becoming coated with TiC»2 or a mixture of TiC>2 and AI2O3.

Alternative or cumulatively, the device that produces the aerosol may comprise wherein one or more mechanical nebulizing devices such as spray nozzles or spinning discs produce liquid droplets approximately 1 pm in diameter, and/or comprising the chlorine-containing precursors specified before, wherein these droplets enter and mix with the fast-flowing gas stream. Such a device may be mounted on and/or operating from: a wind turbine, a marine vessel, that is used as a synonym for ships, boats or hovercraft or the like, aircraft, including helicopters and tethered balloons, road vehicles or trailers, snowcat snow compaction vehicles, chimneys or industrial flue outlets, oil and/or gas platforms.

The process may be alternatively or cumulatively designed by preventing carbon monoxide (CO) from wildfires from depleting °OH radicals from the air. Instead the presence of °CI radicals from the photocatalysis of TOA and ferric particles reacts the CO with water vapour and oxygen, producing new °OH radicals, CO2 and HCI, wherein the HCI educt becomes naturally recycled back into the aerosol particles, making the process effectively catalytic in the presence of sunshine.

Second embodiments

Further, an Aerosol and aerosol generated coat, method and device for its production as a means for Earth’s albedo increase by cloud and/or ice sheet whitening, cloud generation and/or depletion of greenhouse gases is described. Another interesting cooling feature that may be provided by the aerosol is an ability to produce chlorine atoms from its chlorine-containing components for the purpose of atmospheric methane depletion. Chlorine atoms react with methane molecules in the atmosphere to produce methyl radicals by dehydrogenation. These methyl radicals are then rapidly oxidised by the oxygen compounds of the atmosphere to CO2, which has a much smaller greenhouse warming effect than methane.

Chlorine atoms (°CI radicals) are known to oxidise low concentration methane up to 256 times faster than °OH radicals. Additionally, the chlorine atoms produced by the Aerosol destroy tropospheric ozone which also acts as a greenhouse gas. Further, the chlorine atoms change the surfaces of black carbon and smoke particles from hydrophobic to hydrophilic by oxidation. That change makes them more easily washed out from the atmosphere by precipitation. These unburnt particles otherwise also induce a strong climate warming influence.

Once washed out by rain drops or snowflakes onto the slightly basic ocean surface the ferric and/or aluminium salt component of the Aerosol precipitates with spontaneous hydrolysis as floccs. This flocculation process is known to be efficient from its use as water cleaning agents from suspended particles in wastewater treatment plant. Hence by this flocculation process the nano-particular Ti- and Si-oxides become chemically bound within the precipitating aluminium and/or ferric hydroxide flocks. This has the effect of removing the nanoparticles from the water body they entered, removing any potential nanoparticles hazard.

The ferric hydroxide compound acts as a micro-nutrient for the uppermost photic zone life of the ocean. This nutrition increases the photolytic transformation of the greenhouse gas CO2 to organic substance. Thus, the ferric component acts as an additional cooling component for the climate, mimicking natural diffuse ocean fertilisation by windblown dust deposition. This way, a small increase of CO2 absorption rate occurs over a large area of ocean. A further cooling influence occurs as the DMS emitted by phytoplankton induces further marine cloud cover.

Ferric chlorine-containing aerosols have been found to work reasonably well in absorbing chlorine atoms, that return to the aerosol particle as HCI by its liquid ferric chlorine-containing aqueous coat in a photocatalytic cycle. However, ferrous components have been found to maybe produce ochre to brown coloured hydrolysis products from the ferric chlorine-containing aerosol. Iron also fertilises growth of sessile life which also darkens ice fields. Hence a ferrous or mostly ferrous aerosol is better used in a use mode or environment where a decrease of albedo does not occur or is not important.

But for application of an aerosol near or onto ice covered ocean, shelf or land a possible albedo decreasing colouring of the ice surface should be avoided. When other photosensitive compounds such as titanium dioxide, nitrate and nitric acid are used, the albedo of the white ice and snow surfaces might not be affected or even increased. Additionally, the Aerosol may contain more than one photosensitive compound and can thereby accelerate the photolytic generation of chlorine atoms by possibly more than 10-fold in comparison to an aerosol based on ferric chloride only. Also, the recycling of the mobile active components hydrogen chloride and nitric acid undergo a similar cycle to the ferric chloride aerosol system. After photolysis chlorine atoms and NO2 radical molecules leave the aerosol particle but later get recycled by absorption back into the particle as hydrochloric acid and nitric acid.

To produce clouds with high reflectivity or to increase the reflectivity of existing clouds it is helpful to provide the Aerosol with high amounts of hydrolysed TiC»2, and preferably without any ferric salt content. The Aerosol’s particle diameter is below 0.5 pm and has its minimum diameter at around 0.1 pm. This is because the ideal cloud condensation nuclei size for making the brightest clouds is thought to be -100 nm.

Nearly all particles, or the majority of the particles, of the Aerosol are smaller than 1 pm in diameter, preferably 0.1 pm or smaller. This is preferred to increase the total reactive and photo-sensitive surface area in order to emit as many chlorine atoms as possible, to maximise the resulting atmospheric methane depletion rate. More/smaller particles also produce more/smaller cloud droplets, making brighter clouds. These very small aerosol particles are difficult to produce by physical means but can be generated easily by chemical means from the gaseous phase. The chemical method to create the Aerosol uses only gaseous or vaporous compounds as precursors: nitric acid vapour, gaseous NO and NO2, N2O5 vapour, titanium tetrachloride vapour, silicon tetrachloride vapour, aluminium chloride vapour, and ferric chloride vapour.

Coming in contact with air the mixture of these vapours immediately reacts with water vapour to produce a white particle aerosol that contains solid SiO2, solid TO2, a solid or aqueous solution of aluminium chloride hydrate and a solid or aqueous solution of chloride and nitrate salts of ferric iron and aluminium and small amounts of nitric acid or hydrochloric acid for pH adjustment.

The optimum pH range to maximise °CI production is between pH 2 and pH 0. However, in addition to the particles and/or droplets the Aerosol plume also produces gaseous HCI, which is produced by the hydrolysis reaction. This acid component may lower the pH of the aerosol to less efficient negative pH levels unless it is partially neutralized.

To be most effective at producing chlorine atoms the Aerosol needs to have a pH value between 2 and -2, preferably between 2 and 0. To achieve this pH level range the aerosol pH milieu can be adjusted by a basic compound. This is best done by gaseous ammonia.

To prevent the aerosol plume from becoming too acidic gaseous ammonia or evaporated ammonia from ammonium carbonate, ammonia water solutions or other sources may be used. The resulting ammonium salts raise the pH level of the Aerosol. From here on the synonym “ammonia” means either: pure gaseous NH3 or vaporized aqueous NH3 solution (or both in combination).

In an Aerosol precursor emission device to prevent solid hydrolysate precipitation within the Aerosol emission device the hydrolysis and neutralizing reactions between the aerosol precursors and the moist air or flue gas preferably take place within the aerosol plume after aerosol precursor emission from the Aerosol precursor evaporation and emission device. This is best done by emitting some of the gaseous or vaporous precursor compounds separately from each other by a concentric pipe emission system. This arrangement ensures that the vapours begin mixing together before they encounter airborne water vapour, so the hydrolysis reaction occurs well away from the pipe outlets.

The innermost pipe preferably emits silicon tetrachloride vapour. The silicon tetrachloride vapour emission pipe is arranged concentrically within a pipe which provides the aerosol plume with water vapour and gaseous ammonia. The water vapour and ammonia providing pipe is arranged concentrically within a pipe that provides the emission with a mix of titanium tetrachloride and/or aluminiumchloride and/or ferric chloride vapours and/or one or more compounds from the group NOx gases, N2O5 vapour, and nitric acid water vapour mix. Within the atmosphere all of the nitrogen oxide compounds become oxidized, and end absorbed as nitrate and/or nitric acid on the aerosol particles.

Given the need to provide only bright or white coloured hydrolysis products in Arctic areas near permanent ice and snow areas, the ferric chloride content could be replaced by aluminium chloride. Within tropical, subtropical, and other ice-free areas the aluminium chloride could be replaced by ferric chloride.

If the pH levels within the aerosol plume differ among plume particles and/or droplets after the precursors have left the emission pipes, this will eventually change to an essentially uniform pH level because the HCI vapour pressure of the high pH particles will be lower than the vapour pressure of the low pH particles. Hence the HCI gas will become absorbed by the high pH particles and the low pH particles will desorb HCI gas.

As dust and smoke from human activities and smoke from forest fires gets deposited on icefields it darkens them. This dark material provides nutrients for the growth of biofilms, and other sessile life, further lowering the ice albedo. By its nature melting ice increases this darkening effect and accelerates the albedo decrease. Decreased albedo is a major cause of today’s accelerating ice melting rates during summer months, making large glaciers increasingly unstable, threatening accelerated sea level rise and freshwater supplies from glacier fed rivers. Both wet and dry ice surfaces and also the wet black and grey patches on ice sheets may be covered by a brilliant white coat formed from hydrolysis of aerosol precursor formulations that avoid use of ferric iron chloride. This can apply to polar and subpolar ice sheets and mountain ice. For this purpose, a gaseous and/or vaporous precursor formulation with high amounts of TiCk is preferred with eventually SiC I4 as a second compound. This changes wet or dry dark surfaces to a brilliant white or bright colour by at least partially covering them with a jelly-like hydrolysate coat. The white coloured layer is built up to a weight of preferably 1 to 20 g/m ² . A mild photo-generated hydroxyl-radical and chlorine atom effect gives the white coat biocidal properties. Hence the coat inhibits the growth of darkening sessile life such as biofilms, algae and moss.

The coating system acts with a simple liquid spray system and uses a smaller number of precursors than those needed for methane depleting CCN. A hydrolysing gas or sprayed jet is aimed onto the surface of the grey or black colored patches on the ice. The distance between the spray jet outlet and the frozen or thawing ice sheet surface is preferably between 0.5 and 2 m. This ice sheet whitening method may also be used for whitening dark surfaces on mountain glaciers.

The coat precursor mix is different from the cloud whitening precursor mix because it needs no ammonia for pH control. We leave the acidic pH unchanged because ammonia would fertilise biofilm and plant life. Nitric acid and nitrates are also not necessary in the coat precursor formulation because the coat needs no optimized chlorine atom generation for methane depletion. To reduce the heat energy needed for heating the pipe and to simplify the application of the coat we preferably restrict the coat precursors to titanium tetrachloride and silicon tetrachloride only. These coat precursor compounds may be applied as a mixture of both chlorides. They may be applied also as a vapour but the application by nebulization of liquid is preferred. However, since both of the liquids have a rather high vapour pressure the application as a spray implies partial application as a vapour phase anyway.

Application of these hydrochloric acid emitting compounds seems to be neutral with regards to environmental effects because the meltwater from the ice sheets contains anyhow abundant suspended silicate flour (glacial flour) which is seen in these meltwaters as a light opaque colour. This amount of silicate flour easily neutralises the hydrochloric acid produced by whitening / brightening even large ice surfaces.

The contact of concentrated vapour or spray droplets of TiCk and SiCk with the melting or frozen ice sheet surface produces an immediate precipitation of the TiCk and SiCk hydrolysis coating as a sticky white TiC»2 and SiC»2 gel mixture. Most of the generated HCI will not escape into the gaseous phase but will instead be bound into the gel as liquid hydrochloric acid.

To keep the nebulized chlorine-containing aerosol droplets to the area intended for coating the aerosol sprayer and spray emitted from it at the hose end may be shielded from wind drift by a smooth umbrella-like plastic shielding. Both the hose and plastic shielding are preferably constructed from a corrosion resistant organic fluoro polymer. Valves and spray nozzles are made from a corrosion resistant metal or metal alloy.

The hydrogen chlorine-containing acid spots on the ice produced from the chlorine-containing Ti and Si hydrolysis reactions may be totally neutralised by applying a powder made from limestone, chalk or any kind of rock silicate to the dark spot before coating. But in most cases, this is not necessary because, as mentioned earlier, the ice sheet meltwaters are full of silicate powder that will neutralize any acid remnant of the dark spot whitening. The same is true for mountain glaciers.

To summarize, a self-activating chlorine-containing photo-active aerosol containing ammonium in a liquid solution or in a solid salt is described, containing at least one of the photosensitive components solid titanium dioxide and solid silicon dioxide as solid hydrolysate, ferric iron as an ion in liquid solution or in solid state, nitrate and nitric acid in solution. This Aerosol may be containing aluminium ions as an additional compound. In a preferred method for production of such Aerosols the aerosol may be synthesized in the free atmosphere from gaseous and/or vaporous precursor compounds.

With such an Aerosol spray a white or bright coat on ice sheet surfaces may be produced which contains at least titanium dioxide as a white hydrolysate gel. Such a white or bright coat may additionally contain silicon dioxide as a white hydrolysate gel. In a preferred method for production of such a white coat the coat may be synthesized on a frozen or melting ice sheet surface. Additionally, the coat may be synthesized from a gas and/or from a liquid containing titanium tetrachloride. Additionally or alternatively, the coat may be synthesized from a gaseous and/or liquid mixture containing titanium tetrachloride and silicon tetrachloride.

A preferred device for production of such Aerosols enables the different vaporous precursors to be emitted separate from each other by the use of concentric nested pipes for aerosol precursor emission into the atmosphere. Such an emission device may be designed as a fixed land- based facility, road vehicle, boat, or ship, for example. Such an emission device may also be designed as a manned or unmanned aircraft or drone.

In a preferred device for production of a white coat as described above the coat may be synthesized from a nebulized liquid containing at least titanium tetrachloride. Further, the coat may be produced by a drone which carries an up to 50 m long plastic hose with a nebulization sprayer as emission device at the lower hose end and a hydraulic connection at the upper hose end with a tank containing liquid titanium tetrachloride or a titanium tetrachloride silicon tetrachloride mixture.

Third embodiments

A planetary climate adaptation measure proposes the dispersal of aerosols in the lower troposphere that photo-catalyse removal of methane, ozone, and black carbon aerosol from the troposphere only (not the stratosphere), wherein the dispersed aerosols also provide a direct planetary cooling effect by forming either a non-toxic white (or bright) reflective haze or low-lying clouds, depending on relative humidity.

The combined radiative forcing (global warming) impact of atmospheric methane, black soot, tropospheric ozone, and halogenated gases is now over half the total radiative forcing of all atmospheric warming agents including carbon dioxide. Unfortunately, the emissions of several of these warming agents are increasing, most notably methane from fossil fuel extraction, and black soot from combustion of fossil fuels, wood, agricultural waste, forest and brush fires and waste incineration.

However, since industrial times mainly the sulphur content of aerosol pollution has been providing a planetary cooling effect by reflecting away the sun’s radiation, similar to the effect of low-lying clouds. Additionally, aerosol pollution containing NOx appears to have been depleting atmospheric methane and may have been masking underreported extractive and other methane emissions. But legislation is increasingly requiring the removal of sulphur and NOx content of air pollution, which in past decades slowed the warming effect of increased greenhouse gases in the atmosphere by providing a direct cooling effect and possibly reducing methane’s average lifetime in the atmosphere. Today, by curbing the emission of these cooling aerosols the global temperature is increasing faster and this trend looks set to continue. Averaged over decades this warming trend is accelerating the melt rates of polar ice, which threatens medium-term rapid sea level rise. It also threatens to initiate cascading planetary tipping points that could lead to general climate disaster.

The Aerosol to be used can be described as particles/droplets containing any combination of oxides and/or hydroxides of titanium and silicon, titanium peroxohydroxide, aluminium chloride and ferric chloride. Herein, Ferric chloride may be interchanged with titanium peroxohydroxide, depending on geographical deployment location. The chlorine(s) mainly form an aqueous liquid chlorine-containing coat over the particles, making them hygroscopic, so that they absorb water vapour from the air.

The titanium and ferric content is photo active. The addition of NOx or nitric acid vapour is able to transform the aqueous chlorine- containing coat of the particles to a weak acidic nitrate solution (e.g. diluted Aqua Regia solution), which is also photo active. Regarding the diluted nitrate solution that is also referred to as “Aqua Regia Aerosol (ARA)” that is described and claimed by the same applicant in PCT/DE2022/100581. The inclusion of different photo active substances in the same particle enables more bands of the sun’s radiation spectrum to be absorbed and exploited for greenhouse gas removal by a single aerosol deployment.

The present specification introduces titanium peroxohydroxide ( TiO2(OH)2 ) as a new particle constituent. Its extremely high photosensitivity makes it suitable for depleting greenhouse warming agents in conditions of low light intensity such as in the Arctic, and all geographic locations beneath clouds.

The following description concerns photocatalytic removal of greenhouse warming ‘super pollutants’, where super pollutants are definable as oxidable greenhouse warming agents that induce a significantly higher radiative forcing than CO2. These are essentially methane, halogen methanes, VOCs, black soot and tropospheric ozone. In sunshine such Aerosol particles produce chlorine atoms (also known as chlorine radicals) that oxidise the super pollutants, in most cases producing HCI. The HCI is then absorbed back into the particle coat, enabling the cycle to repeat. In this way for example, each chlorine atom is estimated to deplete about 1000 methane molecules before the aerosol gets rained out, what may happen typically 1 to 3 weeks after dispersal.

Chlorine radicals also destroy ozone, which in the troposphere is a harmful greenhouse gas. (In this case the chlorine radical is preserved.) It is noted, as a sidenote, that like all other hygroscopic aerosols also the Aerosol described herein gets rained out before it can migrate up to the stratosphere, therefore it destroys only tropospheric ozone and does not affect the stratosphere. The only aerosol typically known to migrate up to the stratosphere is black/brown carbon aerosol. This is because its particles readily absorb heat from the sun, warming the air around them and thereby creating an updraft that carries the particles up to high altitude. Fresh black/brown carbon particles are typically not readily rained out because they tend to be hydrophobic, so they do not attract a water coat that grows to become a much larger droplet. However, the oxidative effect of chlorine radicals renders black/brown carbon particles hydrophilic, enabling them to attract water vapour from the air and thus be more easily rained out by normal cloud droplet accumulation and coagulation processes.

The Aerosol as described herein also produces OH radicals, which have a similar oxidative effect in the air as chlorine atoms. However, chlorine atoms remove greenhouse warming agents up to around 250 times more efficiently than OH radicals for two reasons: First, chlorine atoms have a lower Henry’s law constant than OH radicals, which means chlorine atoms have a larger affinity to the gaseous phase. The effect is that chlorine atoms evaporate into the gaseous phase from the aqueous coat on the particle surface up to 16 times more readily than OH radicals. And second, the reaction rate of chlorine atoms with methane in the gas phase compared to OH radicals is about 16 times faster.

Chlorine atoms are produced in abundance by the aqueous particle coat because OH radicals are a stronger oxidant than chlorine atoms, which are displaced and evaporated from the particle coat by OH radicals.

Each Aerosol particle contains a nano-sized solid porous core with an aqueous coat, making it operate as a ‘microdroplet’ that naturally generates hydrogen peroxide. This provides two advantages: First, the existence of hydrogen peroxide in the coat stabilizes the solid titanium peroxo-hydroxides in the contained particle. And second, additional OH radicals and/or Cl atoms are generated from the photolytic splitting of hydroperoxides in the presence of sunshine.

In dry air the Aerosol forms a white / bright reflective haze, which provides a long-lived, albeit small cooling effect. In this state the aqueous particle coats are acidic and actively produce chlorine radicals. (Many naturally occurring aerosol particles also have a highly acidic coat.) In air of elevated humidity, the particles nucleate cloud droplets that dominate the contained solid particle by size. This additional water raises the aqueous phase pH and decreases the photo-induced generation of chlorine atoms. However, operating as cloud droplets enables the aerosol to reflect more sun radiation, just as naturally occurring cloud droplets do in clouds. The Aerosol is intended to be dispersed from ships, aircraft, and land-based facilities. It is suitable for deployment into the lower troposphere to cool remote areas such as large icefields and ocean areas. (By ‘large’ it is referred to an order of 10,000 km ² at a time.) If used for preserving icefields in polar and mountainous regions it may be possible to preserve winter snowfalls during the summer months. If deployed sufficiently effectively this could enable glaciers to be restored, catastrophic sea level rise to be averted, and rivers and human water supplies from mountain glaciers to be sustained long-term. This is called a geographical cooling option.

Similarly, if used effectively over the ocean, the current destructive rapid warming of the ocean surface could be reversed. This would provide numerous benefits including: reducing the intensity of extreme weather events; helping to stabilise polar glaciers that are being melted from beneath by warmer ocean water; reducing the risk of an Arctic methane burst from melting methane hydrates beneath shallow seas; and, increasing the rate of oceanic CO2 absorption.

Like all hygroscopic aerosols it is expected to last up to around three weeks in the lower troposphere before getting rained out. Once settled in a water body, the solid particle component flocculates and sticks to other surfaces. This polycondensation process continues until the solid component transforms to clay mineral.

Ferric chloride is preferably not included in aerosols dispersed close to icefields, because iron compounds would colour the surface of the ice and fertilise growth of sessile life, causing ice melt rates to increase.

In terms of geographical formulation adjustments some cases may be discussed. Regarding a deployment close to icefields, a deployment close to Arctic and mountainous regions and the Antarctic may be conducted in order to: deplete methane bursts (most likely in the Arctic); preserve winter snowfalls during the summer, by increasing reflective haze and cloud cover; and increase the reflectivity of ice by sedimented aerosol particles.

Since light intensity in the Arctic is low, a photosensitive iron-free aerosol is desirable. Thus, ferric precursor components for this aerosol are preferably not used and are preferably replaced with precursors for a titanium peroxohydroxide component.

Regarding a deployment over iron-poor ocean areas, if allowed by legislation, the inclusion of ferric chloride is preferred in order to enable diffuse ocean iron fertilisation. This is because phytoplankton growth provides the following climate benefits: increased atmospheric CO2 absorption; and seeding of marine clouds, which have a cooling effect.

In this case ferric chloride and/or ferric nitrate are a preferred part of the Aerosol particles and may mean that hydrogen peroxide cannot be used in any of the aerosol formation methods intended for diffuse ocean iron fertilisation.

Regarding Aerosol precursors a combination of H2O and at least one of the following precursors is preferably used for production of Aerosol particles:

- SiC k gaseous or liquid

- TiCk gaseous or liquid

- AlCh gaseous or solid

- FeCh gaseous or solid

- FeCh x nH2O as a solid or liquid hydrous solution

- Fe(NOs)3 x nH2O as a solid or liquid hydrous solution

- HNO3 as a liquid or a liquid hydrous solution

- NO2 gaseous

- HONO gaseous

- NO gaseous

- N2O4 gaseous

- N2O3 gaseous

- N2O5 gaseous and/or liquid

- CINO gaseous

- CINO2 gaseous

- H2O gaseous or liquid

- H2O2 as a liquid or a liquid hydrous solution

- TO2 as a solid powder or a hydrous liquid suspension Preferable Aerosol constituents, where typically only a subset of these is usually preferred depending on deployment scenario, are indicated below. As such at least one of the following compounds is preferably part of the aerosol particles:

- Si(OH)4 including its more or less condensed polymeric condensates including SiC»2 and SiO2-TiC»2 copolymers

- Ti(OH)4 including its more or less condensed polymeric condensates including TiO2 and TiO2-SiO2 copolymers

- TiO2(OH)2 including its more or less condensed polymeric condensates including TiO2O and TiO2O-SiO2 copolymers

- AlCh as an aqueous liquid and/or solid coat of the solid particle core

- FeCh as an aqueous liquid and/or solid coat of the solid particle core

- HNO3 as an aqueous liquid and/or solid coat of the solid particle core

- H2O2 as an aqueous liquid, such as an aerosol precursor compound and/or solid coat of the solid particle core and/or for the generation of nitrate from NOx and/or for transformation of Titanium tetrachloride during the hydrolysis reaction to titanium peroxo-hydroxide.

Since the chemical reactions of TiCk during hydrolysis with water and hydrogen peroxide and reactions of the hydrolysis products of TiCk with water and hydrogen peroxide are not complete, some peroxide-free Ti(OH)4 or its Ti and Si containing polycondensation products will always be part of the solid components of the Aerosol, i.e. not all or only some Ti and/or Si containing polycondensation product will contain peroxide groups. A list of preferred precursor combinations used to produce the aerosol is given hereinbelow:

- TiCk, liquid or gaseous

- SiC I4, liquid or gaseous

- AICI3, pure or intermixed with FeCh, solid or gaseous

- FeCh, pure or intermixed with AICI3, solid or gaseous

- HNO3, pure or intermixed with H2O, gaseous or liquid

- NO2 gaseous

- HONO gaseous

- NO gaseous

- N2O4 gaseous

- CINO gaseous

- CINO2 gaseous

- H2O2, pure or intermixed with H2O, gaseous or liquid

- H2O, pure or intermixed with H2O2, gaseous or liquid

If the produced aerosol is for emission close to icefields, then ferric chloride is preferably omitted from the above list and H2O2 included. If the produced aerosol is for emission over the ocean, then ferric chloride is preferably included in the above list, and H2O2 may need to be omitted.

Ferric chloride may be sublimated with minimal side products generated. At over 200 °C ferric chloride vapour can undergo side reactions that can produce unwanted, non-evaporable side products, and ferric chloride unfortunately sublimates at around 280°C at atmospheric pressure. However, the sublimation temperature of a mix of solid anhydrous AICI3 and FeCh powder solids is lower, and may be below 200 °C. Therefore, wherever anhydrous FeCIs needs to be sublimated a mixture with AICI3 is preferred, so that they can be sublimated together, preferably below 200 °C. Instead, or additionally it is preferable to carry out this sublimation process at reduced pressure, to further lower the sublimation temperature.

The aerosol’s photosensitive generation of hydroxyl radicals may be further increased as described below. As mentioned above, aerosol microdroplets naturally form hydrogen peroxide. Where Ti(OH)4 is present (titanium hydroxide) this is transformed by hydrogen peroxide to titanium peroxides such as TiO2(OH)2 (titanium peroxohydroxide), which is a more photosensitive producer of OH radicals. However, given that the aerosol’s residence time before raining out is limited, it is preferable for the aerosol to begin with maximum photosensitivity at inception by dispersing it with ready-made TiO2(OH)2. Achieving this is preferably done by adding hydrogen peroxide (H2O2) to the precursor mixture and/or the fully formed aerosol particles. This addition of hydrogen peroxide at least partially transforms the titanium compound content to produce titanium peroxides such as TiO2(OH)2. This can happen during the initial TiCk hydrolysis reaction, and also by converting Ti(OH)4 to TiO2(OH)2 following the hydrolysis step. Herein, however, the use of H2O2 may be mutually exclusive in the presence of FeCh.

The oxidative capacity of liquid and/or gaseous H2O2 is additionally preferred if the gaseous precursors NO2, HONO, NO, N2O4, CINO and CINO2 are used as HNO3 precursors. The chlorine-free nitrogen oxide compounds of that list are oxidized by H2O2 to HNO3 and the halogen- containing nitrogen oxide compounds are oxidized by H2O2 to HNO3 and HCI. This is helpful if NOx containing flue gases or other sources of NOx are used as precursors for the Aerosol.

In the sections below different methods for producing and dispersal of the Aerosol are given: A first one concerns in-situ hydrolysis and oxidation of gaseous phase precursors directly into the troposphere. A second one concerns formation of a particle suspension by hydrolysis and/or oxidation in the aqueous liquid phase, followed by nebulisation and emission into the troposphere of the aqueous particle suspension.

In both of these methods the different compounds NOy, NOyH and NOyCI (y = 1 and 2) may be converted to HNO3 and HCI. As mentioned above, this may be achieved by adding H2O2 precursor.

Ferric nitrate seems to be recommendable for the liquid phase hydrolysis process, that is number 2 above, because it cannot be vaporized. Independent of which method is used to prepare the Aerosol, its particles are highly acidic; therefore, dispersal must be made far enough away from people to minimise any chance of the aerosol affecting them. Dispersal should occur in remote areas, and sufficiently high above ground or the sea surface to enable the aerosol to be blown safely away in the wind from vulnerable materials and equipment. Additionally, to avoid potential over-fertilisation of a small area of the ocean with iron compounds or risk acid rain falling in a small, concentrated area, dispersal should not occur where it is raining or into rainclouds, or when such conditions are forecast to happen soon. Therefore, unmanned dispersal devices should be remotely controlled from a system that is informed by timely local weather forecasts.

A further aspect concerns Aerosol formation in the troposphere by hydrolysis and oxidation of vaporous precursors. Herein, in-situ hydrolysis and/or oxidation of vaporised and/or gaseous precursors produces the aerosol directly into the troposphere. The reaction takes place within a humid gaseous phase before or after the emission of the precursor compounds. The complete oxidation and/or hydrolysis may take place after the emission. Pipes heaters and vapour outlets need to be resistant to corrosion or degradation by precursors operating at 250°C. For example, materials may include polyfluorinated hydrocarbon polymers.

Particles of 100 nm diameter or less are formed from the hydrolysis of vaporous TiCk and SiCk, which react vigorously with moisture in a fast moving air stream to form Ti(OH)4 and Si(OH)4. This combination forms partially polymerised solid porous particles.

Preferably where ferric chloride is not used, an H2O2-H2O vapour mix is included in the emitted precursor vapour, to produce a TiO2(OH)2 content in the aerosol particles by hydrolysis and oxidation. In the emitted vapour mix may be sublimated FeCh and/or AlCh, which hydrolyse and condense in the air, forming an aqueous chlorine-containing coat over each newly formed particle. Where ferric chloride is used it is sublimated in an anhydrous mixture of FeCh and AlCh, enabling sublimation at only a few centigrade above the AlCh sublimation temperature. Further, in the emitted vapour mix may be gaseous/vaporous nitrogen compounds, which form HNO3 that dissolves into the aqueous chlorine- containing coat of each particle, converting it to a diluted aqua regia solution. At this point the Aerosol particles are ready to begin producing chlorine atoms in the presence of sunshine. Particles of 0.1 pm diameter or less form the main mass of the Aerosol produced by this process.

The Aerosol may be prepared by means of several methods from vaporous/gaseous phase precursors, for example by combination of one or more of the gaseous precursors listed below by hydrolysis and/or oxidation:

- SiCk (hydrolysate to Si(OH)4)

- TiCk (hydrolysate to Ti(OH)4)

- TiCk (hydrolysate to Ti(OH)4 and become oxidized to TiO2(OH)2)

- AlCh (acts as a chlorine-containing ion source for chlorine atom generation)

- FeCh (acts as a photolytic hydroxyl radical and chlorine atom precursor)

- HNO3 (acts as an oxidant and as a photolytic hydroxyl radical and chlorine atom precursor)

- NO2 (oxidizes to HNO3)

- HONO (oxidizes to HNO3)

- NO (oxidizes to HNO3)

- N2O4 (oxidizes to HNO3)

- N2O3 (oxidizes to HNO3)

- N2O5 (oxidizes to HNO3)

- CINO (oxidizes to HNO3 and HCI)

- CINO2 (oxidizes to HNO3 and HCI)

- H2O2 (acts as an oxidant)

- H2O (acts as an hydrolysis reactant) Among other advantages of this method is that hydrolysis of these precursors in the gaseous phase makes particles, that can be well under 0.1 pm diameter. This small size maximises their surface area, which maximises the amount of Cl atoms produced by photolysis. It also maximises the surface area by which gaseous HCI, HONO and NOx returns to the particles after °CI atoms have oxidised methane. The Aerosol generates OH radicals that change gaseous nitrogen oxides and nitrous acid to nitric acid. It thereby provides a mechanism for recycling nitric acid as part of its overall photocatalytic cycling mechanism.

The Aerosol may be formed by nebulisation of a suspension of preformed particles, for example by combining the above specified precursors to, first, hydrolyse/oxidise the precursors in liquid water in a reaction chamber to form an aqueous suspension of the Aerosol particles. The oxidation and hydrolysis reactions between these precursors are exothermic, therefore a method of cooling the water is preferred. Preferably the reaction temperature is kept below 60°C. In this process solid primary particles approximately 100 nm diameter are formed. And, second, to subsequently nebulise the aqueous suspension to produce an aerosol in the troposphere.

Droplets of 0.1 pm diameter or greater form the main mass of the aerosol produced by this process. After emission by nebulisation to the air the droplets evaporate, leaving one or more solid/porous particles infused and surrounded by an aqueous acidic liquid. The preferred preparation of the aqueous suspension begins with a reaction chamber vessel which contains preferably icy cold water, to which the following precursors are added preferably in the order given:

1. SiCk

2. H2O2

3. TiCk

4. AICI3

5. Liquid HNO3 and/or any gaseous nitrogen oxygen compounds.

In another alternative preparation method embodiment the order of TiCk and H2O2 addition may switched.

The preparation of aqueous suspension may be performed without addition of H2O2. The AICI3 precursor may be substituted in full or in part by ferric chloride in applications without titanium peroxo compounds and/or where the oxidation of gaseous nitrogen oxygen compounds to HNO3 is not needed.

Additionally, the aluminium and ferric chlorides may be replaced in part by aluminium and ferric nitrates. In this case the chlorine- containing content comes from SiCk and/or TiCk. The most preferred salts are ferric and aluminium salts of chloride and nitrate with crystal water content. In these cases, no H2O2 precursor is necessary in the nebulisation procedure either.

As an alternative H2O2 or HNO3 or both and/or the gaseous nitrogen oxygen compounds may be also added all or in part in the vaporous and gaseous state during and/or after the nebulization procedure.

To improve the performance of the nebulised particle suspension, oxidation reactions by the gaseous reactants may then be combined with none, one or both of the following precursors: Nitric acid vapour; and/or the gaseous nitrogen oxygen compounds - preferably produced from an air stream by electrical discharge; and/or vaporous H2O2.

The result of the nebulisation of all described reaction types is an aerosol of preferably on average -1 micron diameter droplets, or smaller if possible. In dry air the droplets evaporate leaving behind aerosol particles with a thin aqueous acidic coat that begin producing chlorine atoms in the presence of sunshine.

Preferably the conversion of an aqueous Ti(OH)4 suspension to a TiO2(OH)2 suspension and similar peroxides with liquid hydrogen peroxide or liquid aqueous peroxide solutions is done in parallel to the hydrolysis in the aqueous liquid phase of titanium tetrachloride or other titanium salts, or as soon as possible after the hydrolysis to the aqueous Ti(OH)4 suspension has been carried out. However, fortunately even after aging of the Ti(OH)4 suspension or of the mixed Ti(OH)4 and Si(OH)4 suspension, the reaction with aqueous H2O2 or pure hydrogen peroxide converts the titanium content of even the partially polycondensed Ti(OH)4 and Si(OH)4 compounds into a photo-active titanium peroxide content. Herein, it is preferred that the nebulisation equipment is made resistant to acid attack. For example, recommended nozzles may be made of specialised stainless steel, or ceramics.

The Aerosol as described above has the following advantages. Hydrolysis of precursors in the gaseous phase directly into the troposphere makes the smallest particles. This maximises their surface area, which maximises the amount of Cl atoms produced by photolysis. It also maximises the surface area by which gaseous HCI and nitrogen compounds return to the particles after Cl atoms have oxidised pollutants, which maximises the speed of the photocatalytic pollutant removal cycle before the aerosol rains out.

The hydrolysis reaction temperatures in the gaseous phase needed in each method depend on the boiling or sublimation points of the precursors used, and are preferably in the range below 250 °C. This means for the performance of the reaction that the gaseous and/or vaporous

Precursors for production of such a photoactive aerosol as described above by hydrolysis and/or oxidation, contains at least one or more compounds of:

• SiCk gaseous or liquid

• TiCk gaseous or liquid

• AlCh gaseous or solid

• FeCh gaseous or solid

• FeCh x nH2O as a solid or liquid hydrous solution

• Fe(NO3)3 x nH2O as a solid or liquid hydrous solution

• AlCh x nH2O as a solid or liquid hydrous solution

• AI(NOS)3 x nH2O as a solid or liquid hydrous solution

• HNO3 as a liquid or a liquid hydrous solution

• NO2 gaseous

• HONO gaseous • NO gaseous

• N2O4 gaseous

• N2O3 gaseous

• N2O5 gaseous and/or liquid

• CINO gaseous

• CINO2 gaseous

• H2O2 as a liquid or a liquid hydrous solution

• TO2 as a solid powder or a hydrous liquid suspension

• Fe20s as a solid powder or a hydrous liquid suspension

• FeOOH as a solid powder or a hydrous liquid suspension

• Fe(OH)3 as a solid powder or a hydrous liquid suspension.

A method of generating an aerosol as described above and/or using the aerosol precursors as described above by hydrolysis and/or oxidation of the vaporised and/or gaseous precursors directly within a humid gaseous phase before or after the emission of the precursor compounds into the troposphere comprises wherein the complete oxidation and/or hydrolysis takes place before, during and/or after the emission process.

In such a method of generating an aerosol and/or using the aerosol precursors as described above by hydrolysis and/or oxidation of the precursors as liquids and/or gases within the liquid aqueous phase in a reaction containment may comprise inducing the formation of an aqueous particle suspension by hydrolysis and/or oxidation in the aqueous liquid phase, wherein the aqueous particle suspension is subsequently mechanically nebulised and emitted as an aerosol into the troposphere.

Further, in such a method of generating an aerosol as described above the emitted aerosol plume may be combined with the flue gas plume of a combustion process wherein soot particles are hydrophilized in a surface oxidation reaction by chlorine atoms and/or OH radicals and/or hydrogen peroxide, and wherein the 0 containing gaseous N-compounds become oxidized by chlorine atoms and/or OH radicals and/or hydrogen peroxide. For substances that transform slowly from precursor substance to aerosol, such as sulphur dioxide, which takes hours to transform to sulphuric acid aerosol in the atmosphere, this is less relevant. In particular, if the gaseous or vapour precursors are water-soluble substances, such as sulphur dioxide, they may be drawn into the clouds after being dispersed below them before they have converted to aerosol. In the cloud, these water-soluble gases are absorbed by the cloud droplets. The conversion into the desired fine-particle aerosol is thus irreversibly blocked, because even if the cloud evaporates in a dry environment, a coarse-particle and thus ineffective aerosol remains. According to the chosen example of sulphur dioxide gas, its conversion to sulphuric acid then takes place in the liquid cloud phase and cannot lead to the intended formation of condensation nucleus aerosols with particle or droplet diameters below or close to 0.1 pirn.

According to the method, however, the gaseous and/or vaporous precursor substances, which are converted directly into the effective aerosols in the atmosphere, or also the combustion exhaust gases containing aerosols from the outset can be discharged both below and above the cloud layer generated by this method.

On the other hand, gaseous and/or vapour precursor substances such as sulphur dioxide, which convert slowly to aerosols in the atmosphere, are emitted into the atmosphere above clouds or a forming cloud layer according to the invention. However, this does not apply in regions above the ocean where the humidity is insufficient to form clouds, for example in areas of the South Atlantic west of the African coast or the South Pacific west of the Chilean coast. Here, sulphur dioxide can also be emitted without loss at any altitude in the troposphere, without any losses in the formation of the finely divided sulphuric acid aerosol.

Even if the Aerosol is used outside of cloud-forming areas, they have a high probability of reaching areas with high humidity or cloud formation through the movement of the troposphere due to their finely divided aerosol. Thus, the sulphuric acid aerosols released in the meantime from the sulphur dioxide gas can also trigger the formation of the white albedo-lifting clouds without significant loss.

The production of the gaseous or vaporous aerosol precursor substances is preferably carried out by conventional evaporation without direct flame action in the case of low-boiling substances. However, for the high boiling substances, preferably by vaporising or atomising the aerosol precursor substance in the flame of a combustion reaction. Three specific aerosol formation methods are preferred: These are preferably used for the higher boiling substances iron(l lljchloride, aluminium chloride, zinc chloride, as well as the chlorides and sulphates of the alkali and alkaline earth metals sodium, potassium, calcium and magnesium boiling above 1000 °C, here designated A) and B), or they are produced by method C). All three processes described below have in common that they are converted into an aerosol by a flame reaction:

A) This is done by adding the salts, which are crushed to powder, to the combustion air or to the combustion oxygen that is fed to a burner and with which a gaseous or liquid fuel such as hydrogen, methane, propane, butane, petrol, heating oil or also mixtures of these fuels are burnt by means of known burner technology. Flame temperatures of >1900 °C as they occur when burning these substances with air or -2800 °C as they occur when burning these substances with oxygen are sufficient to melt and vaporise the salts added to the flame as powder. This also applies to calcium chloride, which has the highest boiling point of the aforementioned aerosol precursor substances at 1670 °C.

B) This is done by emulsifying a preferably concentrated aqueous solution with the liquid combustible used. Emulsification is preferably carried out with the aid of emulsifiers, for example surfactants. Alcohol solutions of alcohol-soluble salts, for example of aluminium chloride and/or ferric chloride, are also suitable for emulsification. Suitable alcohol solvents for the alcohol-soluble salts such as the ferric chloride are methanol, ethanol or isopropanol. The suitable concentration of the emulsified salt solution in the combustible is given when the aerosol produced in the flame has a particle or droplet size of <0.1 pirn that is as uniform as possible.

C) Chlorine-containing salts such as chloride salt and bromide salts in particular can release elemental halogen in the oxidising flame environment, which is sufficient to halogenate unburnt carbon-containing compounds. These include toxic substances from the aromatics group, for example halogenated biphenyls and halogenated dibenzodioxins and dibenzofurans. This disadvantage can be circumvented by using organic salts from the group of carboxylates, for example iron oxalate, polyphenols, for example tri-catechol titanic acid and tri-catechol silicic acid, carbonyls, for example iron pentacarbonyls, acetylacetonates, for example acetyl acetate, for example acetyl acetate, acetylacetonates, for example iron acetylacetonate, cyclopentadienides, for example di-cyclopentadienyl iron, alcoholates, for example sodium ethanolate, or inorganic nitrate or nitrite salts, for example ferronitrate or ferronitrite, or of hydroxides, for example sodium hydroxide, which are then reacted in the flame according to method A) or B), whereby in the case of iron or other heavy metals, and also silicon, the respective metal oxide and semimetal oxide aerosols remaining after the flame reaction are converted by gaseous hydrogen chloride addition or vaporous hydrochloric acid addition, optionally also vaporous aluminium chloride addition, into the cooled emitted aerosol cloud into the respective finely divided chlorine-containing aerosol to be produced. The emission of HCI or vaporised HCI solution and the aerosols obtained from the flame reaction should, in the case that aerosols and HCI-containing gases and vapours are emitted from the same opening, be arranged in such a way that the temperature at the point of mixing of the two components preferably does not exceed 200 °C in order to avoid the formation of chlorinated carbon compounds. The emission of the aforementioned aerosol precursors or the aerosols generated therefrom can be carried out, for example, by means of aircraft, such as those used for hail control. However, the emission preferably occurs from aircraft such as airships, tethered balloons or also from fixed locations, preferably towers or mountain tops, but also from floating facilities such as fixed or anchored floating off-shore platforms, moving vessels or other watercraft.

Similar to the preferred aerosol formation processes using the flame reaction of salt, a combustion process is also preferably used according to the invention to produce and emit sulphur dioxide into the atmosphere as a precursor substance of the sulphuric acid aerosol. For this purpose, liquid sulphur or other combustible sulphur-containing substances, for example carbon disulphide, hydrogen sulphide, carbon oxysulphide or any liquid or liquefiable organic sulphur- and carbon-containing compounds can be used, which can be burnt by means of air or oxygen with a burner. In all cases, sulphur dioxide is formed, from which the sulphuric acid aerosol suitable for cloud formation is formed in the atmosphere.

The aerosols formed from the salt emulsions in the flame according to the method of the invention or the aerosols formed from gaseous and/or vaporous precursor substances are, with regard to their small particle diameters of 0.1 pirn and smaller as well as their hygroscopic properties, all ideally suited to increase the terrestrial albedo by triggering the formation of new white clouds by the aerosol formers according to the invention or by providing the existing clouds with a higher degree of whiteness. In this way, a comparable albedo increase can be achieved, comparable to that achieved according to the SAI method, but with a substance input several orders of magnitude lower than would be necessary according to the SAI method.

Moreover, the method eliminates the disadvantage of a worldwide reduction of UV radiation, which would be triggered by aerosol formation for albedo amplification in the stratosphere. On the contrary, the effect of the UV radiation on the atmosphere and thus the formation of the methane-degrading hydroxyl radicals is enhanced, since the white clouds also reflect a proportion of the UV sunlight, which thus enhances the photochemical reformation of °OH radicals above the cloud cover white-coloured according to the method of the invention.

A particular advantage of the method according to the invention is the possibility to emit the nano-particulate aerosol over land and over urban regions, because when using the environmentally friendly water-soluble salt aerosols as represented by the alkaline earth and alkali salts, there is no need to fear any health damage due to respiratory diseases, because the nano-salt particles dissolve immediately on contact with the mucous membrane.

Nanosalt particle aerosols and the nanosulphuric acid droplet aerosols formed when the aerosol precursor sulphur dioxide is applied are also natural components of the atmosphere. They are formed over the sea by the spray of seawater and the atmospheric oxidation of sulphur- containing essential oils, such as dimethyl sulphide, which is released into the atmosphere by the unicellular and multicellular algae in the exposed layer of the ocean.

The emission cloud generated according to the invention still contains approx. 1000 nanoparticles or nanodroplets per cm ³ after a distribution period of approx. 1 h after the emission event. Due to the small particle or droplet size, the salt or acid mass is less than 10 |jg/m ³ despite the enormous particle or droplet quantity of 109 particles per m ³ .

In principle, all combustion processes in which liquid fuels are burned can be made usable for the aerosols formed from the salt emulsions in the flame according to the process of the invention. This applies both to combustion systems used for heat or electricity generation and to combustion engines used for vehicle operation, such as diesel engines in ships and motor vehicles and turbine engines in ships and aircraft.

Due to the sustained cooling of the ocean surface caused by the aerosols of the invention above the selected ocean areas suitable for cloud formation, we expect an effect in the ocean that leads to a sinking of the surface water layer enriched with salt. This leads to an exchange with the lower-salinity but more nutrient-rich deep water below the exposed zone. This significantly stimulates phytoplankton production, which, as a consequence of the resulting increase in basicity in the exposed zone, directly triggers increased absorption of the greenhouse gas CO2 by the cooling ocean surface.

To summarize, Aerosols to be spread in the troposphere are described, characterised in that they have been formed by physical separation of a combustible-containing salt solution-fuel emulsion in the flame and/or by physical condensation of a salt vapour and/or by oxidation of sulphur dioxide gas in the troposphere and in that they comprise at least one salt vapour and/or at least one salt solution from the substance group silicon tetrachloride, titanium tetrachloride, iron(ll IJchloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate, magnesium sulphate. Such Aerosols may have been formed by physical and/or chemical reaction inside and outside a flame.

A process for producing such an aerosol may be characterized in that at least one gas and/or vapour selected from the group of substances silicon tetrachloride, titanium tetrachloride, iron(ll IJchloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate, magnesium sulphate and sulphur dioxide is released in the troposphere over the ocean.

Further, in such a process at least one gas and/or vapour may be selected from the group of substances silicon tetrachloride, titanium tetrachloride, iron(lll)chloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate and magnesium sulphate is released below or above the lower cloud cover in the troposphere above the ocean. Additionally or alternatively, sulphur dioxide gas may be released above the lower cloud cover over the ocean. Further additionally or alternatively, at least one gas and/or vapour selected from the group of substances silicon tetrachloride, titanium tetrachloride, iron(lll)chloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate, magnesium sulphate and sulphur dioxide may be released in a dry region over the ocean.

A method of forming white clouds is described by means of Aerosols as described above, wherein at least one gas and/or vapour selected from the substance group iron(l ll)chloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate, and magnesium sulphate, is vaporised by the evaporation of salt particles of a salt aerosol containing oxygen or air in the combustion flame of a gaseous, liquid and/or aerosol combustible.

In such a method for forming (a) white cloud(s) at least one Aerosol may be selected from the group of substances iron(l ll)chloride, aluminium chloride, zinc chloride, potassium chloride, sodium chloride, calcium chloride, magnesium chloride, potassium sulphate, sodium sulphate, calcium sulphate, and magnesium sulphate, which is combusted by burning a liquid emulsion of aqueous or alcoholic solution of one or more of these salts and liquid fuel with an oxidant containing oxygen or air in the combustion flame to form a salt aerosol-containing exhaust gas. Alternatively or additionally, sulphur dioxide gas may be produced and emitted by burning a sulphur-containing gaseous or liquid substance by means of air or oxygen with a burner. Further alternatively or additionally, sulphur dioxide gas may be produced and emitted by combustion of a sulphur-containing gaseous or liquid substance selected from the group of substances liquid sulphur or other combustible sulphur-containing fuels, such as carbon disulphide, hydrogen sulphide, carbon oxysulphide or any liquid or liquefiable organic sulphur- and carbon-containing compounds by means of air or oxygen with a burner. Further alternatively or additionally, the device for producing such an Aerosol is connected to stationary or moving devices selected from the group consisting of lattice towers, towers, off-shore platforms, floating platforms, ships, aircraft, balloons, airships.

Alternatively or additionally in such a method for forming white clouds an aerosol may be produced by evaporation or partial evaporation of one or more active ingredients in the flame and wherein the active ingredients may contain at least one element selected from the group consisting of sodium, potassium, magnesium, calcium, aluminium and titanium, potassium, magnesium, calcium, aluminium and titanium and wherein the addition of active substance to the flame takes place in one or more forms dust, droplet aerosol, droplet aerosol produced from an emulsion, droplet aerosol produced from a solution, droplet aerosol produced from a dispersion, and wherein the elemental compounds are selected from the group consisting of alcoholates, iron carbonyls, cyclopentadienides, polyphenolates, hydroxides, carboxylates, polyphenols, carbonyls, cyclopentadienides, the acetylacetonates, the nitrate salts and the nitrite salts and wherein the aerosols produced in the flame reaction are emitted into the atmosphere at the same time or after mixing with gaseous hydrogen chloride and/or vaporous addition of hydrochloric acid and/or vaporous addition of aluminium chloride.

Further, a process for the formation of white clouds is sketched, wherein combustion processes from the group of combustion plants used for heat or electricity generation, combustion engines for diesel fuels, diesel engines in ships and motor vehicles, turbine engines in ships and aircraft are utilised as the device for the production of the aerosols by evaporation of salt emulsions or salt dusts.

So hereinabove, means and methods are described for the production of aerosols with which the formation of white clouds over the ocean or the mainland can be achieved in order to raise the earthly albedo for the purpose of cooling the earth's surface. For this purpose, one or more states of matter from the group of gases, vapours or emulsions are used, which contain substances from the group of chlorine-containing and sulphate salts and sulphur dioxide. The gases or vapours are preferably released in the troposphere by fragmentation, evaporation and/or chemical reaction in a combustion flame in the troposphere.

Fifth embodiments

Further in this context, means and a method for reducing soot aerosol residence in the atmosphere are presented by doping the soot aerosol particles, with which the reduction of the soot aerosol stay in the atmosphere is achieved. This is achieved by dyeing the soot aerosol particles by means of their doping with a metal halide vapour containing at least one or more elements from the group titanium, iron, silicon and aluminium. In particular, this prevents the soot particles from rising into the stratosphere, depleting stratospheric ozone and accumulating on polar ice surfaces. Soot aerosols are formed during the combustion of organic gases, liquids and solids in industrial plants, land, ship and air traffic, private fireplaces and forest and steppe fires. When they reach the atmosphere, the black soot aerosols absorb sunlight quantitatively and convert it into heat. This causes the soot particles to heat up by 40 to 60 °C. As a result, they impart a lift to the surrounding air parcel by transferring the heat to their immediate surroundings, which carries them up into the stratosphere. There, the aerosol surfaces catalyse the heterogeneous photochemical processes of ozone depletion by halogen-containing substances and nitrogen oxides. In addition, the soot aerosols are enriched during their stay in the troposphere with the organic halogen substances occurring there, such as chlorine, bromine and iodine methanes, and halogen elements, which are formed in the soot particles from inorganic halogen compounds, such as chloric, bromic and hydroiodic acids, halogen acids and perhalogen acids as well as compounds of halogens with nitrogen-oxygen compounds. The various halogen components are fixed in the soot particles by adsorptive forces and as intercalates,

In this way, the soot particles also act as "halogen shuttles" that carry the ozone-depleting substances into the stratosphere. Since the conclusion of the Montreal Protocol, which significantly reduced the emission of ozone-depleting organic halogen compounds in 1987, the "ozone hole" occurring over Antarctica in spring has only become marginally smaller. For the past three years, an "ozone hole" has also appeared over the Arctic in spring that did not exist before. In addition, the warming of the polar regions is increasing up to four times faster than the global average.

A potential cause for this is an increase in global soot emission supported by the Brewer-Dobson circulation of the atmosphere: rising over the equator into the stratosphere of the hemisphere, moving over the hemisphere towards the north pole (for the northern hemisphere and the south pole for the southern hemisphere), sinking over the poles and flowing back to the equator through the troposphere. Thus, the soot emissions accumulate over the poles and turn the respective ice surfaces grey. A solution to the soot problem is presented herein which succeeds in preventing the soot aerosol from rising into the stratosphere.

This is done by contacting the soot particles with a vapour or gaseous medium from which it is doped by intercalation and adsorption with one or more of the metal ions from the group Ti(IV), Fe(lll), Si(IV) and Al(lll). Vaporous dopants of these four metals are particularly known from the group of carbon compounds such as tetraisopropyl titanate, di-pentadienyl iron, iron pentacarbonyl as well as various organic silicon and aluminium compounds. The two mentioned precursors from the group of carbon iron compounds are only divalent with respect to iron, but they would be rapidly converted to the preferred iron(lll) on the soot in the oxidising atmosphere. However, these substances are difficult to produce, they show toxic properties or they carry organic carbon into the environment, which in principle runs counter to the beneficial effect on the environment of the process according to the invention.

Therefore, the vapours from the group of halide compounds, preferably the chlorine-containing compounds with the metal ions mentioned, are preferred for use in an Aerosol. The use of the metal ions Ti(IV) and Fe(lll) is particularly preferred because they accelerate the photocatalytic oxidation of the soot, which thereby loses its water-repellent properties and is converted much more rapidly into hygroscopic particles that act as cloud condensation nuclei and also leads to a rapid washing out of the soot treated in this way from the atmosphere compared to the natural oxidative ageing of the soot in the atmosphere. The contact between the soot aerosol and the vapour containing metal ions for doping the soot may take place by injecting the vapour into the partially enclosed exhaust emission device from which the combustion exhaust gases containing soot are discharged into the atmosphere. To name some examples, this can be the thrust-emitting nozzle of a jet engine-powered aircraft, the stack of a coal-fired power plant, the exhaust of a diesel engine or the stack of a ship. In order to achieve the most uniform doping possible, it makes sense to take measures to improve the mixing of the flue gases with the injected vapour dopants, such as static mixing elements or multiple injection locations within the partially enclosed exhaust emission device.

The metal chlorides adsorbed in the soot particles are converted into hydrolysates such as Ti(OH)4, Si(OH)4 by water absorption from the combustion exhaust gases, depending on the temperature in the reaction chamber, Oxides such as TiO2, SiO2, solid and/or liquid water of crystallisation compounds such as FeCh x 6H2O, AICI3 x 6H2O or hydrolysates and oxides such as Fe(OH)3, FeOOH, Fe20s, AI(OH)3, AIOOH and AI2O3. With the exception of the iron compounds, all of the compounds mentioned are white (or bright) in colour, while the iron oxides formed are coloured red and the iron hydroxides are coloured yellow to ochre and the ferric chloride water of crystallisation compounds are coloured orange. As a result, the outer surfaces of the doped soot aerosol particles in particular acquire these colours or a mixture of the colors that still brightens the soot particle sufficiently. This reduces the absorption of solar radiation by the soot particles to such an extent that their conversion into soot particle heating is no longer sufficient to carry the soot into the stratosphere or into the Arctic or Antarctic.

For the doping of the soot, it is sufficient to inject 1 % by weight or more, preferably 10 % or more, or even up to 100 % by weight based on the weight of soot, into the exhaust emission device, provided that the flue gases are well mixed with the metal chloride vapour. The exhaust emission device can be, for example, a chimney, an exhaust or the exhaust pipe of the exhaust gases from a jet engine or a jet turbine. Especially in the case of soot with a particularly high surface area and/or unfavourable mixing conditions in the exhaust duct of the soot-containing combustion exhaust gas, it may also be necessary to use a multiple of the soot weight to treat the soot.

TiCk vapour is particularly preferred for soot doping, as it leaves an excellent white or bright colour on the soot (carbon black) particles and can therefore be used in small doses, which under favourable conditions can even fall below the 1 % by weight mark given above by a factor of up to ten, i.e. as low as 0.1 % by weight or more, of the soot weight. As a rule, however, the exact dosage always depends on the degree of brightening caused by the metal chloride gas injection. This is sufficient when the soot particles have lost their ability to rise in the strong midday sunlight. In other words, it is not necessary to turn the soot completely white, but maybe a brownish or greyish colour is sufficient to sufficiently diminuish the effect that the soot particles climb high in the atmosphere. So the soot particles are brightened, that is summarized also under the term “whitening” in this disclosure. Above the clouds at altitude where commercial aircraft fly, higher dopings with the colouring metal chlorides may even be necessary because the solar radiation is much stronger here and higher buoyancy forces are triggered in the soot particles.

It is preferred that a fraction of iron(lll) and/or titanium(IV) metal chloride injection vapour is present because the elements iron and titanium in these valence states act as strong oxidising agents which can chemically convert the substance of the originally water-repellent aerosol soot particles to hydrophilic cloud condensation nuclei and even completely degrade the soot substance. Oxygen-containing nitrogen compounds, and/or strong oxygen-containing oxidising agents, such as O3, H2O2, NO2, NO, HNO3, N2O4, N2O5, CINO2, HONO and CINO, which can be injected in addition to the metal chloride vapour injection, can also contribute to enhancing the oxidising effect of the dopants,

At the same time, the iron(lll) and/or titanium(IV) dopants of the carbon black through the described metal chloride vapour injection offer the high advantage that the carbon blacks impregnated with them act as methane degradation catalysts because they can trigger the formation of chlorine atoms from chlorine ions as photolytically active substances. Thus, the invention also has a direct cooling effect on its atmospheric application volume, including the underlying application region, through soot degradation, cloud formation and methane degradation. Under the circumstances that the injection contains iron and takes place over the sea, CO2 degradation as a result of phytoplankton fertilisation with iron is added to the cooling factors mentioned.

Liquid dopants of the mentioned doping elements dissolved in water come in question for use instead of the vaporous dopants for soot doping. However, at present this doesn’t seem possible because the soot freshly formed in the combustion processes is water-repellent and cannot coagulate with the water droplet aerosol. Furthermore, the coagulation method, e.g. when forced by surfactant addition, does not result in sufficiently small aerosol particles or droplets that are beneficial for cloud formation. Moreover, the use of surfactants would pollute the environment.

The effective reduction of the soot aerosol content by colouring the soot aerosol particles by means of elemental compounds other than those mentioned above is also possible, for example with vapours containing the elements zirconium tetrachloride, germanium tetrachloride, molybdenum hexachloride, tungsten hexachloride, gallium trichloride or the carbonyls of transition elements. However, these options are uneconomical because their colouring elements occur much less frequently.

To summarize, Aerosol emissions from technical combustion processes of organic substances containing soot particles are doped with at least one metal ion and/or one metal compound from the group titanium, iron, silicon and aluminium. Preferably, such soot particles can be doped with at least one vaporous dopant from the group of metal halides as listed in the phrase before.

Such a soot (particle) may additionally be doped with at least one vaporous dopant selected from the group consisting of said metal chlorides. Additionally or alternatively, said soot may be doped with at least one vaporous dopant from the group of said metal chlorides, wherein the mass of the vaporous soot dopant can be between 0.1 % by weight relative to the weight of soot and several times the weight of soot. Additionally or alternatively, the soot (particles) may be doped with at least one vaporous dopant from the group of metal chlorides, wherein the mass of the vaporous soot dopant is chosen at least so high that the soot particles have lost their ability to rise in the strong midday sun irradiation at the combustion gas emission point.

Furter, a soot particle(s) may be doped with at least one vaporous dopant from the group of metal chlorides, wherein the mass of the vaporous carbon black dopant injected into the reaction site can be between 0.1% of the weight of the soot and several times the weight of the soot.

Doping soot aerosol from combustion processes with at least one metal ion from the group Ti(IV), Fe(lll), Si(IV) and Al(lll) may be characterised in that the doping of the soot with the vaporous dopant takes place by injection of the vaporous dopant into the exhaust emission device. Additionally or alternatively the doping of the soot may be effected by injection of the vaporous dopant into the exhaust emission device and the exhaust emission device may be a partially enclosed device from which the combustion exhaust gases containing soot are discharged into the atmosphere. Sixth embodiments

In yet another series of embodiments, doped soot from combustion devices, and a process for the decomposition of methane, ozone and other greenhouse gases in the troposphere therewith is described, with which the decomposition of methane, ozone and other organic climateimpacting substances in the troposphere atmosphere is achieved, preferably by enriching soot particles with hydrogen halides and/or acid halides. Preferably, one or more vapour and/or gaseous halides from the group HCI, TiCk, SiCk, AlCh, FeCh are adsorbed by a soot aerosol. The soot aerosol enriched with chlorine is then emitted into the troposphere. In principle, mixtures of the above-mentioned halogen compounds can also be mixed with small vapour fractions of the corresponding bromine and iodine compounds in order to achieve a more complete removal of groundlevel ozone.

For the production of the soot, one or more vapour and/or gaseous halides from the group HCI, TiCk, GeCk, SiCk, AlCh, FeCh are introduced into the exhaust gas duct of a technical combustion plant and mixed with the exhaust gas. The gaseous and/or vapour chlorines / chlorides are adsorbed by the soot particles contained in the combustion exhaust gas. Hydrolysis with the water vapour of the exhaust gas leads to the hydrolysis of TiCk, GeCk and SiCk with the release of HCI, some of which remains in the soot particles and some of which passes into the gas phase. In contrast, the chlorine-containing AlCh and FeCh are transferred to the liquid phase by water absorption, but remain largely completely in the soot particles as water-containing chlorides. A small proportion of the soot may react with the oxidising components of the atmosphere as well as with the oxidising components of the exhaust gas itself, in particular NO2 and NO after the exhaust gas has been emitted into the atmosphere.

The atmosphere contains a number of oxidising agents that convert the chlorides released in the soot particles by the doping with gaseous and vapour halogen compounds and stored therein to elemental chlorine. The graphene molecules in the soot particles act as catalysts. They carry quinoid (=0) and/or hydroquinoid (-OH) groups at their edges, whose reversible absorption and release of electrons is known. Examples of the hydrogen chloride oxidation reactions catalysed by the soot particles or catalysed by the graphene molecules contained in the soot particles are reported in reaction examples 1-11 below. According to a favoured model, the oxidation product CI2 is first stored as a graphene intercalation compound in the soot particle.

According to the increasing CI2 vapour pressure with increasing CI2 loading, CI2 from the soot particle enters the free troposphere and undergoes photolysis by sunlight during the bright daytime. The result of this reaction is chlorine atoms, which are known to initiate the oxidative degradation of methane in the free atmosphere, converting it to hydrogen chloride gas. In addition to hydrogen chloride, oxygen compounds of chlorine, bromine and iodine are also present in the troposphere, which are also effective as oxidants. Of these substances, however, only the chlorine compounds are effective for the decomposition of methane. In contrast, bromine and iodine have a much stronger effect on ozone depletion; however, they are only present in the atmosphere in small quantities.

1) 2HCI + HNO ₃ ° -> NO2 ⁰ + °H ₂ O ⁰ + CI2 ⁰

2) 2HCI + NO2 ⁰ -> NO ⁰ + °H ₂ O° + CI2 ⁰

3) 4HCI + 2CINO ₂ ° -> N2 ⁰ + °4H ₂ O ⁰ + °3Cl2°

4) 4HCI + 2NO -> N2° + 2H ₂ O° + °2Cl2°

5) 2HCI + H2O2 ⁰ -> 2H ₂ O° + CI2 ⁰

6) 2HCI + 2OH ⁰ -> 2H ₂ O° + °Cl2°

7) 2HCI + O3° -> H2O° + °O2 + °Cl2 ⁰

8) 4HCI + O2 ⁰ -> 2H ₂ O° + ^O 2CI ₂ °

9) HCI + HOCI -> H2O + CI2

10) 4HCI + °2BrO° -> 2H ₂ O° + Br ₂ + 2CI ₂ °

11) 8HCI + 2CIO2 -> 4H ₂ O + 5Ch

Of the vapour and/or gaseous halides from the group HCI, TiCk, GeCk, SiCk, AlCh, FeCh that are effective for soot aerosol doping, GeCk is not one of the preferred doping agents due to its rare occurrence. The particularly preferred doping agents include AlCh and FeCh because a higher chlorine-containing content can be built up in the soot particles with these agents.

To summarize, it is proposed herein that soot particles are doped with at least one substance from the group hydrogen chloride, titanium tetrachloride, iron trichloride, silicon tetrachloride germanium tetrachloride and aluminium trichloride. Additionally, such soot particles may be doped with Aluminium chloride and/or ferric chloride. Preferably, such soot may comprise that the mass of the vaporous soot dopant is between 0.1% by weight relative to the weight of soot particle and several times the weight of the soot particle.

A method for doping soot aerosol from combustion processes with at least one substance from the group HCI, Ti(IV), Fe(lll), Si(IV) and Al(lll) is discussed, wherein the doping of the soot with the vaporous dopant takes place by injection of the vaporous dopant into the exhaust gas duct of the exhaust gas emission device. In such a method the doping of the soot may, for example, be effected by injection of the vapour-shaped doping agent into the exhaust gas emission device and/or the exhaust gas duct of the exhaust gas emission device may be a partially enclosed device from which the combustion exhaust gases containing soot are discharged into the atmosphere.

Seventh embodiments

In another aspect of the pool of ideas that is combined in the present specification a several measures that can be combined with each other, or wherein selected features may be combined inter each embodiment, means and methods for increasing precipitation water are presented hereinbelow.

But it is found out that the height of the updraft chimney can be significantly reduced if the rising warm air is fed to the updraft chimney by suitable curved guiding surfaces in such a way that it can rise as a rotating cyclone or as a vortex in the chimney and can also rise in a stabilised manner as a cyclone rotating around its vertical axis after leaving the chimney. Principles of such induced cyclones on parcels of air are described by Mohiuddin & Uzgoren, “Computational analysis of a solar energy induced vortex generator”, Applied Thermal Engineering, 98, 1036-1043, 2016; Leong et al, “Buojancy vortex engine CFD Modelling using ANSYS-CFX”, 23rd Australian Fluid Mechanics Conference - 23AFMC, Sydney, Australia, 4-8 December 2022, Paper No: AFMC2022-222. This method of upwind stabilisation as a vortex by rotation around a vertical axis can also be used for condensation generation (Jasim et al., “Photovoltaic solar chimney system: a review”, Journal of Global Scientific Research, 7(6), 2358-2396, 2022; Kashiwa & Kashiwa, “The solar cyclone: a chimney for harvesting atmospheric water”, Energy, 33, 331-339, 2008.

Particular advantages for precipitation formation, climate cooling and the environmental friendliness of clouds doped with condensation nuclei are:

1. The effect of condensation nuclei on the production and raining out of clouds is advantageous because it promotes the condensation process and optimises precipitation formation. Precipitation formation can thus be increased by up to 20%.

2. Furthermore, it is advantageous to use condensation nucleus particles that are as small as possible in order to minimise the condensation particle mass.

3. Furthermore, it is advantageous to use hygroscopic condensation particles as far as possible, because these already initiate the condensation process at relative humidity below the water dew point. 4. The production of clouds that are as white as possible and have a much higher albedo than clouds with lower droplet density is desirable because they are beneficial for cooling the climate. This can be achieved by providing a condensation nucleus aerosol with high aerosol particle density and particularly small particles below 0.1 pirn particle diameter.

5. The avoidance or at least minimisation of combustion processes for the generation and/or mixing of the condensation key aerosol with the warm air used for cloud generation.

With the known processes for cloud formation described above, the advantages mentioned under 1 to 5 cannot be achieved or it is at least hard to achieve because the condensation nuclei produced with them are too coarse and have a high fossil energy consumption. The condensation nuclei described there contain e.g. rock salt as a hygroscopic substance, which is of much lower hygroscopicity than, for example, iron(ll IJchloride, oxalic acid, sulphonic acids and sulphuric acid, which are among the natural condensation nuclei. Moreover, the rock salt condensation nuclei are produced by conventional nebulisation of liquid aqueous phases. This method cannot produce condensation nuclei with diameters smaller than or equal to 0.1 pirn.

On the other hand, the production of the aerosols with aerosol particle diameters of less than or equal to 0.1 pirn, which are produced from the gas phase and claimed according to the invention, succeeds in fulfilling all of the advantages 1 to 5 as a condensation nucleus aerosol for the doping of vertical warm air streams containing water vapour. Thus, the generation of additional precipitation can be made much more economical and environmentally friendly and can be designed with a great additional effect for the restoration of the climate.

In the case of the condensation nucleus aerosol, the latter is achieved by the aerosol in the atmosphere being photolytically stimulated by solar radiation to emit chlorine atoms into the atmosphere, which additionally decompose atmospheric methane and also tropospheric ozone. The production of the finely divided aerosol is described below.

The aerosol is produced by injecting a vapour containing at least one of the vaporous salts with the chemical formula TiCk, FeCh, AICI3, SiCk preferably by means of a carrier gas stream into a rising stream of warm air or directly into the atmosphere. Preferably, the salt vapours contain mixtures of these salts, such as TiCk + AICI3 + SiCk or FeCh + TiCk + AICI3 + SiCk.

From case to case, it may be desirable to use an aerosol that is particularly effective for methane degradation. For this purpose, hydrogen peroxide in vapour form can be added to the salt mixture vapour, provided that titanium and no iron or , as the case may be, potentially a very small fraction of iron is contained therein. In case the salt vapour mixture contains iron, nitric acid vapour can be added to the vapour mixture for this purpose.

Immediately after release of the salt vapour mixture into the carrier gas stream and with it into the warm air to be doped with the Aerosol, the Aerosol is formed with the water vapour content of the carrier gas and the warm air, which contains the metals contained in the salt vapour as hydrolysates, for example. For example, Ti(OH)4, Si(OH)4, oxides such as TiC>2, SiC>2, solid and/or liquid water of crystallisation compounds such as, for example, FeCh x 6H2O, AICI3 x 6H2O or also hydrolysates and oxides of titanium, silicon, iron and aluminium with a lower water content. Typical examples include Fe(OH)3 , FeOOH, Fe20s, polymeric gel-like silica and titanic acid polycondensates, AICI(OH)3, AI(OH)3, AIOOH. Such compounds, including the formation of polymeric mixed condensate gels, which may contain all cations involved, are also formed in the course of ageing of the claimed condensation nuclei in the atmosphere depending on the moisture content of the air. In the case that the salt gas phase contained TiCk and hydrogen peroxide is used as an additional vapour phase, the hydrolysate also contains additional peroxo compounds in the titanium hydrolysates.

The mixing of the salt vapour phase with the hot air stream to be doped is preferably done by sucking in the salt vapour phase, if necessary also additionally hydrogen peroxide containing vapour, or nitric acid vapour or nitrogen oxides containing vapour through a carrier gas jet according to the Venturi principle and then blowing it mixed with the carrier gas, which is usually air, into the hot air stream as turbulently as possible. Preference is given to the use of claimed salt vapour or salt vapour and additionally added hydrogen peroxide vapour. During this operation, the stressed fine-particle condensation nucleus aerosol forms spontaneously.

In addition to or instead of the above salt vapour composition, other vaporous chlorine-containing salts can also be applied, such as ZrCk, GeCk, MoCle, WCIe, GaCk as well as also the vaporous carbonyls of iron and other transition elements, which are converted into chlorine- containing aerosols with the vaporous chlorine-containing salts after their release. However, these options are less economical because their metal components are rare, or difficult to synthesise or handle, especially with regard to the carbonyls.

For the conveyance of the fine-particle condensation nucleus aerosol to the height of the lower cloud boundary, the known measures described at the beginning, such as vertically radiated jet turbine engine exhaust gases, as well as warm air stacks from greenhouse gas-covered surfaces or their warm air driven up as a cyclone, can be used. Combinations of these methods can also be used. Preference is given to the combination of low greenhouse warm air stack and vortex-stabilised buoyancy. The stressed aerosol produced by injecting the salt vapour into the

Eighth embodiments

Next, in this disclosure the use of the process for the oxidation of fire aerosols in the troposphere is presented by means of aspects of the Aerosol, by which the oxidation of the smoke aerosol from wildfires, in particular forest and moorland fires in the troposphere, is achieved. This is achieved by enriching the flue gases above their area of origin with at least one oxidation and/or photocatalyst from the group of hydroxides, peroxides and oxides of titanium, from the group of hydroxides, oxides, chlorides, carbonyls and nitrates of iron. Preferably, one or more reactants from the group HCI, TiCk, SiCk, AlCh, FeCh and H2O2 are used.

The large forest and moorland fires, which are increasing in the course of climate warming, have shown that the flue gas aerosols formed under high energy release can rise into the stratosphere under favourable conditions. These flue gases are not the primary target for the process described herein. It has been shown that these flue gas aerosols, which are characterised by particularly high thermal buoyancy, are rather the exception. In contrast, most wildfires release predominantly flue gas aerosols with lower thermal energy, which only spread in the troposphere and its near-ground part and lead to far-reaching adverse effects on health. The process described herein targets these flue gases with lower thermal energy.

Reactant gases and/or reactant vapours are released above the burning surface, preferably at an altitude of 0.5 to 2 km above it, by means of manned or unmanned aircraft, which mix with the flue gases. These are individual or several vapour and/or gaseous reactants from the group TiCk, SiCk, AICI3, FeCh, HNO3, H2O2, Fe(CO)5. The selected gas or gas mixture is introduced into the swelling flue gases with the aid of the flying device. Immediately after the release of the reactants, the moisture and oxygen content of the flue gases reacts with the reactants to form the active substance and active substance carrier aerosol. The reactant gases and/or reactant vapours can also be discharged from tethered balloons or tethered airships, provided that these are fixed to land vehicles and can thus be tracked to predetermined non-stationary positions.

The active substances are oxidation catalysts, photooxidation catalysts or chlorides which are converted into chlorine atoms by means of the oxidation catalysts and/or photooxidation catalysts. The active substances generate strong oxidants, in particular hydroxyl radicals and chloride atoms. These react with the organic solid and liquid flue gas components to form CO2 and water, so that their duration of existence in the troposphere is greatly reduced. Agents that can form from individual or several substances from the group of gaseous reactants are, for example:

• Ti(OH)4 , photocatalyst

• TiO2(OH)2, photocatalyst

• Si(OH)4, Active ingredient carrier

• AICI3 Chlorine-containing carrier active substance

• FeCh Oxidation catalyst, photocatalyst, chlorine-containing carrier active substance

• Fe2Os Oxidation catalyst,

• Nitrate, Photocatalyst

With the exception of HNO3, all active substances basically consist of condensed phase. HNO3 is also effective as an active substance in the vapour phase. In contact with the flue gas aerosols, coagulation and/or condensation occurs to the effect that, after a short reaction time, the particles and droplets of the original flue gases contain at least one of the active substances, photocatalysts or oxidation catalysts mentioned.

The iron-containing active ingredients are known to form hydroxyl radicals according to the Fenton reaction. The active substances containing iron and titanium are able to form atomic chlorine in the presence of sunlight and chlorine ions. This is especially true for the photocatalyst TiO2(OH)2. HNO3 and the nitrates titanium-containing agents form from it are also known for their photocatalytic activity by forming hydroxyl radicals. Aluminium chloride therefore acts as an active agent because it can provide the necessary chlorine ions for chlorine atom formation. Chlorine atoms are more effective than OH radicals for the oxidation of organic flue gas constituents.

Silica formed from the gas phase by hydrolysis is very finely divided and acts as an active ingredient carrier as well as a condensation nucleus for cloud formation. Si(OH)4 and its polycondensation products are thus helpful for the condensation of the active substances into particularly fine-particle aerosols. The flue gas aerosols doped with the active substances in this way are subject to rapid oxidation in the atmosphere and also have a condensation nucleating effect on cloud formation and are therefore conducive to the formation of rain, which rapidly leads to the flue gas aerosols that have become hydrophilic through oxidation being washed out of the atmosphere. This considerably reduces the duration of existence of the flue gases in the troposphere and their dispersion over wide regions, so that the damage to health caused by the flue gases can be significantly reduced.

To summarize, herein a method for substantially reducing the duration of existence of the flue gases in the troposphere and their dispersion over wide regions of the troposphere is described, wherein the flue gas aerosols are brought into contact with individual or several active substance reducts from the group of the vapour and/or gaseous substances TiCk, SiCk, AICI3, FeCh, HNO3, H2O2, Fe(CO)s. The method may be further established in that the individual or several active substance reducts may be applied with manned or unmanned aircraft. Additionally or alternatively the application of the active substance reducts in the smoke cloud rising from the burning area may be carried out at an altitude of 0.5 to 2 km above it. Additionally or alternatively the discharge of the reactant gases and/or reactant vapours may also take place from tethered balloons and/or from tethered airships, provided that these are fixed to land vehicles and can thus be tracked to predetermined non-stationary positions.

Ninth embodiments

In the next example, an aqueous (saltwater) aerosol for the decomposition of greenhouse gases in the atmosphere is described, containing a chloride, chlorine-containing salt or a chlorine-containing salt solution, wherein the pH value is less than or equal to 3. The Aerosol is preferably produced by spraying into the atmosphere. The Aerosol is capable of releasing chlorine atoms in the solid, liquid or gaseous aerosol phase. Greenhouse gases, such as methane, are particularly effectively decomposed with it. In addition, the aerosol is able to form clouds due to the salt-containing condensation nuclei it contains. Chlorine or hydrogen chloride can be produced by saltwater electrolysis powered by wind or solar energy. Thus, directly or after atmospheric conversion of the chlorine in sunlight with methane to hydrogen chloride, the generated aqueous aerosol can be transferred to the acidic environment where a pH of 3 or less than 3 persists. In addition, the aerosol has the property of cloud formation if it contains salts or undissolved condensation nucleating agents.

A particularly preferred source for the Aerosol and/or of salt water is seawater. Aerosol formation takes place according to the already described processes of liquid nebulisation or condensation of vaporous chlorine-containing salts. Next to the methods of liquid nebulisation or condensation of vaporous chlorine-containing salts Aerosol formation may also occur by vaporous hydrochloric acid formers with the humidity of the air or the moisture contained in the aerosol.

To form the acidic pH in the aerosol phase, the addition of, e.g. liquid, acids to the aqueous fluid to be nebulised or the addition of gaseous acid-forming agents, such as hydrogen chloride, nitric acid or acid-reacting salts, such as the tetrachlorides of silicon and/or titanium, or the aluminium trichloride or aluminium trinitrate, is suitable. Non-preferred pH regulators include organic acids, sulphurous acid, sulphur dioxide and sulphuric acid.

Aqueous aerosol droplets of the order of less than 5 pirn in diameter spontaneously form hydroxyl radicals. The hydroxyl radicals can leave the liquid droplet phase and act as oxidants on the gaseous or vapour organic matter in the atmosphere and initiate its degradation to CO2. Additionally, it has now been discovered that the degradation of gaseous or vaporous organic substances in the atmosphere can be substantially optimised if the aqueous aerosol droplets are chlorine-containing and have an acid content such that their pH value is less than 3, preferably less than 2. It was found here that in this pH value range of the aerosol, chlorine atoms are formed instead of hydroxyl radicals, which escape into the methane-comprising gas phase much more easily than hydroxyl radicals and which react much more effectively with the greenhouse gas methane.

The addition of liquid acids to the water or aqueous solution to be nebulised or the addition of vaporous acid formers to the aerosol phase is suitable for forming the acidic pH value in the aerosol phase. Such vaporous acid formers are, for example, hydrogen chloride, chlorine, nitric acid or hydrolysing salts such as the tetrachlorides of silicon and/or titanium, or acid salts such as aluminium trichloride or aluminium trinitrate. Further possible pH regulators include organic acids, sulphurous acid, sulphur dioxide, sulphuric acid and acid-reacting sulphates and hydrogen sulphates, such as aluminium sulphate and its sulphate-containing hydrolysis products.

Preferably, the conversion of the droplet aerosol into the acidic phase is done by adding hydrochloric acid to the aqueous fluid prior to its nebulisation or by adding hydrogen chloride gas or chlorine gas to the generated mist. Both chlorine and hydrogen chloride can advantageously be produced by salt water or sea water electrolysis.

Thermal combustion can be used to produce hydrochloric acid or hydrogen chloride gas from the chlorine and hydrogen formed during electrolysis, or cold combustion can be used in the fuel cell to produce electrical energy in a known manner. The alkaline solution formed during electrolysis can be returned to the sea by mixing it with seawater.

When using the chlorine formed during seawater electrolysis, the by-product hydrogen is preferably used as follows: The hydrogen gas produced is reacted with air in a fuel cell to form water or it can be burnt with the addition of air, if necessary using an oxidation catalyst.

In the atmosphere, the chlorine released with the generated fog converts into chlorine atoms in contact with sunlight, which react with the atmospheric methane to form hydrogen chloride. The hydrogen chloride is finally absorbed by the fog droplets and transfers them into the desired acidic environment phase.

Summarized, an Aerosol containing chlorine ions and/or chlorine in the atmosphere whose pH value is less than or equal to 3 is described. The Aerosol is produced with a method with which the aerosol is produced by nebulising an aqueous solution and/or aqueous fluid. In addition, the method may comprise that the aerosol is produced by nebulising a salt solution containing seawater. Additionally or alternatively, the production of the aerosol may be effected by condensation of a vaporous hydrolysable chlorine compound. In the process, alternatively or additionally the conditioning of the pH value of the aerosol may be effected by acidifying the chlorine-containing solution to be nebulised. The conditioning of the pH of the aerosol may also be done by the addition of a vaporous and/or vapour acidifier to the aerosol. Further, at least one vapour-forming acid generator may be selected from the group of substances releasing hydrochloric acid by hydrolysis.

In a process for conditioning the pH of the before-mentioned aerosol at least one vapour-forming acid generator may be selected from the group of substances hydrogen chloride, nitric acid, silicon tetrachloride, titanium tetrachloride, aluminium trichloride and aluminium trinitrate. In such a process gaseous hydrogen chloride and/or gaseous chlorine may be used for this purpose. Additionally or alternatively, in the production of which one or more processes from the group electrolysis, fuel cell, combustion may be used.

The invention is described in more detail and in view of preferred embodiments hereinafter, where these embodiments show some or all aspects of the embodiments described before, and also show further aspects. Reference is made to the attached drawings wherein like numerals have been applied to like or similar components. Brief Description of the Figures

It is shown in

Fig. 1 A first embodiment for a method and a device for releasing an Aerosol according to the invention,

Fig. 2 an enlarged portion of the embodiment shown in Fig. 1 ,

Figs. 3-6 another embodiment for a method and device for releasing an Aerosol according to the invention,

Fig. 7 further embodiment for an apparatus for releasing an Aerosol according to the invention.

In the embodiment of Fig. 1 a vessel 30 such as an airship is used that can float over such a region and deplenish the Aerosol 50 on the area of interest, i.e. the greyed area 82. In this embodiment, whitening particles 60 are stored in a cargo area 32 of the vessel 30 to be carried to the place of use, it is transported through a hose 34 to a windscreen 40 where also a high-velocity air stream is induced, so that an aerosol 50 is mixed, e.g. in turbulent mixing beneath the windscreen 40. Fig. 2 shows an embodiment of a device 2 to produce an aerosol 50, that may be an enlarged portion of the embodiment shown in Fig.1. The whitening particles 60 are introduced through particle inlet 58 into the transport line 34 and to the nozzle 40. Air is fed to air inlet 56 and compressed, either in the vessel 30 or at least before the nozzle 40. At the nozzle the air stream 52 mixes with the agents (or particles) to expel or discharge the particles and in the mixing to form the Aerosol 50 at the end 36 of the transport line 34 and/or beneath the windscreen 42.

Referring now to Figs. 3 to 6 another embodiment is shown where parcels of aerosol are lifted from a ground-based station into the free atmosphere, i.e. above ground layer. Such a device 2 for lifting the hereincalled TOA aerosol 50 (tropospheric oxidation aerosol) up hundreds of metres from ground level uses a principal of blowing rings 51 (toroids) of aerosol 50 vertically out of the device 2, which propagate up in the air a sufficient distance. Each aerosol toroid 51 preferably rotates axially about the vertical axis, to improve its stability. In other words, by means of the rotational stability of the aerosol vortex 51 convection with the surrounding air is reduced or prevented, so that the aerosol toroid 51 can rise a significantly larger distance. Uplift of the toroids 51 is further supported by convection heat, which may come from two sources. Firstly, the expelled air is heated prior to entering the generator chamber. Secondly the air is further heated by heat of condensation of water vapour onto the aerosol particles, as the toroid rises.

For example, such a terrestrial unit may comprise a surface area 10 of an order of a square kilometre of “greenhouse area” (or more) to warm moist air before it enters the main toroid generator chamber 7. However, a scaled down version could apply, e.g., to large ships.

According to Fig. 3 moist air flows from an outside into the device 2, that comprises a greenhouse arrangement 20, where it is warmed. The warmed air 4 enters the vortex generator chamber 7 through opened flap valves 6. At the top of the chamber is a cover 16 with a large closable hole 14 in its centre. The cover 16 is connected to the chamber walls by concertina bellows 8 and is designed to be movable, e.g. to move up and down. The cover is lifted by cams 11 driven by motors 9. The cams 11 of this embodiment are designed to rotate synchronously to lift the cover 16 up gradually, which allows the warmed air 4 to flow into the generator main chamber 7. Springs (not shown) apply a tugging force on the cover, applying a downward force. As is shown in Fig. 4 when the cams 11 have turned past their fullest radius to their lowest position the cover 16 has moved rapidly down, pulled by both the springs and gravity. As the cover 16 moves rapidly down the flap valves 6 close immediately and are shown in Fig. 4 in the closed position, induced by the sudden rise of pressure induced by the downward movement of cover 16. The pressure increase can the be exhaled in a guided manner to generate the toroidal vortex 51 of Aerosol 50. The toroidal vortex 51 of aerosol 50 continues to move up in the air. As soon as the toroidal vortex 51 of aerosol 50 has left the containment, the pressure of the warm greenhouse air outside the containment pushes the flap valves into the open position again, so that the state as shown in Fig. 3 is recycled. Inward air flow 4 can resume from the greenhouse chamber 20 into the buildup chamber 7. Fig. 6 shows a detail of a cam 11 with its axis shaft 11a.

So the device 2 shown in Fig. 3 an apparatus to eject a parcel of Aerosol 50, 51 into the atmosphere, where it is designed in a particularly beneficial way without the need of having an overly long exhaust section. Instead, by means of inducing a rotational movement to the raising parcel of Aerosol 50, 51 it gains an intrinsic stability against stopping and dissolving with surrounding air, that is, adiabatic mixture of the Aerosol parcel 50, 51 is prevented for an initial period long enough to allow it raising to above a ground boundary layer, e.g. several hundred meters high to promote spreading of said Aerosol 50 over a desired area 80 of interest.

In order to induce that intrinsic stability to the parcel of Aerosol 50, 51 the embodiment comprises a greenhouse arrangement 20 with a cover 18 that covers a greenhouse surface 10, where a gas such as air is warmed up like in a greenhouse. The gas may be moist or may be wetted, so it can be saturated with moisture such as with an Aerosol precursor that mixes to form the Aerosol 50. Upon warming of the gas in the greenhouse arrangement 20 a pressure will increase forcing the gas to flow out of the greenhouse arrangement 20. The device 2 is further designed in that the warmed gas/Aerosol will enter a pressure chamber 7 that is accessible, in this embodiment, by means of a multitude of flaps 6. The flaps 6 allow, in an open state as indicated in Fig. 3, an inflow of gas and/or Aeorosol 50 into the pressure chamber 7. The flaps 6 may be designed in such they prevent a backflow of gas and/or Aerosol 50 from the pressure chamber 7 back to the greenhouse arrangement 20. Further, fresh gas, such as outside air, may flow into the greenhouse arrangement 20 through the gas inlet 17. The gas inlet 17 may be just circumferentially open accessible, but may also be designed to prevent outflow of warmed gas.

When warm Aerosol 50 has been accumulated in the pressure chamber 7 the flaps 6 are closed to prevent a backflow into the greenhouse arrangement 20, the outlet closure 16 is adjusted according to prevailing pressure and/or meteorologic conditions, and then the active portion of the top cover is lowered in a rapid movement by means of camshafts 11. The rapid movement increases pressure in the pressure chamber 7 forcing the Aerosol 50 to eject out of the pressure chamber 7, where the shape of the outlet closure 16 helps in forming an Aerosol vortex 51. Such an Aerosol vortex 51 is sufficiently stable to be raised to several hundred meters above the device 2. Movement arrow 12 shows the vertical movement of the containment cover 16 during loading of the vortex generator containment 7. For releasing the Aerosol 50 the rotating camshafts 11 move down to the lower-most position. The flaps 6 (valves) close the open holes immediately, that may be induced by the sudden rising pressure induced by the immediate down-movement of the cover 16. As soon as the toroid aerosol vortex 51 has left the containment the prevailing and rising pressure of the warm greenhouse air outside the containment 7 opens the flaps 6 into an open position again. As indicated in Fig. 4 a sudden down-moving of the containment cover 16 has emitted a toroid vortex 51. This sudden down move is induced by cooperation of rotating camshaft 11 , strong springs draw and gravity. The drawing springs are not shown in the schemes. The emitted toroid vortex aerosol cloud 51 is only sketched schematically, where arrow 15 depicts its direction of movement.

Turning to Fig. 5 guide plates 22 of the outlet cover 16 are shown that are designed to induce a circular rotation to the air flowing into the main chamber 7, enabling the ejected toroid to spin about its vertical axis. Synchronised cams 22 driven by motors 21 drive the cover plate 16 up. Springs included in the same assembly pull the cover rapidly down, as described above. With Fig. 6 one of the synchronous driven rotating camshafts 11 is shown, that is moved through the motor axle 11 a by a motor 9 including the drawing springs.

Fig. 7 shows a further embodiment for the production and emission of an Aerosol plume 53 by fumigation of a nano-sized aerosol powder 60 within the containment 7 of the toroid vortex generator 2. The emission locality is preferably placed below the hole 14 in the containment cover 16, just within the vertical level of the uppermost inflow openings for the warm greenhouse air inflow 6. The aerosol emitter presented in fig. 7 may also be used for the fumigation of other kinds of nano-sized powders such as Fe20s, FeOOH, Fe(OH)3, TiC>2 or SiC>2. It may also be used for the fumigation of gaseous or vaporous substances as like as HCI, SiCk, TiCk, AICI3, FeCh, NO, NO2, HNO3, H2O2. It may also be used for the fumigation of liquid SiCk, because according to its low boiling point of ~50°C it has a high vapour pressure. Some aerosols need a complex precursor recipe and need several substances to become aerosolized. In this case it is helpful to use more than one aerosol emitters.

In other words in Fig. 7 an Aerosol generator 2 is shown in its principal mode of operation, where a reservoir or container 62 is provided for storing and providing a powdered precursor 60 to the making of the Aerosol 50. A second precursor is provided through inlet 56 and second transport line 38 into the exhaust chimney 35. Compressed air 52 is provided as the second precursor in this example, and in order to increase further the local pressure at the point of mixture of the first precursor with the second precursor a venturi nozzle 40 is provided in the exhaust chimney 35. The outflowing precursors are expanded after the venturi nozzle 40 and towards the outlet 14, 36 of the chimney 35 and released into the atmosphere to generate an aerosol plume 53. The first precursor 60 is provided in solid form such as micro particle powder that may be borne by means of an airflow or the like and mixed with a second and/or third precursor to generate the Aerosol 50.

It will be appreciated that the features defined herein in accordance with any aspect of the present invention or in relation to any specific embodiment of the invention may be utilized, either alone or in combination with any other feature or aspect of the invention or embodiment. In particular, the present invention is intended to cover a method for providing an Aerosol, an Aerosol as well as a precursor for providing an Aerosol, each configured to include any feature described herein. Further various embodiments for apparatuses that are capable of generating an Aerosol according to this specification are provided. It will be generally appreciated that any feature disclosed herein may be an essential feature of the invention alone, even if disclosed in combination with other features, irrespective of whether disclosed in the description, in particular in one of the several embodiments as described herein, in the claims and/or the drawings.

It will be further appreciated that the above-described embodiments of the invention have been set forth solely by way of example and illustration of the principles thereof and that further modifications and alterations may be made therein without thereby departing from the scope of the invention.

Finally, it will be appreciated, that the embodiments shown in the present application can be combined with corresponding aspects as shown in the application WO 2023/051858 A1. Reference list:

2 device for generating an Aerosol

4 inflow

6 flap valves

7 buildup chamber, i.e. for pressure buildup before emitting an Aerosol vortex

8 bellow

9 motor, i.e. for spring-loading of the outlet

10 greenhouse surface

11 camshaft

11a camshaft axle

12 direction of movement

13 direction of movement

14 outlet, i.e. for Aerosol outflow

15 direction of movement

16 outlet cover, i.e. adjustable

17 gas inlet

18 cover, such as a building

19 adjustable pressure modulator

20 greenhouse arrangement

21 motor, i.e. for sliding a guide plate

22 guide plate

23 direction of movement, i.e. of air inflow

30 vessel, such as an aircraft, airship or helicopter

32 cargo hold

34 transport line as transport hose

35 transport line as exhaust pipe, chimney or the like

36 outlet of transport line

38 second transport line in transport line, such as for compressed air

40 venturi nozzle

42 wind breaker or windscreen

50 Aerosol, such as brightening agent Aerosol

51 Aerosol vortex

52 Transport fluid such as compressed air

53 Aerosol plume

54 brightening or whitening agent

56 air inlet

58 agent or particle inlet

60 solid particles,

61 solid particles, here nano-sized powder

62 particle container

80 ice surface

82 greyed part of ice surface

84 coating