METHOD AND APPARATUS FOR MIXING WATER OR STEAM INTO LIQUID OR GASEOUS HYDROCARBONS BY ELECTROCHEMICAL TREATMENT

The invention concerns a method and apparatus for mixing water or steam into liquid or gaseous hydrocarbons by electrochemical treatment according to claim 1.

Energy consumption is known to be globally increasing, both in developed countries and in the developing world, where industrialisation and rising quality of life appear to be irreversible trends.

Today, energy production continues to rely primarily on fossil fuels, however the progressive depletion of the most easily accessible deposits, coupled with growing demand, will lead to continually- escalating costs and worsening environmental impact.

The combustion of liquid hydrocarbons, used for example to fuel internal combustion engines or for generating heat, is known to produce a variety of pollutant emissions, such as soot, particulate matter, carbon monoxide, nitrogen oxides and sulphur oxides, all of which significantly contribute to air pollution.

It is likewise known that mixing controlled amounts of water into the fuel can significantly reduce the formation of pollutants, without compromising the efficiency of the combustion process.

Water can be present in hydrocarbon fuels in essentially three forms: in solution, in a suspension or emulsion, or in the free state. Hydrocarbons are normally saturated with water, which is always present in solution in concentrations of a few tens of parts per million.

The presence of water in solution, even at the

saturation point, does not interfere with engine functioning, and in particular, by lowering the peak combustion temperature, the presence of water reduces emissions of nitrogen oxides whose formation is favoured by high temperatures .

What is more, the instantaneous vaporization of the water helps to better disperse the fuel within the combustion chamber, reducing the formation of polluting substances such as soot, particulate matter and carbon monoxide.

Water and liquid hydrocarbons are two essentially immiscible fluids, and therefore various methods have been devised to achieve optimal and stable dispersion of water in the hydrocarbon, both prior to its injection into the combustion chamber or directly inside the chamber.

In chemical terms, an emulsion—for example a water/diesel fuel emulsion—is a dispersions of micro water droplets in the hydrocarbon, stabilised through the addition of surfactant substances.

Emulsification with water thus makes it possible to obtain diesel fuels that, when used in engines of motor vehicles or fixed equipment such as generator sets, have lower exhaust gas emissions of certain pollutants, without penalising the performance of the engine .

Such emulsions must however have high stability over time and across a wide temperature range, to prevent the formation, during storage or while inside the tank, of a layer of separated water deposited on the bottom of the tank, that would compromise performance and damage the engine.

In fact, the water in suspension takes the form of

extremely small droplets that remain dispersed for a certain amount of time before sinking to the bottom of the tank. This form of contamination is harmful because it can cause formation of ice that clogs the filters, as well as short-circuits in the electrical components used for measuring the fuel level, and in the windings of the electric motors of the fuel pumps.

If the water is rich in salts it may also cause corrosion of the metal parts of the electrical and mechanical devices located in the tanks.

It has moreover been shown that emulsifying agents may cause carbonaceous deposits to form during the combustion process, which when deposited on the parts of the engine involved in the combustion process, may compromise its operation.

There is also a known arrangement in which mixers are used to mechanically emulsify water and/or other additives in liquid hydrocarbons, such as diesel fuel. Said mixers can have a complex structure, and also require structural modifications to the combustion apparatus .

The purpose of this invention is to remedy the above described disadvantages with an apparatus that allows mixing of water or steam into liquid hydrocarbons, particularly diesel fuel, or into hydrocarbons in gaseous form.

Said mixing is accomplished without use of surfactants, by placing at least one electrode pair, composed of two metal elements, inside a vessel containing either only liquid water or liquid water combined with a liquid hydrocarbon mixture, whose lower specific weight will cause it to lie above the water layer, and where said electrodes are supplied by a

waveform generator which generates a periodic electrical signal having a "sawtooth" shape.

A particular embodiment of this invention involves use of water having a maximum hardness of 20 °f and conductivity between 150 and 400 μS/cm.

In particular, the aforesaid waveform generator supplying the electrode pair consists of a voltage transformer paired with a full wave rectifier connected in parallel with a polarized capacitor. Said full wave rectifier, constructed preferably, but not necessarily, using rectifier diodes, makes it possible to rectify both the positive and negative half-cycles of the alternating current output by the transformer secondary, in such a way that the voltage downstream of the capacitor has a nonzero average value, in order to obtain, at the inputs of the aforesaid electrode pair, a "sawtooth" waveform whose alternating component no less than 35% of the nominal voltage. In particular, the alternating component of the voltage applied to the terminals of the electrode pair will have a value of between 60 and 100 Volts, preferably between 80 and 95 Volts, and in particular 82 Volts. In a particular embodiment, the device used for electrically supplying the electrodes is a variable reluctance transformer.

Application of the above described waveform produces a unidirectional current flow, allowing the electrodes immersed in water to act as radiating elements, imparting fluctuations to the electric field created within the fluid, such as to interfere with the frequencies of the molecular bonds in the

substances being mixed, to the point of permitting a stable dispersion of the water molecules in the hydrocarbon molecules.

It is important to note that this method imparts fluctuations to the electromagnetic field created by the current flowing between electrodes immersed in a mixture of water and hydrocarbons, in particular water and diesel, and that said frequency fluctuations interfere with the frequencies of the bonds of the "short" hydrocarbon chains which are known to be hydrophobic, thus allowing the "long" hydrocarbon chains to absorb the water molecules present inside the solution in which said electrodes are immersed.

The electrodes operate inside a vessel, holding water or a mixture of water and liquid hydrocarbons.

The shape and dimensions of the metal elements that form the electrodes to be immersed in the liquid mixture to be treated, for example a water/diesel mixture, depend on the quantity of liquid to be treated, in other words depend on the final quantity of hydrocarbon-and-water mixture that is required for a less polluting and better performing combustion process .

The separation distance between the two electrodes is instead determined by the supply voltage applied to the electrodes, which in turn determines the duration of the process for mixing the water molecules into the hydrocarbon mixture.

In order to treat larger quantities of liquid hydrocarbons, it is possible to vary the size of the vessels used for holding the water/hydrocarbon mixtures and/or the size of the electrodes and/or increase the supply voltage to the electrodes, or use multiple

vessels in which to perform the mixing process.

Larger quantities of hydrocarbons can also be treated in a shorter time, by the method of this invention, using a process that generates steam by immersing the electrode pair inside a sealed vessel containing water: the current flowing between the immersed electrodes converts the liquid water into steam, which is injected through multiple inlets into conduits carrying the liquid hydrocarbon mixture, so that by coming into contact with the steam, said hydrocarbon mixture becomes mixed with water. This method delivers the same advantages as the previously described process for mixing water into a liquid hydrocarbon mixture, but for larger quantities of hydrocarbons and with a shorter treatment time.

The steam obtained in this way can also be used to increase the calorific value of fuels in the ^' gaseous state .

In particular, the steam can be injected into a combustion chamber containing a hydrocarbon, or preferably a mixture of hydrocarbons, in the gaseous state.

Water electrolysis is in fact known to cause the formation of hydrogen and oxygen gases which, when added to the hydrocarbon mixture, substantially enhance thermal efficiency.

The quantity of water, hydrogen and oxygen which can be added depends on the chemical-physical properties of the hydrocarbon or hydrocarbon mixture, and these in turn depend on the nature ^■ of the hydrocarbon, the refining process and heat treatments which it has undergone, and the chemical additives with which it has been mixed.

The mixing of water, and of the hydrogen and oxygen gases produced by water electrolysis, into the hydrocarbon makes it possible to optimise combustion while at the same time reducing polluting emissions. A further enhancement of this invention uses the aforesaid sealed vessel also for the liquid water and hydrocarbon mixture, in order to capture the steam which forms inside the vessel and inject it into conduits carrying hydrocarbons, thereby mixing them with water by the method previously described.

The above described processes thus make it possible to modify the behaviour of hydrocarbons, and in particular their water solubility, to obtain water- saturated hydrocarbon mixtures of density suitable for use in known engines for motor vehicles. It is also possible to obtain much denser hydrocarbon mixtures, incorporating large quantities of water molecules in a stable manner, with such mixtures allowing for high thermal efficiencies that result in savings on fuel consumption and reduced polluting emissions.

In particular, the method and apparatus of this invention uses at least one electrode pair, supplied by an electrical signal generator that outputs a sawtooth waveform, and immersed in a water solution or in a mixture of water and liquid hydrocarbons, to electrically interfere with the forces binding the molecules in the water or water/hydrocarbon mixture, thereby sufficiently weakening them to allow immiscible compounds to be mixed together without use of surfactants or mechanical mixers.

These and other characteristics and advantages of the invention are further clarified in the following

description of some example embodiments, illustrated in the enclosed diagrams, where:

Fig. 1 shows a vessel for mixing water into liquid hydrocarbons with the immersed electrodes according to this invention.

Fig. 2 shows a vessel for mixing steam into a mixture of gas hydrocarbons, inside of which are placed the electrodes according to this invention.

Fig. 3 shows an electrode for water electrolysis according to this invention.

Fig. 4 shows the diagram of the electrical circuit upstream of the electrode according to this invention.

Fig. 5 shows a diagram of a- variable reluctance transformer according to this invention. In particular, with reference to the figures, the mixing of water in liquid hydrocarbons such as diesel fuel takes place inside a vessel having sufficient capacity to hold a given quantity of liquid hydrocarbon mixture and a given quantity of water, which the water sinking due to its specific weight to the bottom of vessel 1.

As illustrated in figure 1, the vessel (1.) can be made of fibreglass, in the shape of a cylinder, and have a capacity of 200 litres. It is obviously possible to use a vessel of any shape or capacity, sufficient to hold the desired quantity of hydrocarbon mixture and water.

Inside vessel 1 are immersed the electrodes 2, electrically connected by means of anchoring through- bolts 103 and electrical wires to the secondary of a variable reluctance transformer 3, with a full-wave rectifier connected in parallel with a capacitor, and

in particular a polarized capacitor, interposed between the electrodes and the transformer.

Said vessel 1 can be either open on top or have a sealed cover capable of retaining, and where necessary releasing in a controlled manner, the steam and other gases that may form inside the vessel by effect of the electrode pair 2 supplied by the waveform generator.

Figure 2 shows a particular embodiment of the present invention. The method and apparatus of this invention provides a means for mixing steam into a mixture of liquid or gas hydrocarbons.

In particular, the vessel 1 for mixing the steam is a sealed vessel 1 having a capacity of 50 litres, preferably made of AISI 316 stainless steel with triple-layer laminated glass interior, with said vessel 1 able to enclose the electrodes 2 used for producing steam.

Said vessel 1 can be connected to a water supply conduit, not shown, by means of an inlet fitting on said vessel 1, and in particular a valve 101 for admitting liquid water to be vaporized, and said valve can be positioned on the outer wall of vessel 1 on the lower part of vessel 1. The sealed vessel 1 is furthermore provided with an outlet fitting, in particular an outlet valve 201 situated near the upper part of vessel 1, and in particular on the surface which serves as the cover of vessel 1, with said outlet valve 201 permitting the release of the steam produced.

In one preferred embodiment, said outlet valve 201 is connected to a pressure gauge, not shown, for monitoring the pressure of the outgoing steam which can

then be conveyed, through a suitable conduit, into the combustion chamber where it can react with the gas hydrocarbons .

As described previously, the steam produced can also be injected into the conduits or pipes used for transporting liquid hydrocarbons, so as to favour mixing of the water molecules into the hydrocarbons.

The sealed vessel 1 has sufficient capacity to hold a fraction of water in the liquid state surmounted by a fraction of water in the form of steam. In fact the electrodes 2, immersed inside vessel 1, shown here as having a cylindrical shape, use the conductivity of the water to produce steam by boiling: the electrical current flowing between the electrodes 2 heats up the water, bringing it to its boiling point.

The intensity of the current may vary as a function of the quantity of water in vessel 1 that is in contact with the surface of the electrodes 2, and its conductivity. In a preferred embodiment, the water contained inside vessel 1 has a maximum hardness of 20 °f and a conductivity between 150 and 400 μS/cm.

The transformer makes it possible to measure and vary the current intensity so that, by also operating water inlet valve 101 to adjust the water level inside vessel 1, the consumption of water and electrical energy can be optimised as a function of the amount of steam required to be injected into the combustion chamber. In one preferred embodiment, the wall of said vessel 1 may also be provided with an outlet valve, which can be used not only for adjusting the water level inside the vessel as a function of the amount of

steam to be produced, but also for partially or completely emptying the water from vessel 1, after a certain period of non-use, to prevent the deposition of scale or other particles formed during the. boiling process.

As in the previously described embodiment, the metal components 102 of the electrodes, immersed in the water inside vessel 1, are electrically connected to the secondary of a variable reluctance transformer 3 by means of terminal connectors 202 situated on the wall of vessel 1.

Figure 3 shows a preferred embodiment of the electrodes 2, which according to this invention are immersed in a vessel 1 containing a mixture of water and liquid hydrocarbons, for example diesel fuel, or in a vessel 1 containing liquid water to be converted into steam for injection into a combustion chamber containing hydrocarbons in the gaseous state.

The electrodes 2 consist of at least one pair of metal elements 102 separated from each other by spacers 302 of non conducting material.

The electrodes 2 can be made of aluminium or steel or in other metals.

In a preferred embodiment, the electrode 2 consists of a pair of metal elements 102 placed vertically inside vessel 1 and connected at one end to a second pair of metal elements 102 ¹ placed essentially at right angles to the first pair of metal elements

102, so that the second pair of metal elements 102 ¹ is essentially parallel to the bottom of vessel 1.

The pair of vertically-positioned metal elements 102 consists of solid aluminium cylindrical rods 90 cm long and 38 mm in diameter, while the horizontally

positioned elements 102 ¹ of electrode 2 consist of solid aluminium rods 45 cm long and 30 mm in diameter.

Said metal elements 102, 102 ¹ have through holes for inserting coupling means 402, such as screws or bolts of non-conducting material, to removably couple the metal elements 102, 102 ¹ with spacers of non conductive material 302 used to support said elements

102, 102 ¹ and hold them a pre-established distance apart, thus forming the structure of electrode 2 to be immersed in the water or water/fuel mixtures contained in vessel 1.

Said spacers of non conductive material 302, which keep separate and mechanically support the metal elements 102 and 102 ¹ of electrode 2, may be constructed from cylindrical or square-section segments of non conducting material having length and diameter of 4 cm.

The metal elements will therefore be separated from each other by the distance indicated in the figure with the letter G, of 4 cm. The elements of non conducting material can be made of Teflon.

The coupling means 402 can consist of 8 mm screws of non-conducting material clamped using threaded nuts.

The through holes for inserting said coupling means 402 are located on metal elements 102, 102 ¹ at a distance, indicated with C, D, E, F in figure 3, of approximately 8 cm from their ends.

The structure of electrode 2 described above makes it possible to have at least one electrode pair immersed in a stable manner inside vessel 1, and makes it possible to obtain a large contact area between the metal surfaces and the liquids contained inside vessel

1.

As previously described, the metal elements of electrode 2 are provided at one end, and in particular at the ends of the two vertical metal elements 102, with terminal connectors 202 for electrically connecting electrode 2 to conducting wires, called rheophores, that are in their turn connected to the secondary of a variable reluctance transformer 3. Said terminal connectors may consist of bolts inserted into through holes located on the ends of the metal rods, made for example of aluminium or steel, with said bolts being of 6 mm size and made of stainless steel.

Figure 4 shows the schematic of the electrical circuit upstream of the electrodes.

In particular, 403 denotes the magnetic core of the variable reluctance transformer 3, which in one preferred embodiment is composed of oriented crystal silicon-iron laminations 0.35 mm thick having magnetic inductance of 7000 Gauss, and column dimensions 64X70 mm. Also in figure 4, the letter Pl denotes the first primary 603 of the variable reluctance transformer 3, wound in a clockwise direction with two-hundred and fifty turns of H200 double enamel coated copper wire of 1.25 mm diameter, with a Teflon bobbin and a separator between primary and secondary. P2 denotes the second primary 603, wound on top of the first but in an anticlockwise direction and with an equal number of turns, that is to say two hundred and fifty, of H200 double enamel coated copper wire of 1.25 mm diameter. A 380 Volt sinusoidal alternating voltage is applied across the primary: the letters W and Z denote the input connection of the 380 Volt supply.

Sl and S2 denote the windings that make up the first and second secondaries 503, each consisting of one hundred and eighty-eight turns of H200 double enamel coated copper wire with 1.50 mm diameter, wound one on top of the other and connected in parallel.

As is known, the voltage produced by the secondary 503 is less than the voltage applied to the primary 603, and in particular the electrical terminals R and X of the secondary 503 output a voltage of 280 Volts. According to this invention, as shown in the diagram of figure 4, interposed between the electrical terminals R, X of the transformer secondary which outputs a 280 Volt sinusoidal voltage, and the terminal connectors 202, located on the side wall of vessel 1 which holds the water or water/diesel, and which electrically connect the ends of electrode 2 to the waveform generator, there is a full-wave rectifier 4, and in particular a rectifier consisting of diodes in a Graetz bridge configuration with electrical characteristics 25 A-500V: the letters C and D denote the input connection points for the unrectified alternating voltage output by transformer 3, which are connected to the electrical terminals R and X of the secondary 503 which outputs a 280 Volt voltage. The output of the Graetz bridge is a periodic full-wave rectified signal, that is therefore not constant .

The periodic output signal of a rectifier can be considered as having an alternating component superimposed on a DC component that shifts its average value .

To smooth this output signal, a capacitor 5 is used with charging and discharge resistors chosen to

allow fast charging and slow discharge. The output waveform of this circuit is called a ripple.

In one preferred embodiment, the capacitor 5 used is a 350 microFarad polarized capacitor with 500 Volt insulation resistance and an operating temperature up to 92°C.

In figure 4 the negative sign indicates the terminal which outputs current from the Graetz rectifier in the positive half cycle, called the negative rectification point, while the positive sign indicates the terminal which outputs current in the negative half-cycle, called the positive rectification point .

The letters A and B indicate the terminals, connected to the positive and negative capacitor poles, for the output of a rectified current, and in particular a 286 Volt rectified signal with ripple, that is to say with an alternating component, that makes it possible to obtain an 82 Volt deformed sinusoidal output waveform.

Said output terminals supply, as previously described, the metal elements 102, 102 ¹ of an electrode immersed in the solutions contained in vessel 1.

The current flowing through the metal components of the immersed electrodes 2 allows said electrodes to act as radiating elements which create a fluctuating electric field that interferes with the forces binding the molecules of the compounds being added, and in particular water in either the liquid or gaseous state, to the point of permitting stable mixing of the water molecules with the hydrocarbon molecules.

As previously described, the steam that may be generated by the electrodes immersed in liquid water

can be injected, together with a gaseous fuel or mixture of gaseous fuels, into a combustion chamber, so that the significant concentrations of oxygen and hydrogen gas in the steam thus obtained can result in substantial savings in hydrocarbon consumption.

The water molecules stimulated by the immersed electrodes interfere with the short chains of the hydrocarbons, and at the same time, said electrodes 2 favour the absorption of water molecules by the longer, less hydrophobic hydrocarbon chains, and more specifically the use of electrodes immersed in water facilitates binding with the hydrogen and oxygen gases present .

By way of example, to perform mixing of water into a mixture of liquid hydrocarbons, a 200 litre fibreglass vessel 1 was used, inside which were injected 40 litres of unchlorinated well water having total hardness 20° f and conductivity 340 μS/cm, and

110 litres of a commercial diesel fuel characterised according to the EN 590 standard.

Inside the vessel 1 were immersed the electrodes

2, in particular made of aluminium, having the structure previously described, by resting them on the bottom of said vessel 1. The electrodes 2 were thus immersed in water in the liquid state.

It is also possible to use electrodes made of a different metal, for example stainless steel, without compromising the results of the process.

The power supply described in this invention was connected to a single-phase 380 Volt electricity supply line .

The electrical terminals of the waveform generator, electrically connected to the electrodes 2,

output a 286 Volt rectified voltage with a ripple, that is to say an alternating component, of 82 Volts.

After a few seconds, a movement .was observed within the liquid which caused the water molecules to move upwards in such a way as to become dispersed in the hydrocarbon molecules.

The process was continued for 52 minutes, causing the temperature of the liquid to rise to 60 ⁰ C, and with an energy consumption of 1280 kW. Once the liquid was allowed to cool, a calcium carbonate deposit of a few tens of grams was found on the bottom of vessel 1, produced by the raising of the temperature of the entire solution and the release of material from the electrodes. To obtain faster cooling and further improve the mixing of the final product, it is possible to use a pump to circulate the liquids until they reach ambient temperature.

Use of the above process markedly improved combustion performance at different engine speeds, especially in the UDC urban driving cycle, both in terms of emissions and fuel consumption.

The mixing of water with diesel, as previously described, can thus lead to a substantial reduction in the amount of hydrocarbon product consumed by an engine, contributing to reducing running costs and air pollution.

Figure 5 shows a diagram of the variable reluctance transformer 3, which according to this invention is electrically connected, via the aforesaid full-wave rectifier, to the electrodes 2 immersed in a solution of just water or of water and liquid hydrocarbons inside vessel 1.

The electrodes are supplied through a variable reluctance transformer that makes it possible to optimise efficiency and operate in complete safety, by assuring isolation from the distribution network. As is known, a transformer consists of two electrical conductors, called solenoids, wound on a ring of ferromagnetic material called the magnetic core: the winding to which energy is applied is called the primary, while the winding from which the energy is tapped is called the secondary.

When a sinusoidal alternating voltage is applied to the primary, the effect of magnetic induction creates a sinusoidal magnetic flux inside the core, which induces a sinusoidal voltage in the secondary. In one preferred embodiment, the nucleus 403 of the variable reluctance transformer 3, shown in figure 5, is constructed from oriented crystal silicon iron laminations 0.35 mm thick, in a column 64 mm high and 70 mm thick. The windings 603, 503 are made of copper, and in particular of H 200 double enamel coated copper wire of 1.25 mm diameter for the primaries and 1.50 mm diameter for the secondaries, wound on an insulating bobbin of fire-retardant material. The bobbin and separator of the two primary and secondary windings are indicated with number 303 in figure 5.

The transformer is thus provided with a two-pole terminal block for connecting to the 380 Volt supply line labelled 103, and with a two-pole terminal block for the 280 Volt output of the secondary 203 of the aforesaid variable reluctance transformer 3.

The transformer illustrated in the figures is described here only as an example embodiment, it being possible to use transformers of a variety of constructions and types. As previously described, the waveform generator consists of one variable reluctance transformer 3 and is connected to the electrodes 2 immersed in the vessel 1 through a rectifier, and in particular through a full-wave rectifier 4 connected in parallel with a polarized capacitor 5.

Said waveform generator outputs a periodic electrical signal having a sawtooth shape. In particular, the value of the alternating component of the voltage across the terminals of electrode pair 102, 102 ¹ is never less than 35% of the nominal voltage.

According to the method of this invention, said electrode pair 2 is placed inside a vessel 1 containing a water solution and/or a mixture of water and hydrocarbons in the liquid or gaseous state, in such a way that the periodic electrical signal applied across said electrode pair 102,102 ^{1^} has an AC component that is between 60 and 100 Volts, and preferably between 80 and 95 Volts, allowing said electrodes to act as radiating elements able to generate frequency and amplitude fluctuations of the electrical field formed inside the liquid, such that can interfere with the frequencies of molecular bonds of the substances to be mixed, to the point of permitting a stable mixing of the water molecules with the hydrocarbon molecules. In a further embodiment, the method of this invention can be used for the production of steam, oxygen and hydrogen gas, that is then mixed into hydrocarbon mixtures in the liquid or gaseous state.

The above described embodiments are not to be considered the only possible ones, and the invention also extends to other embodiments that achieve the same advantages using the same operating principle.