DESCRIPTION

Field of the invention

The present invention concerns a process for treating waste plastics in order to produce high value-added products (chemicals) that can be reintroduced and reused in the market and at the same time being able to reduce polluting emissions to zero, obtaining a substantially self-sustainable process. This process can be used for example in an aquatic vehicle, capable of recovering organic sources such as for example plastics present in the oceans, thanks to the fact that the process is able to produce fuel to operate at least partially said aquatic vehicle reducing pollutant emissions also in this case.

Background art

Plastic is a key material for numerous industries and everyday uses. However, over the years, its use has become progressively more inefficient and linear, especially in the case of single-use products, as a result of: (i) the lack of attention and/or laziness of both governments and consumers, which has caused large quantities to be dispersed in the environment, (ii) the real problems of correct disposal of plastics in the medical sector and PPE (PERSONAL PROTECTIVE EQUIPMENT), like during the recent pandemic, and (iii) the few environmentally efficient processes for the chemical conversion of plastic waste into economically sustainable products.

The European Union has been highlighting since 2018 that large quantities of plastic each year cannot re-enter the circular economy processes: the percentage of recycling is still very low, of the order of 30% of the material correctly disposed of. Therefore, losses at sea are very high, often carried by rivers that act as collectors of inland areas. 1.5 to 4% of the world's plastic is estimated to end up in the oceans and that this constitutes more than 80% of the waste present in the sea. The problem is exacerbated by the release of microplastics into the environment, estimated to be between 75,000 and 300,000 tonnes per year for the EU alone.

Therefore, despite countless initiatives to clean up the sea of waste and pollutants, it remains a major global problem, constituted by marine plastic waste that has a transboundary nature in itself. A further problem related to marine plastic waste is their transport in the seas, from one country to another, with the formation of real patches or vortices (“gyres”) of more or less floating plastic waste in different areas of the world. Among these at the time of writing the present patent application, NOAA has identified and catalogued five of these patches, the most famous of which is the NORTH PACIFIC SUBTROPICAL CONVERGENCE ZONE, made up of small plastic pellets and microplastics. Below, there are accumulations of material in which more than 70% of plastic waste is estimated to end up. Since these accumulation areas are located far from any coastline, no country bears the responsibility of providing the necessary funds for the cleaning and restoration action, which is considered very expensive and therefore impracticable.

The known techniques and the means available to address the aforementioned problem and the related disposal of plastic waste are characterized by indirect pollution in addition to the inability to fully recover such waste. In fact, the processes and the means used to move in the sea and/or on land in order to reach and locate such concentrations of plastic waste require substantial amounts of fossil energy and emit polluting exhaust fumes into the environment. In addition, the use of known processes for the disposal of inorganic waste releases additional pollutants into the environment.

In fact, the treatment of plastic material represents one of the biggest problems for environmental pollution that is worsening from year to year. Specifically, processes exist in the state of the art for the disposal of organic sources through thermal treatments of pyrolysis, combustion and gasification. In addition to the syngas that represents the main product, the known processes allow to obtain volatile combustion gases such as some light hydrocarbons, aromatic hydrocarbons and several families of aldehydes, ketones and alcohols, together with CO2. Disposing of effluent by-products from the aforesaid processes is a further pollution problem.

Summary of the invention

In order to overcome the aforesaid problems, a process and a relative plant have been conceived that allow the production of chemicals, such as acetic acid and others, from organic fossil-type, renewable and/or recovery sources such as plastic waste for both recycling and self-sustenance purposes of vehicles for the recovery and treatment of plastic waste itself.

The object of the present invention is therefore a process for producing acetic acid from fossil-type, renewable and/or recoverable organic sources comprising the steps of: a) converting the organic waste source into a mixture comprising syngas, carbon dioxide and water by means of reaction between said organic source and oxygen and optionally water vapour; b) producing acetic acid with carbon monoxide contained in the mixture from step a), in accordance with the following reaction scheme (1):

CH30H + CO = CH3C00H

(I) c) producing methanol with the gas mixture from step b), according to the following reaction scheme:

CO2+ 3H2= CH3OH+ H2O

(II) wherein after step a), a step a-1) is included of partial or complete separation of the carbon dioxide and the water from the gaseous mixture output from step a) and a second step a-2), in which the water is separated, while the carbon dioxide is fed to step c) intended for the production of methanol.

The process, and the related aquatic vehicles associated therewith according to the present invention are preferably aimed at overcoming the difficulties related to the environmental and economic sustainability of the action of cleaning and restoring inland waters, rivers, lakes, seas and oceans from the presence of plastics and microplastics.

The process according to the present invention, with respect to the current known techniques, has substantially the following advantages:

(i) is based on a process for producing syngas from pre-treated recovery plastic polymers capable of reducing pollutant emissions;

(ii) the products obtainable with high efficiency from the treatment of plastic waste are chemicals, including without limitation and only by way of example, methanol and acetic acid, or an advanced eco-fuel such as Dimethyl ether (DME), characterized by different timescales of cascade reuse and carbon sequestration;

(iii) the products obtained, owing to minimal CO2 emissions and limited quantities of process waste, in addition to energetically sustaining the cleaning and restoration of water, have a high market demand and therefore can finance the decontamination activity;

(iv) this activity can be carried out by vessel, directly where the accumulation areas of plastic waste are located, which - for all intents and purposes - will be real new “mines”;

(v) the chemical or advanced eco-fuel in excess with respect to the operating requirements of the cleaning and restoration process can be easily transferred to another means and delivered to the market;

(vi) innovation can be used in numerous other scenarios of accumulation and dispersion, even accidental, of organic sources in the environment, in addition to plastics, including, by way of example only and without limitations, end-of-cycle tyres, natural gas, oil, shale, coal, municipal solid waste, residues from agri-food production chains, textiles. An example consists in the small islands where the waste mentioned above can thus be treated “on demand” without creating a dedicated plant on site.

Further advantages will arise from the detailed description of the invention and from the non-limiting examples attached to the description itself.

LIST OF FIGURES

Figure 1: schematic block representation of the process and of the relative units of a plant in which said process is realizable according to a first embodiment of the present invention in which methanol and acetic acid are co-produced with full CO2 reuse;

Figure 2: schematic block representation of the process and of the relative units of a plant in which such a process is realizable according to a second embodiment of the present invention in which dimethyl ether and acetic acid are co-produced with full CO2 reuse;

Figure 3: schematic block representation of the process and of the relative units of a plant in which such a process is realizable according to a third embodiment of the present invention in which DME and acetic acid are co-produced from plastics with full conversion of CO2 emissions into product;

Figure 4: schematic block representation of the process and of the relative units of a plant in which said process is realizable according to a fourth embodiment of the present invention in which the water-gas shift reactor is inserted;

Figure 5: schematic block representation of the process and of the relative units of a plant in which said process is realizable according to a fifth embodiment of the present invention in which the process water is recycled for steam generation and used in the conversion process, where provided (steam reforming, gasification, etc.) with relative water-gas shift reactor;

Figure 6: schematic block representation of the process and of the relative units of a plant in which said process is realizable according to a sixth embodiment of the present invention in which there is supply of oxygen from electrolysis with supply from solar source;

Figure 7: schematic block representation of an aquatic vehicle with which the embodiment of the process is associated and relative plant of Figure 6 in which there is energy self-sustenance of the entire propulsion/production system through photovoltaic or hybrid solar-DME or solar-methanol generation;

Figure 8: schematic block representation of an aquatic vehicle of Figure 7 in which the surplus of demineralised water from the electrolysis system is drawn;

Figure 9: schematic representation of a front view of a portion of a sea plastics collection system according to a preferred embodiment;

Figure 10: schematic representation of a side view of the sea plastics collection system associated with a marine vehicle;

Figure 11: schematic block representation of an aquatic vehicle of Figure 7 combined with the plastic recovery system in which there is self-supply of raw materials from plastic islands, hybrid solar-DME or solar-methanol energy self-sustenance, total recovery and conversion of CO2 emissions with co-production of DME and acetic acid.

DETAILED DESCRIPTION

The process in accordance with the present invention allows the chemical conversion of organic sources into high value-added chemicals that can also be used as fuel in addition to reducing emissions of pollutants into the environment. The process, in accordance with the present invention and relative plant, when associated with an aquatic medium allows the self-sustenance of the process itself and the movement of the vehicle through the recovery of organic sources, preferably combined with renewable sources.

Specifically, the process object of the present invention allows converting the aforementioned organic sources (natural gas, plastics, oil, shale, coal, municipal solid waste, agri-food residues, plastics to name a few) into fuel and chemicals without any emission, in energy self-sustainability and, in case, with integration with terrestrial or naval mobility systems for the direct recovery of organic waste materials distributed on the territory or at sea.

The process of the present invention comprises a step a) of converting the organic waste source, preferably plastic, into a mixture comprising syngas, carbon dioxide and water by means of reaction between said organic source and oxygen and optionally water vapour. Preferably, the syngas produced in step a) of conversion consists of carbon monoxide and hydrogen in different C0/H2 ratios. It is worth noting that the conversion step is associated with the type of organic source used and/or recovered and therefore the reactions in it can be different and combined. Specifically, step a) includes supplying the organic, fossil, renewable or recovery source to the relative unit so that it can be converted into gas as previously described.

Preferably, step a) may receive oxygen and/or vapour depending on the organic source.

In accordance with a preferred embodiment, the conversion step a) is chosen from gasification of plastics or coal, by catalytic route, and/or by steam reforming.

Below is an example of the conversion step when the organic source for recycling plastics is polyethylene. Specifically, this is degraded in accordance with the following overall reaction:

[- CH2 -] + 0.5 02 = H2 + CO

It should be noted that, regardless of the type of conversion process used, an amount of carbon dioxide is obtained due to the oxidation reactions such as to be used in the subsequent steps following a separation and/or kept in mixture with the rest of the syngas and products derived from the conversion.

Preferably, the conversion step a) must preferably provide high syngas yields such as, for example, the GASIFORMING process as described in patent application WO2021/019433 in the name of Politecnico di Milano and Consortium INSTM.

Specifically, after step a) a step a-1) is included of partial or complete separation of the carbon dioxide and the water from the gaseous mixture coming from step a), thus generating a process flow. In detail, step a-1) includes separating the carbon dioxide and water from the syngas, preferably by means of known processes, to be sent to subsequent steps of the process for the realization of relative reactions. Preferably, step a-1) includes totally separating the carbon dioxide and the water from the syngas produced.

It is worth noting that the process, after step a), may include a second step a-2) in which the water is separated for further uses, while the carbon dioxide is fed to step c) intended for the production of methanol, as we will discuss in more detail later in the description.

The process in accordance with the present invention comprises step b) of producing acetic acid with carbon monoxide contained in the Syngas from step a-1) with the methanol obtained in step c) in accordance with the following reaction scheme (I):

CH30H + CO = CH3C00H

(I)

The process according to the present invention comprises step c) of producing methanol with the unreacted hydrogen coming from step b), and the CO2 separated from the water in step a2) according to the following reaction scheme:

CO2+ 3H2= CH30H+ H2O

(II)

The process includes a specific catalyst for the methanol synthesis in step c).

Preferably the process includes that the flow rates expressed as the number of moles per unit time of each component of the flow coming from step b) and the carbon dioxide fed to step c) are such as to respect the equation SN = (H2-CO) / (CO2+CO) = 2.1, in order to optimize the production of acetic acid and methanol.

Methanol produced in step c) is supplied at least in part to step b) for producing acetic acid. In this way the process is able to co-produce for further uses at least methanol (not supplied at step b) and acetic acid (Figure 1). Preferably, the production of methanol includes a separation of the water from the methanol itself. The water can possibly be recycled in any and subsequent steps of the process of the invention as reported in the following of the present description.

In accordance with a preferred embodiment illustrated in Figures 2 and 3, the process comprises a step of converting methanol to dimethyl ether d) by dehydration of the synthesized methanol and subsequently separating the dimethyl ether from the formed water. Specifically, the methanol produced in step c) is sent at least in part to step b) for producing acetic acid and the remainder to step d) for producing dimethyl ether (DME). In this way, the process allows to co-produce acetic acid and dimethyl ether (DME). It is worth noting that the water separated from the DME can be destined to further purposes in combination with the water from step a-2) and step c)

In accordance with a preferred embodiment combinable with the above and illustrated in Figures 4 and 5, the process comprises a step a-3) in which a portion of the CO2 and H2O stream coming from step a-1) is subjected prior to step b) to the Water-gas-shift reaction which proceeds according to the following scheme (IV):

C0+H20 = CO2+H2

(IV)

Specifically, step a-3) includes receiving in part carbon dioxide and water from step a-1) so as to mix them with the syngas comprising carbon monoxide and hydrogen in order to regulate the ratios between hydrogen, carbon monoxide and carbon dioxide to optimize the subsequent steps of the process. In detail, step a-2) is preferably carried out upstream of step a-3) so that the amount of carbon dioxide to be added with respect to water can also be adjusted. Preferably, the carbon dioxide separated at step a-2) is sent to step c) and that coming from step a3) is sent via step b) to step c) together with hydrogen.

Preferably the water obtained in step c) and in step d) of conversion is optionally used in step a) as water vapour, for example, in cases where step a) includes steam reforming and gasification as illustrated in Figure 5.

In accordance with a preferred embodiment illustrated in Figure 6, the process comprises an electrolysis step e) for producing oxygen to be sent to step a) of conversion of the organic source and hydrogen to be sent to the methanol synthesis step c). In this way it is possible to regulate and manage in an optimized way the reactions of the process avoiding the need for external integrations of reagents. Preferably, the electrolysis step e) is fed by water extracted from the process stream in step a-2), and/or separated from the reaction products exiting from the methanol production step c) and/or those exiting from the dimethyl ether production step d).

More preferably, the electrolysis step e) is fed with renewable sources associated with a mobile aquatic vehicle or a fixed terrestrial plant, for example, located near the sea.

Below is an example of the process in which the following technologies from organic source End-of-Life Plastic Wastes (EoLPW) were used:

- for the plastic conversion step, the technology reported in WO2021/019433 on behalf of the same holders, is used with lOOOkg/h EoLPW, 18.98 kmol/h vapour and 20.58 kmol/h oxygen (GASIFORMING technology);

- for the methanol conversion step, the technology described in WO2019/003213 in the name of Politecnico di Milano (BIG-SQUID technology) is used;

- for the acetic acid production step, the CATIVA™ (The Cativa Process for the Manufacture of Acetic acid) technology is used;

- for the DME production step, the technology disclosed in IT 102020000019945 (RECS Technology) on behalf of Politecnico di Milano is used;

- for the Water-Gas shift step, a technology known to the person skilled in the art. Finally, Table 1 shows the molar flow rates (kmol/h) for the main species involved along the process object of the invention using the aforementioned processes for the relative steps.

According to an embodiment mode of the present invention, as clarified below, it is possible to use part of the DME produced as naval diesel and to supply an aquatic and/or terrestrial vehicle that directly transports the plant of the entire synthesis process (Figure 7).

In accordance with a preferred embodiment, the process comprises a step f) of capturing and treating exhaust gas preferably performed in a mobile aquatic plant or in a fixed mobile plant using as fuel at least in part the dimethyl ether produced. Preferably, the exhaust gases are sequestered by a conventional capture system (e.g., amine washing) or with sustainable systems, such as water-only processes and fully electrified as disclosed in patent application 102021000011162 on behalf of Politecnico di Milano.

Specifically, the step of capture and treatment f) is configured to sequester carbon dioxide to be sent to the methanol synthesis step, c) release nitrogen into the atmosphere and/or optionally produce water to be sent to the electrolysis step, e) or extract from the process. Advantageously, the use of DME alone as a fuel, for example, for an aquatic or terrestrial vehicle, makes it possible to avoid the formation of particulate matter (PM10 and PM2.5) and NOx according to what is demonstrated in the prior art (by car manufacturer Volvo).

It is worth noting that the process, using DME as fuel for an aquatic vehicle such as a ship, allows at the same time self-feeding with a small amount of fuel compared to production. The aquatic vehicle itself, however, can provide for a photovoltaic system (with storage included) to move or to produce the necessary oxygen via electrolysis. In this case, the required photovoltaic surface area can be calculated by estimating the kg of oxygen:

20.58 kmol/h oxygen * 32 kg/kmol 02 = 658.56 kg/h oxygen

Each kg of H2 produced is accompanied by 16 kg of 02; as per literature, assuming a consumption of 50 kWh per kg of hydrogen:

658.56 kg 02 * (50 kW / 16 kg/kg) = 2,058 MW

Assuming an average solar incidence of 1 kW/m2, 2060 m ² of photovoltaic are required. If the sizes of the ship do not permit it, a hybrid system with solar and DME generation engine and emissions recovery makes possible the self-production of oxygen and therefore the entire production-propulsion system of the ship (Figure 8). The water produced in the various steps of conversion and propulsion of the aquatic vehicle is superabundant with respect to the uses envisaged by the process and can be discharged into the sea after treatment or destined to other possible uses.

In accordance with a preferred embodiment illustrated in Figures 9-11, the process comprises a step of supplying g) the organic source to be used in step a) of converting the same. In this way it is possible to self-sustain the movement of the vehicle, preferably aquatic vehicles, and that of the process. Such a step makes possible an automatic supply of the organic source preferably during the movement of the terrestrial or aquatic plant. The following describes the step of supply in the event that the process was used in water, for example, on an aquatic vehicle (boat and/or submarine) or platform. This does not exclude the applicability of the process and relative supply step on land, for example, on a terrestrial vehicle moving on accumulations of organic sources or, in both cases, stationary with related systems capable of carrying out the supply step.

Preferably, the supply step includes step g-1) of cyclically collecting an amount of water containing macro-plastics and micro-plastics by means of a collection system (Figures 9 and 10) described in detail below.

Step g-1) is followed by step g-2) able to remove a first amount of water from the macro-plastics and micro-plastics collected preferably by drip. In fact, thanks to the collection system it is possible to drain an amount of water from the relative containers in which the macro-plastics and micro-plastics have been collected. Subsequently, the supply step comprises a step g-3) of first washing of the collected macro-plastics to remove impurities and almost totally collected water residues, by means of the use of waste water from the electrolysis step e), from the separation step a2) and/or from the methanol production step c), and/or from the conversion step d) to dimethyl ether and/or optionally from the capture of the exhaust gases step g). Specifically, step g-3) includes using the demineralised waste water produced by the various steps to eliminate marine impurities, scale and most of the seawater.

Once most of the water is removed from the collected plastics, a step g-4) of shredding of the washed macro-plastics, for example mechanical, is included.

Once shredded, the supply step includes step g-5) to perform a second wash to eliminate any metal elements by means of the use of waste water. It is worth noting that these metal elements can be recovered.

The final steps of the supply step comprise a step g-6) for cleaning at least a part of the collection system from the micro-plastics collected by filtration with the use of waste water. Specifically, microplastics, or anything that permeates from the mesh of the collection systems like baskets, is pumped from the collection basin (slurry basin) by means of a slurry pump, located immediately after the basket collection section. The stream is pumped to a filtration section, for example with leaf or plate filters, or to membrane systems that collect the microplastics and discharge the cleaned seawater. After that, the step includes a step g-7) for mixing the extracted micro-plastics with the shredded macroplastics sending the micro-plastics to the second wash. Finally, the supply step comprises a step g-8) for sending the micro-plastics and the shredded macro-plastics to the conversion step.

Preferably, the process includes that the waste water performs sequentially the second washing, the first washing and the cleaning by filtering of the collection devices, as illustrated in Figure 11. Specifically, the water coming from the plant is used for washing starting from the second wash, then sent to the first wash and finally to the wash/filtering for microplastics.

In accordance with a preferred embodiment, in case the demineralised water produced by the syntheses and purified by the chemicals is not sufficient, it is possible to provide a water desalination reverse osmosis system (An Innovative Design of an Integrated MED-TVC and Reverse Osmosis System for Seawater Desalination: Process Explanation and Performance Evaluation Al Hotmani et al Processes 2020, 5(5), 607; h ps://doi.org./IO.3390/pr8O5O6O7 ).

The process object of the invention is preferably carried out in a plant indicated with 1 in the figures.

For the purposes of the present invention, plant means a system of one or more operating units associated with each other and configured to perform one or more steps of a process. It is worth noting that the operating units may be in fluid communication so that the products of one are the reactants of one or more subsequent operating units.

As will be clear from the description, each operating unit comprises one or more steps of the process of the invention.

In particular, the system (1) comprises:

A) a unit used for:

• conversion (Conversion process), (Plastic conversion) of the organic source preferably end-of-life waste plastic into syngas, and

• the separation of syngas from carbon dioxide and water, contained in the process flow;

B) a unit for producing acetic acid Carbonylation arranged downstream of unit A);

C) a unit used for producing acetic acid (Methanol Synthesis), wherein the flow of Syngas leaving the carbonylation section and the CO2 coming from the unit A) and further purified by water react to form methanol according to reaction scheme (II).

In Section A) defined in Figures 1-8 and 11 as Plastic Conversion or Conversion Process, steps a) and a-1) are carried out while step a-2) of CO2 separation is carried out externally to section A).

In the operating unit B) defined in figures Carbonylation, step b) of the process of the invention is carried out.

In operating unit C) or Methanol Synthesis arranged downstream of the unit C), step b) of the process of the invention is carried out according to reaction scheme (II) which includes the separation of methanol from water. Such water may be discarded or recovered for subsequent process steps as described hereinafter in the present description.

It is worth noting that the operating units of the plant described so far allow the production of acetic acid and methanol by regulating the amount of reagents in the relative units in order to guarantee self-sustenance once the organic source has been received and the relative disposal of waste as well as an optimization in production and degradation while reducing harmful emissions into the environment.

The plant in order to carry out the process of the invention preferably comprises a methanol to dimethyl ether conversion unit D) (Dimethyl Ether Synthesis) arranged downstream of the methanol synthesis unit (Methanol Synthesis) and configured to receive at least in part the methanol produced by the methanol synthesis unit (Methanol Synthesis) to produce dimethyl ether and water.

In this operating unit of the plant 1, step d) of the process according to the present invention according to reaction scheme (III) is carried out.

The plant 1 preferably contains an operating unit E) formed by a Water-Gas Shift or WGSR reactor in which step a3 is carried out).

This unit is arranged downstream of the unit A) and upstream of the unit B) and is fed with a part of the gaseous flow of CO2 and water output from the unit A) and with syngas output from the same section, to make the Water-Gas Shift reaction occur according to scheme (IV).

In accordance with a preferred embodiment illustrated in Figures 6-8 and 11, the plant 1 comprises an electrolysis unit F) or Water Hydrolysis configured to produce oxygen to be sent to the unit A) for the conversion of the organic source Plastic Conversion, to produce hydrogen to be sent to the unit for the methanol synthesis Methanol Synthesis and to release and/or recycle produced and/or excess water. Preferably, the unit for the electrolysis Water Hydrolysis is fed at least in part by water coming from the process flow and/or recycled from the unit for the production of methanol Methanol Synthesis, and/or for the conversion of methanol to dimethyl ether Dimethyl Ether Synthesis and/or optionally recycled from a unit G) for the capture of the exhaust gases CO2 Capture.

More preferably, the plant may comprise a unit for producing electricity from renewable sources 10, in turn comprising relative means for producing electricity from renewable sources 10a. This unit can feed some units of the plant and, if this were associated with a vehicle, also the production means.

A further object of the present invention is an aquatic vehicle energetically selfsustained by organic sources collected, preferably by the vehicle itself.

Preferably, the aquatic vehicle 100 in the form of a vessel and/or a submarine is predominantly configured to recover plastics from floating plastic islands in the middle of the sea. In the eventual, but very unlikely, collection of living beings (fish), a identification and movement system will indicate the need to open the basket, throwing the entire collection into the sea. The slow climb of the baskets, in any case, guarantees the recognition and, therefore, the total safety of each animal species.

The aquatic vehicle 100 comprises a plant 1 for producing chemicals comprising at least the operating conversion units Plastic Conversion, methanol synthesis Methanol Synthesis, DME synthesis Dimethyl Ether Synthesis, for carbonylation Carbonylation and preferably the electrolysis unit Water Hydrolysis. In preferred and non-illustrated embodiments the plant associated with the aquatic vehicle also comprises the Water-Gas Shift reactor unit WGSR.

The aquatic vehicle 100 comprises propulsion means configured to move the aquatic vehicle along a route and fed at least in part by the dimethyl ether or methanol used as fuels and produced in section D) or C) of the plant (1 ). Specifically, the vehicle according to the present invention provides for the use of DME produced for propulsion making it in part, after start-up, self-sustainable.

Preferably, the aquatic vehicle 100 comprises a unit G) for the capture of the exhaust gases CO2 Capture associated with the propulsion means and configured to sequester at least CO2 from the exhaust gases produced by the propulsion means to be sent to the unit for the synthesis of methanol Methanol Synthesis, to release nitrogen into the atmosphere and optionally to produce water to be sent to the unit F) for the electrolysis Water Hydrolysis or to be extracted from the process.

As anticipated, the aquatic vehicle 100 comprises means for producing electricity from renewable sources 10a for operating the electrolysis Water Hydrolysis and/or the propulsion means and/or the units of the plant 1.

The aquatic vehicle 100 comprises a collection system 20 configured to collect macro-plastics and micro-plastics. One possible type of collection system 20 is illustrated in Figures 9 and 10. Specifically, the collection system 20 comprises blades 21 rotated by friction with water during the movement of the aquatic vehicle. The collection system comprises collection means 22 associated with the blades 21 and configured to collect the plastics and transport them from the sea to a raised position. In detail, the rotating blades 21, by means of mechanical or pneumatic transmission means, activate the collection means 22 to transport the plastics from the sea to the relative units of the plant. In accordance with the illustrated embodiment, the collection means 22 comprise a movable ladder with baskets with a certain mesh, for example equal to 1 cm, configured to pick up plastics inside a conveying basin 23 of the surface waters at the bow of the ship. It is worth noting that the collection means move from bow to stern more or less quickly according to the speed of the ship and embark the macro-plastics draining them from the water during the movement.

The aquatic vehicle 100 comprises a macro-plastic and micro-plastic treatment system configured to pre-treat the macro-plastics and micro-plastics before sending them to the organic source conversion unit in accordance with the steps described above. Specifically, the treatment system comprises, downstream of the collection system 20 that collects the plastics and by dripping removes a first amount of water, a first washing unit Pre-washing configured to perform a first washing of the collected macro-plastics to remove impurities and almost totally residues of collected water, by using waste water from the electrolysis step e), from the separation step a2) and/or from the methanol production step c), and/or from the dimethyl ether conversion step d) and/or optionally from the capture of the exhaust gases step g). Next, the system comprises a shredding unit Comminution. Before performing the second wash in the second washing unit Fine- washing, a cleaning unit of the collection means Filters/Membranes is provided. Specifically, the cleaning unit Filters/Membranes is configured to clean the collection means from the micro-plastics sent from the basin 23 by filtering with the use of waste water from the first washing unit Pre-washing. The separated micro-plastics are sent to the second washing unit Fine-washing with the macro-plastics. Finally, the system includes sending the cleaned plastics to the conversion unit to feed the process and therefore the plant.

Optionally, the aquatic vehicle may comprise a reverse osmosis unit for water desalination to produce water to be sent to the unit for electrolysis Water Hydrolysis and/or to the relative units for carrying out the process and/or to the treatment system.

A further object of the present invention is a terrestrial plant energetically selfsustained by collected organic sources. It is worth noting that the terrestrial plant is applicable for example to on-shore environments, such as plastics on the wetland (for example after rough sea), or in compromised sites, such as unauthorised landfills.

The terrestrial plant comprises a chemical production plant comprising at least the operating conversion units A) Plastic Conversion, C) methanol synthesis Methanol Synthesis, D) DME synthesis Dimethyl Ether Synthesis, B) for carbonylation Carbonylation and preferably the electrolysis unit F) Water Hydrolysis. In preferred and non-illustrated embodiments the plant associated with the aquatic vehicle also comprises the Water-Gas Shift reactor unit WGSR.

The terrestrial plant comprises energy means configured to operate the plant and powered at least in part by dimethyl ether used as fuel. Preferably if the plant is mobile, the energy means are also configured to move the plant along a trajectory making it at least in part, after the start-up, self-sustainable.

The plant further comprises a unit for the capture of the exhaust gases CO2 Capture associated with the energy means and configured to sequester at least CO2 from the exhaust gases produced by the energy means to be sent to the methanol synthesis unit Methanol Synthesis, to release nitrogen into the atmosphere and optionally to produce water to be sent to the electrolysis unit Water Hydrolysis or to be extracted from the process.

Preferably, the terrestrial plant comprises means for producing electricity from renewable sources associated with the electrolysis unit Water Hydrolysis and/or the energy means and/or units for carrying out the process Plastic Conversion, Methanol Synthesis, Dimethyl Ether Synthesis, Carbonylation, WGSR, CO2 Capture.

The terrestrial plant comprises a collection system configured to collect macroplastics and micro-plastics. A macro-plastic and micro-plastic treatment system configured to pre-treat the macro-plastics and micro-plastics before sending them to the unit for the conversion of the organic source into a first syngas flow Plastic Conversion and start the process by using water produced by the unit for electrolysis Water Hydrolysis is also included in the terrestrial plant.

Finally, the terrestrial plant comprises a system for discharging and accumulating the chemical products comprising acetic acid and possibly dimethyl ether in access.