Systems and methods for the conversion of plastic waste

Abstract

The present invention provides a system and method for converting plastic waste into high value products.

Description

[Technical field]

[0001] The present invention relates generally to an integrated process for converting mixed plastics and / or biomass and metal-containing waste into high value products. [Background technology]

[0002] The steady increase in the amount of discarded plastic material has prompted the development of modern technologies to effectively convert plastics into reusable materials. Recycling of plastic waste is carried out in a variety of ways, but in most developing countries, incineration, open burning and landfilling are the common methods of disposal of plastic waste.

[0003] Pyrolysis, a common technique used to convert plastic materials into liquid oils, involves the thermal decomposition of plastic waste at different temperatures (300-900 °C) in the absence of oxygen. Different catalysts are usually used to improve the pyrolysis method and increase the processing efficiency. Unlike mechanical processing, chemical recycling can also be used to process waste with complex materials, such as multi-layer flexible packaging, metal-containing waste, and biomass waste. However, currently available thermochemical recycling methods have two main drawbacks. First, they require high energy intensity, and second, they require significant auxiliary infrastructure and materials (e.g., hydrogen gas) for upgrading the product stream.

[0004] Many plastic decomposition systems have been developed for plastic chemical recycling, but all of them rely on external fossil energy resources as the energy source for the decomposition and upgrading process, or on the combustion of about 10–20% of the decomposition products, all of which involve direct greenhouse gas (GhG) emissions. [Brief description of the drawings]

[0005] In order to better understand the subject matter disclosed herein, and to illustrate how it may be carried into practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Figure 1A] 3 shows different system designs according to the present invention. [Figure 1B] 3 shows different system designs according to the present invention. [Figure 1C] 3 shows different system designs according to the present invention. [Diagram 2] 1 illustrates a system according to some embodiments of the present invention. [Diagram 3] 1 illustrates system and method flows according to some embodiments of the present invention. [Figure 4] 1 shows an exemplary high-level mass balance in comparison of the proposed method and the conventional method. [Diagram 5] Present a complete life cycle analysis of GHG impacts. Summary of the Invention

[0006] Figure 2 illustrates a system according to some embodiments. As shown, the system of the present invention includes two reactors or vessels: a thermochemical decomposition reactor and a hydrogen gas reactor or generator (labeled AI-H2O reactor in Figure 2). In the embodiment depicted in Figure 2, the system operates in the presence of aluminum metal.

[0007] FIG. 3 illustrates an example system and method flow according to some embodiments.

[0008] A high level mass balance example of the proposed method compared to the conventional method for a one tonne mixed waste feed is shown in Figure 4. In the top row of Figure 4, the method according to the invention is shown, and in the bottom row of Figure 4, the conventional method is shown.

[0009] As shown in Figure 4, by utilizing the system and method of the present invention, regardless of the tonnage of plastic waste, at least 10% or more of the final product can be recovered. All the required hydrogen gas can be obtained from the reaction of aluminum with water at a rate of 20 kg / hour or more.

[0010] Also, 0.55 kg of CO2 can be displaced per kg of distillate obtained from the recovered alumina (metal oxide) by-product. This is further illustrated in the full life cycle analysis of GHG impacts shown in Figure 5. Emissions include the full life cycle (pre-treatment and sorting) and are based on commercial data from BASF's chemical loop method. The negative results of the Life Cycle Assessment (LCA) are due to the yield improvement as well as the recovery of the alumina by-product and hydrogen production (1.2 kg and 8-12 kg of CO2 and hydrogen per kg of alumina, respectively). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The inventors of the presently disclosed technology have developed an integrated methodology that not only overcomes many of the drawbacks associated with the thermochemical processing of plastic materials, but also provides substantial product improvements. In the most general terms, in the system and method according to the present invention, energy harnessed from the production of exothermic hydrogen from a metal-bearing waste feedstock is used in the thermochemical decomposition of another waste feedstock. Thus, the system and method of the present invention provide an alternative to existing thermochemical decomposition reactions that:

[0012] 1) An integrated process for converting mixed plastic and metal-containing waste into high value products, including a water treatment reactor for simultaneous thermochemical cracking and hydrogenation / hydrocracking / hydrothermal liquefaction, where both heat and hydrogen requirements are met by coupling to a high temperature aluminum water reactor.

[0013] 2) A scalable, commercially viable, high-yield method for thermochemical regeneration of plastics to provide high-value fuels / feedstock chemicals.

[0014] 3) The yield of the process is improved by utilizing the reaction of waste-grade aluminum with water to provide the hydrogen gas and energy required for the endothermic decomposition of plastics to produce high-quality products.

[0015] 4) In-situ generation of hydrogen gas eliminates the need for hydrocracking using external gas sources.

[0016] 5) Sufficient hydrogen gas is produced to maintain a hydrogen atmosphere that minimizes coking.

[0017] 6) Although the process does not require a catalyst, commercially available catalysts can be used to control various side reactions.

[0018] 7) Recovery and upcycling of waste metals such as aluminum.

[0019] 8) Increased scalability of method units through direct heat transfer.

[0020] 9) Improved process (thermal) efficiency and selectivity in the water pyrolysis pathway.

[0021] Thus, in the most general terms, there is provided an integrated system for producing distillates (and combustible gases, fuels, petrochemicals, oils) from waste plastic materials (or for converting mixed plastic waste into high value products), the system comprising a thermochemical reactor configured to carry out thermochemical decomposition (e.g., hydrogenation, hydrocracking, and / or hydrothermal liquefaction) of sorted or unsorted plastic waste, and a water treatment metal-water reactor coupled or associated therewith, configured and operable to produce thermal energy (heat), gases and other products, as well as hydrogen gas that is fully or partially recovered for carrying out the thermochemical decomposition in the thermochemical reactor.

[0022] Thus, in one configuration, the system according to the invention can be a closed loop system where hydrogen gas produced in one reactor is used in another reactor to produce high value products which are then separated and stored. Although each reactor can operate under different conditions in processing different batches of waste, the harvesting of energy from thermal energy, reactants such as hydrogen gas and steam, and heated molten plastic decomposition products allows for effective energy harvesting and efficient production of products without the need to introduce external hydrogen gas into the system.

[0023] As used herein, a "thermochemical reactor" or "thermochemical decomposition reactor" is a reactor in a system in which the thermochemical decomposition of waste occurs in the presence of hydrogen gas or a mixture of hydrogen and steam, or molten plastics and other gaseous materials received directly or indirectly from a hydroprocessing metal-water reactor, as further disclosed herein. The term thermochemical decomposition refers to reactions in which hydrocarbons contained in waste are converted into one or more other substances or distillates at high temperatures in the absence of oxygen (thermochemical recycle). Decomposition reactions or chemical conversions include pyrolysis, hydrocracking, hydrothermal cracking, hydrothermal liquefaction processes, and other related reactions well known in the art.

[0024] A "hydrogen processing metal water reactor", also known as a "hydrogen gas reactor or generator", is a reactor system in which hydrogen is produced by the reaction of metals with plastics in the presence of water. In addition to hydrogen gas, the process also produces steam, molten plastics, plastic decomposition vapors (various gaseous substances), and in some cases metal oxides. Each of these substances, alone or in combination with other products, is used as an energy carrier to drive the thermochemical decomposition in the thermochemical reactor.

[0025] "Waste plastic" refers to waste that contains a certain amount of plastic material that is a synthetic or semi-synthetic polymerization product, i.e., a plastic material that is generally a hydrocarbon-based polymer. Waste plastic may also include biomass and other synthetic, semi-synthetic, and natural polymeric materials. Generally, waste plastic materials are a mixture of materials consisting of polyethylene, such as low-density or high-density polyethylene, and / or polypropylene. In some cases, waste plastic may further include polyvinyl chloride, polystyrene, and PET. Waste plastic may come from any waste source, such as industrial waste or municipal waste. Waste may consist of a single polymeric or plastic component, or a combination of multiple components, and may be pre-sorted or used as is without any kind of pre-treatment or sorting. Waste may consist of two- or three-dimensional plastic products or materials that may be mechanically treated to reduce size, for example by crushing or grinding, or may be used as is.

[0026] Waste plastics may or may not generally contain metal components or metals. Plastic waste may contain metal waste and / or plastic materials containing metals as additives or other separate waste components. In some configurations, the waste contains both plastic and metal or metal-plastic objects or materials, which may be pre-sorted into two separate waste feedstocks: a plastic waste feedstock that is substantially free of metal components (i.e., metal-free as further defined herein) and a metal-rich plastic waste feedstock. If the waste does not contain the required amount of zero bullet metal-containing products, the waste may be enriched with metal-containing products that are themselves waste or low-grade materials. The waste materials used may contain non-recycled or non-recyclable materials.

[0027] As disclosed herein, the products obtained by thermochemical cracking under the conditions disclosed herein include various non-plastic end products or "distillates," such as various petrochemicals, fuels, naphtha, monomers, etc. Each of these materials can be distilled or separated from the resulting distillates using appropriate separation and / or purification techniques. The term "non-plastic," when referring to other materials present in the end product or waste, refers to any material that is not a hydrocarbon-based polymer, regardless of its origin.

[0028] Although the systems and methods of the present invention are of great environmental importance in converting waste plastics into high-end products, the methods of the present invention can be used to convert any plastic material as well.

[0029] Thus, in a first aspect, the present invention provides an integrated system for the thermochemical recycling of plastic materials, such as waste plastics, comprising a hydrotreating reactor or hydrogen gas generator and a thermochemical reactor, each independently adapted to receive the plastic waste, and the hydrogen gas and thermal energy generated in the hydrotreating reactor are utilized to effect the thermochemical decomposition of the plastic waste in the thermochemical reactor.

[0030] The system of the invention includes a first vessel (reactor) configured to receive metal-rich plastic waste (or a combination of metal and plastic); a first vessel (reactor) for hydrotreating (thermal treatment of the waste in the presence of water) the metal-rich plastic waste (or combination) to produce hydrogen gas (and decomposed plastic chunks, steam, gaseous products, and metal oxides); a second vessel (reactor) configured to receive plastic waste (optionally with or in combination with biomass, virgin plastics and / or non-waste plastics) and, in the presence of at least the hydrogen gas produced in the first vessel, pyrolyze the plastic waste (or combination thereof) and produce plastic decomposition products (or distillates); and means for directing hydrogen gas, and optionally other heating materials, from the first vessel to the second vessel.

[0031] Also provided is a system for thermochemical recycling of plastic materials, e.g., waste plastics, the system comprising: a first vessel (reactor) configured to receive metal-rich plastic waste and thermally treat the waste in the presence of water to produce hydrogen gas, steam, and decomposed plastic chunks or gaseous products; a second vessel (reactor) configured to receive the plastic waste and pyrolyze the plastic waste in the presence of hydrogen gas and optionally the decomposed plastic solid and gas products produced in the first vessel to produce plastic decomposition products (or distillates); and means for directing the hydrogen gas and optionally heated decomposed plastic solids and gas products from the first vessel to the second vessel.

[0032] In some embodiments, the first vessel (reactor) is provided as two or more reactors each configured to receive a different component of the metal-rich plastic waste. In some embodiments, one of the reactors is configured to receive the plastic waste and thermally convert it into molten plastic and gaseous products without substantially decomposing the plastic, and another of the reactors is configured and operatively configured to receive the metal waste and water and produce hydrogen gas. Thus, the second vessel may be configured to receive a stream of molten plastic and gaseous products and another stream of hydrogen gas and steam.

[0033] In some embodiments, the system thus comprises a vessel (reactor) arrangement of two or more reactors, a first of said reactors configured to receive metal-free plastic waste and thermally treat the metal-free plastic waste to produce molten plastic mass and gaseous products, and a second of said reactors configured to receive metal waste and hydrotreat the metal waste to produce hydrogen gas and water vapor (and energy in the form of heat); a second vessel (reactor) configured to receive plastic waste (optionally with or in combination with biomass, virgin plastics, or non-waste plastics) and operable to pyrolyze the plastic waste (or combination) in the presence of hydrogen gas, and optionally molten plastic solids and gas products to produce plastic decomposition products (or distillates); and means for directing the hydrogen gas and optionally heated decomposed plastic solids from the first vessel to the second vessel.

[0034] In some embodiments, the system further comprises, is connected to, or is associated with a metal-rich plastic waste stream configured to supply the metal-rich plastic waste feedstock to the first vessel.

[0035] In some embodiments, the metal laden plastic stream is treated to separate the metal components from the plastic material. In such cases, the system is comprised of, connected to, or associated with two independent metal and plastic streams (metal laden source or two separate waste sources, one metal and one plastic).

[0036] In some embodiments, the system further comprises a plastic waste stream or is configured to provide a plastic waste stream to a second vessel.

[0037] In some embodiments, the plastic waste stream is combined with a stream or amount of biomass material.

[0038] The present invention further provides a system for continuous thermochemical conversion of plastic waste to distillates (and other decomposition by-products), the system comprising a vessel for receiving metal-rich waste material and converting it to hydrogen gas, steam, and pyrolyzed plastic chunks, and gaseous products as disclosed herein, or comprising a thermochemical reactor associated therewith, configured to receive the hydrogen gas, pyrolyzed plastic chunks, and metal-free plastic waste and cause thermochemical decomposition of the metal-free (or substantially metal-free) plastic waste.

[0039] Further provided is a system consisting of two or more reactors, at least one of which is a hydrogen gas generator and another of said two or more reactors is a thermochemical decomposition reactor, the hydrogen gas generator and the thermochemical decomposition reactor being in physical and / or thermal communication therebetween that allows for the transfer of heated hydrogen gas and / or heated molten plastic mass (and thermal energy) from the hydrogen gas generator to the thermochemical decomposition reactor.

[0040] In another aspect, the invention provides a system for thermochemical recycling of plastic materials (e.g., a system for producing distillates or fuels / petrochemicals from plastic waste), the system comprising at least two reactors, at least one of the reactors being a hydrogen gas generator and at least one other reactor being a decomposition reactor that is a thermochemical decomposition reactor, the at least one hydrogen gas generator configured to receive metal rich waste plastic material from an external source, the thermochemical decomposition reactor configured to receive a substantially metal free heated mass and heated hydrogen gas and steam from the hydrogen gas generator.

[0041] Furthermore, the present invention provides a plant for operating an integrated thermochemical process for converting plastic waste into high value added or commodity products, said plant comprising: a first reactor equipped with a first heater for hydrotreating mainly metal-rich plastic waste to obtain hydrogen gas, steam, pyrolyzed plastic chunks, gaseous products and metal oxides; - a second reactor for thermochemical decomposition of plastic waste, comprising a second heater, connected to the first reactor by at least one pipe, for separately receiving plastic waste from an external raw material or source, receiving the amount of hydrogen gas, steam, heated plastic mass, gaseous products produced in the first reactor, and obtaining products; a heat exchanger configured to receive heat from the first reactor and to transfer heat to the second reactor in order to recover heat produced in the hydrotreatment stage within the process; an electrical control panel connected to the first and second heaters for regulating the temperature of at least the hydrotreating and thermochemical cracking processes.

[0042] The integrated system and method allows for direct or indirect heat transfer between the exothermic (hydrogen generation) and endothermic (thermochemical decomposition process) steps. As shown in Figures 1A-C, the reactor system of the present invention can be integrated in various ways. The configurations shown in Figures 1A and 1B show direct heat transfer between the hydrogen generator and the thermochemical reactor. In the system of Figure 1A, the hydrogen gas generator (metal-H2O reactor) is associated (physically and thermally) with the thermochemical reactor. The hydrogen gas generator is fed with metal-rich waste material through a suitable inlet and mixed with water introduced through the same inlet (as a mixture of metal-rich waste and water) or through a separate inlet. Under suitable hydrothermal conditions as disclosed herein, heated hydrogen gas and steam are obtained along with the molten decomposed plastic mass. The hydrogen gas, steam, various gaseous products, and the thermodecomposed plastic mass are flowed from the hydrogen gas generator to the thermochemical decomposition reactor configured to separately receive the plastic waste through a designated waste stream inlet. The metal oxides formed in the hydrogen gas generator may be separated separately from the reactor. The distillate, liquid products, and solid products formed in the thermochemical reactor may each be collected separately.

[0043] In a further configuration shown in FIG. 1B, the metal-rich waste material is pre-treated to separate the metal components from the plastic material. Alternatively, two separate material streams are used, namely a metal stream and a plastic stream. The system thus comprises a plastic waste material reactor and a separate hydrogen gas generator. The plastic waste container is configured to receive and thermally process the plastic waste to obtain molten plastic without substantially causing thermal decomposition of the plastic material. In the gas generator, the metal combines with water to generate hydrogen gas. The hydrogen gas generator and the plastic waste reactor each have an outlet for discharging the hydrogen gas and the molten polymer, respectively, directly into a thermochemical reactor configured to receive and hold the plastic waste as described herein.

[0044] In a further configuration, as shown in FIG. 1C, the system comprises or is provided with a heat transfer unit (the operation of which is described in detail in the mass and energy balance) and a downstream system for fractionation of the generated steam. Heat recovery is achieved by passing the hydrogen steam mixture (which can be obtained from the hydrogen gas generator of FIG. 1A or FIG. 1B) through a condensing heat exchanger shell. Hydrogen gas is separated from the shell and can be further hydrocracking reactions. Condensed water can be collected and reused as make-up water to the hydrogen gas generator. Another heat recovery is possible by feeding the hydrogen gas and water vapor mixture directly to the thermochemical decomposition reactor. The thermochemical decomposition reactor can be fed with plastic waste (plastic only waste and molten plastic from the hydrogen gas generator or plastic recovery system), gaseous substances, and other liquid components.

[0045] In some embodiments, the hydrogen gas generator and the thermochemical decomposition reactor are each separate reactor units or vessels, capable of receiving waste from different, optionally independent, external sources. Each reactor is provided with an inlet valve and an outlet valve, and means for associating the two reactors for flowing hydrogen gas and thermodecomposed plastic mass (decomposed or not), usually liquefied mass, from the hydrogen gas reactor or a separation vessel to the thermochemical decomposition reactor. Each reactor inlet valve is configured to allow the inflow of material into the reactor from an external unit, such as a waste source or a storage tank, or from another unit, such as a hydrogen generator, to the thermochemical reactor. Similarly, the outlet valve is configured to output or distribute a certain amount of material (or the entire contents of the vessel), whether in gas, liquid or solid state, from the reactor to another vessel or storage tank.

[0046] The hydrogen gas generator and thermochemical reactor may be associated through a heated pipeline for flowing heated liquid polymer mass, gas, and hydrogen gas from the hydrogen gas generator or the intended vessel for converting the polymer waste to molten mass to the thermochemical decomposition reactor. Metal-rich waste or individual metals (fresh feed and / or recovered from the metal plastic separator) may be fed through a pressurized feeder in solid or dispersed form in water. Make-up water may be fed through a high pressure pump. The hydrogen gas generator with metal and water may be equipped with a top outlet for releasing the extracted hydrogen gas and vapor through a pressure control valve and back pressure regulator, the composition being influenced by the rate and ratio of metals and reaction conditions. The oxidized metal product may be removed as a suspension through a throttling valve.

[0047] A hydrogen gas generator, as disclosed herein, is a vessel or reactor capable of operating at high pressure and temperature, constructed and sized to accommodate a volume of metal-rich plastic waste and water, and to process the plastic waste water in the presence of metals to produce hydrogen gas, heated liquefied or decomposed plastic mass, and other gaseous products. Metal oxide (e.g., alumina) deposits may also be recovered as a by-product.

[0048] The hydrogen gas, heated mass, and metal oxides can be collected and stored for later use. Additionally or alternatively, the hydrogen gas and / or heated mass can be transferred or flowed into a thermochemical reactor as a clean energy source to drive the thermochemical decomposition. Thus, in some configurations, the hydrogen gas reactor or generator can be provided with an outlet for collecting hydrogen gas.

[0049] The hydrogen gas generator may be associated with the thermochemical reactor by various means to allow the flow of hydrogen gas, steam, and other gaseous products, optionally liquefied plastic mass. Such means may be provided in the form of pipes, optionally with heated pipe segments to allow the flow of plastic in a molten state, and may include gas release lines, flow measurement systems, one or more high pressure dosing units, a hydrogen compressor, thermal flow and level controls, and other units or elements.

[0050] Each reactor of the system according to the invention may be fed by one or more waste streams. Metal-rich waste may be fed to the reactor where the metal reacts with water / saturated steam / superheated steam according to the exothermic metal-water reaction, depending on the reaction conditions. The gaseous or liquid reaction products are used to transfer heat directly or indirectly from the hydrogen gas reactor or generator to the thermochemical decomposition reactor, depending on the reactor operation mode (isothermal / adiabatic) and the level of pretreatment of the feedstock. The heat and hydrogen required for optimal thermochemical decomposition reaction conditions are recovered from the integration with the hydrogen gas reactor.

[0051] The mixed plastic waste is fed to a thermochemical cracking reactor where it is cracked into various types of hydrocarbons. The hydrocarbons may include a mixture of gaseous and liquid products that can be separated. In some embodiments, the products include various distillates and petrochemicals, such as jet fuel, naphtha, and the like, for example, liquid petroleum materials in an amount of 50-90% of the total amount of products, and liquid petroleum materials and gases, for example, in an amount of 10-50% of the total amount of products, and carbonaceous materials or ash, for example, in an amount of less than 5% of the total amount of products. These products are separated from the reactor via a product stream and may be further separated into various components or groups of components.

[0052] Metal-rich plastic waste may contain various metals in various forms. Metal-rich plastic waste suitable for producing energy and hydrogen gas is waste containing zero-valent forms of metals that can react with water to generate metal hydroxides or oxides, as well as hydrogen gas, other gaseous substances, and liquefied decomposed plastic mass. Metals present in the metal-rich waste may be calcium, aluminum, magnesium, zinc, etc. In some embodiments, the metal is aluminum. In some embodiments, the metal-rich plastic waste is aluminum-rich plastic waste.

[0053] Typically, metal-rich plastic waste, e.g., aluminum-rich plastic waste, is waste in which the metal is embedded or bound within the plastic material and sometimes cannot be separated from it. The metal is typically bound to the plastic material rather than added to the waste. However, in some embodiments, low-grade metals (such as those used in metal-containing packaging, beverage cans, etc.) may be added as additives to enhance production capacity and stabilize processing. The type and amount of metal used may depend on various factors, including the amount of metal contained in the metal-containing plastic waste.

[0054] In some embodiments, the metals are waste metals, which may be separated from municipal waste and combined with plastic waste. Typically, the amount of metal is up to 30% by weight of the metal-containing stream, but this can be increased by adding lower grade metals, such as aluminum, and thus may be at least 30% by weight in some cases. Plastic:metal load ratios typically range from 3:1 to 15:1. Plastic waste, unlike metal-rich plastic waste, does not usually contain zero-valent metals, but may contain metal salts, complexes or oxides.

[0055] Metal-rich plastic waste contains amounts of zero-valent metals that convert water and metals into metal oxides and hydrogen gas, releasing water vapor, various gases, and heat energy. This transforms the plastic waste into liquid plastic mass and various gaseous substances that are usually metal-free or have low metal content. A "metal-free or "metal-poor" or substantially metal-free waste or liquefied mass is a plastic mass that is usually in a liquid state and is deficient in zero-valent metal content. This is because most of the metals have been converted to oxide, salt, or complex forms. Thus, while metal-rich plastic waste may contain zero-valent metals as defined and disclosed herein, processed plastic waste or plastic waste used in a thermochemical reactor may contain much less of the zero-valent metal form and therefore may be considered metal-free, metal-poor, or substantially free of metals. In some embodiments, a substantially "metal-free" waste or mass may be comprised of 10 wt% or less of zero-valent metals, or 9, 8, 7, 6, 5, 4, 3, 2, 1 wt% or less of zero-valent metals.

[0056] As mentioned herein, metal-free plastic waste may be used sorted or unsorted. In some cases, waste streams may contain polyvinyl chloride (PVC), in which case chlorine gas in the waste may contaminate the hydrogen atmosphere. In such cases, the waste can be pretreated by melting, degassing, and / or neutralizing the released chlorine gas, since in the hydrogen atmosphere chlorine gas is converted to hydrogen chloride. Neutralization can be achieved by scrubbing the steam with water to produce a hydrogen chloride solution (as an additional by-product) or in a caustic solution. Thus, in some embodiments, the waste stream is pretreated by melting at atmospheric pressure.

[0057] In some configurations, the plastic waste is derived from municipal solid waste. The waste may be composed of a single polymer or plastic component, or a combination of components such as polyethylene (e.g., low density polyethylene or high density polyethylene) and polypropylene. In some embodiments, the waste may further include PVC, polystyrene, and PET. In some embodiments, the plastic waste does not include PVC.

[0058] An exemplary waste material combination may include low density polyethylene (e.g., 23 wt%), high density polyethylene (e.g., 19 wt%), polypropylene (e.g., 14 wt%), PVC (e.g., 6 wt%), polystyrene (e.g., 9 wt%) and PET (e.g., 10 wt%). Additionally, plastic waste may be combined with biomass.

[0059] The present invention further provides a method for thermochemical recycling of plastic material, such as plastic waste (e.g., for conversion to fuels or petrochemicals), the method comprising: - hydrothermal liquefaction of metal-rich plastic waste to produce hydrogen gas and decomposed molten plastic chunks and / or gaseous substances (e.g., produced by decomposition of the plastic chunks); and -The process comprises pyrolysis of metal-free plastic waste in the presence of hydrogen gas and molten plastic chunks and / or gaseous substances to produce fuels and petrochemicals.

[0060] In some embodiments, production of hydrogen gas can be achieved separately from the decomposed molten plastic mass or gas products resulting from the decomposition of the plastic mass. The present invention further comprises: - thermally reacting metal-rich plastic waste with water to produce metal-poor or metal-free molten plastic mass, gaseous products, and hydrogen gas; - transferring at least a portion of the metal-deficient or metal-free plastic solids and hydrogen gas to a thermochemical decomposition reactor containing or configured to receive metal-free plastic waste; - reacting the metal-low or metal-free plastic chunks, hydrogen gas, and metal-free plastic waste to produce fuels and petrochemicals.

[0061] Further provided is a continuous method for producing fuels and petrochemicals from plastic waste, the method comprising: feeding plastic waste to at least two reaction vessels, a first vessel being fed with plastic waste free of metal components and a second vessel being fed with plastic waste rich in metals; feeding the metal-rich plastic waste and water under conditions that allow metals in the metal-rich plastic waste to react with the water to generate heat and hydrogen gas; transferring at least a portion of the hydrogen gas to the first vessel; and producing the fuels and petrochemicals in the first vessel under thermochemical conditions.

[0062] The water used in the hydrogen gas generator can be obtained from any source. The water does not need to be clean, but can be sewage, tap water, sea water, saline water, etc. During operation, the reactor is in water vapor equilibrium or supercritical conditions. In some embodiments, the amount of water used in the hydrogen gas reactor or generator depends on the estimated amount of metals present in the metal-rich waste. Typically, a metal:water ratio between 1:1 and 1:10 is used.

[0063] In some embodiments, hydrogen gas is produced at elevated temperature, for example, between 270° C. and 450° C., and optionally at elevated pressure, for example, between 60 atmospheres and 200 atmospheres. In some embodiments, the temperature is between 300° C. and 400° C.

[0064] In some embodiments, the production of fuels and petrochemicals is carried out at elevated temperatures, e.g., 200° C. to 400° C., and moderate pressures, e.g., 10 atm to 70 atm. In some embodiments, the temperature is between 300° C. and 350° C. In some embodiments, the method includes placing the plastic waste in a vessel. In some embodiments, the method includes sorting the waste to separate metal-containing plastic waste from non-metal-containing plastic waste.

[0065] The present invention further provides an integrated thermochemical process for the recovery of hydrogen gas and distillates from plastic waste consisting of hydrocarbons and potentially biomass, the process comprising: -a- feeding metal-rich plastic waste into a first reactor, in the presence of water, and treating at a temperature within the process value range of 270°C to 450°C to obtain at least hydrogen gas and water vapor; -b- feeding the plastic waste into a second reactor and treating it at a temperature within the range of process values ​​between 200 ° C and 400 ° C; -c- feeding to a second reactor at least the amount of hydrogen gas and water vapor produced in the first reactor, wherein steps a and b, or b and c, occur simultaneously or sequentially.

[0066] In some embodiments, the method includes providing at least one metal-rich plastic waste feedstock, where the feedstock is premixed with water or fed to a first reactor containing water.

[0067] In some embodiments, metal-laden plastic waste is provided as a source of metal waste and a source of metal-free plastic waste, each of which is fed separately to separate reactors. In some embodiments, the reactor fed with metal waste contains water to produce hydrogen gas and steam, and the reactor fed with said metal-free plastic waste is operable to produce molten plastic mass and gaseous products, where said hydrogen gas, steam, molten plastic mass and gaseous products are fed to a second reactor.

[0068] Further, the invention provides an integrated thermochemical process for obtaining improved fuels and petrochemical compositions from plastic waste derived feedstocks, comprising a hydrotreating step of reacting a metal-rich plastic waste derived feedstock with water to obtain a hydrogen gas composition (comprising molten plastic mass, water vapor, gaseous products, and metal oxides), and a step of using the hydrogen gas composition to thermochemically decompose the plastic waste feedstock, thereby producing the improved fuels and petrochemical compositions.

[0069] The methods and systems of the present invention do not involve the external addition of hydrogen gas. All hydrogen gas utilized in the methods of the present invention is generated in situ in a defined hydrogen gas reactor or generator. Furthermore, all energy utilized in the thermochemical decomposition is generated in situ in a hydrogen generator and transferred to the thermochemical decomposition unit as disclosed herein.

[0070] In some embodiments, the methods of the present invention are implemented on the defined systems of the present invention.

[0071] The process of the present invention operates thermally and does not require the use of a catalyst. However, a catalyst may be used at any process stage to improve selectivity, yield and reduce the operating temperature. The plastic cracking catalyst may be selected from among zeolites and bifunctional hydrogenation / hydrocracking catalysts, such as zeolites and FCC. The amount of catalyst may be less than 0.1 wt%.

[0072] In some cases, small amounts of NaOH may additionally or alternatively be used as a catalyst for hydrogen gas production in the hydrogen gas generator. The amount of NaOH may be selected to strip or remove oxide coatings present on the metal components of the metal-rich waste material and facilitate the hydrogen gas generation process. Other caustic materials may be used instead of or in addition to NaOH. The amount of caustic material or NaOH may be less than 0.1% by weight and may range from 0.1 to 5% by weight.

[0073] The products produced by the process of this invention can be gaseous, liquid or solid, commonly referred to as fuels and petrochemicals, ranging from 5-50 wt%, 5-50 wt%, and 0-10 wt%, respectively. By-products such as metal oxides may also be produced. Gaseous products may include low carbon content products containing 1-4 carbon atoms and hydrogen gas. Liquid products range from pyrolysis oil to hydrocracked pyrolysis oil fractions (from naphtha to jet fuel). Solid products may include heavy wax products and ash from pyrolysis in an inert environment or may be completely absent in the case of hydrocracking.

[0074] Thus, the fuels and petrochemicals produced by the methods and systems of the present invention may be any of olefins, aromatics, paraffins, isoparaffins, naphthenes, heavy hydrocarbons, etc. Product selection and yields may depend on cracking process conditions, heating rate, feed composition, and other process parameters. The present invention provides a system for thermochemical recycling of plastic materials, comprising: a first vessel (reactor) configured and operable to receive metal laden plastic waste and hydrotreat the metal laden plastic waste to produce hydrogen gas, pyrolyzed plastic chunks, and gaseous substances; a first vessel (reactor) configured and operable to pyrolyze the plastic waste in the presence of the hydrogen gas and, optionally, the pyrolyzed plastic chunks and gaseous substances from the first vessel, and the plastic waste in the presence of the hydrogen gas, and, optionally, the pyrolyzed plastic chunks and gaseous substances to produce a distillate; and means for directing hydrogen gas, and optionally the pyrolyzed plastic mass and gaseous substances from the first vessel to the second vessel.

[0075] In some cases, the first vessel (reactor) is provided as two or more reactors, each configured to receive a different component of the metal-rich plastic waste.

[0076] In some cases, one of the two or more reactors is configured to receive and thermally convert plastic waste into molten plastic and gaseous products, and another of the two or more reactors is configured to receive metal waste and water and produce hydrogen gas.

[0077] In some cases, the second vessel is configured to receive a single stream of hydrogen gas and the optionally heated molten plastic and gaseous products, or a stream of molten plastic and gaseous products and separate streams of hydrogen gas and steam.

[0078] In some cases, the system includes a vessel (reactor) arrangement of two or more reactors, one of which is configured to receive metal free plastic waste and thermally treat the metal free plastic waste to produce heated molten plastic mass and gaseous products, and a second of which is configured to receive metal waste and hydrotreat the metal free plastic waste in the presence of water to produce hydrogen gas in the presence of water, a second vessel (reactor) configured to pyrolyze the plastic waste in the presence of hydrogen gas, steam, and optionally heated molten plastic mass and gaseous products, and means for directing hydrogen gas and optionally heated decomposed plastic mass and gaseous products from the first vessel arrangement to the second vessel.

[0079] In some cases, the system is associated with a metal laden plastic waste stream configured to provide the metal laden plastic waste to the first vessel.

[0080] In some cases, the system is associated with two independent streams of metal and plastic waste.

[0081] In some cases, the system is associated with a plastic waste stream configured to provide plastic waste to the second vessel.

[0082] In some cases, the system is configured to continuously thermochemically convert plastic waste to a distillate.

[0083] Also provided is a system comprising two or more reactors, at least one of which is a hydrogen gas generator and another of said two or more reactors is a thermochemical decomposition reactor, the hydrogen gas generator and the thermochemical decomposition reactor being in a material and / or heat transfer relationship that enables the transfer of hydrogen gas and / or molten plastic mass and gaseous products from the hydrogen gas generator to the thermochemical decomposition reactor.

[0084] In some cases, the system includes a heat transfer unit and a downstream system for fractionation of the vapor.

[0085] In some cases, the hydrogen gas generator and the thermochemical reactor are associated via a heated pipeline.

[0086] In some cases, the plastic to metal load ratio (plastic:metal) is between 3:1 and 15:1.

[0087] In some cases, the metal in metal-rich plastic waste is aluminum.

[0088] A plant for operating an integrated thermochemical process for converting plastic waste into high value products is provided, the plant comprising: a first reactor equipped with a first heater for hydrotreating the mainly metal-rich plastic waste to obtain hydrogen gas, steam, heated plastic mass, gaseous products and metal oxides; - a second reactor for the thermochemical decomposition of plastic waste, comprising a second heater, connected to the first reactor by at least one pipe and adapted to receive separately the plastic waste from an external feedstock or source, hydrogen gas, steam, heated plastic mass, gaseous products produced in the first reactor and products; a heat exchange unit configured to receive heat from the first reactor and to transfer it to the second reactor in order to recover heat produced in the hydrotreatment stage within the process.

[0089] In some cases, the plant or system includes an electrical control panel connected to the first and second heaters to at least regulate the temperature of the hydrotreating and thermochemical cracking processes.

[0090] There is also provided a method for thermochemical recycling of plastic materials, the method comprising: hydrothermal liquefaction (or metal-water reaction) of metal-laden plastic waste with water to produce hydrogen gas, steam, heated molten plastic mass, and gaseous products; and pyrolysis of the metal-free plastic waste in the presence of hydrogen gas and optionally steam, with heated molten plastic mass and gaseous products, said hydrothermal liquefaction and pyrolysis being carried out in separate vessels within the thermochemical system, thereby producing fuels and petrochemicals.

[0091] In some cases, the production of hydrogen gas can be accomplished separately from the production of the molten plastic mass and gaseous products.

[0092] Also provided is a method for thermochemical recycling of plastic materials, the method comprising: thermally reacting the metal-rich plastic waste with water to produce a molten plastic mass with little or no metals, gaseous products, and hydrogen gas; transferring at least a portion of the hydrogen gas, and optionally the metal-poor or metal-free plastic chunks and gaseous products, to a thermochemical decomposition reactor containing the metal-free plastic waste; and reacting at least the metal-free plastic waste in the presence of hydrogen gas to produce fuels and petrochemicals.

[0093] In some cases, the water is sewage, tap water, sea water, or saline water. In some cases, the weight ratio of metal to water is between 1:1 and 1:10. In some cases, hydrogen gas is produced at a temperature between 270° C. and 450° C., and optionally at a pressure between 60 and 200 atmospheres. The production of fuels and petrochemicals may take place at temperatures between 200° C. and 400° C. and pressures between 10 and 70 atmospheres.

[0094] An integrated thermochemical process for recovering hydrogen gas and distillates from plastic waste consisting of hydrocarbons and potentially biomass is provided, the process comprising: - a - feeding metal-rich plastic waste into a first reactor and treating said waste in the presence of water at a temperature maintained within the process value range of 270°C to 450°C inclusive, in order to obtain at least hydrogen gas and water vapor; -b- feeding the amount of plastic waste into a second reactor within a process value range of between 200 ° C and 400 ° C; -c- supplying at least the amount of hydrogen gas and water vapor produced in the first reactor to a second reactor; Steps a and b, or b and c, may be carried out simultaneously or sequentially.

[0095] Optionally, the method is performed on a system according to the invention.

Claims

1. A system for the thermochemical recycling of plastic materials, A first vessel (reactor) configured and operational to accept metal-rich plastic waste and hydrogenate the metal-rich plastic waste in order to produce hydrogen gas, thermally decomposed plastic lumps, and gaseous substances, A second vessel (reactor) configured and operable to receive plastic waste and at least a certain amount of the hydrogen gas from the first vessel, and optionally receive the thermally decomposed plastic mass and the gaseous substance from the first vessel, and to thermally decompose the plastic waste in the presence of the hydrogen gas and the thermally decomposed plastic mass and the gaseous substance, in order to produce a distillate, Means for introducing the hydrogen gas from the first container to the second container, and optionally introducing the thermally decomposed plastic mass and the gaseous substance, A system equipped with these features.

2. The system according to claim 1, The first vessel (reactor) is provided as two or more reactors, Each of the two or more reactors is configured to receive different components of the metal-rich plastic waste. system.

3. The system according to claim 2, One of the two or more reactors is configured to receive plastic waste and thermally convert it into molten plastic and gaseous products. Another of the two or more reactors is configured to receive metal waste and water and produce hydrogen gas. system.

4. The system according to claim 1 or 2, The second vessel is configured to receive a single flow of hydrogen gas and optionally also receive heated molten plastic and gaseous products, or to receive a flow of molten plastic and gaseous products and separate flows of hydrogen gas and vapor. system.

5. The system according to claim 1, A vessel (reactor) arrangement comprising two or more reactors, One of the two or more reactors is configured to receive metal-free plastic waste and heat-treat the metal-free plastic waste to produce a heated molten plastic mass and gaseous products. The second of the two or more reactors is configured to receive metal waste and hydrogenate the metal waste in the presence of water to generate hydrogen gas. A second vessel (reactor) configured to receive plastic waste and to thermally decompose the plastic waste in the presence of hydrogen gas and vapor, and the heated molten plastic mass and optionally the gaseous products, Means for introducing the hydrogen gas from the first container arrangement to the second container, and optionally introducing the thermally decomposed plastic mass and the gaseous product, A system equipped with these features.

6. The system according to claim 1, A flow of metal-rich plastic waste is associated with a flow of metal-rich plastic waste configured to supply metal-rich plastic waste raw materials to the first container, system.

7. The system according to claim 1, Associated with two separate flows of metal waste and plastic waste, system.

8. The system according to claim 1, A flow of plastic waste is associated with a flow of plastic waste configured to supply plastic waste material to the second container, system.

9. The system according to claim 1 or 2, It is configured to continuously thermochemically convert plastic waste into distillates. system.

10. A system comprising two or more reactors, At least one of them is a hydrogen gas generator. One of the two or more reactors mentioned above is a thermochemical decomposition reactor. The hydrogen gas generator and the thermochemical decomposition reactor are physically and / or thermally connected to each other so that hydrogen gas and / or molten plastic mass and gaseous products can be transferred from the hydrogen gas generator to the thermochemical decomposition reactor. system.

11. The system according to claim 1 or 10, It further comprises a heat transfer unit and a downstream system for fractional distillation of steam. system.

12. The system according to claim 1 or 10, The hydrogen gas generator and the thermochemical reactor are connected via a heated pipeline. system.

13. The system according to claim 1 or 10, The load ratio of plastic to metal (plastic:metal) is from 3:1 to 15:

1. system.

14. The system according to claim 1 or 10, The metal found in plastic waste containing a large amount of metal is aluminum. system.

15. To operate an integrated thermochemical method for converting plastic waste into high-value products It is a plant, - A first reactor equipped with a first heater for hydrogenating plastic waste materials, mainly containing a large amount of metal, to obtain hydrogen gas, steam, heated plastic mass, gaseous products, and metal oxides. - Equipped with a second reactor for the thermochemical decomposition of plastic waste materials, The second reactor is equipped with a second heater and is connected to the first reactor by at least one pipe to separately receive external raw materials or plastic waste material from a supply source, and a certain amount of the hydrogen gas, vapor, heated plastic mass, and gaseous products produced in the first reactor, and to obtain the products. - In order to recover the heat generated in the hydrogenation treatment stage within the method, the method includes a heat exchange unit configured to receive heat from the first reactor and transfer that heat to the second reactor. plant.

16. The system according to claim 1 or 10, To at least adjust the temperature of the hydrogenation treatment and thermochemical decomposition method, an electrical control panel connected to the first heater and the second heater is provided. system.

17. A method for the thermochemical recycling of plastic materials, - A process of hydrothermally liquefying (or reacting with metals) a stream of plastic waste containing a large amount of metal with water to produce hydrogen gas, steam, heated molten plastic mass, and gaseous products, - A step of thermally decomposing metal-free plastic waste in the presence of a certain amount of hydrogen gas, and optionally in the presence of vapor, heated molten plastic mass, and gaseous products, The aforementioned hydrothermal liquefaction and thermal decomposition are carried out in separate containers within a thermochemical system, thereby producing fuel and petrochemical products. method.

18. The method according to claim 17, The generation of the hydrogen gas can be achieved independently of the generation of the molten plastic mass and the gaseous product. method.

19. A method for the thermochemical recycling of plastic materials, - A process of generating a molten plastic mass containing little or no metal, a gaseous product, and hydrogen gas by thermally reacting plastic waste containing a large amount of metal with water, - A step of transferring at least a portion of the hydrogen gas to a thermochemical decomposition reactor containing metal-free plastic waste, and optionally transferring the metal-poor or metal-free plastic lumps and at least a portion of the gaseous products, - A step of reacting the metal-free plastic waste in the presence of at least hydrogen gas in order to produce fuel and petrochemical products, A method that includes this.

20. The method according to claim 17 or 19, The water in question is sewage, tap water, seawater, or water with a high salt content. method.

21. The method according to claim 17 or 19, The weight ratio of metal to water is between 1:1 and 1:

10. method.

22. The method according to claim 17 or 19, Hydrogen gas is produced at temperatures ranging from 270°C to 450°C, and optionally at pressures ranging from 60 to 200 atmospheres. method.

23. The method according to claim 17 or 19, The production of fuels and petrochemical products takes place at temperatures ranging from 200°C to 400°C and pressures ranging from 10 to 70 atmospheres. method.

24. An integrated thermochemical method for recovering hydrogen gas and distillates from hydrocarbons and potentially biomass-containing plastic waste, -a- A step of processing the waste in the presence of water at a temperature maintained within a process range of 270°C and 450°C, by introducing a certain amount of metal-rich plastic waste into a first reactor in order to obtain at least hydrogen gas and steam, -b- A step of introducing a certain amount of plastic waste into a second reactor within a process temperature range of 200°C and 400°C, -c-The process includes the step of introducing a certain amount of at least hydrogen gas and vapor produced in the first reactor into the second reactor, Process a and process b, or process b and process c, are performed simultaneously or sequentially. method.

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