Method and apparatus for converting polymers into products

Abstract

The present invention provides a method and apparatus for converting polymeric materials into hydrocarbon products.

Description

[Technical Field]

[0001] Incorporation by cross-reference This application claims priority to Australian Provisional Patent Application No. 2019903756, filed October 4, 2019, the entire text of which is incorporated herein by cross-reference.

[0002] Technical Field The present invention relates generally to the field of waste treatment, and more particularly to a method and apparatus for converting polymeric materials, such as plastics, into hydrocarbon products. [Background technology]

[0003] The current widespread single-use use of plastic products is unsustainable and has led to a waste plastic problem that is hindering the environment. Plastic waste is poorly biodegradable, increasing environmental problems and harm to wildlife. Most plastic waste still ends up in landfills, which means that a significant amount of processing materials and energy is lost / unutilized.

[0004] As crude oil reserves are a finite resource, it is important to make plastics more sustainable by avoiding single-use plastics, increasing recycling and avoiding plastics that are simply dumped into landfills.

[0005] Because there are limits to the extent to which plastics can be mechanically recycled, a significant amount of waste plastic remains that cannot be mechanically recycled. In fact, many types of polymeric waste are not suitable for recycling.

[0006] Currently, the primary disposal options for this waste plastic are incineration or landfilling. Because this is unsustainable and potentially polluting, many countries discourage landfills. For example, due to small amounts of chlorine from the polyvinyl chloride (PVC) content of polymeric waste, incineration operates at relatively inefficient conditions and requires extensive flue gas treatment to avoid polluting the environment. While allowing for some energy recovery, incineration still results in the loss of useful hydrocarbon raw materials.

[0007] A further option for this waste plastic is thermochemical recycling (e.g., pyrolysis or catalytic pyrolysis or vaporization) to produce fuels or chemicals by thermal or catalytic cracking of the polymer. These methods suffer from the problem of applying heat externally, outside the vessel containing the waste plastic, and therefore can suffer from char formation and have hot surfaces that clog. Furthermore, some plastics decompose and sublimate, producing chemicals that clog downstream equipment. Heat transfer to the polymer aggregates is also a problem, leading to blockages in the plant. Catalytic processes can be sensitive to ash, metals, cellulose (paper), inorganic fillers, and additives as impurities in the polymer feed. As a result of these problems, several waste plastic pyrolysis plants that attempted to operate commercially have shut down.

[0008] A need exists for improved methods and / or equipment that can convert polymeric materials (e.g., plastics) into hydrocarbon feedstocks from which new plastics can be produced, creating a fully circular economy for plastics. Summary of the Invention

[0009] The present invention addresses one or more problems present in the prior art by providing an improved means for converting polymeric materials, such as waste plastics, into useful hydrocarbon products and / or transportation fuels and / or other chemicals.

[0010] By practicing the methods described herein, the useful chemical components of waste plastics can be chemically recycled to produce hydrocarbon products that can be reused in a variety of applications, including, for example, the production of new plastics. The present invention also provides a solution to the problem of plastic waste accumulation, reducing the consumption of finite crude oil reserves.

[0011] Disclosed herein are methods and apparatus for processing polymeric materials to produce hydrocarbon products.

[0012] In some embodiments, the polymeric material under treatment may be processed through a suitable extruder, which may increase the pressure and therefore the temperature of the polymeric material as it exits the extruder. The polymeric material may be further heated with supercritical water as it exits the extruder to produce a reaction mixture, which may include the polymeric material, water, and other components as needed. A mixer may be used to further mix the reaction mixture, and / or a heater may be used to further heat the reaction mixer. The reaction mixture, which includes the polymeric material and a solvent (e.g., an aqueous solvent), may be received in a reactor containing or comprising a reaction zone to provide a predetermined reaction temperature and / or pressure. The reaction mixture may be processed in the reaction zone for a time suitable to convert all or a portion of the polymeric material present in the reaction mixture into a product, which may exit the reaction zone in the form of a fluid product stream.

[0013] In certain embodiments, the fluid product stream exiting the reaction zone at high temperature and pressure may be rapidly depressurized in a flash vessel in a manner that vaporizes a majority of the fluid product stream to produce a vapor comprising hydrocarbon products, water vapor, and gases, which may be collected in a collection device. The inventors have advantageously determined that fractionation of the vapor into individual gas-containing components can be enhanced by the rapid depressurization of the fluid product stream and utilization of steam energy, as described above.

[0014] In the method of the present invention, the gas from the steam may be utilized as energy. For example, the gas may be transferred to a device such as a boiler to generate energy for heating the supercritical water. The energy of the gas may be used for any step of the method.

[0015] As described in more detail below, the present invention addresses one or more of the deficiencies in the prior art described above by having one or more of the following features, including, but not limited to:

[0016] Polymeric materials, such as waste plastics, may be readily produced by means known in the art for extrusion through a suitable extruder. The polymeric material extrudate exiting the extruder at high pressure may be mixed with a heated / pressurized aqueous solvent (superheated water) to provide a mixture containing a higher concentration of polymeric material compared to the same reaction mixture produced without the extrusion of the polymeric material. The superheated aqueous phase may provide efficient heat transfer to the polymer melt due to its high diffusivity, and / or the presence of water may suppress char formation. Halogens (e.g., chlorine) present in the reaction mixture may largely migrate to the aqueous phase as inorganic halides, thereby reducing concerns surrounding dioxin production. Cellulosic impurities, such as paper, may be largely vaporized or converted to oil components. Ash-like components and inorganic fillers may be largely carried through the process and can be separated from the product by means known in the art (e.g., fractional distillation). The design of the extruder-reactor interface and / or the mixing interface for dilution with supercritical or superheated aqueous solvent (e.g., water) are at least partially responsible for providing advantages over prior art processes, for example.

[0017] One or more collection devices according to the present invention may be provided in various configurations. If substantial energy is introduced in the process steps, the steam energy may be used to fractionate the steam into components. For example, a vertical tank may include various vertically arranged containers that receive the components, as their energy propels them to various heights within the tank so that they land in specific containers. The containers may be accompanied by collection pipes to direct the components to their respective reservoirs for further processing. Water may be a component and may be collected for washing. Gas may be at least one component of the fractionated steam that is utilized as energy in the process.

[0018] Depending on the energy stored in the various components of the vapor, the components may self-separate so that they are captured separately. Providing components with the opportunity to self-separate avoids the need for an additional separation step, which may require reheating the product, which requires additional energy and wasted time. The self-separation of a component of the fractionated vapor may be, for example, a hard wax residue.

[0019] Using the methods and apparatus described herein, so-called waste plastics produced with impurities can be processed to exhibit various characteristics. The impurities may, for example, cause the plastic to become opaque and colored. These impurities may be, for example, TiO2, CaCO3, ZnO, and / or NaCl. The weight of the impurities allows them to sink to the bottom of one or more reaction vessels, where they can be collected. Later, one of the various containers of the collection device may contain a product useful as bitumen. The methods and apparatus may include means for adding the impurities to one or more bitumen products for safe disposal. As described above, the water component of the fractionated steam may be washed, and the impurities may be collected and added to a product useful as bitumen for safe disposal. For example, the bitumen may be used in road construction.

[0020] As described herein, processing the reaction mixture in a reactor at various reaction temperatures and pressures for various times suitable to convert all or a portion of the polymeric material present in the reaction mixture into a fluid product stream can determine the ultimate end product fractionated vapor. Depending on the available raw materials and the desired product output, various parameters may be adjusted.

[0021] The process of the present invention can involve substantially harsh conditions due to the high pressures and temperatures. Therefore, proper selection of vessel and piping steel is beneficial. Depending on the steel selected, the reaction mixture interacts with the steel, which can act as a catalyst, resulting in various end-product characteristics. Depending on the desired end-product, additional surfaces may be added, for example, to the reactor vessel. One such surface may include, for example, nickel, to initiate a specific target reaction.

[0022] The present invention relates at least in part to the following embodiments.

[0023] Embodiment 1. 1. A method for processing a polymeric material to produce a hydrocarbon product, said method comprising: forming a reaction mixture comprising the polymeric material and an aqueous solvent; treating the reaction mixture in a reactor at a reaction temperature and pressure for a time suitable to convert all or a portion of the polymeric material present in the reaction mixture into a fluid product stream; reducing the pressure of the fluid product stream; The fluid product stream has a temperature of at least 350°C and a pressure of at least 180 bar (1.80 x 10 7 Pa), The pressure reduction is performed by reducing the pressure of the fluid product stream to 25 bar (2.5 x 10 6 reducing the pressure to less than 100 Pa (3 Pa), thereby vaporizing at least a portion of the fluid product stream to produce a vapor comprising hydrocarbon product, water vapor, and gaseous constituents; said vaporizing providing energy to facilitate fractionation of said vapor into said constituent components; collecting the fractionated vapor; A method comprising:

[0024] Embodiment 2. 2. The method of claim 1, wherein the fluid product stream is at a temperature of at least: 380°C, 400°C, 420°C, 450°C, or 470°C immediately prior to said depressurization.

[0025] Embodiment 3. The fluid product stream has a pressure of at least 200 bar (2.00×10) just prior to the pressure reduction. 7 Pa), 220 bar (2.20 × 10 7 Pa), 240 bar (2.40 × 10 7 Pa), 260 bar (2.60 × 10 7 Pa), 280 bar (2.80 × 10 7 Pa) or 300 bar (3.00 x 10 7 3. The method of claim 1 or 2, wherein the pressure is 0.05 Pa.

[0026] Embodiment 4. 4. The method of any one of the preceding claims, wherein the flash vessel is directly connected to an accumulator, is an integral part of the accumulator, or is directly connected to one or more staged product coolers.

[0027] Embodiment 5. 5. The method of any one of the preceding claims, comprising fractionating and cooling the vapor into fractions having a maximum atmospheric equivalent boiling point of less than 400°C, less than 450°C, less than 500°C, less than 550°C, or less than 600°C, and collecting a residual fraction having a minimum atmospheric equivalent boiling point of more than 400°C, 450°C, 500°C, 550°C, or 600°C.

[0028] Embodiment 6. 6. The method of any one of the preceding claims, wherein the solid filler and / or inorganic material and / or metal salts from the reduced pressure product stream are retained within a residue matrix produced by the vaporization and fractional distillation.

[0029] Embodiment 7. 7. The method of any one of claims 1 to 6, wherein the depressurization and fractionation allows for separation of the aqueous solvent from the hydrocarbon product, comprising separation of the aqueous solvent from lower boiling hydrocarbons at the following temperatures: 10°C, 20°C, 30°C, 40°C, 50°C, or 60°C.

[0030] Embodiment 8. Separation of the aqueous solvent from the low boiling point hydrocarbons was performed at 9.8±0.1 m / s 2 8. The method of embodiment 7, wherein the method is performed under an effective gravity of

[0031] Embodiment 9. 9. The method of claim 7 or 8, wherein the separated aqueous solvent comprises a total organic carbon content (TOC) of less than 15,000 mg / L, less than 10,000 mg / L, less than 5000 mg / L, less than 2500 mg / L, less than 1000 mg / L, or less than 500 mg / L.

[0032] Embodiment 10. 10. The method of any one of the preceding claims, further comprising injecting steam into the flash vessel and contacting the fluid product stream with the steam.

[0033] Embodiment 11. The formation of the reaction mixture comprises: providing a molten stream of said polymeric material; injecting the aqueous solvent into a molten stream of the polymeric material; mechanically mixing the aqueous solvent and the melt stream of the polymeric material; 11. The method of any one of embodiments 1 to 10, comprising:

[0034] Embodiment 12. 12. The method of embodiment 11, wherein the aqueous solvent is supercritical prior to the injection.

[0035] Embodiment 13. 13. The method of claim 11 or claim 12, wherein the aqueous solvent is water or substantially water.

[0036] Embodiment 14. 14. The method of any one of embodiments 11 to 13, wherein said mechanical mixing comprises the use of a solvent distribution grid in an assembly comprising one or more stationary mechanical mixing devices.

[0037] Embodiment 15. 13. The method of embodiment 12, wherein the flow rate output by any said mechanical mixing device has a volume uniformity of greater than about 94%, greater than about 95%, greater than about 96%, greater than about 97%, or greater than about 98%.

[0038] Embodiment 16. 16. The method of any one of embodiments 11-15, wherein the aqueous solvent is injected into the molten stream of polymeric material through a series of nozzles spanning the periphery of any of the mixing devices and solvent distribution grids.

[0039] Embodiment 17. During the formation of the reaction mixture, the pressure is increased to 2 bar (2×10 5 Pa), less than 5 bar (5 × 10 5 Pa), less than 10 bar (1.0 × 10 6 Pa), less than 20 bar (2.0 × 10 6 Pa), or less than 30 bar (3.0 x 10 6 17. The method of any one of embodiments 14-16, wherein there is a pressure drop across the mixing device of less than 100 Pa.

[0040] Embodiment 18. 18. The method of any one of embodiments 12-17, wherein the supercritical aqueous solvent is produced in a boiler system comprising a burner fueled by gas released from the fluid product stream.

[0041] Embodiment 19. 19. The method of embodiment 18, wherein the supercritical aqueous solvent is produced in a boiler system comprising a burner fueled by natural gas.

[0042] Embodiment 20. 20. The method of claim 18 or claim 19, wherein the supercritical aqueous solvent exits the boiler system at a temperature of at least 450°C, at least 500°C, or at least 550°C.

[0043] Embodiment 21. The boiler system is configured to operate at a pressure of at least 180 bar (1.80×10 7 Pa) or at least 200 bar (2.00 × 10 7 Pa) or at least 220 bar (2.20 × 10 7 Pa) or at least 240 bar (2.40 × 10 7 Pa) or at least 250 bar (2.50 × 10 7 Pa), at least 270 bar (2.70 × 10 7 Pa), or 290 bar (2.90 x 10 7 Pa), or 310 bar (3.10 x 10 7 Pa) or 330 bar (3.30 x 10 7 21. The method of any one of embodiments 18 to 20, wherein the method is operated at a pressure of 1000 Pa.

[0044] Embodiment 22. 22. The method of any one of claims 18-21, comprising heating the gases emitted from the fluid product stream in the boiler system to a temperature of at least 850°C for at least 2 seconds, thereby destroying halogenated organic compounds including any one or more of chlorinated dioxins, chlorinated furans, chlorinated biphenyls, and other dioxin-like compounds of environmental concern.

[0045] Embodiment 23. The treating may include contacting the reaction mixture with a supplemental metal catalyst in addition to any metal surfaces that are in contact with the reaction mixture during the producing or treating, the supplemental metal catalyst comprising: a solid material component mixed into the reaction mixture to promote contact between the fluid and the supplemental metal catalyst; and / or Ingredients of any of the above mixing devices 23. The method of any one of embodiments 1 to 22, wherein

[0046] Embodiment 24. 24. The method of embodiment 23, wherein the supplemental metal catalyst is a solid transition metal catalyst.

[0047] Embodiment 25. 25. The method of embodiment 23 or embodiment 24, wherein the supplemental metal catalyst is a solid transition metal catalyst and the oxidation state of the transition metal is initially a formal valence zero oxidation state.

[0048] Embodiment 26. 26. The method of embodiment 25, wherein the zero valent metal is selected from either zero valent iron and nickel.

[0049] Embodiment 27. 27. The method of any one of embodiments 23 to 26, wherein the supplemental metal catalyst catalyzes the transfer of hydrogen atoms from the aqueous solvent to the hydrocarbon products resulting from the processing of the polymeric material.

[0050] Embodiment 28. further comprising removing solid materials from the reaction mixture during said treating; the solid material is an inorganic material present within the polymeric material; the solid material has a density greater than the fluid in the reaction mixture and separates from the reaction mixture by gravity during the processing; and performing said treatment by blowing down into a receiving vessel during said treatment by means of a remotely operated valve to remove said solid material from the reactor; 28. The method of any one of embodiments 1 to 27.

[0051] Embodiment 29. the inorganic material is a filler or contaminant present in the polymeric material prior to performing the method; and / or the inorganic material reacted with the aqueous solvent and / or carbon-rich material produced in small amounts by side reactions during the treatment; 29. The method of embodiment 28.

[0052] Embodiment 30. 30. The method of embodiment 28 or embodiment 29, wherein the solid material is blown down into the receiving vessel along with a portion of the hydrocarbon product, wax, high molecular oligomers, or partially depolymerized material.

[0053] Embodiment 31. the method, a system for testing the pressure level in the valve adjustment and vacuum tank in the reactor; a system for cooling the material blown down into the reactor receiving vessel; a final collection pot with a removable lid for the blown down material connected to its lid and interconnecting pipes and valves to prevent accidental release of said pot and its contents; venting to release gases generated during or after said treatment; providing an inert atmosphere comprising nitrogen, argon, carbon dioxide and / or other inert gas to prevent ignition and combustion of materials contained within said drop pot and collection pot; a sequencing system for minimizing mechanical shock in the reactor; 31. The method of any one of embodiments 1 to 30, carried out in a reactor comprising any one or more of:

[0054] Embodiment 32. indirectly heating the reaction mixture to the reaction temperature using one or more heat exchangers; the one or more heat exchangers do not include an expansion bellows assembly; and the one or more heat exchangers comprise a dual heating probe type assembly comprising a steam pipe and / or a steam pipe within an electric heating element used to indirectly heat the steam and / or reaction mixture; 32. The method of any one of embodiments 1 to 31.

[0055] Embodiment 33. 11. The method of claim 10, comprising utilizing a superheated furnace to heat the steam prior to injecting the steam into the flash vessel.

[0056] Embodiment 34. 34. The method of any one of the preceding embodiments, wherein the reaction temperature is at least 380°C, at least 400°C, at least 450°C, or at least 500°C.

[0057] Embodiment 35. The hydrocarbon product comprises a naphtha component boiling at an AEBP of 10°C to 210°C, the naphtha component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10%, 20%, 30%, and 40% by mass of aromatic compounds 35. The method of any one of embodiments 1 to 34, comprising:

[0058] Embodiment 36. The hydrocarbon product comprises a gas oil component boiling at an AEBP of 210°C to 360°C, the gas oil component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10%, 20%, 30%, and 40% by mass of aromatic compounds 36. The method of any one of embodiments 1 to 35, comprising:

[0059] Embodiment 37. The hydrocarbon product comprises a heavy gas oil component boiling at an AEBP of 360°C to 550°C, the heavy gas oil component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10%, 20%, 30%, and 40% by mass of aromatic compounds 37. The method of any one of embodiments 1 to 36, comprising:

[0060] Embodiment 38. the polymeric material used to form the reaction mixture is a molten polymeric material extrudate; diverting the polymeric material extrudate to a collection vessel prior to forming the reaction mixture; the collection vessel is provided with an inert atmosphere to avoid combustion of the molten polymeric extrudate; and connecting the collection tank with the reactor by one or more lines, providing double valve isolation on each line to prevent backflow of the molten polymeric material extrudate from the reactor; 38. The method of any one of embodiments 1 to 37.

[0061] Embodiment 39. 16. The method of claim 14 or 15, wherein the temperature measurement system provides a warning of backflow from the mixing equipment towards an extrusion device connected to the mixing equipment, allowing operation of an isolation valve, thereby preventing backflow from the mixing equipment.

[0062] Embodiment 40. 40. The method of any one of embodiments 1 to 39, wherein the reactor is a continuous flow reactor.

[0063] Embodiment 41. 41. The method of any one of the preceding embodiments, wherein the treating is carried out under continuous flow conditions.

[0064] Embodiment 42. 42. The method of any one of the preceding claims, wherein the polymeric material does not include any one or more of: lignocellulosic materials, natural carbohydrate polymers; lignin; cellulose; hemicellulose; a combination of any two of lignin, cellulose, and hemicellulose; lignite (brown coal); subbituminous coal; or any combination thereof.

[0065] Embodiment 43. 1. A continuous flow reactor for processing polymeric materials, comprising: an extruder for producing an extrudate comprising a molten stream of said polymeric material; a boiler system for producing and adding supercritical water to the extrudate; a mechanical mixing device configured to mix the extrudate with the supercritical water, thereby forming a reaction mixture; a reaction zone in communication with said mechanical mixing device and indirect heater, said reaction zone for processing said reaction mixture at a specified temperature and pressure for a specified residence time, thereby producing a fluid product stream; a pressure reduction device for reducing the pressure of the fluid product stream, the pressure reduction device being in communication with the reaction zone and the flash tank; a fractionation device for separating vapor produced in the flash vessel; A continuous flow reactor comprising:

[0066] Embodiment 44. 44. A continuous flow reactor according to embodiment 43, wherein the indirect heater is not circumferential.

[0067] Embodiment 45. the flash vessel is in direct communication with the fractionation unit; or the flash vessel is an integral part of the flash tower; or The flash vessel and the fractionator are separate product coolers. 45. The continuous flow reactor of embodiment 43 or embodiment 44.

[0068] Embodiment 46. 46. ​​The continuous flow reactor of any one of embodiments 43-45, wherein the mechanical mixing device is a static mechanical mixing device.

[0069] Embodiment 47. 47. The continuous flow reactor of any one of embodiments 43-46, comprising a series of nozzles spanning the periphery of the mechanical mixing device or portion thereof for injecting and distributing the supercritical water into the molten stream of polymeric material.

[0070] Embodiment 48. 48. The continuous flow reactor of any one of embodiments 43-47, wherein the boiler system comprises a burner in communication with the fractionator (e.g., a vessel in the fractionator) for receiving gas.

[0071] Embodiment 49. 49. The continuous flow reactor of any one of embodiments 43-48, wherein the boiler system comprises a burner in communication with a natural gas source.

[0072] Embodiment 50. 50. The continuous flow reactor of any one of embodiments 43-49, wherein one or more components of the reaction zone comprise a source of metal catalyst for the reaction mixture.

[0073] Embodiment 51. 51. The continuous flow reactor of embodiment 50, wherein the metal catalyst is a solid transition metal catalyst.

[0074] Embodiment 52. connecting a collection vessel with the reactor by one or more lines, the collection vessel configured to collect the molten polymeric extrudate prior to forming the reaction mixture; the one or more lines providing double valve isolation on each line to prevent backflow from the reactor; the collection vessel is provided with an inert atmosphere to avoid combustion of the extrudate; 52. The continuous flow reactor according to any one of embodiments 43 to 51.

[0075] Embodiment 53. 53. The continuous flow reactor of any one of embodiments 43 to 52, comprising a blowdown component for removing solid material from the reaction mixture, and a receiving vessel for said solid material.

[0076] Embodiment 54. 54. The continuous flow reactor of any one of embodiments 43 to 53, comprising means for separating solid residues and / or bottoms produced during the pretreatment of the polymeric material and / or the treatment of the reaction mixture, and means for mixing the solid residues and / or bottoms with the fluid product stream in the flash tank, thereby vaporizing volatile components of the solid residues and / or bottoms.

[0077] Embodiment 55. a heat exchanger for indirectly heating the reaction mixture to the predetermined temperature at a plurality of points along the reactor vessel containing the reaction zone through which the reaction mixture flows; and a means for supplying supercritical steam generated by a supercritical steam generator to the heat exchanger. 55. The continuous flow reactor of any one of embodiments 43 to 54.

[0078] definition As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, the term "catalyst" also refers to a plurality of catalysts.

[0079] As used herein, the term "comprising" means "including." Variations of the word "comprising," such as "comprise" and "comprises," have corresponding modified meanings. Thus, for example, a solvent that "comprising" water may consist exclusively of water, or may include one or more additional components (e.g., alcohol).

[0080] As used herein, the terms "polymer" and "polymeric material" will be understood to include prepolymers, oligomers, homopolymers (e.g., made from a single monomer species), copolymers (e.g., made from at least two monomer species), terpolymers, graft polymers, plastics, elastomeric materials, rubber materials, and mixtures thereof. In some embodiments, the polymeric material is synthetically produced. In some embodiments, the polymeric material may be a natural material having a carbon-carbon backbone, such as natural rubber and its derivatives. As used herein, the terms "polymer" and "polymeric material" will be understood to specifically exclude lignocellulosic materials; natural carbohydrate polymers; lignin; cellulose; hemicellulose; a combination of any two of lignin, cellulose, or hemicellulose; lignite (brown coal); subbituminous coal; or any combination thereof.

[0081] As used herein, the term "continuous flow" refers to a mixture containing raw materials (and, for example, any one or more of an aqueous solvent, a reagent, a catalyst additive, and / or an oil additive): (a) heating and pressurizing to a target temperature and pressure; (b) treatment at a target temperature and pressure for a specified time ("residence time"); and (c) Cooling and decompression Attached to "Continuous flow" as intended herein is defined by the start point of heating (i.e., (a) above) and the end point of cooling and depressurization (i.e., (c) above). Continuous flow as intended herein implies no particular limitations regarding the flow rate or phase behavior of the mixture, provided that it is maintained in a continuous flow.

[0082] As used herein, "end of life plastic" or "waste plastic" will be understood to mean plastic material that contains at least some proportion of non-plastic contaminants, such as, for example, at least 0.1%, at least 0.5%, at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40% non-plastic material. Non-limiting examples of such contaminants include dirt, paper, wood, food waste, soil, agricultural residues, metals, perishable materials, mineral matter, cardboard, plant and animal matter, textiles or textile fibers.

[0083] As used herein, a "supercritical" substance (eg, a supercritical solvent) refers to a substance that exists at a temperature and pressure above the substance's critical point.

[0084] As used herein, a "subcritical" substance (e.g., a subcritical solvent) refers to a substance at a temperature and / or pressure below the substance's critical point. Thus, a substance can be "subcritical" at a temperature below its critical point and a pressure above its critical point, at a temperature above its critical point and a pressure below its critical point, or at a temperature and pressure below its critical point.

[0085] As used herein, the term "aqueous solvent" refers to a solvent that contains at least 1% water based on the total weight of the solvent. Thus, an "aqueous solvent" can contain 1% to 100% water based on the total weight of the solvent. "Aqueous solvent" will also be understood to include within its scope "aqueous alcohol," "aqueous ethanol," and "aqueous methanol."

[0086] As used herein, the term "endogenous catalyst" will be understood to be a catalyst that is inherently present in the reaction mixture treated by the process of the present invention and / or one or more other components of the materials secondary to the process (including mixers, vessel walls of the reactor in which the process is carried out), and / or a catalyst that is generated in situ during the performance of the process.

[0087] As used herein, a "supplemental catalyst" is a catalyst contained in a feed stream, solvent stream, and / or reaction mixture that supplements the catalyst compound, other reaction mixture components that are endogenously present (i.e., supplements the "endogenous catalyst"), and is separately added to or contacted with the reaction mixture as a separate / independent component. The supplemental catalyst may be in the form of a fixed, solid catalyst located within the equipment that contacts the reaction mixture.

[0088] As used herein, the terms "reactor" and "reactor equipment" are used interchangeably and have the same meaning. Each term encompasses any equipment suitable for carrying out the process of the present invention, including, for example, continuous flow reactors and batch reactors. As used herein, the term "about" when used in reference to a stated numerical value includes the stated numerical value and numerical values ​​within ±10% of the stated value.

[0089] As used herein, the term "between" when used in reference to a range of numerical values ​​includes the numerical values ​​at each of the endpoints of the range.

[0090] The mention of any prior art document in this specification, or any statement in this specification derived from or based on such document, is not an admission that the document or the statement from which it is derived is part of the common general knowledge in the relevant art. [Brief explanation of the drawings]

[0091] For purposes of description, all documents referenced herein are incorporated by reference in their entirety unless otherwise indicated.

[0092] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1-1] 1 is a process flow diagram of an apparatus according to an embodiment of the present invention. [Figure 1-2] 1 is a process flow diagram of an apparatus according to an embodiment of the present invention. [Figure 2] 1 illustrates an indirect heater design according to an embodiment of the present invention. [Figure 3] 1 is a process flow diagram showing an assembly for removing solid material from a pressurized reactor. [Figure 4] 1 is a process flow diagram showing a cooler step leading to a flash vessel in accordance with an embodiment of the present invention. [Figure 5] 1 is a process flow diagram illustrating a flash tank coupled to a fractionation column in accordance with an embodiment of the present invention. [Figure 6] 1 shows a process flow diagram illustrating a fractionation column and a flash tank with an additional vacuum distillation unit according to an embodiment of the present invention. [Figure 7] 1 illustrates a demister device according to an embodiment of the present invention. [Figure 8] 1 illustrates a boiler and indirect heater configuration according to an embodiment of the present invention. [Figure 9] 1 shows a naphtha product (top layer, yellow) according to an embodiment of the present invention easily separating from the aqueous solvent (bottom layer). [Figure 10] 1 is a graph illustrating a simulated product boiling point distribution of products resulting from a complete temperature flash combined with a fractionation tower. [Figure 11] 1 is a further graph illustrating a simulated product boiling point distribution of products resulting from a complete temperature flash combined with a fractionation tower. [Figure 12] 1 is a further graph illustrating a simulated product boiling point distribution of products resulting from a complete temperature flash combined with a fractionation tower. [Figure 13] 1 illustrates a pipe mixer design according to an embodiment of the present invention. [Figure 14] 1 illustrates a pipe mixer design with two static mixer elements according to an embodiment of the present invention. [Figure 15] 1 illustrates a pipe mixer design with four static mixer elements according to an embodiment of the present invention. [Figure 16] 1 illustrates a pipe mixer design according to an embodiment of the present invention showing bar locations. [Figure 17] 1 illustrates a pipe mixer design with two mixer elements according to an embodiment of the present invention. [Figure 18] 1 illustrates a pipe mixer design with four mixer elements according to an embodiment of the present invention. [Figure 19] 1 is a bar graph illustrating volume uniformity of volume fractions of molten plastic according to an embodiment of the present invention. [Figure 20] 1 illustrates a configuration for mixing supercritical water with a polymeric material according to an embodiment of the present invention without a mixer. [Figure 21] 1 illustrates a configuration for mixing supercritical water with a polymeric material according to an embodiment of the present invention, comprising two mixer elements. [Figure 22] 1 shows the temperature profile (downstream of the injection point) resulting from mixing supercritical water with a polymeric material according to an embodiment of the present invention with two mixer elements. [Figure 23] 1 is a process flow diagram of an apparatus according to an embodiment of the present invention. [Figure 24] 1 is a flow diagram of a depressurization and fractionation system according to an embodiment of the present invention. [Figure 25] 1 is a graph showing the results of thermogravimetric analysis (TGA) of a total synthetic crude oil sample under a nitrogen atmosphere. [Figure 26] 1 illustrates an assembly of parts for a pressure reduction / fractionation system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0093] The present invention provides a method and apparatus for converting a polymer or polymeric material into a product.

[0094] As a non-limiting example, a polymer or polymeric material may be passed through an extrusion apparatus, extruding the extrudate under elevated temperature and pressure into a mixing zone where the extrudate can be mixed with a supercritical aqueous solvent. Optionally, the mixture may be further heated and passed through one or more reactors equipped with a reaction zone having a residence time sufficient for depolymerization and other chemical reactions to occur. The resulting product stream mixture may then be rapidly depressurized, and the product at least partially vaporized into its constituent parts, for example, in a fractionation unit. At least a portion of the thermal energy initially retained in the product stream mixture and released by vaporization may be used to fractionate the mixture into fractions with different boiling ranges and / or to separate and recover the supercritical aqueous solvent from one or more products. Optionally, a portion of the fractionated material may be recycled for further fractionation. Optionally, a catalyst or reagent may be added at any step of the process. Optionally, a solid catalyst may be included in the apparatus, particularly in the reactor. Optionally, mixing equipment, particularly a static mixer, may be used, for example, after injection of the supercritical aqueous solvent. The solvent may also be involved in the chemical reaction that produces the product. The gases and uncondensed vapors produced in the chemical reaction are exothermic and can be burned, for example, in a purpose-designed boiler to provide heat energy for the process and / or to destroy chemicals that may be toxic and / or of environmental concern. Solid materials that are or become sparingly soluble in the reaction mixture can be separated from the reaction mixture by gravity during the process due to their higher density and can be removed from the process by a valve at the bottom of the equipment, if desired.

[0095] polymer material According to the method of the present invention, raw polymeric materials can be processed. The polymeric materials may include, for example, plastics. The polymeric materials may be unsuitable for physical recycling methods. The polymeric materials may currently only be suitable for landfill or incineration. The polymeric materials may be waste plastics (ELP). The polymeric materials (e.g., plastics) may be contaminated with non-plastic materials, including, but not limited to, one or more of food waste, soil, agricultural residues, metals, perishable materials, paper, cardboard, plant and animal matter, textiles or textile fibers.

[0096] Non-limiting examples of polymeric materials suitable for use in the methods and apparatus of the present invention include prepolymers, oligomers, homopolymers, copolymers, terpolymers, graft polymers, plastics, waste plastics, plastic waste, elastomeric materials, rubber materials, mixtures of which may be included in the feedstock and subjected to cracking in the reactor. Other non-limiting examples include polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polyester, polyethylene terephthalate (PET), polylactic acid (PLA), polyvinyl chloride (PVC), polystyrene (PS), polyamide, nylon, nylon 6, nylon 6,6, acrylonitrile-butadiene-styrene (ABS), polyethylene vinyl alcohol (E / VAL), polymelamine-formaldehyde (MF), polyphenol-formaldehyde (PF), epoxy resin, polyacetal (acetal resin), polyacrylate (acrylic resin), polyacrylonitrile (PAN), polyamide-imide (PAI), polyaryletherketone (PEAK), polybutadiene (PBD), polybutylene (PB), polycarbonate (PC), polydicyclopentadiene (PDCP), polyketone (PK), condensation polymer, polyetheretherketone (PEEK). Examples of such materials include polyetherimide (PEI), polyethersulfone (PES), chlorinated polyethylene (PEC), polyimide (PI), polymethylpentene (PMP), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyphthalamide (PTA), polysulfone (PSU), polyurethane (PU), polyvinylidene chloride (PVDC), polytetrafluoroethylene (PTFE), polyfluoroxyalkane (PFA), polysiloxane, silicone, thermoplastic resin, thermosetting polymer, natural rubber, tire rubber, ethylene propylene diene monomer rubber (EPDM), chloroprene rubber, acrylonitrile butadiene (nitrile) rubber, polyacrylate rubber, ethylene acrylic rubber, styrene butadiene rubber, polyester urethane rubber, polyether urethane rubber, fluorosilicone rubber, silicone rubber, and copolymers having a carbon-carbon skeleton, synthetic polymer materials, natural polymer materials, and mixtures thereof.

[0097] Without limitation, the polymeric material may include a low content of elements other than carbon, hydrogen, and oxygen. For example, the polymeric material may include, as a percentage of the total weight of the polymeric material, less than about 5% by weight nitrogen, less than about 1% by weight nitrogen, less than about 0.5% by weight nitrogen, less than about 0.1% by weight nitrogen, or less than about 0.01% by weight nitrogen.

[0098] Additionally or alternatively, the polymeric material may contain, as a percentage of the total polymeric material weight, less than about 5% total halogens, less than about 1% total halogens, less than about 0.5% total halogens, less than about 0.1% total halogens, less than about 0.05% total halogens, or less than about 0.01% total halogens.

[0099] Additionally or alternatively, the polymeric material may comprise a high hydrogen to carbon (H / C) molar ratio, for example, the H / C molar ratio may be greater than 2.15, greater than 2.0, greater than 1.8, greater than 1.6, greater than 14, greater than 1.2, greater than 1.0, or greater than 0.8.

[0100] In some embodiments, the polymeric material may be in the form of mixed or sorted waste plastics, which may in some cases be contaminated with organic and inorganic impurities. The plastic waste may require some pre-treatment before being treated by the method of the present invention. For example, the waste plastic may require sieving or screening to remove abrasive particles.

[0101] Without limiting the mode of action, the polymers treated by the method of the present invention may be cracked to liquids with low boiling and melting points, and / or these may act directly or indirectly as a source of hydrogen, which is incorporated into the product liquid.

[0102] As a non-limiting example, the reaction mixture processed by the methods of the present invention may comprise at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 98 wt% polymeric material (as a percentage of the total weight of the raw materials and / or reaction mixture).

[0103] By way of non-limiting example, the reaction mixture processed by the methods of the present invention may contain less than 98% by weight, less than 95% by weight, less than 90% by weight, less than 80% by weight, less than 70% by weight, less than 60% by weight, less than 50% by weight, less than 45% by weight, less than 40% by weight, less than 35% by weight, less than 30% by weight, less than 25% by weight, less than 20% by weight, less than 15% by weight, less than 10% by weight, less than 5% by weight, less than 4% by weight, less than 3% by weight, less than 2% by weight, or less than 1% by weight of polymeric material (as a percentage of the total weight of the raw materials and / or reaction mixture).

[0104] As a non-limiting example, the reaction mixture treated by the method of the present invention may have a solubility of about 2% by weight to about 70% by weight, about 2% by weight to about 60% by weight, about 2% by weight to about 50% by weight, about 2% by weight to about 40% by weight, about 2% by weight to about 30% by weight, about 5% by weight to about 70% by weight, about 5% by weight to about 60% by weight, about 5% by weight to about 50% by weight, about 5% by weight to about 40% by weight, about 5% by weight to about 30% by weight, about 10% by weight to about 20% by weight, about 20% by weight to about 30% by weight, about 20% by weight to about 40% by weight, about 20% by weight to about 50% by weight, about 20% by weight to about 60% by weight, about 5% by weight to about 50% by weight, about 5% by weight to about 40% by weight, about 5% by weight to about 30% by weight, about 10% by weight to about 20% by weight, about 20% by weight to about 30% by weight, about 20% by weight to about 30% by weight, about 20% by weight to about 4 ... It may comprise about 70% by weight, about 10% to about 60% by weight, about 10% to about 50% by weight, about 10% to about 40% by weight, about 10% to about 30% by weight, about 15% to about 70% by weight, about 15% to about 60% by weight, about 15% to about 50% by weight, about 15% to about 40% by weight, or about 15% to about 30% by weight of polymeric material (as a percentage of the total weight of the raw materials and / or reaction mixture).

[0105] In some embodiments, the raw polymeric material fed to the extruder and / or reaction mixture comprises, on a dry basis (db), at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% polyethylene by weight.

[0106] In some embodiments, the raw polymeric material fed to the extruder and / or reaction mixture comprises, on a dry basis (db), at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% polypropylene by weight.

[0107] In some embodiments, the raw polymeric material fed to the extruder and / or reaction mixture comprises, on a dry basis (db), at least 30%, at least 40%, at least 50%, 60%, at least 70%, at least 80%, or at least 90% polystyrene by weight.

[0108] As a non-limiting example, a polymeric material suitable for the method of the present invention may have a melt mass-flow rate (MFR) of 0.05 g / 10 min to 20 g / 10 min, or 0.1 g / 10 min to 10 g / 10 min, or 0.01 g / 10 min to 5 g / 10 min, as measured according to ISO 1133-1-2011 Plastics - Determination of Melt Mass-Flow Rate (MFR).

[0109] Solvent Components The reaction mixture for use in accordance with the method of the present invention may include a solvent, such as, for example, an aqueous solvent.

[0110] In some embodiments, the aqueous solvent comprises more than 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% water by weight as a percentage of the total weight of the reaction mixture, hi some embodiments, the aqueous solvent comprises less than 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% water by weight (as a percentage of the total weight of the reaction mixture).

[0111] In some embodiments, the water used in the aqueous solvent of the present invention may be recycled from the production of feedstocks containing polymeric material previously processed by the process. For example, some water present after processing of a given reaction mixture may be removed as a side stream and recycled to the process (as part or all of a separate stream of supercritical solvent contacted with the extruded polymeric material).

[0112] The solvent may comprise or consist of one or more aqueous alcohols. Non-limiting examples of suitable alcohols include methanol, ethanol, isopropyl alcohol, isobutyl alcohol, pentyl alcohol, hexanol, isohexanol, and any combination thereof. By way of non-limiting example only, the solvent may comprise, as a percentage of the total weight of the reaction mixture, more than 5%, more than 10%, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, or more than 95% alcohol by weight. In some embodiments, the solvent may comprise less than 10%, less than 20%, less than 30%, less than 40%, less than 50%, less than 60%, less than 70%, less than 80%, less than 90%, or less than 95% alcohol by weight (as a percentage of the total weight of the reaction mixture).

[0113] Pretreatment of polymer materials Optionally, but not necessarily, the polymeric material may be pretreated prior to containing the reaction mixture according to the present invention, including, but not limited to, prior to extrusion in an extruder, for example, to produce a material in a state that is readily extrudable, to remove contaminants, and / or to control the processing of a particular polymer.

[0114] Pretreatment of polymeric materials may include physical methods, non-limiting examples of which include grinding, pelletizing, granulating, flaking, pulverizing, crushing, milling (e.g., vibratory ball milling), compacting / expanding, agitating, density separation, washing, air classification, filtration, drying, and / or pulsed electric field (PEF) treatment. Polymeric materials may be pretreated using, for example, shredders, screens and / or sieves, magnetic and eddy current separators to remove metals, dry cleaning techniques, and / or optical, infrared, or ultraviolet induced sorting to remove, for example, polyvinyl chloride and other chlorinated or halogenated polymers and metals.

[0115] Pretreatment processes can be wet (i.e., involving washing with water or another solvent) or dry. Pretreatment can include air separators to remove glass, magnetic and eddy current separators to remove metals, dry or wet washing to remove food waste and paper, plastic drying using waste heat, and / or optical, infrared, or ultraviolet induced sorting to remove, for example, polyvinyl chloride and other chlorinated or halogenated polymers. Other types of polymeric materials that are unsuitable for certain embodiments of the present invention may also be removed by sorting techniques known in the art. Non-limiting examples of polymers that may be removed are polyethylene terephthalate (PET) and polyamide.

[0116] Additionally or alternatively, pretreatment of the polymeric material may include physicochemical methods, non-limiting examples of which include pyrolysis, steam explosion, ammonia fiber extrusion (AFEX), ammonia cycle percolation (ARP), and / or carbon dioxide explosion. For example, steam explosion involves exploding the polymeric material into high-pressure steam in a containing environment, followed by explosively venting the resulting product to atmospheric pressure. Pretreatments involving steam explosion may further include agitating the polymeric material.

[0117] Additionally or alternatively, pretreatment of the polymeric material may include chemical methods, non-limiting examples of which include ozonolysis, acid hydrolysis (e.g., dilute acid hydrolysis using H2SO4 and / or HCl), alkaline hydrolysis (e.g., dilute alkaline hydrolysis using sodium hydroxide, potassium hydroxide, calcium hydroxide and / or ammonium hydroxide), and / or oxidation treatments.

[0118] Polymer Extrusion The polymeric material processed by the method of the present invention may be subjected to extrusion before forming the main reaction mixture. The extrusion of the polymeric material may be carried out in a suitable extruder, non-limiting examples of which include single-screw extruders, multi-screw extruders (e.g., twin-screw extruders), intermeshing screw extruders, and roll-type extrusion presses. Multi-screw extruders may be counter-rotating or co-rotating. The extruder may be equipped with kneading disks and / or other screw elements for mixing or dispersing the melt.

[0119] Suitable extruders may typically be from about 1 meter to about 50 meters in length and may be specifically designed for processing waste plastics by shaping and increasing the pressure of the plastics, which may occur as either a single-screw extruder process or a multi-screw extruder process, with or without extruder venting.

[0120] By way of non-limiting example, the energy required by the extruder to heat the polymeric material can be supplied by friction and / or shear of the material in the extruder and / or by heating elements. The extruder may include one or multiple heating zones.

[0121] In the extruder, the polymeric material may be heated to a temperature sufficient to melt and flow the material. For example, the polymeric material may be heated to above 50°C, above 75°C, above 100°C, above 150°C, above 200°C, above 250°C, above 300°C, above 350°C, or above 400°C. Thus, in the extruder, the polymeric material may be heated to, for example, about 250°C to about 350°C, about 275°C to about 375°C, about 300°C to about 400°C, about 50°C to about 350°C, about 50°C to about 300°C, about 50°C to about 200°C, about 50°C to about 150°C, about 80°C to about 300°C, about 80°C to about 200°C, or about 80°C to about 150°C.

[0122] The residence time of the polymer raw material in the extruder may be, for example, from about 30 seconds to about 20 minutes, from about 2 minutes to about 6 minutes, or from about 3 minutes to about 5 minutes.

[0123] The extruder may be equipped with suitable feeding equipment (eg, hoppers, compactors, cutter compactors) for applying the polymeric material to the extruder.

[0124] Additionally or alternatively, the extruder may be equipped with a die to facilitate the generation of back pressure.

[0125] The molten stream of polymeric material may exit the extruder at a desired temperature and pressure. For example, the material stream exiting the extruder may be at a temperature of about 150° C. to about 400° C. and at a pressure of about 200 bar (2.00×10 7 Pa) ~ 350 bar (3.50 × 10 7 a pressure of about 250 bar (2.50 × 10 Pa); a temperature of about 250 °C to about 350 °C; 7 Pa) ~ 350 bar (3.50 × 10 7or a temperature of about 220°C to about 280°C and a pressure of about 200 bar (2.00 x 10 7 Pa) ~ 350 bar (3.50 × 10 7 The pressure may be 100 Pa.

[0126] Mixing polymeric materials with aqueous solvents According to the present invention, a polymeric material (e.g., an extrudate comprising or consisting of a polymeric material) may be mixed with a solvent (e.g., an aqueous solvent) to form a reaction mixture. The solvent may be heated and / or pressurized prior to contacting the polymeric material. The solvent may be heated and / or pressurized using any suitable means.

[0127] For example, the aqueous solvent used in the methods of the present invention can be in a subcritical or supercritical state prior to and during contact with the extruded polymeric material.

[0128] In some embodiments, the aqueous solvent is water or water vapor (eg, supercritical water, superheated steam, or subcritical water).

[0129] Contacting a supercritical aqueous solvent with an extruded polymeric material can cause the aqueous solvent to go from a supercritical phase to a subcritical phase (i.e., when the temperature and / or pressure of the solvent is below its critical point, it reaches a supercritical state). The phase change can cause energy release, which in turn can aid in better mixing of the aqueous solvent with the extruded polymeric material.

[0130] Alternatively, contacting the supercritical aqueous solvent with the extruded polymeric material may not cause the supercritical phase to become a subcritical phase in the aqueous solvent.

[0131] By way of non-limiting example only, the aqueous solvent may be supercritical (e.g., supercritical water) and may be at a temperature of about 375°C to about 800°C, about 375°C to about 600°C, about 375°C to about 550°C, about 375°C to about 500°C, or about 375°C to about 450°C during the time of contact with the extruded polymeric material.

[0132] Mixing an independently heated / pressurized solvent (e.g., an aqueous solvent such as water) with extruded polymeric material according to the methods of the present invention may provide a means to produce a reaction mixture containing a higher concentration of extruded polymeric material than can be achieved, for example, by (i) mixing an equivalent amount of polymeric material that has not been subjected to the aforementioned extrusion process with an equivalent amount of independently heated / pressurized aqueous solvent; and / or (ii) mixing an equivalent amount of polymeric material that has not been subjected to the aforementioned extrusion process with an equivalent amount of aqueous solvent and heating / pressurizing the mixture to the same level.

[0133] In some embodiments, a supercritical solvent, including, for example, an aqueous supercritical solvent such as water, may be applied to the polymeric extrudate at the point where it exits the extruder and / or at multiple injection points along the length of a vessel connecting the extruder to another device or component thereof, including, for example, a static mixing vessel or reaction zone of a reactor (e.g., a hydrothermal reactor, a continuous flow hydrothermal reactor). Such an arrangement may be used to facilitate further mixing of the polymeric extrudate and / or to maintain the extrudate at an elevated temperature.

[0134] mixture After initial contact of the extrudate with the aqueous solvent, mixing of the extrudate and aqueous solvent may be improved, if desired, by using static mixing equipment.

[0135] Thus, the methods described herein may: promote rapid heating of the polymeric material through intimate contact of the hot solvent, and / or reduce overall system pressure drop through improved flow characteristics, and / or provide wide channels that are not blocked by material passing through the extruder, and / or avoid high stresses in the pipe walls through nozzle design and solvent distribution system, and / or promote initiation of the depolymerization reaction through catalyst material selection. Additionally or alternatively, the installation may include slight heating to avoid solidification of the polymeric material.

[0136] Pressurization and heating A reaction mixture comprising a polymeric material according to the present invention (eg, an extrudate of a polymeric material) and a solvent (eg, an aqueous solvent such as water) may be heated and pressurized using means known in the art.

[0137] For example, pressurization in an apparatus according to the present invention may be caused by an extruder and / or pump used to pressurize the aqueous solvent before contacting it with the extruded polymeric material. In a continuous flow system, the pressure will generally change from atmospheric pressure to the target pressure in the time it takes to traverse the extruder and / or pump (i.e., nearly instantaneously).

[0138] In some embodiments, the reaction mixture may be brought to the target temperature and / or pressure in a time period ranging from about 30 seconds to about 30 minutes.

[0139] In some embodiments, the reaction mixture may be brought to the target temperature and / or pressure in less than about 15 minutes, less than about 10 minutes, less than about 5 minutes, or less than about 2 minutes.

[0140] In certain embodiments, the reaction mixture may be brought to the target pressure substantially instantaneously or over a period of about 30 seconds to about 30 minutes, and may be brought to the target temperature in less than about 20 minutes, less than about 10 minutes, or less than about 5 minutes, or less than 2 minutes.

[0141] In other embodiments, the reaction mixture can be brought to the target pressure substantially instantaneously and to the target temperature in less than about 2 minutes, hi other embodiments, the reaction mixture can be brought to the target pressure substantially instantaneously and to the target temperature in about 1 minute to about 2 minutes, or in less than 20 seconds.

[0142] In some embodiments of the present invention, the reaction mixture may be further heated using one or more indirect heaters, if desired, after mixing with a solvent (e.g., a supercritical aqueous solvent). The indirect heaters may, for example, increase the temperature of the reaction mixture by an additional 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 120°C, or by about an additional 150°C, 130°C, 110°C, 90°C, 70°C, 50°C. Indirect heating may increase the average temperature of the reaction mixture from about 380°C to about 450°C, or from about 400°C to about 460°C.

[0143] In some embodiments, the indirect heater is not circumferential.

[0144] In some embodiments, the indirect heater uses superheated steam or supercritical water from a process boiler to supply thermal energy to the reaction mixture. Figure 2 shows an example of such a heater design. Advantages of this design include, but are not limited to, that steam can be easily produced from combustion of process gases and that the incoming steam temperature can be easily controlled, thereby avoiding excessive metal temperature rise that would cause excessive carbonization of the plastic mixture. By using steam that is ultimately supplied to the process, the pressure drop across each heater element is minimal, and any inner tube leaks will result in small steam flows into the process.

[0145] In some embodiments, further indirect heating of the reaction mixture may be by electric heating elements, and / or fluid heat exchangers and / or fluidized beds of ilmenite heated, for example, by combustion of a heat content adjusting gas. In some embodiments, the heating elements are not circumferential. In some embodiments, such heat content adjusting gas may include process gases and steam generated by depolymerization of polymeric materials.

[0146] In some embodiments, the electric heating element is not circumferential.

[0147] Reaction parameters After the independently heated / pressurized aqueous solvent is mixed with the extruded polymeric material, the reaction mixture so produced can be further heated and / or pressurized, as needed, to achieve and / or maintain the desired temperature and / or pressure levels.

[0148] For example, the reaction mixture may be fed to a reactor (e.g., a hydrothermal reactor, a continuous flow hydrothermal reactor) in which the polymeric material is subjected to predetermined levels of temperature and pressure for a predetermined period of time to promote conversion to one or more hydrocarbon products having a lower average molecular weight than the polymeric material prior to conversion.

[0149] Thus, according to the methods of the present invention, a reaction mixture comprising an extruded polymeric material and an aqueous solvent may be processed at a target temperature (or within a target temperature range) and a target pressure (or within a target pressure range) for a specified time ("hold time" or "residence time") to produce a product.

[0150] The average residence time or retention time may be determined or measured or limited by the flow rate of the extrudate and / or the aqueous solvent.

[0151] The optimum reaction temperature and / or pressure for a given reaction mixture can be readily determined by one of ordinary skill in the art by setting up and running a series of reactions that vary only by analysis of the temperature and / or pressure utilized and the product yield and / or quality.

[0152] In certain embodiments, the aqueous solvent used in the methods of the present invention may be heated and pressurized above its critical temperature and / or above its critical pressure (i.e., above the "critical point" of the solvent) during processing in the reactor. Thus, the solvent may be a "supercritical" aqueous solvent when heated and pressurized above the "critical point" of the aqueous solvent.

[0153] In some embodiments, the aqueous solvent (e.g., water) in the reaction mixture comprising the extruded polymeric material to be treated by the methods of the present invention may be heated and pressurized to levels above its critical temperature and pressure (i.e., above the "critical point" of the aqueous solvent). Thus, the mixture may comprise a "supercritical" aqueous solvent when performing the method.

[0154] In other embodiments, the aqueous solvent (e.g., water or superheated steam) in the reaction mixture containing the extruded polymeric material to be treated by the methods of the present invention may be heated and pressurized to a level below its critical temperature and pressure (i.e., below the "critical point" of the aqueous solvent). Thus, the mixture may contain "subcritical" aqueous solvent when carrying out the method. For example, the "subcritical" solvent may be heated and pressurized to a level approaching the "critical point" of the solvent (e.g., about 10°C to about 50°C below the critical temperature and / or 10 bar (1.0 x 10) above its critical pressure). 6 Pa) ~ 50 bar (5.0 × 106 (low) heat and / or pressure may be applied.

[0155] In yet other embodiments, the aqueous solvent (e.g., water) in the reaction mixture comprising the extruded polymeric material to be treated by the methods of the present invention may be heated and pressurized to levels both above and below its critical temperature and pressure (i.e., heated and / or pressurized to levels both above and below the "critical point" of the solvent at different times). Thus, the aqueous solvent of the mixture may fluctuate between "subcritical" and "supercritical" states when carrying out the methods.

[0156] In certain embodiments, the reaction mixture comprising the extruded polymeric material, an aqueous solvent (e.g., water), and optionally one or more of: (i) a supplemental catalyst, and / or (ii) an oil (none of which is derived from the polymeric feedstock, the aqueous solvent, or the walls of the reactor where the processing is taking place, and none of which is a product generated in situ during the production and / or processing of the reaction mixture) is treated at a temperature above 370°C and 20 bar (2.0 x 10 6 pressures above 40 bar (4.0 × 10 Pa); temperatures above 370 °C and 6 pressures above 60 bar (6.0 × 10 Pa); temperatures above 370 °C and 6 pressures above 80 bar (8.0 × 10 Pa); temperatures above 370 °C and 6 pressures above 100 bar (1.00 × 10 7 pressures above 120 bar (1.20 × 10 Pa); temperatures above 370°C and 7 pressures above 140 bar (1.40 × 10 Pa); temperatures above 370°C and 7 pressures above 160 bar (1.60 × 10 7 pressures above 180 bar (1.80 × 10 7 pressures above 200 bar (2.00 × 10 7 pressures above 220 bar (2.20 × 10 7 pressures above 240 bar (2.40 × 10 7pressures above 260 bar (2.60 × 10 7 pressures above 280 bar (2.80 × 10 7 pressures above 300 bar (3.00 × 10 7 pressures above 370°C and 350 bar (3.50 x 10 7 pressures above 20 bar (2.0 × 10 Pa); temperatures above 400 °C and 6 pressures above 40 bar (4.0 × 10 Pa); temperatures above 400 °C and 6 pressures above 60 bar (6.0 × 10 Pa); temperatures above 400 °C and 6 pressures above 80 bar (8.0 × 10 Pa); temperatures above 400 °C and 6 pressures above 100 bar (1.00 × 10 Pa); temperatures above 400°C and 7 pressures above 120 bar (1.20 × 10 Pa); temperatures above 400°C and 7 pressures above 140 bar (1.40 × 10 Pa); temperatures above 400 °C and 7 pressures above 160 bar (1.60 × 10 Pa); temperatures above 400 °C and 7 pressures above 180 bar (1.80 × 10 Pa); temperatures above 400 °C and 7 pressures above 200 bar (2.00 × 10 Pa); temperatures above 400 °C and 7 pressures above 220 bar (2.20 × 10 7 pressures above 240 bar (2.40 × 10 7 pressures above 260 bar (2.60 × 10 7 pressures above 280 bar (2.80 × 10 7 pressures above 300 bar (3.00 × 10 Pa); temperatures above 400 °C and 7 pressures above 350 bar (3.50 × 10 7 pressures above 221 bar (2.21 x 10 Pa); temperatures above 374°C and 7 pressures above 225 bar (2.25 x 10 Pa); temperatures above 375°C and 7 pressures above 20 bar (2.0 × 10 Pa); temperatures between 370 °C and 550 °C;6 Pa) ~ 400 bar (4.00 × 10 7 374°C to 500°C and a pressure of 221 bar (2.21 x 10 7 Pa) ~ 400 bar (4.00 × 10 7 374°C to 550°C and a pressure of 221 bar (2.21 x 10 7 Pa) ~ 400 bar (4.00 × 10 7 375°C to 550°C and a pressure of 221 bar (2.21 x 10 7 Pa) ~ 400 bar (4.00 × 10 7 375°C to 550°C and a pressure of 221 bar (2.21 x 10 7 Pa) ~ 400 bar (4.00 × 10 7 The reaction may be carried out at a pressure of 100 Pa.

[0157] In certain embodiments, the process of the present invention involves processing a mixture comprising an extruded polymeric material and an aqueous solvent (e.g., water) at a temperature of 400°C to 550°C and 100 bar (1.00 x 10 7 Pa) ~ 300 bar (3.00 × 10 7 The reaction may be carried out at a pressure of 100 Pa.

[0158] In certain embodiments, the reaction mixture may be processed at temperatures between 370°C and 500°C, between 370°C and 480°C, between 374°C and 500°C, between 380°C and 500°C, between 380°C and 450°C, between 400°C and 480°C, between 440°C and 480°C; and at pressures of 100 bar (1.00 x 10 7 The temperature may be greater than 1000 Pa.

[0159] In some embodiments, the reaction mixture may be treated at a temperature greater than about 350° C., greater than about 360° C., greater than about 370° C., greater than about 380° C., greater than about 390° C., greater than about 400° C., greater than about 410° C., greater than about 420° C., greater than about 430° C., greater than about 440° C., greater than about 450° C., greater than about 460° C., greater than about 470° C., or greater than about 480° C. In some embodiments, the reaction mixture may be treated at any one of the temperatures mentioned in this paragraph and at a temperature greater than about 180 bar (1.80×107 Pa), approximately 200 bar (2.00 × 10 7 Pa), approximately 220 bar (2.20 × 10 7 Pa), approximately 240 bar (2.40 × 10 7 Pa), approximately 260 bar (2.60 × 10 7 Pa), approximately 280 bar (2.80 × 10 7 Pa), approximately 300 bar (3.00 × 10 7 Pa), or about 320 bar (3.20 x 10 7 The process is carried out at a pressure higher than 100 Pa.

[0160] In certain embodiments, the pH of the polymeric melt stream / extrudate, the supercritical aqueous solvent, and / or the reaction mixture may be maintained at a pH greater than 6, greater than 7, greater than 8, greater than 9, greater than 10, or greater than 11, for example, by the addition of a base. This may serve to minimize acid-catalyzed isomerization and / or hydration reactions of alkanes, particularly 1-alkanes, during the process. The pH may be measured after depressurization of the product stream. The pH may be measured after cooling the product stream to a temperature less than 100° C.

[0161] retention time The particular time (i.e., "retention time") for which the reaction mixture of the present invention, including polymeric material (e.g., polymeric material extrudate) and solvent (e.g., aqueous solvent), may be processed at a target temperature and pressure to obtain a product can depend on a number of different factors, including, for example, the type of polymeric material being processed and the relative proportions or types of components in the reaction mixture (e.g., aqueous solvent, additive catalyst, and / or other additive components), and / or the type of equipment in which the process is carried out. These and other factors may be varied to optimize a given process to maximize the yield of a particular product and / or reduce processing time. Preferably, the retention time is sufficient to convert substantially all of the polymeric material used as feedstock into hydrocarbon products.

[0162] In certain embodiments, the hold time is less than about 60 minutes, 45 minutes, 30 minutes, 25 minutes, 20 minutes, 15 minutes, 10 minutes, or less than about 5 minutes. In certain embodiments, the hold time is greater than about 60 minutes, 45 minutes, 30 minutes, 25 minutes, 20 minutes, 15 minutes, 10 minutes, or greater than about 5 minutes. In other embodiments, the hold time is from about 1 minute to about 60 minutes. In further implementations, the hold time is from about 5 minutes to about 45 minutes, from about 5 minutes to about 35 minutes, from about 10 minutes to about 35 minutes, or from about 15 minutes to about 30 minutes. In further embodiments, the hold time is from about 20 minutes to about 30 minutes.

[0163] The optimal hold time for a given set of reaction conditions described herein can be readily determined by one of skill in the art by preparing and running a series of reactions that differ only by the hold time and analyzing the yield and / or quality of the improved product produced.

[0164] The average residence time or retention time may be determined or measured or limited by the flow rate of the extrudate and / or the aqueous solvent.

[0165] In some embodiments, the retention time in the reactor, calculated using the density of an ideal mixture of water and oil derived from the polymeric material at the reaction temperature and assuming plug flow of fluid, is about 30 seconds, about 1 minute, about 2 minutes, about 5 minutes, between 5 and 10 minutes, between 10 and 20 minutes, between 20 and 30 minutes, between 30 and 40 minutes, more than 40 minutes, or less than about 60 minutes.

[0166] Solids Removal One non-limiting advantage of the present invention is that it can provide a means for removing materials from a process stream that are solid at reaction temperatures and pressures. Without limitation, the solids can be minerals contained within the polymeric raw material, such as fillers, rheology modifiers, and the like. The solids can be ash. The solids can be contaminants in the raw material, such as glass, pebbles, metal particles, or metal flakes. The solids can be carbon-containing materials produced during chemical reactions in the process. Solids generally have a higher density than the process fluid at reaction temperatures and pressures, and (in vertical reactors) solid particles will settle under gravity, under conditions where the particle settling velocity is greater than the fluid velocity.

[0167] As a non-limiting example, the inventors have found that 2700 kg / m 3 A material with a density of 0.1 g (e.g., calcium carbonate) and a particle size greater than about 20 microns will have a melting point of about 450°C and about 200 bar (2.00 x 10 7 Pa) using the process described herein and with about 60 wt. % polyolefin plastic feedstock containing about 40 wt. % water, has a settling velocity of about 2.5 mm / sec.

[0168] The upward flow velocity of the reaction fluid may range, for example, from 1 to 1000 mm / sec in a vertical reactor tube fed from the bottom. For diameters greater than about 10, or 20, or 50 microns, the upward flow velocity of the reaction fluid may be about 1000 kg / m 3 Higher density particles are expected to settle in a vertical reactor under the conditions of the process, depending on the upflow velocity and the nature of the flow regime (e.g., turbulent or laminar conditions). Solid particles settling in the lower part of the (vertical) reactor may be discharged from the bottom of the reactor by short-term operation of a blowdown valve at the bottom of the vessel, which may be periodic or intermittent, as required, in a controlled manner.

[0169] A simplified diagram illustrating one non-limiting example of the operation of a solids removal system is shown in Figure 3. In the scheme shown in Figure 3, the system design discharges a defined volume into a sealed, pressurized catch pot to prevent reactor depressurization and provide a means of quantifying the amount to be removed. The sealed pot is then depressurized to a vent system and then empties into an inert gas-inerted final pot for further processing. The objective is to prevent the hydrocarbon oil associated with the removed solids from igniting, for example, if it is above its autoignition temperature in air. For example, the final pot may be a metal skip with a lid. An interlock on the catch pot may be designed to test the integrity of the valve as part of the sequence. The catch pot will only flow into the final pot if it is depressurized. In some embodiments of such a design, all drains have double isolation, which may be achieved by having isolation valves on the pipes at the bottom of each reactor, plus a common isolation valve before the catch pot and the final pot. In normal operation, the reactor contents will be above the autoignition temperature of the product oil. Additionally, significant amounts of vapors may be released - design downstream systems to mitigate applicable risks. Without this method of removing solids, downstream equipment equipped with pressure reducing valves can rapidly foul, requiring cleaning operations at a frequency that makes plant operation uneconomical. Optionally, the solids removed in this manner may be mixed with residues from product fractionation and used as a blendstock or additive for bitumen and asphalt. Optionally, the solids removed in this manner may be further purified to recover metals by means known in the art.

[0170] Decompression and fractional distillation According to an embodiment of the present invention, the reaction mixture may be converted to a product stream that can be depressurized by means of flash depressurization at the reaction temperature. Flash depressurization may constitute a form of heat recovery, for example, a distillation column directly connected to the flash depressurization unit may be used to fractionate the product into at least two different boiling ranges using the heat energy released during depressurization. Otherwise, the fractionation process would require subsequent heating of the product stream under vacuum, for example in a vacuum distillation unit, which would require energy input.

[0171] In certain embodiments, the reaction mixture is heated to a temperature of at least 350° C., 375° C., 400° C., 410° C., 420° C., 430° C., 440° C., 450° C., or at least 460° C. and 200 bar (2.00×10 7 Pa), 220 bar (2.20 × 10 7 Pa), 240 bar (2.40 × 10 7 Pa), 260 bar (2.60 × 10 7 Pa), 280 bar (2.80 × 10 7 Pa), 300 bar (3.00 × 10 7 Absolute pressure of 25 bar (2.5 × 10 6 Pa), less than 20 bar (2.0 × 10 6 Pa), 15 bar (1.5 × 10 6 Pa), 10 bar (1.0 × 10 6 Pa), 8 bar (8 × 10 5 Pa), 6 bar (6 × 10 5 Pa), 4 bar (4 × 10 5 Pa), 2 bar (2 × 10 5 Pa), 1.5 bar (1.5 × 10 5 Pa), 1.2 bar (1.2 × 10 5 The pressure may be flash reduced to an absolute pressure of 1000 Pa.

[0172] In certain embodiments, the flush vacuum may be regulated using one or more valves.

[0173] In the present invention, the vacuum stream is directed to a vacuum-fractionation vessel or vessel that fractionates the stream into at least three boiling range fractions plus a gas and / or vapor stream, thereby using a portion of the energy in the process fluid to fractionate the product stream into product fractions, such as gas / vapor, naphtha, middle distillates or gas oil, heavy gas oil, heavy waxy residue.

[0174] In certain embodiments, the vacuum-fractionation unit may include a flash tank and two or more condensers in series, as illustrated in Figure 4. When two condensers are used, a first condenser may be used to cool the effluent boiling in the range of about 200°C to 400°C AEBP, or 450°C or 500°C AEBP, and a second condenser may be used to cool the effluent boiling in the range of about 20°C to 200°C AEBP, with the fraction boiling above about 400°C, 450°C, or 500°C AEBP being retained in the bottom of the flash tank and periodically or continuously discharged to a storage tank. Water may be separated from the output of the second condenser by decantation, where it becomes more concentrated and becomes miscible with the liquid product.

[0175] In certain embodiments, the vacuum-fractionation unit comprises a flash tank and a fractionation column in series, as illustrated in FIG. 5. In certain embodiments, a tank comprising a fractionation column can also function as a flash tank (i.e., the fractionation column is itself a flash tank). The fractionation column may be used to separate the product fraction into at least three boiling ranges. The boiling ranges may be, for example, about 20°C to about 200°C AEBP, about 200°C to about 360°C AEBP, about 360°C to about 400°C AEBP, about 360°C to about 450°C AEBP, or about 360°C to about 500°C AEBP. Gases and vapors not condensed by the primary cooler may be directed to a boiler and / or a flare for combustion. Water may be separated from the lowest boiling liquid fraction (e.g., the fraction boiling between about 20°C and about 200°C AEBP) or other liquid fractions using a separator. The separator may be, for example, a gravity plate separator, an API separator, or an electrostatic separator. Alternatively or additionally, the separator may be a high-gravity separator, such as a centrifuge, a decanter centrifuge, or a hydrocyclone. The fraction boiling above about 500° C. AEBP may be retained in the bottom of the flash tank and periodically or continuously discharged to a storage tank.

[0176] In certain embodiments, steam or superheated steam or supercritical water may further be introduced into the vacuum vessel to facilitate fractionation of the liquid product.

[0177] The heating / pressurizing and cooling / depressurizing and fractional distillation processes can be carried out in a continuous flow system (see below under the heading "Continuous Flow").

[0178] The fractionation column may include distillation trays for separating the condensed liquid products.

[0179] A fractionation tower may fractionate a product stream into different boiling ranges. As used herein, boiling point will be understood to mean atmospheric pressure equivalent boiling point (AEBP) unless otherwise specified. For example, a fractionation tower may separate a product stream by boiling range into a naphtha fraction boiling from about 70°C to about 210°C AEBP, a gas oil fraction boiling from about 210°C to about 360°C AEBP, and a heavy gas oil fraction boiling from about 360°C to about 400°C AEBP, about 360°C to about 450°C AEBP, or 360°C to about 500°C AEBP. The gas oil and heavy gas oil fractions may be wholly or partially waxy solids at 25°C. Gases and vapors not condensed in the tower may pass through a cooler that may condense the bottom-boiling oil (naphtha fraction). The naphtha fraction and other condensed fractions may be wholly or partially recycled to the fractionation tower. The gas and steam passing through the cooler may be directed to a boiler where the gas may be combusted, optionally with additional fuel gas such as natural gas, to produce the supercritical aqueous solvent. Combustion may recover energy from the gas and may destroy any compounds of environmental concern in the combustion process. Optionally, some or all of the gas and steam may be directed to a flare. The flare may be a closed flare.

[0180] In some embodiments, for example, the non-distillable portion of the product stream (heavy wax residue) having a boiling point >500°C may be continuously or intermittently removed from the bottom of a vacuum vessel (located at the bottom of the fractionation tower).

[0181] It will be apparent to those skilled in the art that the fractionation column may be operated in a known manner where it provides the desired boiling point range of the product fractions.

[0182] In some embodiments, the non-distilled residue from the flash tank and / or fractionator may be optionally distilled in a vacuum distillation unit to obtain a vacuum gas oil fraction and a heavy residue as shown in Figure 6. The boiling point range of the VGO fraction may be, for example, 360°C to 650°C AEBP.

[0183] In some embodiments of the present invention, the bottom of the flash tower can be a demister. Without limitation, the mixture entering the flash tower after being decompressed from a very high pressure to near atmospheric pressure can be primarily a gas phase containing droplets of high-boiling hydrocarbons, including aerosols. Therefore, the design of the bottom of the flash tower serves the function of a demister, separating the high-boiling hydrocarbon droplets from the gas mixture.

[0184] Upon entering the tower, the product gas stream is forced into a tight turn by a partition, and while the gas returns, the momentum of the droplets impacts the partition, causing them to coalesce and flow downward as a liquid to the bottom of the flash tower. A non-limiting example of an apparatus suitable for the process is shown in Figure 7.

[0185] The flash column bottom may have a diameter large enough to ensure very low upward velocities within that section of the column. The diameter at the column bottom may be selected so that the largest droplets carried by the vapor phase are about 50 microns in diameter, or about 40 microns in diameter, or about 30 microns in diameter, or about 20 microns in diameter, or about 10 microns in diameter, or about 5 microns in diameter. Droplets larger than approximately this diameter may not be transported upward and will fall into the liquid residue at the column bottom.

[0186] Combustion of process gases In some embodiments of the present invention, the gas products (including uncondensed vapors) of the processes described herein may be combusted to provide energy for the production of supercritical aqueous solvents, for example, in a supercritical fluid boiler. The supercritical fluid boiler may be specifically designed for the purpose of burning the process gases at temperatures that destroy the amounts of pollutants of environmental concern. Such pollutants may include, for example, sulfides, haloalkanes, haloaromatic hydrocarbons, haloalkenes, and / or polychlorinated dibenzo-p-dioxins.

[0187] It is known in the art and is mandated by environmental regulations in certain authorities (e.g., UK, EU, European Industrial Emissions Directive) that combustion gases must be held at temperatures above 850°C in the presence of excess oxygen for residence times greater than 2 seconds to ensure destruction of the above species.

[0188] In some embodiments of the present invention, process gases, in addition to air and recycled flue gas from the boiler exhaust, may be burned in a second chamber, e.g., an uncooled refractory-lined chamber, large enough to achieve a 2-second residence time with the flue gas at temperatures above 850°C. The refractory can isolate the boiler metals from the potentially severely corrosive environment of the redox atmosphere cycling near the burner flame. Cycling between oxidizing and reducing conditions is known in the art to increase chloride corrosion rates of steel. Using recycled flue gas can avoid overheating the chamber and minimize the production of nitrogen oxides (NOx emissions). This can also result in lower metal temperatures (and therefore lower corrosion rates) when the flue gas is presented to rows of boiler tubes. To achieve the required volume, the custom boiler design includes an uncooled horizontal refractory-lined section long enough to allow the burner flame to complete without impacting the boiler walls. This is followed by a larger, vertically arranged boiler section. Optionally or additionally, this system may be combined with a selective catalytic reduction system to control NOx, meaning the plant can achieve the stringent emissions limits applicable to gas-fired boilers.

[0189] A non-limiting example of a suitable boiler indirect heater configuration for combusting process gases and steam and / or natural gas or other heat content adjusting gases and providing thermal energy to the reaction mixture according to the method of the present invention is shown in FIG. 8. Here, the process gases and steam from the depolymerization of polymeric material, and optionally other heat content adjusting gases, are combusted using a burner. The hot combustion products are held in a refractory-lined chamber at a minimum temperature of 850°C for a minimum residence time of 2 seconds. The hot gases heat a pressurized aqueous solvent in tubes within a water-walled, refractory-lined box furnace, which slowly cools the process gases. This heats the aqueous solvent to a temperature above 374°C but below about 600°C, thereby generating a supercritical aqueous solvent stream. The supercritical aqueous solvent is fed to a mixer, mixed with the polymeric raw materials, and optionally, fed to one or more indirect heaters to further heat the reaction mixture. After the steam passes through the indirect heaters, the cool steam returns to the boiler for reheating. The steam passes through a convection heat transfer tube located in the second passage of the boiler, and hot gases from the boiler superheat the steam. Once reheated, the steam is reused in the next pair of indirect heaters before being reheated again. Multiple reheat phases can be used to obtain the heat transfer required for a four-phase polymer + aqueous solvent mixture, for example.

[0190] In some embodiments, the steam supply to the indirect heater is at a lower pressure, for example, 2 bar (2×10 5 Pa), 5 bar (5 × 10 5 Pa), 10 bar (1.0 × 10 6 Pa) or 20 bar (2.0 × 10 6 Pa), or 50 bar (5.0 x 10 6 Pa) or 100 bar (1.00 x 10 7 Pa), 221 bar (2.21 x 10 7 There may be a separate circuit supplying the supercritical aqueous solvent to the mixer at less than 450°C, at least 470°C, at least 500°C, less than 520°C, less than 550°C.

[0191] In some embodiments, the indirect heater is not circumferential.

[0192] Aqueous solvent separation The fractionation columns described herein can provide a means to separate the aqueous solvent from the product, which without fractionation may be difficult or impossible to separate.

[0193] Without limitation, the depolymerization product of plastic raw material may contain a significant wax fraction and / or have a high viscosity at ambient temperatures (e.g., 25°C). The aqueous solvent may become physically entrained in the waxy product; therefore, demulsifying chemicals combined with centrifugation or supplemental gravity decantation may be necessary to separate the aqueous solvent. One advantage of the present invention is that the aqueous solvent easily separates from the low-boiling (naphtha) product fraction after fractionation, as illustrated in Figure 9. The aqueous solvent is denser than the product fraction, is less soluble in the product fraction, and can be easily separated under normal gravity by means known in the art, such as decantation. A further advantage of the present invention is that the aqueous solvent so separated may contain low concentrations of suspended solids and metals, as well as soluble organic compounds. The total organic carbon (TOC) content, measured according to European Standard EN1484 method, can be less than 10,000 mg / L, less than 5000 mg / L, less than 2500 mg / L, less than 1000 mg / L, or less than 500 mg / L. The low organic content of the separated aqueous solvent means that the aqueous solvent can be easily processed for discharge into the environment. Without limitation, the aqueous solvent may be discharged into the environment or recycled as a solvent.

[0194] Continuous flow The process according to the invention is carried out under continuous flow conditions.

[0195] Conducting the process of the present invention under continuous flow conditions may provide several advantages. For example, continuous flow may accelerate operation and / or facilitate removal of heat and / or pressure applied to the reaction mixture. This may aid in achieving desired mass and heat transfer rates, heating / cooling and / or pressurization / depressurization. Continuous flow may also allow for tight control of residence time. Without being limited to a particular mode of operation, the increased rate of heating / cooling and / or pressurization / depressurization facilitated by continuous flow conditions, along with the ability to tightly control residence time, may help prevent undesirable side reactions (e.g., repolymerization, char formation) from occurring as the reaction mixture heats / pressurizes and / or cools / depressurizes. Continuous flow is believed to enhance reactions contributing to the conversion of polymeric materials to hydrocarbon products by generating mixing and shear forces believed to aid in emulsification.

[0196] Thus, the process of the present invention is carried out under continuous flow conditions. As used herein, the term "continuous flow" means: (i) maintaining a reaction mixture precursor (e.g., polymeric material to be extruded, aqueous solvent, and optionally catalyst and / or oil stream) in continuous motion flow into a reactor; (ii) maintaining the reaction mixture in continuous motion flow through the reactor; (iii) maintaining the product stream in continuous motion exiting the reactor; and Represents the method of

[0197] Thus, in a continuous flow system, the reaction mixture is maintained in a continuous flow of motion along the length (or partial length) of a given face of the reactor from the point where it enters the reactor to the point where it exits the reactor.

[0198] Continuous flow as intended herein includes the meaning of no particular limitation as to the flow rate of the reaction mixture provided that it is maintained in continuous motion.

[0199] Continuous flow conditions may be facilitated, for example, by carrying out the process of the present invention in a suitable reactor, which will generally be equipped with heating / cooling, pressure / vacuum, and reaction components to maintain a continuous flow of the reaction mixture.

[0200] The use of an appropriate flow rate (under continuous flow conditions) can be advantageous in preventing scale formation along the length of a particular surface (e.g., reactor vessel wall) from which the reaction mixture leaves and / or creating an effective mixing regime for efficient heat transfer to and within the reaction mixture.

[0201] Additional Reagents and Catalysts If desired, additional (ie, supplemental) reagents and / or catalysts may be added to the process.

[0202] In some embodiments, the supplemental reagents and / or catalysts may be solid at room temperature and may be mixed with the polymeric raw materials before the polymeric material enters the extruder. In some embodiments, the additives may be solid at room temperature and may be mixed with the polymeric raw materials before the polymeric material enters the extruder.

[0203] In some embodiments, the supplemental catalyst may be a solid calcium salt selected from calcium oxide, calcium hydroxide, calcium carbonate, calcium bicarbonate, hi some embodiments, the supplemental catalyst may be a solid base selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, lithium carbonate, magnesium oxide, magnesium hydroxide, barium oxide, and barium hydroxide.

[0204] Without limiting the mode of action, the additive may react with an organic halide or halogen-containing species, such as hydrogen chloride, to produce an inorganic halide, which may be removed as a solid by blowdown in a hydrothermal reactor.

[0205] Without limiting the mode of action, the additive may accelerate the decomposition of compounds such as terephthalic acid (TPA) and / or benzoic acid (BA) produced from the degradation or depolymerization of polyethylene terephthalate present in the polymeric raw material. TPA and BPA may be decomposed into other aromatic compounds, including, but not limited to, benzene, toluene, benzophenone, and benzaldehyde. The additive may be removed as a solid by blowdown, and the form of the additive may have been altered by chemical reaction prior to said removal.

[0206] In some embodiments, the supplemental reagent and / or catalyst may be added as a liquid (e.g., an aqueous solution). The liquid may be added using a high-pressure dosing pump or similar means. The liquid may be added at any step in the process before the depressurization step. The liquid may be added to the extruder between the extruder and the supercritical aqueous fluid addition point, after the supercritical aqueous fluid addition point but before any additional heating steps, if present, or before any of the reaction zones, or before the depressurization step.

[0207] In some embodiments of the present invention, a base may be included in the polymeric material melt stream / extrudate, the aqueous solvent stream, and / or the reaction mixture. There are no particular limitations on the type or form of base that may be used or the point in the process at which the base may be introduced. As a non-limiting example, the base may be introduced, for example, as a solid co-fed with the polymeric material into the extruder and / or as a liquid at any point after the extrusion step (e.g., directly into the extrudate / melt stream, the aqueous solvent stream, and / or the reaction mixture). In continuous or semi-continuous versions of the process of the present invention, at least some of the base may be added before the final reactor leg.

[0208] Non-limiting examples of bases suitable for this purpose are carbonates, hydroxides, bicarbonates, oxides of Group I and Group II metals and materials containing significant amounts thereof (e.g., black liquor, white liquor, green liquor, red mud, limestone, calcite).

[0209] The reaction mixture for use in accordance with the method of the present invention may include a catalyst that may enhance the production of the desired product.

[0210] The catalyst may be an "endogenous catalyst" derived from other components of the reaction mixture itself (e.g., from the polymeric material, aqueous solvent, other reaction mixture components), understood to be generated in situ during processing of the reaction mixture by the method of the present invention, and / or derived from the mixer materials and walls of the reactor processing the reaction mixture. For example, the catalyst may be hydronium ions / hydroxide ions of water in the reaction mixture, compounds in the polymeric material, and / or transition metals / noble metals from the reaction bed walls. The waste plastic polymer processed by the method of the present invention may contain contaminants with catalytic activity.

[0211] Additionally or alternatively, the catalyst may be a "supplemental catalyst" that is not derived from other components of the reaction mixture itself, is not generated in situ during treatment of the reaction mixture by the methods of the present invention, and is not derived from the construction or wall materials of the reactor in which the reaction mixture is treated. Rather, the supplemental catalyst is added separately to the reaction mixture as a separate / independent component, and thus in addition to the endogenous catalyst present in the reaction mixture.

[0212] Although the addition of a supplemental catalyst may be advantageous in certain circumstances, those skilled in the art will recognize that the process of the present invention may also be carried out without the use of a supplemental catalyst.

[0213] A supplemental catalyst as contemplated herein may be any catalyst that enhances the production of desired hydrocarbon products, such as fuels and chemicals, from polymeric feedstocks using the methods of the present invention, non-limiting examples of which include base catalysts, acid catalysts, alkali metal hydroxide catalysts, transition metal hydroxide catalysts, alkali metal formate catalysts, transition metal formate catalysts, reactive carboxylic acid catalysts, transition metal catalysts, sulfide catalysts, noble metal catalysts, water gas shift catalysts, metals supported on nitrogen-doped carbon materials, and combinations thereof.

[0214] Without being limited by theory, the supplemental base catalyst may serve multiple roles in terms of promoting product formation and controlling pH, may be beneficial for reducing corrosion rates on reactor metal components, and may promote the precipitation of halogens contained in the raw materials as metal halides that are insoluble or poorly soluble in supercritical water. Cooling and decompression allow the metal halides to redissolve in the aqueous phase. This practice is advantageous because halogens, especially chlorine, can be efficiently removed from the gas and / or oil phases. Chlorine is undesirable in the gas and oil phases because it ultimately produces dioxins and other environmental pollutants if incompletely combusted in subsequent processes.

[0215] In some embodiments, a supplemental catalyst known in the art to promote the water-gas shift (WGS) reaction may be included in the reaction mixture to promote the transfer of hydrogen from water to the oil product. Any WGS catalyst or hydrogen transfer catalyst known in the art may be utilized. Without limitation, the catalyst may be in the form of a finely dispersed solid added to the extruder feed. Additionally or alternatively, the catalyst may be in the form of a fixed bed. Additionally or alternatively, the catalyst may be homogeneous when present in the reaction stream (e.g., aqueous solvent, polymeric extrudate, and / or reaction mixture) under subcritical and / or supercritical conditions.

[0216] Without being bound by theory, the addition of a WGS and / or hydrogen transfer catalyst may increase the saturation of hydrocarbons in the product, which may be desirable because it may increase the cetane number of the middle distillates in the bookbinding product and also increase the proportion of n-paraffins in the wax fraction of the product, making the wax more useful due to its high purity and sharp, discrete melting point range.

[0217] solid metal catalyst In some embodiments of the present invention, a solid metal catalyst is contacted with the reaction stream.

[0218] In some embodiments, the solid metal catalyst is a fixed metal surface within the reaction image. The solid metal catalyst may be in any shape known in the art, such as, for example, a wire, a mesh, a foil, and a Raschig ring.

[0219] In some embodiments, the solid metal catalyst comprises nickel. In some embodiments, the nickel is in the Form 0 oxidation state. The nickel may be present as an alloy with other metals, for example, stainless steel 310 or 316.

[0220] Without being bound by theory, nickel may facilitate the transfer of hydrogen from the aqueous solvent to the depolymerized products of the polymeric feedstock.

[0221] Those skilled in the art will recognize that numerous variations and / or modifications can be made to the invention disclosed in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. [Example]

[0222] While this invention will be described with reference to specific examples, this should not be construed as limiting in any way.

[0223] Example 1 The behavior of flash depressurization coupled with a fractionation column was demonstrated as follows: Two broad types of post-consumer plastics were prepared for extrusion. Hard plastics from post-consumer collections known as PTT (pots, tubs, and trays, e.g., food containers, personal hygiene product containers, toys, laundry baskets, milk carton crates) were shredded or shredded to sizes of approximately 1-20 mm. Metals were removed by magnetic and eddy current separation. Plastics denser than water (e.g., PVC, PET) were largely removed by buoyancy in water. The shredded PTT plastics were dewatered by centrifugation and bagged in preparation for extrusion. Soft plastics known as film (e.g., LDPE disposable plastic bags, plastic sachets, food wrapping, etc.) were shredded. Metals were removed by magnetic and eddy current separation. Plastics denser than water (e.g., PVC, PET) were largely removed by buoyancy in water. The shredded film plastics were dewatered by centrifugation and compacted by agglomeration / granulation. If necessary, the agglomerates were extruded and passed through a screen filter to remove small pieces of, for example, aluminum foil, and the extrudate was then chopped into pellets. The film pellets / agglomerates were bagged ready for processing.

[0224] PTT and film materials were mixed in various ratios as listed in Table 1 and depolymerized in a continuous-flow reactor consisting of an extruder, a supercritical water injection zone, a series of heaters, three or four reactors, a cooler, a depressurization step, and one or more product tanks in series. The experimental conditions are listed in Table 1. The depolymerized product was a synthetic crude oil. Syncrude samples were dried in the laboratory to remove water, and their boiling point ranges were characterized by distillation simulation according to ASTM D7169 and vacuum distillation according to ASTM D1160. The distillation simulation results are listed in Tables 2–4. The crude distillation simulation curves were used to build a model of the flash distillation and fractionation behavior of synthetic crude oil at flash depressurization from the full reaction temperature and pressure into a fractionation column. Simulations were performed using AspenTech's HYSYS software. The resulting boiling point distributions of the four fractions are shown for the three modeled cases in Figures 10, 11, and 12. The modelling assumed a mass flow leaving the reactor and a 1.2 m diameter fractionation column of 3893 kg / hr.

[0225] [Table 1]

[0226] [Table 2]

[0227] [Table 3]

[0228] [Table 4]

[0229] Example 2 The results presented in this example demonstrate the importance of using a static mixer to obtain good mixing between the molten polymer extrudate and the supercritical aqueous solvent. This is important for obtaining good heat transfer from the supercritical aqueous solvent, which is hotter than the molten polymer, and also for intimately mixing the solvent and polymeric material, thereby allowing the solvent to influence the reaction pathway of the polymeric material during polymerization, including enabling hydrogen transfer from the solvent to the depolymerized product. The mixing profiles for two different scenarios (Iteration 1: Figures 13-15; Iteration 2: Figures 16-17) were investigated by computational fluid dynamics (CFD) modeling. The supercritical aqueous solvent was modeled as supercritical water (SCW) at 500°C. Other modeling parameters were as follows: -Molten plastic inlet: Mass flow rate: 2782 kg / h, temperature: 350°C -SCW Entrance: Mass flow rate across 4 inlets: 1762 kg / hr, temperature: 500°C -Pipe wall: Thermal insulation.

[0230] Tables 5, 6 and 7: Fluid properties used in modeling

[0231] [Table 5]

[0232] [Table 6]

[0233] [Table 7]

[0234] Iteration 1 (Figures 13-15) modeled a 6-inch (152 mm) diameter pipe with a radial 4-way 10 mm diameter SCW inlet in a single plane, and iterations were modeled with 0, 2, and 4 static mixer elements.

[0235] Iteration 2 (Figures 16-19) modeled a 6-inch (152 mm) pipe with a four-way 10 mm diameter SCW inlet on two sides 50 mm apart and a triangular bar just upstream of the SCW inlet, and iterations were modeled with 0, 2, and 4 static mixer elements.

[0236] The geometry of the static mixer element modeled as part of the assembly was a design provided by NOV, Process and Flow Technologies, Mixing Technologies, 5870 Poe Ave, Dayton, Ohio 45414.

[0237] Modeling findings showed that the static mixer enhanced the mixing of the SCW and the molten polymer. Mixing homogeneity at a distance of approximately 9 pipe diameters from the SCW injection point is shown in Figure 19. Mixing homogeneity also indicates better heat transfer from the SCW to the polymeric material.

[0238] The pressure drop induced by the static mixer elements is modeled to be approximately 2.5 bar (2.5 x 10) per element. 5 This pressure drop is approximately 4.5 bar (1.0 × 10 6 Pa)) and below are functionally easy to handle.

[0239] The performance of the mixer configuration is illustrated in the accompanying charts. First, Figure 20 shows that without a mixer, there is poor mixing of the supercritical water and polymeric material, resulting in two-phase flow over the length of the pipe.

[0240] Computational fluid dynamics modeling (CFD modeling) performed on various mixer designs showed the benefit of having a supercritical fluid distributor with a standard industrial mixer design, resulting in good mixing, as illustrated by the results shown in FIG. 21.

[0241] Good mixing is reflected in the temperature profile of the polymer material, which shows how the cold (blue) fluid is superheated and how the supercritical fluid (red) temperature is cooled to quickly reach the homogeneous mixing temperature (Figure 22).

[0242] Example 3 The results shown in this experiment indicate that the method of the present invention allows for easy separation of the depolymerization product, e.g., supercritical aqueous solvent, from demulsification chemicals without the need or facilitating gravity methods such as centrifuges / decanters.

[0243] The behavior of flash depressurization coupled with a fractionation column was demonstrated as follows: Two broad types of post-consumer plastics were prepared for extrusion. Hard plastics from post-consumer collections known as PTT (pots, tubs, and trays, e.g., food containers, personal hygiene product containers, toys, laundry baskets, milk carton crates) were shredded or shredded to sizes of approximately 1-20 mm. Metals were removed by magnetic and eddy current separation. Plastics denser than water (e.g., PVC, PET) were removed by buoyancy in water. The shredded PTT plastics were dewatered by centrifugation and bagged in preparation for extrusion. Soft plastics known as film (e.g., LDPE disposable plastic bags, plastic sachets, food wrapping, etc.) were shredded. Metals were removed by magnetic and eddy current separation. Plastics denser than water (e.g., PVC, PET) were removed by buoyancy in water. The shredded film plastics were dewatered by centrifugation and compacted by agglomeration / granulation. If necessary, the agglomerates were extruded and passed through a screen filter to remove small pieces of, for example, aluminum foil, and the extrudate was then chopped into pellets. The film pellets / agglomerates were bagged ready for processing.

[0244] The PTT and film material were mixed in a 3:1 ratio by mass and depolymerized in a continuous-flow reactor consisting of an extruder, a supercritical water injection zone, a series of heaters, three or four reactors, a cooler, a depressurization step, and one or more product tanks in series. The depolymerized product was a synthetic crude oil that was waxy in nature and contained approximately 30% of its mass as entrained water. Since no visible separation of oil and water was observed, the separated entrained water could not be physically separated from the waxy synthetic crude oil by simple means such as decantation at temperatures below 95°C.

[0245] The product fractionation process of the present invention was simulated by atmospheric distillation of a low-boiling fraction of synthetic crude oil. The low-boiling fraction of crude and water, or naphtha (boiling point approximately 40-210°C), from an aqueous solvent was co-distilled and concentrated together. Water and naphtha (Figure 9) spontaneously phase separated, had low mutual solubility, and could be easily separated at ambient temperature by means known in the art, such as decantation or by means of a simple valve outlet.

[0246] Analysis of the aqueous phase showed it to have a low organic and metal content, and as such could be easily recycled or treated for discharge or reuse.

[0247] [Table 8]

[0248] [Table 9]

[0249] [Table 10]

[0250] [Table 11]

[0251] [Table 12]

[0252] [Table 13]

[0253] By comparison, to remove aqueous solvent (water) from waxy synthetic crude oil at a level of approximately 1000 ppm, it was necessary to add a chemical emulsion beaker (SUEZ PROSOLV AI8565) and a centrifuge at high temperature (approximately 90°C).

[0254] Example 4 The chemical composition of the depolymerized products from post-consumer polymeric materials treated by the method of the present invention is detailed in Table 9 below.

[0255] [Table 14]

[0256] Example 5 The results shown in this example demonstrate the principle of blowdown of solid material from a reactor.

[0257] Two broad types of post-consumer plastics were prepared for extrusion. Hard plastics from post-consumer collections known as PTT (pots, tubs, and trays, e.g., food containers, personal hygiene product containers, toys, laundry baskets, milk carton crates) were shredded or shredded to sizes of approximately 1-20 mm. Metals were removed by magnetic and eddy-current separation. Plastics denser than water (e.g., PVC, PET) were removed by buoyancy in water. The shredded PTT plastic was dewatered by centrifugation and bagged in preparation for extrusion. Soft plastics known as film (e.g., LDPE disposable plastic bags, plastic sachets, food wrapping, etc.) were shredded. Metals were removed by magnetic and eddy-current separation. Plastics denser than water (e.g., PVC, PET) were removed by buoyancy in water. The shredded film plastic was dewatered by centrifugation and compressed by agglomeration / granulation. If necessary, the agglomerates were extruded and passed through a screen filter to remove small pieces of, for example, aluminum foil, and the extrudate was then chopped into pellets. The film pellets / agglomerates were bagged ready for processing.

[0258] PTT and film materials were mixed in various ratios and depolymerized in a continuous-flow reactor consisting of an extruder, a supercritical water injection zone, a series of heaters, three horizontally oriented reactor tubes in series, a cooler, a depressurization step, and one or more product tanks. Typical experimental conditions are shown in Table 10. The depolymerized product was synthetic crude oil.

[0259] [Table 15]

[0260] After the run, the horizontal tubular reactor was opened and inspected and found to contain residual solid material that had settled from the fluid phase during the course of the run and accumulated by gravity settling at the bottom of the reactor tube. The solid was analyzed and found to have the following composition, as shown in Table 11:

[0261] [Table 16]

[0262] Analysis showed that the solids were mostly inorganic ash, with a minor component of toluene-soluble heavy wax also present. Reactor Samples 1 and 2 in Table 11 correspond to Analysis Nos. 1 and 2 in Table 12.

[0263] [Table 17]

[0264] [Table 18]

[0265] Elemental analysis shows that the ash (Table 13) consists mostly of metals such as Si, Ti, Fe, Ca, Al, etc., which are commonly found in plastic formulations as fillers, additives, opacifiers, modifiers, etc., and demonstrates that these precipitated from the plastic during polymerization and became insoluble in the supercritical phase.

[0266] Example 6 The results presented in this experiment demonstrate the addition of flash vacuum from atmospheric to slightly elevated pressures at or within 50° C. of the full reaction temperature and pressure.

[0267] The experimental setup used is shown in Figure 23. Industrial waste and post-consumer plastics were prepared for extrusion, including off-spec condiment bottles (approximately 68%), paper pellets (approximately 20%), recycled PET (approximately 10%), and polyethylene from discarded neoprene wetsuits (approximately 2%). The mixed feedstock was depolymerized in a continuous-flow reactor in series consisting of an extruder, a supercritical water injection zone, a series of heaters, three or four reactors, a cooler, a depressurization step, and one or more product tanks. One product tank equipped with a reflux condenser was used as a flash tank. The product stream was passed through a capillary pipe to a temperature of approximately 420°C and approximately 240 bar (2.40 x 10 7The flash vessel was depressurized at a pressure of 1.1 bar (1.1 x 10 Pa). The capillary end was optionally immersed in the water initially present in the flash vessel and optionally cooled by an external water jacket surrounding the flash vessel. Optionally and / or alternatively, the capillary outlet was not immersed in water. The flash vessel outlet was at near atmospheric pressure (e.g., 1.1 bar absolute (1.1 x 10 5 Pa) or 1.2 (1.2 x 10 5 1 bar (1 x 10 Pa) 5 Pa), and the volatile products passed through a reflux condenser and then through a flare for combustion.

[0268] The product hydrocarbons were collected in the flash tank as a waxy synthetic crude product mixed with water. There was no precipitation of terephthalic acid or other insoluble materials from the hydrolysis of PET either on cooling or elsewhere in the vacuum / product collection system.

[0269] Example 7 In a feedstock composition similar to that of Example 6, but consisting of off-spec condiment bottles (approximately 80%) and recycled PET (approximately 20%), the end of the vacuum capillary was oriented vertically downward, a few centimeters above the surface of a small amount of water in the flash tank. In this case, precipitation of terephthalic acid and other PET hydrolysis products was detected at the top surface of the flash tank.

[0270] Example 8 Pellets of PET (20% by weight) were mixed with waste PE pellets (80% by weight). The mixture was fed into a single-screw extruder equipped with an electric heating element, and the polymer mixture was heated to approximately 240 bar (2.40 x 10°C) by the time it reached the extruder exit. 7 The extrudate was fed into a pressure mixing zone and heated to about 490°C and 240 bar (2.40 x 10 7The polymer mixture was mixed (contacted) with supercritical water at 1000 kJ / s (2000 kcal / s). The fluid mixture was then heated to a reaction temperature of 440-450°C using three trimmer heaters in series. The fluid then passed into three 30-liter 310 stainless steel tubular reactors arranged horizontally in series, with the reaction zone maintained at the reaction temperature by a gas-bleed box enclosure. During residence in the reaction zone, the polymer mixture depolymerized to produce an oil product. The mass flow rate of the polymer was 33 kg / h, the mass flow rate of the supercritical water was 27 kg / h, and the total mass flow rate was 60 kg / h, with a mass flow rate ratio of plastic to water of approximately 55:45.

[0271] Then, the high-temperature fluid was heated to 400°C to 440°C and 240 bar (2.40 × 10 7 The pressure was released to a first flash tank at a pressure slightly above atmospheric pressure (at 1000 kJ / sq. mbar) and the flash tank was connected to a second tank for collecting condensate. The temperature of the flash tank was monitored and initially rose to about 70°C, then to 21°C over the course of the experiment, which was about 165 minutes. The gas and vapor passing through the condensate tank were cooled and metered using a rotary volumetric flow meter. In this process, the product fluid leaving the reactor was fractionated into heavy, old, and waxy hydrocarbon oil fractions, which were retained in the flash tank; light hydrocarbon oil and water fractions, which had low viscosity and a density lower than water, which were retained in the condensate tank; and a gas-vapor fraction. The gas-vapor fraction was further passed to a second cooling / fractionation tank step, where a small amount (1.1 kg) of naphtha and water were cooled and separated. The composition of the gas / vapor passing through the second cooling step was analyzed offline by GC from a grab sample. The flash tank contained approximately 20 kg of water and 53.5 kg of heavy oil, and the condensate tank contained approximately 54 kg of water and 12.5 kg of light oil after the run. The light oil in the condensate tank separated easily from the gravity sewer. Approximately 11.1 kg of gas and condensate was estimated to have been produced over the corresponding period based on the estimated densities of the mixed gas and vapor compositions.

[0272] The vacuum and fractionation system used is illustrated diagrammatically in FIG.

[0273] Vacuum distillation of the heavy waxy oil held in the flash tank was carried out at approximately 10 torr (7.50 x 10 -2 The results showed an initial boiling point of 115°C at 100°C (at 100°F / Pa) or approximately 240°C AEBP, indicating that the naphtha boiling range portion of the product fractionated efficiently into the condensate tank. The thermogravimetric analysis (TGA) of the total synthetic crude (condensate and proportionally recombined flash tank heavy waxy oil sample) is shown in Figure 25 and is consistent with the distillation analysis of the heavy waxy oil.

[0274] The gas-vapor composition analysis is shown in Table 14.

[0275] [Table 19]

[0276] Example 9 Radiata pine wood was mixed with polypropylene pellets (PP) and the mixture was pelletized to produce mixed wood-PP pellets. The composition of the feed mixture was: 29% by weight dry basis wood flour, 2% by weight wood flour and associated water, and 69% by weight polypropylene dry basis. The mixture was fed into a single-screw extruder equipped with an electric heating element, and the mixture was heated to approximately 230-240 bar (2.30 x 10°C) by the time it exited the extruder. 7 Pa~2.40×10 7 The extrudate was fed into a pressure mixing zone and heated to about 440°C and 240 bar (2.40 x 10 7 The feed mixture was mixed (contacted) with supercritical water at a pressure of 1000 Pa. The fluid mixture thereby achieved a target reaction temperature of approximately 390-400°C. The fluid then passed into two horizontally arranged, 30-liter 310 stainless steel tubular reactors in series, with the reaction zone maintained at the reaction temperature by a gas-bleed box enclosure. During residence in the reaction zone, the feed mixture depolymerized to produce an oil product. The feed extrudate mass flow rate was 29-32 kg / hr, the supercritical water mass flow rate was 34 kg / hr, and the total mass flow rate was 63-66 kg / hr.

[0277] Then, the high-temperature fluid was heated to 380°C to 400°C and 240 bar (2.40 × 10 7 The pressure was released at 1000kJ / cm2 (Pa) to a first flash tank at a pressure slightly higher than atmospheric pressure. The flash tank was connected to a second tank for collecting condensate. The layout is partially shown in Figure 26. The first flash tank is labeled MBT. The gas and vapor passing through the condensate tank were cooled and metered using a rotary volumetric flow meter. In this method, the product fluid leaving the reactor was fractionated into heavy, old, and waxy hydrocarbon oil fractions, which were retained in the flash tank; light hydrocarbon oil and water, which have low viscosity and are less dense than water, which were retained in the condensate tank, and a gas-vapor fraction (labeled NCG in Figure 26). The gas-vapor fraction was further passed to a second cooling step to cool a small amount of naphtha and water. The composition of the gas / vapor passing through the second cooling step was analyzed by GC from a grab sample.

[0278] Example 10 Recycled polyethylene (PE) pellets were fed at 15 kg / h and at 275°C, 240-260 bar (2.40 x 10 7 Pa~2.60×10 7 The extrudate is extruded into a continuous flow hydrothermal reactor at a flow rate of 22.5 kg / hr and 420 co, 240-260 bar (2.40 x 10 Pa) in a mixing zone containing a spiral static mixer element to obtain good mixing of the SCW and molten PE. 7 Pa~2.60×10 7 The PE was depolymerized to synthetic crude oil during its residence in the reactor. The product stream was cooled to approximately 150°C and then depressurized to atmospheric pressure in a product tank. The product tank was fitted with a reflux condenser, and non-condensable gases and vapors passing through the condenser were analyzed offline by GC from grab samples.

[0279] Example 11 The waste plastic feedstock was processed according to the method described in Example 1. The composition of the feedstock and naphtha boiling range fraction of the resulting syncrude product is summarized in Table 15 below.

[0280] [Table 20]

Claims

1. 1. A method for processing a synthetic polymeric material to produce a hydrocarbon product, said method comprising: forming a reaction mixture comprising a synthetic polymeric material and an aqueous solvent; treating said reaction mixture in a reactor at a reaction temperature and pressure for a time suitable to convert all or a portion of said synthetic polymeric material present in said reaction mixture into a fluid product stream; wherein said fluid product stream has a temperature of at least 350°C and a pressure of at least 180 bar (1.80 x 10 ７ Pa); reducing the pressure of the fluid product stream in a flash vessel, thereby vaporizing at least a portion of the fluid product stream and producing a vapor comprising hydrocarbon product, water vapor, and gaseous constituents; injecting steam, superheated steam, or supercritical water into the flash vessel and transferring energy to the remainder of the fluid product stream within the flash vessel to generate additional vapor comprising hydrocarbon product, steam, and gas constituents; wherein the depressurizing comprises reducing the pressure of the fluid product stream to less than 25 bar in a flash vessel; The vaporizing provides energy to facilitate fractionation of the vapor into its constituent components; and collecting the fractionated vapor; A method comprising:

2. 10. The method of claim 1, wherein the fluid product stream is at a temperature of at least: 380°C, 400°C, 420°C, 450°C, or 470°C immediately prior to the pressure reduction.

3. The fluid product stream has a pressure of at least: 200 bar (2.00 x 10 ７ Pa), 220 bar (2.20×10 ７ Pa), 240 bar (2.40×10 ７ Pa), 260 bar (2.60×10 ７ Pa), 280 bar (2.80×10 ７ Pa) or 300 bar (3.00 x 10 ７ 3. The method according to claim 1 or claim 2, wherein the pressure is 0.05 Pa.

4. 4. The method of any one of claims 1 to 3, wherein the flash vessel is in direct communication with a fractionation unit, is an integral part of the fractionation unit, or is in direct communication with one or more staged product coolers.

5. 5. The method of any one of claims 1 to 4, comprising fractionating and cooling the vapor into fractions having a maximum atmospheric equivalent boiling point of less than 400°C, less than 450°C, less than 500°C, less than 550°C or less than 600°C, and collecting a residual fraction having a minimum atmospheric equivalent boiling point of more than 400°C, 450°C, 500°C, 550°C or 600°C.

6. 6. The method of any one of claims 1 to 5, wherein solid filler and / or inorganic material and / or metal salts from the depressurized fluid product stream are retained within a residue matrix produced by the vaporization and fractional distillation.

7. 7. The method of any one of claims 1 to 6, wherein the depressurization and fractionation allows for separation of the aqueous solvent from the hydrocarbon product, including separating the aqueous solvent from lower boiling hydrocarbons at the following temperatures: 10°C, 20°C, 30°C, 40°C, 50°C, or 60°C.

8. The separation of the aqueous solvent from the low boiling hydrocarbons was performed at 9.8±0.1 m / s ２ 8. The method of claim 7, wherein the method is carried out under an effective gravity of 0.

15.

9. 9. The method of claim 7 or claim 8, wherein the separated aqueous solvent comprises a total organic carbon content (TOC) of less than 15,000 mg / l, less than 10,000 mg / l, less than 5000 mg / l, less than 2500 mg / l, less than 1000 mg / l, or less than 500 mg / l.

10. The formation of the reaction mixture comprises: providing a molten stream of said synthetic polymeric material; injecting the aqueous solvent into a molten stream of the synthetic polymeric material; mixing the aqueous solvent and the molten stream of the synthetic polymeric material; The method according to any one of claims 1 to 9, comprising:

11. 11. The method of claim 10, wherein the aqueous solvent is supercritical prior to the injection.

12. 12. The method of claim 10 or claim 11, wherein the aqueous solvent is water or substantially water.

13. The method of any one of claims 10 to 12, wherein the mixing comprises the use of a solvent distribution grid in an assembly comprising one or more static mixing devices.

14. 14. The method of claim 13, wherein the aqueous solvent is injected into the molten stream of synthetic polymeric material through a series of nozzles spanning the periphery of the mixing device.

15. During the preparation of the reaction mixture, 2 bar (2 x 10 ５ Pa), less than 5 bar (5 x 10 ５ Pa), less than 10 bar (1.0 x 10 ６ Pa), less than 20 bar (2.0 x 10 ６ Pa), or less than 30 bar (3.0 x 10 ６ 15. The method of claim 13 or 14, wherein there is a pressure drop across the mixing device of less than 1000 Pa.

16. 16. The method of any one of claims 11 to 15, wherein the supercritical aqueous solvent is produced in a boiler system comprising a burner fueled by gas released from the fluid product stream.

17. 17. The method of claim 16, wherein the supercritical aqueous solvent is produced in a boiler system comprising a burner fueled by natural gas.

18. 18. The method of claim 16 or claim 17, wherein the supercritical aqueous solvent exits the boiler system at a temperature of at least 450°C, at least 500°C, or at least 550°C.

19. The boiler unit is configured to generate the supercritical aqueous solvent at a pressure of at least 180 bar (1.80 x 10 ７ Pa), or at least 200 bar (2.00 x 10 ７ Pa), or at least 220 bar (2.20 x 10 ７ Pa), or at least 240 bar (2.40 x 10 ７ Pa), or at least 250 bar (2.50 x 10 ７ Pa), at least 270 bar (2.70 x 10 ７ Pa), or 290 bar (2.90 x 10 ７ Pa), or 310 bar (3.10 x 10 ７ Pa), or 330 bar (3.30 x 10 ７ The method according to any one of claims 16 to 18, wherein the process is carried out at a pressure of 1000 Pa.

20. 20. The method of any one of claims 16 to 19, comprising heating the gases emitted from the fluid product stream in the boiler system to a temperature of at least 850°C for at least 2 seconds, thereby destroying halogenated organic compounds including any one or more of chlorinated dioxins, chlorinated furans, chlorinated biphenyls and other dioxin-like compounds of environmental concern.

21. 21. The method of any one of claims 1 to 20, comprising utilizing a superheated furnace to heat the steam prior to injecting it into the flash vessel.

22. The method of any one of claims 1 to 21, wherein the reaction temperature is at least 380°C, at least 400°C, at least 450°C, or at least 500°C.

23. The hydrocarbon product comprises a naphtha component boiling at an AEBP of 10°C to 210°C, the naphtha component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10 mass%, 20 mass%, 30 mass%, 40 mass% of aromatic compounds The method of any one of claims 1 to 22, comprising:

24. The hydrocarbon product comprises a gas oil component boiling at an AEBP of 210°C to 360°C, the gas oil component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10 mass%, 20 mass%, 30 mass%, 40 mass% of aromatic compounds The method of any one of claims 1 to 23, comprising:

25. The hydrocarbon product comprises a heavy gas oil component boiling at an AEBP of 360°C to 550°C, the heavy gas oil component comprising: greater than 10%, 20%, 30%, 40% by weight of olefins; and / or greater than 10%, 20%, 30%, 40% by weight of n-paraffins; and / or greater than 10%, 20%, 30%, 40% by weight of cycloalkanes or cycloalkenes; and / or More than 10 mass%, 20 mass%, 30 mass%, 40 mass% of aromatic compounds The method of any one of claims 1 to 24, comprising:

26. 14. The method of claim 13, wherein the temperature measurement system provides a warning of backflow from the mixing device towards an extrusion device connected to the mixing device to enable operation of an isolation valve, thereby preventing backflow from the mixing device.

27. The method of any one of claims 1 to 20, wherein the reactor is a continuous flow reactor.

28. A method according to any one of claims 1 to 27, wherein the treatment is carried out under continuous flow conditions.

29. 29. The method of any one of claims 1 to 28, wherein the synthetic polymeric material does not include: lignocellulosic materials; natural carbohydrate polymers; lignin; cellulose; hemicellulose; lignite (brown coal); subbituminous coal; or any combination thereof.

30. 1. A continuous flow reactor for processing synthetic polymeric materials, comprising: an extruder for producing an extrudate comprising a molten stream of said synthetic polymeric material; a boiler system for producing supercritical water and adding the supercritical water to the extrudate; a mixing device configured to mix the extrudate with the supercritical water, thereby forming a reaction mixture; a reaction zone in communication with said mixing device and indirect heater, said reaction zone treating said reaction mixture at a prescribed residence time, temperature and pressure suitable to convert all or a portion of said synthetic polymeric material present in said reaction mixture into a fluid product stream; a pressure reduction device for reducing the pressure of the fluid product stream, the pressure reduction device being in communication with the reaction zone and the flash vessel, the pressure reduction vaporizing at least a portion of the fluid product stream in the flash vessel to produce vapor comprising hydrocarbon product, water vapor, and gaseous components, the pressure reduction comprising reducing the pressure of the fluid product stream in the flash vessel to less than 25 bar, the vaporization providing energy to facilitate fractionation of the vapor into its component parts; a superheater or steam generator that produces steam, superheated steam, or supercritical water that is injected into the flash vessel and contacts the remainder of the fluid product stream within the flash vessel to produce additional steam containing hydrocarbon product, steam, and gas components; and a fractionation device for separating vapor produced in the flash vessel; A continuous flow reactor comprising:

31. the flash vessel is in direct communication with the fractionation unit; or the flash vessel is an integral part of the fractionation apparatus; or the flash vessel and the fractionator are separate product coolers; 31. The continuous flow reactor of claim 30.

32. 32. A continuous flow reactor according to claim 30 or 31, wherein the mixing device is a static mixing device.

33. 33. The continuous flow reactor of any one of claims 30 to 32, comprising a series of nozzles spanning the periphery of said mixing device for injecting and distributing said supercritical water into the molten stream of said synthetic polymeric material.

34. 34. The continuous flow reactor of any one of claims 30 to 33, wherein the boiler system comprises a burner in communication with the fractionator for receiving gases.

35. 35. The continuous flow reactor of any one of claims 30 to 34, wherein the boiler system comprises a burner in communication with a source of natural gas.

36. 36. The continuous flow reactor of any one of claims 30 to 35, wherein one or more components of the reaction zone comprise a source of metal catalyst for the reaction mixture.

37. 37. The continuous flow reactor of claim 36, wherein the metal catalyst is a solid transition metal catalyst.

38. 38. A continuous flow reactor according to any one of claims 30 to 37, comprising a blowdown component for removing solid material from the reaction mixture, and a receiving vessel for said solid material.

39. 39. The continuous flow reactor of any one of claims 30 to 38, comprising means for separating solid residues and / or bottoms produced during the pretreatment of the synthetic polymeric material and / or the treatment of the reaction mixture, and means for mixing the solid residues and / or bottoms with the fluid product stream in the flash tank, thereby vaporizing volatile components of the solid residues and / or bottoms.

40. a heat exchanger for indirectly heating the reaction mixture to the predetermined temperature at a plurality of points along the reactor vessel containing the reaction zone through which the reaction mixture flows; a means for supplying supercritical steam generated by a supercritical steam generator to the heat exchanger; The continuous flow reactor according to any one of claims 30 to 39, comprising:

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