Catalytic pyrolysis preparation for resin production in petrochemical feedstock manufacturing.

Abstract

The invention relates to a catalytic composition comprising a mesoporous active matrix and phosphorus-stabilized ZSM-5, and a method for the preparation and use of such composition in a fluidized bed or conical spray reactor for the catalytic pyrolysis of resins into olefins and aromatic compounds. The method for the use of such composition for the catalytic pyrolysis of resins (e.g., waste resins) to produce petrochemical feedstocks, such as ethylene, propylene, and butylene, with higher gasification rates and better selectivity.

Description

CATALYTIC PYROLYSIS OF PLASTICS TO PRODUCE PETROCHEMICALFEEDSTOCKCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional ApplicationNo. 63 / 580,579 filed September 5, 2023, the contents of which are incorporated by reference herein in their entirety.FIELD

[0002] The present technology is generally related to the conversion of plastics to olefin and aromatics through pyrolysis. Specifically, the technology is related to catalyst compositions that include a mesoporous active matrix and a phosphorus-stabilized ZSM-5, and methods of preparing and using such compositions in fluidized bed or a conical spouted bed reactor for the catalytic pyrolysis of plastics to olefins and aromatic compounds.BACKGROUND

[0003] Catalytic pyrolysis, which involves the degradation of the polymeric materials by heating them in the absence of oxygen and in the presence of a catalyst, represents an attractive method for recycling plastic waste. Silica-alumina, zeolites, and fluid catalytic cracking (FCC) catalysts are commonly used to lower the energy barrier, influence the composition of the product through cracking, and reduce the process time. While catalytic pyrolysis has been extensively studied, there remains a need to develop more efficient catalytic pyrolysis methods that maximize of the yield of desirable products, such as light olefins and aromatic compounds, and minimize the yield of undesirable products, such as methane and ethane. In particular, propylene is a particular light olefin in high demand as it is used in many of the world’s largest and fastest growing synthetic materials and thermoplastics.

[0004] This disclosure provides catalyst compositions that include a mesoporous active matrix and a phosphorus-stabilized ZSM-5, and methods of preparing and using suchcompositions in fluidized bed or a conical spouted bed reactor for the catalytic pyrolysis of plastics to olefins and aromatic compounds. The methods of using such compositions for the catalytic pyrolysis of plastics (e.g., waste plastics) provide petrochemical feedstocks, such as ethylene, propylene, butylene, with a high gasification rate and better selectivity.SUMMARY

[0005] In one aspect is a catalyst composition comprising: a mesoporous active matrix; and a phosphorus-stabilized ZSM-5.

[0006] In some embodiments, the mesoporous active matrix comprises one or more of kaolin clay and peptized alumina. In some embodiments, the catalyst composition comprises greater than about 30% of one or more of kaolin clay and peptized alumina, based on the total weight of the catalyst composition.

[0007] In some embodiments, the catalyst composition comprises greater than about 10% of peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises greater than about 30% of peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises from about 10% to about 70% of peptized alumina, based on the total weight of the catalyst composition.

[0008] In some embodiments, the mesoporous active matrix comprises pores having a pore size from about 20 Å to about 600Å, or about 40 Å to about 600Å. In some embodiments, the mesoporous active matrix comprises pores having a pore size of greater than about 600Å.

[0009] In some embodiments, the mesoporous active matrix has a surface area from about 50 m2 / g to about 250 m2 / g prior to deactivation. In some embodiments, the mesoporous active matrix has a surface area from about 60 m2 / g to about 200 m2 / g, from about 80 m2 / g to about 150 m2 / g, or from about 90 m2 / g to about 120 m2 / g prior to deactivation.

[0010] In some embodiments, the mesoporous active matrix has a pore volume of greater than about 0.01 cc / g. In some embodiments, the mesoporous active matrix has a pore volume from about 0.1 cc / g to about 0.4 cc / g.

[0011] In some embodiments, the catalyst composition comprises greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises from about 5% to about 70% of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

[0012] In some embodiments, the phosphorus-stabilized ZSM-5 further comprises one or more of metals selected from iron, copper, zinc, nickel, titanium, vanadium, chromium, manganese, cobalt, gallium and boron. In some embodiments, the phosphorus- stabilized ZSM-5 has a crystallite size from about 0.05 microns to about 2 microns.

[0013] In some embodiments, the catalyst composition comprises from about 0.5 % w / w to about 15% w / w P2O5, based on the total weight of the composition.

[0014] In some embodiments, the phosphorus-stabilized ZSM-5 and the mesoporous active matrix are separate particles in the catalyst composition.

[0015] Provided in another aspect is a process of preparing a catalyst composition, the process comprising:(a) providing an aqueous Slurry A comprising solid particles of phosphorus stabilized pentasil zeolite;(b) combining Slurry A with peptized alumina, kaolin clay, and alumina sol to provide Slurry B;(c) spray-drying Slurry B to form catalyst particles; and(d) calcining the spray-dried catalyst particles at a temperature and for a time sufficient to remove volatiles and recover the catalyst composition; wherein: the catalyst composition comprises a mesoporous active matrix; and a phosphorus-stabilized pentasil zeolite.

[0016] In some embodiments, the process further comprises washing the calcined catalyst particles with water and an ammonia solution at a pH from about 3 to about 7.5.

[0017] In some embodiments, the phosphorus stabilized pentasil zeolite is phosphorus stabilized ZSM-5. In some embodiments, the phosphorus stabilized ZSM-5 is prepared by any one of the stabilization methods, such as impregnating, incorporating by slurry-addition, spray-drying, and optionally, milling ZSM-5 particles with an appropriate phosphorus compound, such as H3PO4, (NH4H2PO4, (NH4)2HPO4, and (NH4)3PO4; drying at a temperature of about 120 °C; and calcining at about 600 °C for about 1 hour. In some embodiments, the phosphorus stabilized ZSM-5 is derived from a commercially available ZSM-5.

[0018] In some embodiments, the aqueous Slurry A comprises solid particles of phosphorus stabilized ZSM-5 in an amount sufficient to provide a catalyst composition comprising greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

[0019] In some embodiments, the aqueous Slurry B comprises peptized alumina in an amount sufficient to provide a catalyst composition comprising greater than about 10% w / w of peptized alumina, based on the total weight of the catalyst composition.

[0020] In some embodiments, the alumina sol is present in the slurry in an amount sufficient to provide binding for a catalyst comprising from about 5% to about 50% alumina, based on the total weight of the catalyst composition.

[0021] In some embodiments, spray drying provides catalyst particles having a particle size from about 20 microns to about 200 microns.

[0022] Provided in another aspect is a process of producing at least one or more of olefins and aromatic compounds from a plastic feedstock, the process comprising: contacting a plastic feedstock and any one of the catalyst compositions described herein at a temperature from about 400°C to about 700°C in a fluidized bed or a conical spouted bed reactor and for a time period sufficient and under an anaerobic environment (such as a low-oxygen or no oxygen environment) toallow at least a portion of the plastic feedstock to be converted to a product stream comprising olefins, aromatic compounds, or a mixture comprising olefins and aromatic compounds.

[0023] In some embodiments, contacting the plastic feedstock and the catalyst composition is at a temperature from about 500 °C to about 600 °C.

[0024] In some embodiments, the plastic feedstock comprises at least one of polyethylene, polypropylene, polystyrene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide, polycarbonate, polyurethane, polyester, natural and synthetic rubber, tires, filled polymers, composites, plastic alloys, and plastics dissolved in a solvent.

[0025] In some embodiments, the plastic feedstock comprises polyethylene, such as LLDPE and HOPE. In some embodiments, the plastic feedstock comprises polypropylene, such as HPP.

[0026] In some embodiments, the product stream comprises olefins comprising ethylene, propylene, butene, or a mixture of any two or more thereof. In some embodiments, the product stream comprises from about 15 wt% to about 60 wt% olefins, such as ethylene, propylene, and butenes.

[0027] In some embodiments, the product stream comprises aromatic compounds comprising benzene, toluene, xylene, or a mixture of any two or more thereof.

[0028] In some embodiments, the process uses a conical spouted bed reactor comprising a draft tube and a confiner. In some embodiments, the process uses a fluidized bed reactor.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a schematic depiction of a conventional spouted bed reactor from the prior art.

[0030] FIG. 2 is a schematic depiction of a spouted bed reactor with a draft tube and a confiner, according to an illustrative embodiment.

[0031] FIG. 3 is a schematic depiction of two illustrative embodiments of draft tubes, with open side wall and closed side wall.

[0032] FIG. 4 is a schematic depiction of the arrangement of a draft tube and confiner with the dimensions illustrated.DETAILED DESCRIPTION

[0033] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment^).

[0034] As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term.

[0035] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0036] Disclosed herein are catalyst compositions that include a mesoporous active matrix and a phosphorus-stabilized ZSM-5, and methods of preparing and using such compositions. Specifically, the catalyst compositions described herein are useful for converting waste plastics to valuable petrochemical feedstocks, such as ethylene, propylene, and butylene, in high yields using a fluidized bed or a conical spouted bed reactor including a draft tube and a confiner. These petrochemical feedstocks may be reprocessed into useful plastics for a more circular economy.

[0037] As demonstrated in the Examples, the advantages of using the compositions disclosed herein for the catalytic pyrolysis of plastics (e.g., waste plastics) is the high gasification rate of polymers combined with ZSM-5, which imparts better selectivity. At certain conditions with optimal catalysts, these advantages resulted in higher light olefin yields. For instance, in Example 12, the HDPE embodiment showed lower yields but still high gasification rate; and in Example 16, maximum yields of light olefins were achieved by optimization of phosphorus input with high ZSM-5 loadingZSM-5 Catalyst Compositions

[0038] The catalyst compositions described herein include a mesoporous active matrix; and a phosphorus-stabilized ZSM-5.

[0039] The mesoporous active matrix described herein is catalytically active, porous silica-alumina material, however, in contrast to the zeolite, it is non-crystalline, i.e., amorphous. Also, the mesoporous active matrix described herein is acidic (e.g., silica / alumina, or alumina, etc). The acidity of the mesoporous active matrix may be determined as Lewis Acid or Bronsted acid by diffuse reflectance pyridine IR. In some embodiments, the acidity of the mesoporous active matrix is not diminished by A1PO4.

[0040] The mesoporous active matrix described herein comprises one or more of kaolin clay and peptized alumina, hi some embodiments, the mesoporous active matrix comprises one or more of kaolin clay and peptized alumina. In some embodiments, the catalyst composition comprises greater than about 30% of one or more of kaolin clay andpeptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises from about 30% to about 70% of one or more of kaolin clay and peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, and about 70% of one or more of kaolin clay and peptized alumina, based on the total weight of the catalyst composition.

[0041] In some embodiments, the catalyst composition comprises greater than about 10% of peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises greater than about 30% of peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises from about 10% to about 70% of peptized alumina, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises including about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, and about 70% of peptized alumina, based on the total weight of the catalyst composition.

[0042] In some embodiments, the mesoporous active matrix comprises pores having a pore size from about 20 Å to about 600Å or about 40 Å to about 600Å, including about 20 Å, about 30 Å, about 40 Å, about 50 Å, about 60 Å, about 70 Å, about 80 Å, about 90 Å, about 100 Å, about 110 Å, about 120 Å, about 130 Å, about 140 Å, about 150 Å, about 170 Å, about 180 Å, about 190 Å, about 200 Å, about 210 Å, about 220 Å, about 230 Å, about 240 Å, about 250 Å, about 260 Å, about 270 Å, about 280 Å, about 290 Å, about 300 Å, about 310 Å, about 320 Å, about 330 Å, about 340 Å, about 350 Å, about 360 Å, about 370 Å, about 380 Å, about 390 Å, about 400 Å, about 410 Å, about 420 Å, about 430 Å, about 440 Å, about 450 Å, about 460 Å, about 470 Å, about 480 Å, about 490 Å, about 500 Å, about 510 Å, about 520 Å, about 530 Å, about 540 Å, about 550 Å, about 560 Å, about 570 Å, about 580 Å, about 590 Å, and about 600 A.

[0043] In some embodiments, the mesoporous active matrix comprises pores having a pore size from of greater than about 600Å (e.g., macropores). In some embodiments, the mesoporous active matrix comprises pores having a pore size from about 600Å to about10, 000 Å, including about 600 Å, about 700Å, about 800Å, about 900Å, about l,000Å, about 2,000Å, about 3,000Å, about 4,000Å, about 5,000Å, about 6,000Å, about 7,000Å, about 8,000Å, about 9,000 Å, and about 10,000Å. In some embodiments, the mesoporous active matrix comprises pores having a pore size from about 600Å to about l,000Å, including about 600Å, about 700Å, about 800 Å, about 900Å, and about l,000Å.

[0044] In some embodiments, the mesoporous active matrix comprises pores having a pore size from about 1,000Å to about 10, 000 Å, including about 1,000Å, about 2,000Å, about 3,000Å, about 4,000Å, about 5,000Å, about 6,000Å, about 7.000Å, about 8.000Å, about 9,000Å, and about 10,000Å.

[0045] The mesoporous active matrix described herein have a surface area from about 50 m2 / g to about 250 m2 / g prior to deactivation, wherein the surface area is determined by N2- BET (Brunauer, Emmett and Teller) method and porosity and pore size distribution measured by mercury porosimetty. In some embodiments, the mesoporous active matrix has a surface area from about 50 m2 / g to about 250 m2 / g prior to deactivation, including about 50 m2 / g, about 60 m2 / g, about 70 m2 / g, about 80 m2 / g, about 90 m2 / g, about 100 m2 / g, about 110 m2 / g, about 120 m2 / g, about 130 m2 / g, about 140 m2 / g, about 150 m2 / g, about 160 m2 / g, about 170 m2 / g, about 180 m2 / g, about 190 m2 / g, about 200 m2 / g, about 210 m2 / g, about 220 m2 / g, about 230 m2 / g, about 240 m2 / g, and about 250 m2 / g prior to deactivation. In some embodiments, the mesoporous active matrix has a surface area from about 60 m2 / g to about 200 m2 / g, from about 80 m2 / g to about 150 m2 / g, or from about 90 m2 / g to about 120 m2 / g prior to deactivation.

[0046] In some embodiments, the mesoporous active matrix has a pore volume of greater than about 0.01 cc / g. In some embodiments, the mesoporous active matrix has a pore volume from about 0.1 cc / g to about 0.4 cc / g, including about 0.1 cc / g, about 0.15 cc / g, about 0.2 cc / g, about 0.25 cc / g, about 0.3 cc / g, about 0.35 cc / g, and about 0.4 cc / g.

[0047] In some embodiments, the catalyst composition comprises greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition. In some embodiments, the catalyst composition comprises from about 5% to about 70% of phosphorus-stabilized ZSM-5, based on the total weight of the catalystcomposition. In some embodiments, the catalyst composition comprises about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, and about 70% of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

[0048] In some embodiments, the phosphorus-stabilized ZSM-5 further comprises one or more of metals selected from iron, copper, zinc, nickel, titanium, vanadium, chromium, manganese, cobalt, gallium and boron.

[0049] In some embodiments, the ZSM-5 has a crystallite size from about 0.05 microns to about 2 microns, including about 0.05 microns, about 0.06 microns, about 0.07 microns, about 0.08 microns, about 0.09 microns, about 0.1 microns, about 0.2 microns, about 0.3 microns, about 0.4 microns, about 0.5 microns, about 0.6 microns, about 0.7 microns, about 0.8 microns, about 0.9 microns, about 1 microns, about 1.5 microns, and about 2 microns.

[0050] The catalyst composition described herein may include from about 0.5 % w / w to about 15% w / w P2O5, based on the total weight of the composition. In some embodiments, the catalyst composition includes about 0.5% w / w, about 1% w / w, about 2% w / w, about 3% w / w, about 4% w / w, about 5% w / w about 6% w / w, about 7% w / w, about 8% w / w, about 9% w / w, about 10% w / w, about 11% w / w, about 12% w / w, about 13% w / w, about 14% w / w, or about 15% w / w of P2O5, based on the total weight of the composition.

[0051] In some embodiments, the phosphorus-stabilized ZSM-5 and the mesoporous active matrix are separate particles in the catalyst composition.

[0052] Provided in another aspect is a process of preparing a catalyst composition, the process comprising:(a) providing an aqueous Slurry A comprising solid particles of phosphorus stabilized pentasil zeolite;(b) combining Slurry A with peptized alumina, kaolin clay, and alumina sol to provide Slurry B;(c) spray-drying Slurry B to form catalyst particles; and(d) calcining the spray-dried catalyst particles at a temperature and for a time sufficient to remove volatiles and recover the catalyst composition; wherein: the catalyst composition comprises a mesoporous active matrix; and a phosphorus-stabilized pentasil zeolite.

[0053] In some embodiments, die process further comprises washing the calcined catalyst particles with water and an ammonia solution at a pH from about 3.0 to about 7.5.

[0054] In some embodiments, the phosphorus stabilized pentasil zeolite is phosphorus stabilized ZSM-5. In some embodiments, the phosphorus stabilized ZSM-5 is prepared by any one of the stabilization methods, such as impregnating incorporating by slurry-addition, spray-drying, and optionally, milling ZSM-5 particles an appropriate phosphorus compound, such as with H3PO4, (NH4)H2PO4, (NH4)2HPO4, and (NH4)3PO4; drying at a temperature of about 120 °C; and calcining at about 600 °C for about 1 hour. In some embodiments, the phosphorus stabilized ZSM-5 is derived from a commercially available ZSM-5.

[0055] In some embodiments, the aqueous Slurry A comprises solid particles of phosphorus stabilized ZSM-5 in an amount sufficient to provide a catalyst composition comprising greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

[0056] In some embodiments, the aqueous Slurry B comprises peptized alumina in an amount sufficient to provide a catalyst composition comprising greater than about 10% w / w of peptized alumina, based on the total weight of the catalyst composition.

[0057] In some embodiments, the alumina sol is present in the slurry in an amount sufficient to provide binding for a catalyst comprising from about 5% to about 50% alumina, based on the total weight of the catalyst composition. In some embodiments, the alumina sol is present in the slurry in an amount sufficient to provide binding for a catalyst comprising about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, and about 50% alumina, based on the total weight of the catalyst composition.

[0058] In some embodiments, spray drying provides catalyst particles having a particle size from about 20 microns to about 200 microns, about 20 microns, about 30 microns, about 40 microns, about 50 microns, about 60 microns, about 70 microns, about 80 microns, about 90 microns, about 100 microns, about 110 microns, about 120 microns, about 130 microns, about 140 microns, about 150 microns, about 160 microns, about 170 microns, about 180 microns, about 190 microns, and about 200 microns.Catalytic Pyrolysis

[0059] Described herein is a process of producing at least one or more of olefins and aromatic compounds from a plastic feedstock, the process comprising: contacting a plastic feedstock and any one of the catalyst compositions described herein at a temperature from about 400°C to about 700°C in a fluidized bed or a conical spouted bed reactor and for a time period sufficient and under an anaerobic environment to allow at least a portion of the plastic feedstock to be converted to a product stream comprising olefins, aromatic compounds, or a mixture comprising olefins and aromatic compounds.

[0060] In some embodiments, contacting the plastic feedstock and the catalyst composition is at a temperature from about 500°C to about 600°C, including about 525°C to about 575°C. In some embodiments, contacting the plastic feedstock and the catalyst composition is at a temperature of about 400°C, about 410°C, about 420°C, about 430°C, about 440°C, about 450°C, about 460°C, about 470°C, about 480°C, about 490°C, about 500°C, about 510°C, about 520°C, about 530°C, about 540°C, about 550°C, about 560°C, about 570°C, about 580°C, about 590°C, about 600°C, about 610°C, about 620°C, about 630°C, about 640°C, or about 650°C. In some embodiments, contacting the plastic feedstock and the catalyst composition is at a temperature of about 550°C.

[0061] The plastic feedstock described herein may include at least one of polyethylene, polypropylene, polystyrene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide, polycarbonate, polyurethane, polyester, natural and syntheticrubber, tires, filled polymers, composites, plastic alloys, and plastics dissolved in a solvent.In some embodiments, the plastic feedstock includes polyethylene (e.g., high-density polyethylene (HDPE) and linear low density polyethylene (LLDPE)). In some embodiments, the plastic feedstock includes polypropylene (e.g., HPP).

[0062] For the catalytic processes described herein, the product stream may include at least one or more olefins selected from ethylene, propylene, and butenes (e.g., light olefins). In some embodiments, the product stream comprises greater than about 15% wt, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, or about 60 wt% of ethylene, propylene, and butenes. In some embodiments, the product stream comprises from about 15 wt% to about 60 wt% of ethylene, propylene, and butenes. In some embodiments, the product stream comprises about 15% wt, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, or about 70 wt% of ethylene, propylene, and butenes.

[0063] In some embodiments, the product stream comprises aromatic compounds comprising benzene, toluene, xylene, or a mixture of any two or more thereof.

[0064] In some embodiments, the process uses a conical spouted bed reactor comprising a draft tube and a confiner. In some embodiments, the process uses a fluidized bed reactor.Conical Spouted Bed Reactors

[0065] The use of spouted bed reactors to carry out reactions of plastics pyrolysis has been disclosed; however, the spouted bed reactors that have been disclosed prior to this disclosure do not have a draft tube or a confiner.

[0066] FIG. 1 shows a schematic diagram of a conventional conical spouted bed reactor disclosed in the prior art and does not have a draft tube or a confiner. An inert gas, such as nitrogen or steam, is introduced into the bed of catalyst through an orifice at the base of the reactor. The flowing gas creates a cylindrical path, or spout, through the catalyst bed. Catalyst, entrained by the gas flowing through the spout, is propelled above the surface of thecatalyst bed and settles back down in the shape of a fountain. The catalyst moves downward in the annular region back to the bottom of the conical bed, thus completing the cycle. The rapid circulation of the catalyst and reactants ensures good mixing in the reactor. The fountain is a region of low catalyst density, called the dilute phase, and the annulus is a region of high catalyst density, called the dense phase. In the absence of a draft tube, some of the gas flows around the spout and through the annular region.

[0067] In contrast, the catalytic pyrolysis process of plastic waste described herein uses a conical spouted bed reactor including a draft tube and a confiner. FIG. 2 shows a schematic diagram of an illustrative embodiment. FIG. 3 shows two examples of draft tubes, with open side wall and closed side wall. The gas, flowing through the draft tube, creates a region of negative pressure, at the bottom of the tube, which pulls in catalyst from the annular region and propels it up the draft tube. The confiner, which is closed at the top, redirects the catalyst downward.

[0068] The draft tube directs the gas through the spout so that less gas travels through the annulus, as compared to the conventional spouted bed reactor. Thus, the minimum spouting velocity, in the presence of the draft tube, is much lower than in the absence of the draft tube.

[0069] The confiner confines the dilute phase to a smaller volume with more turbulent mixing. The feedstock, added to the confiner, is rapidly mixed with the catalyst. The higher collision frequency between the catalyst and the plastics leads to faster heat transfer, melting of plastics and distribution of molten plastics throughout the catalyst.

[0070] FIG. 4 shows an illustrative embodiment of draft tube and confiner arrangement with key dimensions. The conical spouted bed reactor has a gas inlet opening of Do and a diameter of the cylindrical section of the conical spouted bed reactor of De. The confiner has a diameter of Do. The draft tube has a distance from the top of the draft tube and the bottom of the draft tube of Ho.

[0071] In some embodiments, Ho may be from about 3 to about 4 x Do or from about1.5 to 2.5 x Do. In some embodiments, Ho is about 2 x Do.

[0072] In some embodiments, Do may be from about 3 x Do to about 0.7 De or from about 4 to about 6 x Do. In some embodiments, Dois about 5 x Do.

[0073] The present invention, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present invention.EXAMPLES

[0074] Background Example A

[0075] The use of spouted bed reactors to carry out reactions of plastics pyrolysis has been disclosed; however, the spouted bed reactors that have been disclosed prior to this disclosure do not have a draft tube or a confiner. Furthermore, the catalysts used with these spouted bed reactors were extrudates containing approximately 20 to 25% fresh ZSM-5 and were not deactivated to simulate commercial performance.

[0076] A schematic diagram of a conventional conical spouted bed reactor, with no draft tube or confiner, is shown in FIG. 1 and was used in the following examples. An inert gas, such as nitrogen or steam, is introduced into the bed of catalyst through an orifice at the base of the reactor. The flowing gas creates a cylindrical path, or spout, through the catalyst bed. Catalyst, entrained by the gas flowing through the spout, is propelled above the surface of the catalyst bed and settles back down in the shape of a fountain. The catalyst moves downward in the annular region back to the bottom of the conical bed, thus completing the cycle. The rapid circulation of the catalyst and reactants ensure good mixing in the reactor. The fountain is a region of low catalyst density, called the dilute phase, and the annulus is a region of high catalyst density, called the dense phase. In the absence of a draft tube, some of the gas flows around the spout and through the annular region.

[0077] Background Example B

[0078] FIG. 2 shows a schematic diagram of a spouted bed reactor with a draft tube and a confiner (top) that was used in the following examples. Two examples of draft tubes, with open side wall and closed side wall, are shown in FIG. 3. The gas, flowing through thedraft tube, creates a region of negative pressure, at the bottom of the tube, which pulls in catalyst from the annular region and propels it up the draft tube. The confiner, which is closed at the top, redirects the catalyst downward.

[0079] The draft tube directs the gas through the spout so that less gas travels through the annulus, as compared to the conventional spouted bed reactor. Thus, the minimum spouting velocity, in the presence of the draft tube, is much lower than in the absence of the draft tube.

[0080] The confiner confines the dilute phase to a smaller volume with more turbulent mixing. The feedstock, added to the confiner, is rapidly mixed with the catalyst. The higher collision frequency between the catalyst and the plastics leads to faster heat transfer, melting of plastics and distribution of molten plastics throughout the catalyst.

[0081] The key dimensions of the draft tube and confiner arrangement are shown inFIG. 4. DO refers to the gas inlet opening of the spouted bed. DC refers to the diameter of the cylindrical section of the spouted bed and DG refers to the diameter of the confiner. HG refers to the distance from the top of the draft tube and the bottom of the confiner. HG may be from about 3 to 4 x DO. In some embodiments, HG may be from about 1.5 to 2.5 DO. In some embodiments, HG should be about 2 x DO. In some embodiments, DG may be from about 3 x DO to 0.7 x DC. In some embodiments, DG may be from about 4 to 6 x DO, or about 5 x DO.

[0082] Introduction

[0083] Catalytic pyrolysis inplies the initial cracking of molten plastic into gaseous products on catalyst particles is promoted by the catalyst, not the same as passing the product gas from thermal pyrolysis through a catalyst bed. This was made clear by comparing the thermal pyrolysis with catalytic pyrolysis at lower temperatures where thermal pyrolysis is very slow. As indicated by Sharratt (P. Sharratt et al. Ind. Eng. Chem. Res. 36 (1997) 5118), thermal pyrolysis of HDPE over silicalite can be compared with catalytic pyrolysis over a ZSM-5 catalyst in the temperature range of 360-430 °C in Table 1 below. It can be seen that thermal pyrolysis at 360 °C was very slow and 60 mins’ reaction can only achieve ~6wt%gasification. At the same temperature, contact of molten HDPE with ZSM-5 catalyst had more than 95wt% HDPE gasified. Even at 360 °C, catalytic pyrolysis of HDPE over ZSM-5 generated significant amount of C2= to C4= olefins and other mid-range distillates as gasolines (C5-C9). However, in this study, catalysts were made from pressed pellets of pure zeolites and not deactivated to simulate commercial performance.Table 1. Pyrolysis of HDPE in a fluidized bed Reactor with ID=10 mm in accordance with SharrattSilicalite was a pure SiO2with a pentasil structure and is non-catalytic and inert.

[0084] Motivated by the significant differences between the catalytic pyrolysis and thermal pyrolysis at lower temperatures, A iso-thermal TGA method was developed and used in this disclosure to screen catalyst with higher gasification rate in the temperature range of 360-430 °C. All catalysts used in the invention were formulated and spray dried into micro- spheres (APS ~65 micron) for commercial use, and hydrothermally deactivated at 1500 °F for 24 hours in 100v / v% steam to simulate commercial performance.

[0085] In addition to the conventional fluidized bed reactor, the use of spouted bed reactor to carry out reactions of plastics pyrolysis has been disclosed by Aguado (R. Aguado et al., Ind. Eng. Chem. Res. 41 (2002) 4559), where the thermal pyrolysis of HDPE, LDPE and PP pellets (~4mm) was carried out over sand particles (~lmm). The results of thermal pyrolysis at 550 °C reported by Aguado can be summarized in Table 2 below. With shorterresidence time of the gas phase product than a normal fluidized bed, at least 60wt% of the products are wax and about 32wt% or less of light gases (C1-C4) were produced, with very little product (10wt% or less) in the mid boiling point (gasoline, C5-C9) range. The comparison between the thermal pyrolysis and catalytic pyrolysis in the conical sprouted bed reactor can be made by using testing data from Elordi (G. Elordi et al., INT. J. CHEM. REACT. ENG., 5 (2007) A72). The testing data at 500 °C over HDPE from Aguado and Elordi are summarized in Table 3 below. It can be seen that catalytic pyrolysis of HDPE over a ZSM-5 based catalyst eliminated wax and improved production of gasoline and especially light olefins when compared to the thermal pyrolysis. However, in Aguado and Elordi, catalysts were 1mm particles from extrudates and not deactivated to simulate expected performance in a commercial unit with regeneration. The better selectivity with respect to the lighter hydrocarbons over ZSM-5 might be explained by better catalytic pyrolysis and / or better catalytic cracking of wax (gaseous heavy hydrocarbons) on the acid sites of zeolite. However, there was no clear indication on the role of ZSM-5 zeolite and how to further improve the performance of catalyst. As such, this disclosure focuses on using the spray dried micro-sphere catalyst (APS=60-l 50 pm) in the conical sprouted bed reactor for high yields of light olefins from catalytic pyrolysis of plastics. The optimized catalysts in this disclosure were tested in the conical sprouted bed reactor at 550 °C to investigate the yield and selectivity improvement of the new catalysts.Table 2.Table 3.

[0086] To use the spray dried micro-sphere catalyst (APS=60-l 50 pm) in the conventional fluidized bed and / or conical sprouted bed reactor for plastic pyrolysis, in addition to the improvements on the structure of reactor with draft tube and fountain confiner, catalyst with higher gasification activity is critical and much needed, as it can reduce the thickness of the molten plastic coated in the catalyst particles, therefore decrease the chance of defluidization and reduce the size of the reactor for commercial use. Therefore, one of the focuses of this disclosure is how to improve the catalyst for higher activity on gasification of plastics, especially polyolefins such as polypropylene and polyethylene which have high volume in plastic waste for sustainable recovery.

[0087] As cited in the papers earlier, ZSM-5 zeolite is considered as a good candidate for the catalytic pyrolysis of plastics. However, there are two issues need to be resolved for it to be a practical catalyst in the commercial pyrolysis of plastics: (1 ) The hydrothermal stability, it is well known in the industry that un-stabilized ZSM-5 loses acidity and porosity and therefore catalytic activity and selectivity due to hydrothermal deactivation. So in this disclosure, the P-stabilized ZSM-5 was chosen based on its proven stability; (2) Because the size of the molecules of the molten plastics is much larger than the micro-pores of the ZSM-5 zeolite, which is only ~5.5 Å as noted by Degnan (T. F. Degnan et al.. Studies in Surface Science and Catalysis, Vol. 76 (1993) 499), gasification of molten plastic, may only happen on the acidic sites of its external surface of the zeolite crystalline and only if the zeolite particle is in a porous structure and accessible by the molecules of the molten plastics. In order to increase the pre-cracking sites for the molten plastic molecules in addition to the acidic sites of ZSM-5, the mesoporous active matrix is introduced and optimized in thisinvention. Similar to an FCC catalyst, the typical components of a pyrolysis catalyst are zeolite and matrix materials which may include binder, clay, high surface area AI2O3, SiO2, and / or SiO2- AI2O3. Pre-cracking of the large molten plastic molecules can happen on the acidic sites in a purposely added mesoporous active matrix material such as clay, AI2O3and / or SiO2-AlO3. It is a very successful approach used in Y zeolite-based FCC catalyst formulation in the past, where high surface area matrix material can be used for improved bottoms cracking (See, W.-C. Cheng et al. US Patent No. 8,642,499). However, the use of mesoporous active matrix is rarely seen for ZSM-5 based catalysts as they are often used to treat the smaller size molecules in the C5 to CIO range. Surprisingly, when mesoporous active matrix (as kaolin clayand / or peptized mesoporous AI2O3,) is included in the same catalyst particle as P-stabilized ZSM-5, significantly increased rate of catalytic pyrolysis of HPP and LLDPE was observed. This proves that there is a synergy among the clay, active AI2O3, and zeolite for better gasification activity. The gasification rate of the catalyst with mesoporous active matrix over HPP and LLDPE increased 5 to 10 times at 400 °C when compared to the catalyst without mesoporous active matrix, even though this approach is not as effective in the pyrolysis of HOPE. Further investigation of the effects of mesoporous surface area found that the gasification rate of LLDPE, HPP and HOPE increases with the increase of the AI2O3 content in the range of 12 wt% to 40 wt%. Also, the selectivity testing in the conical sprouted bed reactor seems to suggest that the yields of light olefins significantly improves with the increase of ZSM-5 content at 550 °C in the catalytic pyrolysis of the HPP and LLDPE. These results suggest that ZSM-5 content is more important for the catalytic reactions post-gasification.

[0088] To maximize the yields of light olefins, especially propylene and ethylene, in the same reactor for catalytic pyrolysis of plastics, the catalyst needs to have not only the high activity to convert molten plastic into gas phase hydrocarbons, but also the high activity from phosphorus stabilized ZSM-5 which has good hydrothermal stability and superior selectivity to convert gasoline range olefins into light olefins such as butene, propylene and ethylene (A. Corma et al., J of Catalysis vol 237 (2006) 267). The disclosed P-ZSM5 catalyst successfully combined high mesoporous active matrix content with up to 50-60wt% P-ZSM5 loading without sacrificing the activity from either component. Pyrolysis testing of HPP, LLDPE and HOPE in the bench scale conical sprouted bed reactor over the high P-ZSM5 loading catalysts at 550C, showed ~ 27-28wt% of propylene yield, which is 2-8 wt% higher than the base case. The total light olefins yield is also among the highest in our invention and in the range of 52-55 wt% over HPP, LLDPE and HOPE, which is 5-15wt% higher than the base case.

[0089] Example 1 (base, Cat B).

[0090] Cat B is a phosphorus stabilized ZSM-5 additive, commercially available from W.R. Grace. It contains 55 wt% ZSM-5, rest of the raw materials include alumina sol binder, Boehmite alumina, phosphoric acid, and Natka clay. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalysts are as shown in Table 4 below.

[0091] Example 2 (comparative Cat C-l).

[0092] Comparative catalyst C-l was prepared with 40% acid peptized alumina and 60 wt% Natka clay. A slurry containing these two raw materials was milled in a Netzsch mill and then spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 600 °C. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 4 below.

[0093] Example 3 (invention, D-l).

[0094] Catalyst D-l, containing 25 wt% CAT B, 40 wt% acid peptized alumina, 3% wt% alumina sol, and 32 wt% Natka clay was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with acid peptized alumina, alumina sol, and Natka clay. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray- dried product was calcined in a muffle furnace for 1 hour at 600 °C. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the steamed catalyst are as shown in Table 4 below. Total Surface area (TSA) is measured by the standard Nitrogen BET technique. Each samplewas measured to determine its TSA. The Zeolite surface area (ZSA) for each sample was determined by the percentage of ZSM-5 in catalyst formulation times a factor of 3.4 (m2 / g ZSA per 1% ZSM-5) for steam deactivated samples and 3.2 (m2 / g ZSA per 1% ZSM-5) for fresh samples. This factor is determined based on the nitrogen / argon adsorption analysis data reported by Shen et al. (Microporous and Mesoporous Materials, Volume 344, 2022, Article 112210). The matrix surface area (MSA) was then calculated by the difference between TSA and ZSA. The pore volume (PV) in the range of 40-600 Å was measured using Micromeritics AutoPore V, Mercury Pore Size Analyzers complies with the requirements of ASTM test method D4284.

[0095] The Table 4 below is showing properties of steamed properties of cat B, Cl ,DI. Table 4.

[0096] Example 4 TGA testing at 400 °C for B, Cl, DI.

[0097] The lab testing for the gasification rate of the catalytic pyrolysis was carried out on a computerized thermobalance (TA Q500). The thermobalance was pre- loaded with well blended 3-9 mgs of catalyst and 20-30 mgs of plastic powders (< 0.5mm) before the test. The test started with the introduction of an inert atmosphere using 110 seem N2 which is controlled by a Mass Flow Controller. This flow rate was maintained as a constant during thecourse of the experiment At the same time, temperature increased to 250 °C in a heating rate of 50 °C / min. Then, maintained at 250 °C for 15 min to get a stabilized balance reading without the influence of moisture while the plastic sample was completely melted. Then the temperature increased to 400 °C at the rate of 50 °C / min, maintained at 400 °C for 2 hours as the step of isothermal pyrolysis of plastic. Rate of weight loss was then calculated using the equation below. After the two hours' pyrolysis, carrier gas was switched to 100 seem air and temperature was increased to 600 °C at 10 °C / min, after maintaining for 1 hr at 600 °C to complete the regeneration (coke bum) of the catalyst The furnace slowly was cooled down to room temperature, where the sample was blended with another plastic sample and repeated the procedure above for the second test. The reported result is an average of the two tests. In general, the difference between the results of the two tests are within 10%.

[0098] Avg. rate for 90% conversion (g plastic / gcat.min) = (1 / time to reach 90% conversion)*(weight of plastic / weight of catalyst).

[0099] Three commercially available plastic samples were used in the TGA experiments. They included a sample of HPP, a HDPE and a LLDPE. The original form of the samples were pellets of ~4mms that were cryogenically milled into powders (< 0.5mm) before the TGA testing. Details of the three plastic powders are listed in the Table 5 below.Table 5

[0100] Before the activity testing, the flesh sample of catalyst B, C-l and D-l were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steamatmosphere to simulate the performance of a commercial equilibrium catalyst. The testing result is listed in the Table 6 below.Table 6

[0101] It can be seen from the results that the mesoporous active matrix (C-l) was very active by itself, more active than the P-stabllized ZSM-5 catalyst without matrix activity (CAT B). After combining the mesoporous active matrix with P-stabilized ZSM-5 catalyst together through a catalyst in accordance to this disclosure (D-l), the gasification rate further inproved, proving there is a synergy between the mesoporous active matrix and the zeolite component. Compared to the ZSM-5 catalyst without mesoporous active matrix, gasification rate of D-l increased over ~10 fold in the pyrolysis of HPP and LLDPE, ~2 fold for HOPE.

[0102] Example 5 (invention, D-2).

[0103] Catalyst D-2, containing 25 wt% CAT B, 0 wt% acid peptized alumina, 20% wt% alumina sol, and 55 wt% Natka clay was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with alumina sol and Natka clay. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 600 °C. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the flesh and steamed catalyst are as shown in Table 7 below.

[0104] Example 6 (invention, D-3).

[0105] Catalyst D-3, containing 25 wt% CAT B, 12 wt% acid peptized alumina, 8% wt% alumina sol, and 55 wt% Natka clay was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with acid peptized alumina, alumina sol, and Natka clay. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray- dried product was calcined in a muffle furnace for 1 hour at 400 °C, followed by water and ammonia solution wash. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 7 below.

[0106] Example 7 (invention, D-4).

[0107] Catalyst D-4, containing 25 wt% CAT B, 26 wt% acid peptized alumina, 8% wt% alumina sol, and 41 wt% Natka clay was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with acid peptized alumina, alumina sol, and Natka clay. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray- dried product was calcined in a muffle furnace for 1 hour at 400 °C, followed by water and ammonia solution wash. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the steamed catalyst are as shown in Table 7 below.Table 7

[0108] Example 8 TGA testing at 400 °C for D-2, D-3, D-4

[0109] Before the activity testing, the fresh sample of catalyst D-2, D-3 and D-4 were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere to simulate the performance of a commercial equilibrium catalysts. Following the testing procedure in Example 5, the steamed samples were tested and compared with D-l, The TGA testing result is listed in the table below.Table 8

[0110] It can be seen from the results that matrix activity increased with the increase of the content of the peptized AbCh, which helped to introduce mesoporous structure and MSA into the catalyst, in addition to the acidity.

[0111] Example 9 (invention, D-5)

[0112] Catalyst D-5, containing 35 wt% CAT B, 40 wt% acid peptized alumina, 5% wt% alumina sol, and 20 wt% Natka clay was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with acid peptized alumina, alumina sol, and Natka clay. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray- dried product was calcined in a muffle furnace for 1 hour at 400 °C. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 9 below.

[0113] Example 10 (invention, D-6).

[0114] Catalyst D-6, containing 53 wt% CAT B, 40 wt% acid peptized alumina, and 7 wt% alumina sol, was prepared as follows. The CAT B dry powder was slurried with water and milled before being used as a raw material. The milled CAT B slurry was then mixed with acid peptized alumina and alumina sol. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 400 °C. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the steamed catalyst are as shown in Table 9 below.Table 9

[0115] Example 11 TGA testing at 400 °C for D-5 and D-6

[0116] Before the activity testing, the fresh sample of catalyst D-5 and D-6 were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere to simulate the performance of a commercial equilibrium catalysts. Following the testing procedure in Example 5, the steamed samples were tested and compared with D-l. The TGA testing result is listed in the Table 10 below.Table 10

[0117] It can be seen from the results that the gasification rate did not show much difference when the loading of CAT B (containing P-stabilized ZSM-5) varied in the range of 25-53wt%. However, ZSM-5 content can still be a very important for the selectivity of the products, which needs to be verified in specific reactor and reactor conditions.

[0118] Example 12 Selectivity testing of B, D-5 and D-6 at 550 °C.

[0119] Before the activity testing, the fresh sample of catalyst D-5 and D-6 were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere to simulate the performance of a commercial equilibrium catalysts. In the selectivity test, 135 grams of catalyst, was charged into a spouted bed reactor equipped with a draft tube and a confiner as described herein and heated to 550 °C, while 5.2 NL / min of nitrogen was used as the spouting gas. Pellets of the plastic samples, which were HPP, LLDPE and HOPE and same as the plastic samples in Example 5, were charged to the reactor at 1 g / min. The test reached steady state operation within 30 min, and the product distribution of the steady state operation were recorded. The testing results of D-5 and D-6 are compared with B in the Tables 11, 12 and 13 below.Table 11. Selectivity testing results over HPP at 550 °C

[0120] It can be seen from the results in the pyrolysis of HPP at 550 °C that propylene and the overall C2-C5 olefins yield from this catalysts prepared in accordance to this disclosure were much higher than the conventional ZSM-5 based catalyst B, mainly due to their lower selectivity to the saturated products. Although the yield of gasoline fraction was higher, it provided very high gasoline olefins, which are easier to be cracked into lighter C2-C4 olefins by using additional gasoline to olefins technology. Propylene yield of the catalysts in accordance with this disclosure increased with the loading of ZSM-5 catalyst, which is a clear indication of the role of ZSM-5 and pointing to the direction to further improve the C3= yield.Table 12. Selectivity testing results over LLDPE at 550 °C

[0121] The results in the pyrolysis of LLDPE at 550 °C were very similar to the results from HPP, where the selectivity to the light olefins was much higher for the catalyst prepared in accordance with the disclosure.Table 13

[0122] The results in the pyrolysis of HDPE at 550 °C were similar to HPP and LLDPE in terms of better C3 and gasoline olefinicity for the catalysts in accordance with this disclosure. However, somewhat different trends were observed on the yields of propylene. A possible explanation is that the gasification rate promotion in the pyrolysis of HDPE benefited the least from this catalyst (see results in Example 5), and thus, thermal gasification of HDPE was still significant, while addition of active matrix diluted the content of ZSM-5 for other gas phase reactions post gasification.

[0123] Example 13 (invention, D-7)

[0124] Catalyst D-7, containing 53 wt% phosphorous pre-stabilized ZSM-5 (P-ZSM- 5), 40 wt% acid peptized alumina, 7 wt% alumina sol, and 0 wt% Natka clay was prepared as follows. ZSM-5 slurry was mixed with phosphoric acid and milled, then spray dried and calcined for 1 hr at 600°C before being used as a raw material. The spray dried P-ZSM-5, which contains 9.4% P2O5, was then mixed with acid peptized alumina and alumina sol. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 400 °C, followed by water and ammonia solution wash. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 14 below.

[0125] Example 14 (invention, D-8)

[0126] Catalyst D-8, containing 53 wt% phosphorous pre-stabilized ZSM-5 (P-ZSM- 5), 40 wt% acid peptized alumina, 7 wt% alumina sol, and 0 wt% Natka clay was prepared as follows. ZSM-5 slurry was mixed with phosphoric acid and milled, then spray dried and calcined for 1 hr at 600°C before being used as a raw material. The spray dried P-ZSM-5, which contains 11.6% P2O5, was then mixed with acid peptized alumina and alumina sol. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 400 °C, followed by water and ammonia solution wash. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 14 below.

[0127] Example 15 (invention, D-9)

[0128] Catalyst D-9, containing 53 wt% phosphorous pre-stabilized ZSM-5 (P-ZSM- 5), 40 wt% acid peptized alumina, 7 wt% alumina sol, and 0 wt% Natka clay was prepared as follows. ZSM-5 slurry was mixed with phosphoric acid and milled, then spray dried and calcined for 1 hr at 600°C before being used as a raw material. The spray dried P-ZSM-5, which contains 14.1% P2O5, was then mixed with acid peptized alumina and alumina sol. The resulting mixture was milled in a Netzsch mill and spray dried in a Bowen spray dryer. The spray-dried product was calcined in a muffle furnace for 1 hour at 400 °C, followed by water and ammonia solution wash. Prior to any performance testing, the catalyst was steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere. Properties of the fresh and steamed catalyst are as shown in Table 14 below.Table 14 Properties of Catalyst D-7, D-8 and D-9

[0129] Example 15 TGA testing at 400 °C for D-7, D-8 and D-9

[0130] Before the activity testing, the fresh sample of catalyst D-7, D-8 and D-9 were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere to simulate the expected performance of a commercial equilibrium catalysts. Following the testing procedure in Example 5, the steamed samples were tested and compared with the base catalyst (B) and catalyst D-6, The TGA testing result is listed in the Table 15 below.Table 15 TGA testing of catalyst B, D-6, D-7, D-8 and D-9

[0131] The results showed that, by using the phosphorus pre-stabilized ZSM-5 instead of Cat B, the combination of mesoporous active matrix and P- ZSM-5 also generated much more active catalysts for gasification of plastics than the conventional ZSM-5 catalyst (B), and catalyst D-7, D-8 and D-9 had similar gasification activity to D-6 in the pyrolysis of HPP, LLDPE and HOPE at 400 °C. With the increase of P2O5level from D-7 to D-9, the gasification activity only decreased slightly, may be due to the increased chances of poisoning of matrix by phosphorus migration.

[0132] Example 16 Selectivity testing of D-7, D-8 and D-9 at 550 °C.

[0133] Before the testing, the fresh sample of catalyst D-7, D-8 and D-9 were steam deactivated in a fluidized bed reactor for 24 hours at 816 °C in a 100% steam atmosphere to simulate the performance of a commercial equilibrium catalysts. In the selectivity test, each catalyst was tested in a spouted bed reactor at the conditions described in Example 13. The test reached steady state operation within 30 min, and the product distribution of the steady state operation were recorded. The testing results of D-7, D-8 and D-9 are compared with catalyst B and D-6 in the Tables 16, 17 and 18 below.Table 16. Selectivity testing results over HPP at 550 °C

[0134] It is clear from the results in the pyrolysis of HPP at 550 °C that propylene and the overall C2-C5 olefins yield from catalysts D-7, D-8 and D-9 were not only higher than the base catalyst B but also higher than catalyst D-6, which is mainly benefited from the higher P-ZSM-5 input. With the help from the mesoporous active matrix, the yield of gasoline was higher in the case of D-6 with high fraction of gasoline olefins. With 53wt% loading of P-ZSM-5, D-7, D-8 and D-9 were able to convert the gasoline olefins further into light olefins. Propylene yield reached the maximum with catalyst D-8, where P2O5loading reached an optimal balance with good hydrothermal stability of P-ZSM-5 and less P migration to poison the matrix.Table 17. Selectivity testing results over LLDPE at 550 °C

[0135] The results in the pyrolysis of LLDPE at 550 °C over catalysts D-7, D-8 and D-9 were very similar to the results from HPP, where the yields to the light olefins was much higher for the catalysts prepared in accordance with the disclosure. Propylene yield reached the maximum with catalyst D-9 with the least gasoline yield where the yield of gasoline aromatics over catalyst D-9 is still much less than that from the base catalyst B.Table 18 Selectivity testing results over HOPE at 550 °C

[0136] Similar to D-6, the results in the pyrolysis of HOPE over catalyst D-7, D-8 and D-9 at 550 °C had better C3 and gasoline olefinicity than the base catalyst B. With the increase of P-ZSM-5 loading from D-6 to D-7, 8 and 9, the yields of propylene increased back to > 26wt% .exceeding the level of catalyst B. Propylene yield reached the maximum with catalyst D-8 as 27.8wt%, 2.3wt% higher than that from catalyst B. The increase of light olefins yield is the least from the pyrolysis of HDPE among those from LLDPE and HPP. Again, this may be explained from the least catalytic gasification rate promotion in the pyrolysis of HDPE.

[0137] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

[0138] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intentionin the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of’ will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of’ excludes any element not specified.

[0139] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, or compositions, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0140] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0141] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than," and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges asdiscussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member.

[0142] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0143] Other embodiments are set forth in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A catalyst composition comprising: a mesoporous active matrix; and a phosphorus-stabilized ZSM-5.

2. The catalyst composition of claim 1, wherein the mesoporous active matrix comprises one or more of kaolin clay and peptized alumina.

3. The catalyst composition of claims 1 or 2, wherein the catalyst composition comprises greater than about 30% of one or more of kaolin clay and peptized alumina, based on the total weight of the catalyst composition.

4. The catalyst composition of any one of claims 1-3, wherein the catalyst composition comprises greater than about 10% of peptized alumina, based on the total weight of the catalyst composition.

5. The catalyst composition of claim 4, wherein the catalyst composition comprises greater than about 30% of peptized alumina, based on the total weight of the catalyst composition.

6. The catalyst composition of any one of claims 1-5, wherein the catalyst composition comprises from about 10% to about 70% of peptized alumina, based on the total weight of the catalyst composition.

7. The catalyst composition of any one of claims 1-6, wherein the mesoporous active matrix comprises pores having a pore size from about 20 A to about 600Å, or about 40 A to about 600Å.

8. The catalyst composition of any one of claims 1-6, wherein the mesoporous active matrix comprises pores having a pore size of greater than about 600Å.

9. The catalyst composition of any one of claims 1-7, wherein the mesoporous active matrix has a surface area from about 50 m2 / g to about 250 m2 / g prior to deactivation.

10. The catalyst composition of claim 9, wherein the mesoporous active matrix has a surface area from about 60 m2 / g to about 200 m2 / g, from about 80 m2 / g to about 150 m2 / g, or from about 90 m2 / g to about 120 m2 / g prior to deactivation.

11. The catalyst composition of any one of claims 1-10, wherein the mesoporous active matrix has a pore volume of greater than about 0.01 cc / g.

12. The catalyst composition of claim 11, wherein the mesoporous active matrix has a pore volume from about 0.1 cc / g to about 0.4 cc / g.

13. The catalyst composition of any one of claims 1-12, wherein the catalyst composition comprises greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

14. The catalyst composition of claim 13, wherein the catalyst composition comprises from about 5% to about 70% of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

15. The catalyst composition of any one of claims 1-14, wherein the phosphorus-stabilized ZSM-5 further comprises one or more of metals selected from iron, copper, zinc, nickel, titanium, vanadium, chromium, manganese, cobalt, gallium, and boron.

16. The catalyst composition of any one of claims 1-15, wherein the phosphorus-stabilized ZSM-5 has a crystallite size from about 0.05 microns to about 2 microns.

17. The catalyst composition of any one of claims 1-16, wherein the catalyst composition comprises from about 0.5 % w / w to about 15% w / w P2O5, based on the total weight of the composition.

18. The catalyst composition of any one of claims 1-17, wherein the phosphorus-stabilized ZSM-5 and the mesoporous active matrix are separate particles in the catalyst composition.

19. A process of preparing a catalyst composition, the process comprising:(a) providing an aqueous Slurry A comprising solid particles of phosphorus stabilized pentasil zeolite;(b) combining Slurry A with peptized alumina, kaolin clay, and alumina sol to provide Slurry B;(c) spray-drying Slurry B to form catalyst particles; and(d) calcining the spray-dried catalyst particles at a temperature and for a time sufficient to remove volatiles and recover the catalyst composition; wherein: the catalyst composition comprises a mesoporous active matrix; and a phosphorus-stabilized pentasil zeolite.

20. The process of claim 19, wherein the process further comprises washing the calcined catalyst particles with water and an ammonia solution at a pH from about 3 to about 7.5.

21. The process of claims 19 or 20, wherein phosphorus stabilized pentasil zeolite is phosphorus stabilized ZSM-5.

22. The process of claim 21 , wherein phosphorus stabilized ZSM-5 is prepared by any one of the stabilization methods, such as impregnating, incorporating by slurry-addition, spray-drying, and optionally, milling ZSM-5 particles with an appropriate phosphorus compound, such as H3PO4, (NH4)H2PO4, (NH4)iHPO4, and (NH4)3PO4; drying at a temperature of about 120 °C; and calcining at about 600 °C for about 1 hour.

23. The process of claims 21 or 22, wherein phosphorus stabilized ZSM-5 is derived from a commercially available ZSM-5.

24. The process of any one of claims 21-23, wherein the aqueous Slurry A comprises solid particles of phosphorus stabilized ZSM-5 in an amount sufficient to provide a catalyst composition comprising greater than about 5% w / w of phosphorus-stabilized ZSM-5, based on the total weight of the catalyst composition.

25. The process of any one of claims 19-24, wherein the aqueous Slurry B comprises peptized alumina in an amount sufficient to provide a catalyst compositioncomprising greater than about 10% w / w of peptized alumina, based on the total weight of the catalyst composition.

26. The process of any one of claims 19-25, wherein the alumina sol is present in the slurry in an amount sufficient to provide binding for a catalyst comprising from about 5% to about 50% alumina, based on the total weight of the catalyst composition.

27. The process of any one of claims 19-26, wherein spray drying provides catalyst particles having a particle size from about 20 microns to about 200 microns.

28. A process of producing at least one or more of olefins and aromatic compounds from a plastic feedstock, the process comprising: contacting a plastic feedstock and a catalyst composition of any one of claims 1-16 at a temperature from about 400°C to about 700°C in a fluidized bed or a conical spouted bed reactor and for a time period sufficient and under an anaerobic environment to allow at least a portion of the plastic feedstock to be converted to a product stream comprising olefins, aromatic compounds, or a mixture comprising olefins and aromatic compounds.

29. The process of claim 28, wherein contacting the plastic feedstock and the catalyst composition is at a temperature from about 500 °C to about 600 °C.

30. The process of claims 28 or 29, wherein the plastic feedstock comprises at least one of polyethylene, polypropylene, polystyrene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide, polycarbonate, polyurethane, polyester, natural and synthetic rubber, tires, filled polymers, composites, plastic alloys, and plastics dissolved in a solvent.

31. The process of claim 30, wherein the plastic feedstock comprises polyethylene, such as LLDPE and HOPE.

32. The process of claim 30, wherein the plastic feedstock comprises polypropylene, such as HPP.

33. The process of any one of claims 28-32, wherein the product stream comprises olefins comprising ethylene, propylene, butene, or a mixture of any two or more thereof.

34. The process of claim 33, wherein the product stream comprises from about 15 wt% to about 60 wt% olefins, such as ethylene, propylene, and butenes.

35. The process of any one of claims 28-30, wherein the product stream comprises aromatic compounds comprising benzene, toluene, xylene, or a mixture of any two or more thereof.

36. The process of any one of claims 28-35, wherein the process uses a conical spouted bed reactor comprising a draft tube and a confiner.

37. The process of any one of claims 28-35, wherein the process uses a fluidized bed reactor.

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