Microwave-assisted catalytic pyrolysis process and reactor for selective conversion of plastics to olefins

Abstract

The present disclosure provides a pyrolysis process for converting a plastic comprising a polyolefin polymer to an olefin. The method includes contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350 DEG C and about 500 DEG C; wherein the catalyst comprises a solid acid. The present disclosure also provides a one-pot pyrolysis system and the use of a solid acid in a pyrolysis process for converting a plastic comprising a polyolefin polymer to an olefin.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 389,065, filed on July 14, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] The environmental, social and economic impacts of plastic waste are profound. However, global plastic production is rising, with annual production exceeding 365 million metric tons in 2020. A large proportion of plastic waste is single-use plastics, typically consisting of polyolefins (PO) (about 60%), including low-density and high-density polyethylene (LDPE, HDPE) and polypropylene (PP). Mechanical recycling is insufficient to effectively process these materials, leading to a surge in chemical upcycling technologies, including pyrolysis, hydrogenolysis and hydrocracking. The latter two require high-pressure hydrogen, whose production causes significant CO2 emissions, as well as expensive precious metal catalysts (Pt or Ru) to produce a range of alkanes, mainly in the fuel range, which are of lower value. Pyrolysis is a feedstock-independent, ambient-pressure process that operates at high temperatures (about 500-700°C); it is energy-intensive and produces a non-selective hydrocarbon pool (C2-C50 range), the separation of which is challenging and energy-intensive (see Zhao, D. et al., The Chemistry and Kinetics of Polyethylene Pyrolysis: A Process to Produce Fuels and Chemicals, ChemSusChem 13(7)(2020)1764-1774).

[0004] Catalytic pyrolysis at lower temperatures produces a narrower product distribution, such as light olefins (see K. Pyra et al., Towards a greater olefin share in polypropylene cracking–Amorphous mesoporousaluminosilicate competes with zeolites, Appl. Catal. B 297 (2021); M. Artetxe et al., Production of Light Olefins from Polyethylene in a Two-Step Process: Pyrolysis in a Conical Spouted Bed and Downstream High-Temperature Thermal Cracking, Ind. Eng. Chem. Res. 51 (43) (2012) 13915–13923; A. Eschenbacher et al., Maximizing light olefins and aromatics as high value base chemicals via single step catalytic conversion of plastic waste, Chem. Eng. J. 428 (2022), 132087), BTX (benzene, toluene and xylene, see Y. Uemichi et al., Conversion of Polyethylene into Gasoline-Range Fuels by Two-Stage Catalytic Degradation Using Silica-Alumina and HZSM-5 Zeolite, Ind. Eng. Chem. Res. 38(2)(1999)385–390), or gasoline-diesel fuel, Id.Although light olefins (C2-C4) have been produced, the selectivity for long-chain olefins (>C4; valued at $1700 / ton) (which are building blocks used in the chemical industry for lubricants, jet fuels, surfactants, plasticizers, polyethylene comonomers, etc.) is generally very low (see Zhao, D. et al., The Chemistry and Kinetics of Polyethylene Pyrolysis: A Process to Produce Fuels and Chemicals, Chem Sus Chem 13(7)(2020) 1764–1774); W. E. Garwood et al., Process for converting olefins to high viscosity index lubricants, in: US Patent (Ed.) Mobil Oil Corporation, New York, NY, United States, 1985; P. Das et al., Value-added products from thermochemical treatments of contaminated e-waste plastics, Chemosphere 269(2021), 129409; C. Jia et al., Applications, treatments, and reuse of plastics from electrical and electronic equipment, J. Ind. Eng. Chem. 110 (2022) 84–99; or K. Li et al., Catalytic pyrolysis of film waste over Co / Ni pillared montmorillonites towards H2 production, Chemosphere 299 (2022), 134440. Larger olefins are usually made from smaller olefins, mainly ethylene and C4; producing them directly from plastic waste could fill a huge market gap and save additional processing steps, but this has rarely been achieved so far.

[0005] In addition, an overlooked challenge in plastic recycling is its extremely low thermal conductivity (see K. Eiermann et al., Thermal conductivity of high polymers from -180°C. to 90°C, Journal of Polymer Science 57 (165) (1962) 99–106), which leads to slow heating and long processing of hours to days. Long processing times mean that huge reactors are required, which hinders processing close to the source. Most of the methods studied operate at extremely high temperatures and result in moderate to low yields of intermediate olefins.

[0006] Microwaves (MW) can efficiently heat materials quickly and volumetrically, and eliminate associated CO2 emissions by using renewable electricity (see JA Menendez et al., Microwave heating processes involving carbon materials, Fuel Proc, Technol. 91(1)(2010)1–8; or A. Malhotra et al., Temperature Homogeneity under Selective and Localized Microwave Heating in Structured Flow Reactors, Ind. Eng. Chem. Res. 60(18)(2021)6835–6847). However, the poor dielectric properties of plastics (low tan δ) make them poor MW susceptors. A common approach to overcome this challenge is to mix the polymer feedstock with a MW-sensitive dielectric material such as carbon (see C. Ludlow-Palafox et al., Microwave-Induced Pyrolysis of Plastic Wastes, Ind. Eng. Chem. Res. 40(22) (2001) 4749–4756; A. Undri et al., Efficient disposal of waste polyolefins through microwave assisted pyrolysis, Fuel 116 (2014) 662–671; or X. Zhang, H. et al., Gasoline-range hydrocarbons produced from microwave-induced pyrolysis of low-density polyethylene over ZSM-5, Fuel 144 (2015) 33–42). However, many such MW-assisted deconstruction methods are non-catalytic and carried out at high temperatures (500-1000°C), resulting in a wide distribution of products (see C. Ludlow-Palafox et al., Microwave-Induced Pyrolysis of Plastic Wastes, Ind. Eng. Chem. Res. 40(22) (2001) 4749–4756; or A. Undri et al., Efficient disposal of waste polyolefins through microwave assisted pyrolysis, Fuel 116 (2014) 662–671).Some catalytic methods have been reported; however, these methods generally involve a two-stage device, including a pyrolysis reactor followed by a catalytic reactor, in which one or both reactors are heated using MW (see X. Zhang, H. et al., Gasoline-range hydrocarbons produced from microwave-induced pyrolysis of low-density polyethylene over ZSM-5, Fuel 144 (2015) 33–42; or N. Zhou et al., A structured catalyst of ZSM-5 / SiC foam for chemical recycling of waste plastics via catalytic pyrolysis, Chem. Eng. J. 440 (2022), 135836). Recently, Jie et al. proposed a one-pot device using an iron-based dielectric catalyst as a MW receptor to initiate the catalytic deconstruction process (see X. Jie et al., Microwave-initiated catalytic deconstruction of plastic waste into hydrogen and high-value carbons, Nat. Catal. 3 (11) (2020) 902–912). However, a common limitation of most methods is the use of powdered or granular MW susceptors, which are prone to temperature non-uniformity due to the formation of hot spots, especially at high heating rates.

[0007] Therefore, there is a need for an improved catalytic technology that is energy-efficient, low-temperature and easy to operate, and thereby significantly reduces the environmental footprint of modern plastics and upcycles plastics into high-value products, namely long-chain olefins.

[0008] Overview

[0009] The present disclosure provides a pyrolysis method for converting a plastic comprising a polyolefin polymer into an olefin, comprising contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350° C. and about 500° C.; wherein the catalyst comprises a solid acid; and wherein the one-pot pyrolysis system comprises a microwave-assisted slurry reactor. In some embodiments, the plastic comprises high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or a mixture thereof.

[0010] The present invention also provides a one-pot pyrolysis system, comprising a microwave-assisted slurry reactor; and a condenser section; wherein the microwave-assisted slurry reactor comprises a reaction vessel and a microwave source. In some embodiments, the reaction vessel comprises a microwave susceptor.

[0011] The present disclosure also provides the use of a solid acid in a pyrolysis process for converting a plastic comprising a polyolefin polymer into olefins; wherein the solid acid is selected from the group consisting of P-SiO2, 15WZr, 25WZr, H-ZSM-5, Al-MCM-41, Al-SBA-15 and HY(30). BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A shows the technology of medium-sized olefins disclosed in the art and proposed in this disclosure. The naphtha conversion and steam cracking disclosed in the art are carried out in two steps: production of ethylene and its oligomerization to medium-sized olefins. The technology disclosed in this disclosure achieves this in one step.

[0014] Figure 1 B shows a MW slurry reactive distillation pyrolysis reactor for the selective production of olefins from LDPE.

[0015] Figure 1 C is a diagram of gas bubbling through a polymer catalyst melt containing a microwave absorbing SiC monolith.

[0016] Figure 2 A shows the experimental setup for microwave-assisted pyrolysis of LDPE.

[0017] Figure 2 B shows a reactor for conventional pyrolysis of LDPE with heating belts.

[0018] Figure 2 C shows a SiC monolith used as a MW susceptor.

[0019] Figure 2 D shows the temperature distribution obtained from an infrared (IR) imager during microwave pyrolysis of LDPE.

[0020] Figure 3 A typical temperature profile for the MW pyrolysis of LDPE is shown.

[0021] Figure 4 Shown is the experimental setup for conventional heating pyrolysis of LDPE.

[0022] Figure 5 A GC-MS chromatogram of a hydrocarbon mixture calibration standard 1 is shown.

[0023] Figure 6 A GC-MS chromatogram of a hydrocarbon mixture calibration standard 2 is shown.

[0024] Figure 7 The GC-MS chromatogram of the hydrocarbon mixture calibration standard 3 is shown.

[0025] Figure 8 AC shows the experimental setup for microwave heating temperature distribution measurements using different filler materials.

[0026] Fig. 9 An overview of the stages involved in an integrated process for producing lubricants starting from pyrolysis of LDPE is shown.

[0027] Fig.10 A portion of the process of depolymerization and separation of the products is shown.

[0028] Fig.11 The oligomerization of butene and propylene into a lubricant is shown.

[0029] Fig.12 A process for producing lubricants from α-olefins by oligomerization is shown.

[0030] Fig.13 The system boundaries analyzed in the LCA are shown.

[0031] Fig.14 A shows a comparison of MW pyrolysis using TGA at different temperatures.

[0032] Fig.14 B shows the effect of varying the gas flow rate in microwave pyrolysis of LDPE in N2 at 375°C.

[0033] Fig.14 C shows the comparison of MW pyrolysis performance using H2 and N2 at different flow rates.

[0034] FIG. 15A shows the LDPE conversion in MW pyrolysis over various solid acid catalysts (reaction conditions: 375° C., 100 mL / min N 2 flow, reaction time 200 s).

[0035] FIG. 15B shows the selectivity (based on C number) of extractable products in MW pyrolysis over various solid acid catalysts (reaction conditions: 375° C., 100 mL / min N 2 flow, reaction time 200 s).

[0036] Fig. 15C The alkane / olefin selectivity in MW pyrolysis over a variety of different solid acid catalysts is shown (reaction conditions: 375° C., 100 mL / min N 2 flow, reaction time 200 sec).

[0037] FIG. 15D shows a typical product distribution using HY (30) in MW pyrolysis (reaction conditions: 375° C., 100 mL / min N 2 flow, reaction time 200 sec).

[0038] FIG. 15E shows a typical product distribution using Al-SBA-15 in MW pyrolysis (reaction conditions: 375° C., 100 mL / min N 2 flow, reaction time 200 sec).

[0039] Fig.16 A shows the LDPE conversion as a function of time.

[0040] Fig.16 B shows the major product selectivity on 0.5Pt-HY.

[0041] Fig.16 C shows the main product selectivity over the Al-SBA-15 catalyst.

[0042] Figure 17A shows the performance of MW and CH pyrolysis over the HY catalyst, also demonstrating the effect of the monolith in CH.

[0043] FIG. 17B shows the MW and CH pyrolysis performance over the Al-SBA-15 catalyst.

[0044] FIG. 17C shows the char from MW and CH pyrolysis.

[0045] FIG. 17D shows the Raman spectrum of coke on 0.5Pt-HY.

[0046] Fig.17E-F Raman spectra of MW and CH pyrolysis on Al-SBA-15 in N 2 flow are shown, respectively.

[0047] FIG. 17G shows the weight loss percentage of MW and CH char obtained from pyrolysis of LDPE on 0.5Pt-HY in TGA.

[0048] FIG. 17H shows the effect of flow rate between the monolith and the wall and filler quartz particle size on the thermal gradient in MW heating.

[0049] Fig.17I The effect of the Nusselt number on the thermal gradient in MW heating predicted by multiscale, multiphysics simulations is shown.

[0050] Fig.18A Shown is the product distribution of extractables obtained from CH pyrolysis of LDPE on 0.5Pt-HY(30) (reaction conditions: temperature - 375°C, gas flow rate - 100 ml / min N2 and time - 200 sec).

[0051] Fig.18BShown is the product distribution of extractables obtained from MW pyrolysis of LDPE on 0.5Pt-HY(30) (reaction conditions: temperature - 375°C, gas flow rate - 100 ml / min N2 and time - 200 sec).

[0052] Fig.19 Reaction pathways for the MW-assisted catalytic pyrolysis of LPDE over solid acid catalysts are shown. (A) Unimolecular pyrolysis. (B) Bimolecular pyrolysis. (C) Coke formation pathway. (D) H-transfer pathway.

[0053] Fig. 20 A shows a comparison of TGA profiles of coked HY catalysts obtained from CH and MW pyrolysis of LDPE in N2 gas stream.

[0054] Fig. 20 B shows a comparison of the DSC profiles of the coked HY catalysts obtained from CH and MW pyrolysis of LDPE in N2 gas stream.

[0055] Fig.21 A shows the TGA profile of the coked Al-SBA-15 catalyst obtained from CH and MW pyrolysis of LDPE in N2 gas stream.

[0056] Fig.21 B shows the DSC profile of the coked Al-SBA-15 catalyst obtained from CH and MW pyrolysis of LDPE in N2 gas stream.

[0057] Fig. 22 The percent weight loss of MW and CH char in TGA obtained from pyrolysis of LDPE on Al-SBA-15 is shown.

[0058] Fig.23 Shown is the deconvolution of the Raman spectrum of a char sample obtained from pyrolysis of a MW slurry of LDPE over HY catalyst.

[0059] Fig.24 Shown is the Raman spectrum of char in the MW pyrolysis of LDPE on Al-SBA-15 in H2 flow.

[0060] Fig.25 The temperature distribution measured by optical fiber and pyrometer for microwave heating using N2 as filler material is shown.

[0061] 26 shows the temperature distribution measured by optical fiber and pyrometer for microwave heating using quartz with particle sizes of (A) 30-40 mesh, (B) 40-60 mesh, and (C) >60 mesh as filler material.

[0062] Figure 27 shows the temperature distribution of microwave heating using LDPE as filler material measured by optical fiber and pyrometer, measured at different N2 flow rates: (A) 3 mL / min, (B) 50 mL / min, (C) 100 mL / min and (D) 150 mL / min.

[0063] Fig.28 Cost allocation is shown.

[0064] Fig.29 The CAPEX distribution of the units in each segment is shown.

[0065] Fig.30 The effect of LDPE prices on lubricant MSP is shown. The green area corresponds to prices below the lowest lubricant prices reported in the past decade. The blue area is the price range of the past decade. The red area corresponds to the area above the highest lubricant prices seen in the past decade.

[0066] Fig.31 The effect of scale on the MSP of lubricants in the MW-Al case is shown.

[0067] Fig.32 The MSP of lubricants for different MW generator costs is shown.

[0068] Fig.33 The relationship between the lubricant selling price and the IRR expected by investors for different LDPE prices is shown for a plant with a processing capacity of 32 kt / yr. The upper limit of the error bar is obtained by the pessimistic scenario (MW reactor cost of $700 / kWh, electricity cost of 16.6 cents / kWh, IF = 2.5). The lower limit of the error bar is MW reactor cost of $300 / kWh, electricity cost of 3.6 cents / kWh, IF = 1.1.

[0069] Fig.34 A breakdown of the positive contributors to the MW-Al effect is shown.

[0070] Fig.35 A breakdown of the positive contributors to the impact of MW-Pt is shown.

[0071] Fig.36 A breakdown of the positive contributions to the overall-Pt effect is shown.

[0072] Fig.37 A breakdown of the positive contributors to the overall-Al impact is shown.

[0073] Fig.38 The influence distribution between different process contributing factors of Conv is shown.

[0074] Detailed Description

[0075] 1. Methods of the present disclosure

[0076] In a first embodiment, the present disclosure provides a pyrolysis method for converting a plastic comprising a polyolefin polymer into olefins, comprising contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350°C and about 500°C; wherein the catalyst comprises a solid acid; and wherein the one-pot pyrolysis system comprises a microwave-assisted slurry reactor.

[0077] In a second embodiment, the present disclosure provides a method according to the first embodiment, wherein the plastic comprises a homopolymer of an olefin, a copolymer of an olefin, or a mixture thereof.Definitions for the remaining variables are provided in the first embodiment and other embodiments described herein.

[0078] In a third embodiment, the present disclosure provides a method according to the first embodiment or the second embodiment, wherein the plastic comprises polyethylene, polypropylene, polybutylene, polyisobutylene, polypentene, polyhexene, polyoctene, polystyrene or a mixture thereof. The definitions of the remaining variables are provided in the first embodiment or the second embodiment and in other embodiments described herein.

[0079] In a fourth embodiment, the present disclosure provides a method according to any one of the first to third embodiments, wherein the plastic comprises high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS) or a mixture thereof. The definitions of the remaining variables are provided in any one of the first to third embodiments and other embodiments described herein.

[0080] In a fifth embodiment, the present disclosure provides a method according to any one of the first to fourth embodiments, wherein the plastic is selected from isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, low molecular weight isotactic polypropylene, amorphous polypropylene, polypropylene bottles, polypropylene transparent bags, and mixtures thereof. The definitions of the remaining variables are provided in any one of the first to fourth embodiments and other embodiments described herein.

[0081] In a sixth embodiment, the present disclosure provides a method according to any one of the first to fifth embodiments, wherein the plastic is selected from isotactic polypropylene, low molecular weight isotactic polypropylene, amorphous polypropylene, polypropylene bottles, polypropylene transparent bags, and mixtures thereof. The definitions of the remaining variables are provided in any one of the first to fifth embodiments and other embodiments described herein.

[0082] In a seventh embodiment, the present disclosure provides a method according to any one of the first to sixth embodiments, wherein the pyrolysis process is carried out in a gas flow at a rate of about 5 ml / min to about 150 ml / min. The definitions of the remaining variables are provided in any one of the first to sixth embodiments and other embodiments described herein. In one embodiment, the rate of the gas flow is from about 10 ml / min to about 150 ml / min, from about 20 ml / min to about 150 ml / min, from about 30 ml / min to about 150 ml / min, from about 40 ml / min to about 150 ml / min, from about 50 ml / min to about 150 ml / min, from about 60 ml / min to about 150 ml / min, from about 70 ml / min to about 150 ml / min, from about 80 ml / min to about 150 ml / min, from about 90 ml / min to about 150 ml / min, from about 90 ml / min to about 140 ml / min, from about 90 ml / min to about 130 ml / min, from about 90 ml / min to about 120 ml / min, or from about 90 ml / min to about 110 ml / min. In one embodiment, the rate of the gas flow is about 10 ml / min, about 15 ml / min, about 20 ml / min, about 25 ml / min, about 30 ml / min, about 35 ml / min, about 40 ml / min, about 45 ml / min, about 50 ml / min, about 55 ml / min, about 60 ml / min, about 65 ml / min, about 70 ml / min, about 75 ml / min, about 80 ml / min, about 85 ml / min, about 90 ml / min, about 95 ml / min, about 100 ml / min, about 105 ml / min, about 110 ml / min, about 115 ml / min, about 120 ml / min, about 125 ml / min, about 130 ml / min, about 135 ml / min, about 140 ml / min, about 145 ml / min, or about 150 ml / min.

[0083] In an eighth embodiment, the present disclosure provides a method according to the seventh embodiment, wherein the rate of gas flow is from about 15 ml / min to about 125 ml / min. Definitions for the remaining variables are provided in the seventh embodiment and other embodiments described herein.

[0084] In a ninth embodiment, the present disclosure provides a method according to the seventh and eighth embodiments, wherein the rate of the gas flow is from about 25 ml / min to about 100 ml / min. The definitions of the remaining variables are provided in the seventh and eighth embodiments or other embodiments described herein.

[0085] In the tenth embodiment, the present disclosure provides a method according to any one of the seventh to ninth embodiments, wherein the rate of the gas flow is about 25 ml / min, about 50 ml / min, about 75 ml / min, or about 100 ml / min. The definitions of the remaining variables are provided in any one of the seventh to ninth embodiments and other embodiments described herein.

[0086] In an eleventh embodiment, the present disclosure provides a method according to any one of the seventh to tenth embodiments, wherein the rate of the gas flow is about 100 ml / min. The definitions of the remaining variables are provided in any one of the seventh to tenth embodiments and other embodiments described herein.

[0087] In a twelfth embodiment, the present disclosure provides a method according to any one of the seventh to eleventh embodiments, wherein the gas stream comprises nitrogen or hydrogen. The definitions of the remaining variables are provided in any one of the seventh to eleventh embodiments and other embodiments described herein.

[0088] In a thirteenth embodiment, the present disclosure provides a method according to the twelfth embodiment, wherein the gas stream is a nitrogen stream.Definitions for the remaining variables are provided in the twelfth embodiment and other embodiments described herein.

[0089] In a fourteenth embodiment, the disclosure provides a method according to any one of the first to thirteenth embodiments, wherein the temperature is from about 350°C to about 475°C. The definitions of the remaining variables are provided in any one of the first to thirteenth embodiments and other embodiments described herein. In one embodiment, the temperature is from about 350°C to about 450°C, from about 350°C to about 425°C, from about 350°C to about 400°C, from about 350°C to about 375°C, from about 375°C to about 450°C, from about 400°C to about 450°C, or from about 425°C to about 450°C. In one embodiment, the temperature is about 350°C, about 355°C, about 360°C, about 365°C, about 370°C, about 375°C, about 380°C, about 385°C, about 390°C, about 395°C, about 400°C, about 405°C, about 410°C, about 415°C, about 420°C, about 425°C, about 430°C, about 435°C, about 440°C, about 445°C, about 450°C, about 455°C, about 460°C, about 465°C, about 470°C, about 475°C, about 480°C, about 485°C, about 495°C or about 500°C.

[0090] In a fifteenth embodiment, the present disclosure provides a method according to any one of the first to fourteenth embodiments, wherein the temperature is from about 350° C. to about 450° C. The definitions of the remaining variables are provided in any one of the first to fourteenth embodiments and other embodiments described herein.

[0091] In a sixteenth embodiment, the present disclosure provides a method according to any one of the first to fifteenth embodiments, wherein the temperature is about 350° C. to about 400° C. The definitions of the remaining variables are provided in any one of the first to fifteenth embodiments and other embodiments described herein.

[0092] In a seventeenth embodiment, the present disclosure provides a method according to any one of the first to sixteenth embodiments, wherein the temperature is about 375°C.

[0093] In an eighteenth embodiment, the present disclosure provides a method according to any one of the first to seventeenth embodiments, wherein the pyrolysis process is performed for a period of less than 10 minutes. In one embodiment, the period of time is from about 5 seconds to about 600 seconds, from about 10 seconds to about 600 seconds, from about 15 seconds to about 600 seconds, from about 20 seconds to about 600 seconds, from about 25 seconds to about 600 seconds, from about 30 seconds to about 600 seconds, from about 35 seconds to about 600 seconds, from about 40 seconds to about 600 seconds, from about 45 seconds to about 600 seconds, from about 50 seconds to about 600 seconds, from about 55 seconds to about 600 seconds, from about 60 seconds to about 600 seconds, or from about 60 seconds to about 600 seconds. 0 seconds, about 65 seconds to about 600 seconds, about 70 seconds to about 600 seconds, about 75 seconds to about 600 seconds, about 80 seconds to about 600 seconds, about 85 seconds to about 600 seconds, about 90 seconds to about 600 seconds, about 95 seconds to about 600 seconds, about 100 seconds to about 600 seconds, about 105 seconds to about 600 seconds, about 110 seconds to about 600 seconds, about 115 seconds to about 600 seconds, about 120 seconds to about 600 seconds, about 12 150 sec to about 600 sec, about 160 sec to about 600 sec, about 165 sec to about 600 sec, about 170 sec to about 600 sec, about 175 sec to about 600 sec, about 180 sec to about 600 sec, about 185 sec to about 600 sec, about 190 sec to about 600 sec, about 200 sec to about 600 sec, about 210 sec to about 600 sec, about 220 sec to about 600 sec, about 230 sec to about 600 sec, about 240 sec to about 600 sec, about 250 sec to about 600 sec, about 260 sec to about 600 sec, about 270 sec to about 600 sec, about 280 sec to about 600 sec, about 290 sec to about 600 sec, about 300 sec to about 600 sec, about 310 sec to about 600 sec, about 320 sec to about 600 sec, about 330 sec to about 600 sec, about 340 sec to about 600 sec, about 350 sec to about 600 sec, about 360 sec to about 600 sec, about 370 sec to about 600 sec, about 380 sec to about 600 sec, about In one embodiment, the time period is about 5 seconds, about 10 seconds, about 50 seconds, about 100 seconds, about 150 seconds, about 200 seconds, about 250 seconds, about 300 seconds, about 350 seconds, about 200 seconds to about 450 seconds, about 200 seconds to about 400 seconds, about 200 seconds to about 350 seconds, about 200 seconds to about 300 seconds, about 200 seconds to about 250 seconds, or about 200 seconds to about 225 seconds. In one embodiment, the time period is about 5 seconds, about 10 seconds, about 50 seconds, about 100 seconds, about 150 seconds, about 200 seconds, about 250 seconds, about 300 seconds, about 350 seconds, about 400 seconds, about 450 seconds, about 500 seconds, about 550 seconds, or about 600 seconds.

[0094] In a nineteenth embodiment, the present disclosure provides a method according to the eighteenth embodiment, wherein the time period is from about 10 seconds to about 400 seconds.Definitions for the remaining variables are provided in the eighteenth embodiment and other embodiments described herein.

[0095] In a twentieth embodiment, the present disclosure provides a method according to the eighteenth or nineteenth embodiment, wherein the time period is from about 50 seconds to about 250 seconds.Definitions for the remaining variables are provided in the eighteenth or nineteenth embodiment, as well as other embodiments described herein.

[0096] In a twenty-first embodiment, the present disclosure provides a method according to any one of the eighteenth to twentieth embodiments, wherein the time period is about 200 seconds.Definitions for the remaining variables are provided in the eighteenth to twentieth embodiments and other embodiments described herein.

[0097] In a twenty-second embodiment, the present disclosure provides a method according to any one of the first to twenty-first embodiments, wherein the olefin is C4-C 12 A mixture of olefins. The definitions for the remaining variables are provided in any of the first through twenty-first embodiments, and other embodiments described herein.

[0098] In a twenty-third embodiment, the present disclosure provides a method according to any one of the first to twenty-second embodiments, wherein the olefin is selected from C4 olefins, C5 olefins, C7-C 12 Mixtures of olefins and mixtures thereof. Definitions for the remaining variables are provided in the first through twenty-second embodiments, as well as other embodiments described herein.

[0099] In the twenty-fourth embodiment, the disclosure provides a method according to any one of the first to twenty-third embodiments, wherein the weight ratio between plastic and catalyst is about 40: 1 to about 2: 1. The definitions of the remaining variables are provided in any one of the first to twenty-third embodiments and other embodiments described herein. In one embodiment, the weight ratio between plastic and catalyst is about 40: 1 to about 2: 1, about 35: 1 to about 2: 1, about 30: 1 to about 25: 1, about 20: 1 to about 2: 1, about 15: 1 to about 2: 1, about 10: 1 to about 2: 1, about 5: 1 to about 2: 1, about 3: 1 to about 2: 1, about 40: 1 to about 5: 1, about 40: 1 to about 10: 1, about 40: 1 to about 15: 1, about 40: 1 to about 20: 1, about 40: 1 to about 25: 1, about 40: 1 to about 30: 1, or about 40: 1 to about 35: 1. In one embodiment, the weight ratio between plastic and catalyst is about 40:1, about 35:1, about 30:1, about 25:1, about 20:1, about 15:1, about 10:1, about 5:1, about 3:1, or about 3:1.

[0100] In a twenty-fifth embodiment, the present disclosure provides a method according to any one of the first to twenty-fourth embodiments, wherein the weight ratio between the plastic and the catalyst is from about 30: 1 to about 5: 1. The definitions of the remaining variables are provided in any one of the first to twenty-fourth embodiments and other embodiments described herein.

[0101] In a twenty-sixth embodiment, the present disclosure provides a method according to any one of the first to twenty-fifth embodiments, wherein the weight ratio between the plastic and the catalyst is from about 20: 1 to about 8: 1. The definitions of the remaining variables are provided in any one of the first to twenty-fifth embodiments and other embodiments described herein.

[0102] In a twenty-seventh embodiment, the present disclosure provides a method according to any one of the first to twenty-sixth embodiments, wherein the weight ratio between the plastic and the catalyst is about 10: 1. Definitions for the remaining variables are provided in the first to twenty-sixth embodiments and other embodiments described herein.

[0103] In a twenty-eighth embodiment, the disclosure provides a method according to any one of the first to twenty-seventh embodiments, wherein the conversion rate of plastics is at least about 25%. The definitions of the remaining variables are provided in any one of the first to twenty-seventh embodiments and other embodiments described herein. In one embodiment, the conversion rate of plastics is at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% or at least 95%.

[0104] In a twenty-ninth embodiment, the present disclosure provides a method according to any one of the first to twenty-eighth embodiments, wherein the conversion rate of the plastic is at least about 40%. The definitions of the remaining variables are provided in any one of the first to twenty-eighth embodiments and other embodiments described herein.

[0105] In a thirtieth embodiment, the present disclosure provides a method according to any one of the first to twenty-ninth embodiments, wherein the conversion rate of the plastic is at least about 60%. The definitions of the remaining variables are provided in any one of the first to twenty-ninth embodiments and other embodiments described herein.

[0106] In a thirty-first embodiment, the present disclosure provides a method according to any one of the first to thirtieth embodiments, wherein the conversion rate of the plastic is at least about 90%. The definitions of the remaining variables are provided in any one of the first to thirtieth embodiments and other embodiments described herein.

[0107] In the 32nd embodiment, present disclosure provides the method according to any one in the first to the 31st embodiment, wherein the yield of alkene is at least about 25%. The limitation of remaining variables is provided in any one in the first to the 31st embodiment and other embodiments as described herein. In one embodiment, the yield of alkene is at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% or at least 95%.

[0108] In a thirty-third embodiment, the present disclosure provides a method according to any one of the first to thirty-second embodiments, wherein the yield of olefins is at least about 70%.Definitions for the remaining variables are provided in any one of the first to thirty-second embodiments and other embodiments described herein.

[0109] In a thirty-fourth embodiment, the present disclosure provides a process according to any one of the first to thirty-third embodiments, wherein the yield of olefins is at least about 80%.Definitions for the remaining variables are provided in any one of the first to thirty-third embodiments and other embodiments described herein.

[0110] In a thirty-fifth embodiment, the present disclosure provides a method according to any one of the first to thirty-fourth embodiments, wherein the catalyst is selected from P-SiO2, 15WZr, 25WZr, H-ZSM-5, Al-MCM-41, Al-SBA-15 and HY(30). The definitions of the remaining variables are provided in any one of the first to thirty-fourth embodiments and other embodiments described herein.

[0111] In a thirty-sixth embodiment, the present disclosure provides a method according to any one of the first to thirty-fifth embodiments, wherein the method further comprises separating the obtained liquid pyrolysis product from the obtained gaseous pyrolysis product by a condenser portion. The definitions of the remaining variables are provided in any one of the first to thirty-fifth embodiments and other embodiments described herein.

[0112] In a thirty-seventh embodiment, the present disclosure provides a method according to any one of the first to thirty-sixth embodiments, wherein the microwave-assisted slurry reactor comprises a reaction vessel and a microwave source. The definitions of the remaining variables are provided in any one of the first to thirty-sixth embodiments and other embodiments described herein.

[0113] In a thirty-eighth embodiment, the present disclosure provides a method according to the thirty-seventh embodiment, wherein the reaction vessel comprises

[0114] A plastic inlet for adding plastic; and

[0115] Gas inlet for injecting gas flow into the reaction vessel.

[0116] Definitions for the remaining variables are provided in the thirty-seventh embodiment and other embodiments described herein.

[0117] In a thirty-ninth embodiment, the present disclosure provides a method according to the thirty-seventh or thirty-eighth embodiment, wherein the reaction vessel is a tubular reactor.

[0118] In the 40th embodiment, the present disclosure provides a method according to any one of the 37th to 39th embodiments, wherein the reaction vessel further comprises a porous block (frit). The definitions of the remaining variables are provided in any one of the 37th to 39th embodiments and other embodiments described herein.

[0119] In a forty-first embodiment, the present disclosure provides a method according to the fortieth embodiment, wherein the porous block is a porous quartz block fixed in a reaction vessel.Definitions for the remaining variables are provided in the fortieth embodiment and other embodiments described herein.

[0120] In a forty-second embodiment, the present disclosure provides a method according to any one of the thirty-seventh to forty-first embodiments, wherein the reaction vessel comprises a microwave susceptor. The definitions of the remaining variables are provided in any one of the thirty-seventh to forty-first embodiments and other embodiments described herein.

[0121] In a forty-third embodiment, the present disclosure provides a method according to the forty-second embodiment, wherein the microwave susceptor is a SiC monolith.Definitions for the remaining variables are provided in the forty-second embodiment and other embodiments described herein.

[0122] In a 44th embodiment, the present disclosure provides a method according to any one of the 37th to 43rd embodiments, wherein the microwave source emits microwaves to melt the plastic to form a slurry in a reaction vessel. The definitions of the remaining variables are provided in any one of the 37th to 43rd embodiments and other embodiments described herein.

[0123] In a forty-fifth embodiment, the present disclosure provides a method according to any one of the thirty-seventh to forty-fourth embodiments, further comprising a temperature probe for measuring the core temperature within the reactor vessel. The definitions of the remaining variables are provided in any one of the thirty-seventh to forty-third embodiments and other embodiments described herein.

[0124] 2. One-pot pyrolysis system

[0125] In a forty-sixth embodiment, the present disclosure provides a one-pot pyrolysis system comprising

[0126] A microwave-assisted slurry reactor; and

[0127] Condenser section;

[0128] The microwave-assisted slurry reactor includes a reaction container and a microwave source.

[0129] In a forty-seventh embodiment, the present disclosure provides a one-pot pyrolysis system according to the forty-sixth embodiment, wherein the reaction vessel comprises

[0130] A plastic inlet for adding plastic; and

[0131] Gas inlet for injecting gas flow into the reaction vessel.

[0132] Definitions for the remaining variables are provided in the forty-sixth embodiment and other embodiments described herein.

[0133] In a forty-eighth embodiment, the present disclosure provides a one-pot pyrolysis system according to the forty-sixth or forty-seventh embodiment, wherein the reaction vessel is a tubular reactor. Definitions for the remaining variables are provided in the forty-sixth or forty-seventh embodiment and other embodiments described herein.

[0134] In a forty-ninth embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to forty-eighth embodiments, wherein the reaction vessel further comprises a porous block. The definitions of the remaining variables are provided in any one of the forty-sixth to forty-eighth embodiments and other embodiments described herein.

[0135] In a fiftieth embodiment, the present disclosure provides a one-pot pyrolysis system according to the forty-ninth embodiment, wherein the porous block is a porous quartz block fixed in the reaction vessel. Definitions of the remaining variables are provided in the forty-ninth embodiment and other embodiments described herein.

[0136] In a fifty-first embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to fiftieth embodiments, wherein the reaction vessel comprises a microwave susceptor. The definitions of the remaining variables are provided in any one of the forty-sixth to fiftieth embodiments and other embodiments described herein.

[0137] In a fifty-second embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-first embodiment, wherein the microwave susceptor is a SiC monolith.Definitions for the remaining variables are provided in the fifty-first embodiment and other embodiments described herein.

[0138] In a fifty-third embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to fifty-second embodiments, wherein the microwave source emits microwaves to melt the plastic to form a slurry in the reaction vessel. The definitions of the remaining variables are provided in any one of the forty-sixth to fifty-second embodiments and other embodiments described herein.

[0139] In a fifty-fourth embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to fifty-third embodiments, further comprising a temperature probe for measuring the core temperature within the reaction vessel. The definitions of the remaining variables are provided in any one of the forty-sixth to fifty-third embodiments and other embodiments described herein.

[0140] In a fifty-fifth embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to fifty-fourth embodiments, wherein the condenser portion is connected to the microwave-assisted slurry reactor by a connecting device. The definitions of the remaining variables are provided in any one of the forty-sixth to fifty-fourth embodiments and other embodiments described herein.

[0141] In a fifty-sixth embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-fifth embodiment, wherein the connecting device is a glass tube. Definitions of the remaining variables are provided in the fifty-fifth embodiment and other embodiments described herein.

[0142] In a fifty-seventh embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-sixth embodiment, wherein the glass tube is surrounded by a heating belt. Definitions for the remaining variables are provided in the fifty-sixth embodiment and other embodiments described herein.

[0143] In a fifty-eighth embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to fifty-seventh embodiments, wherein the condenser portion separates the liquid pyrolysis products from the gaseous pyrolysis products. The definitions of the remaining variables are provided in any one of the forty-sixth to fifty-seventh embodiments and other embodiments described herein.

[0144] In a fifty-ninth embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-eighth embodiment, wherein the condenser portion comprises at least one cooling system.Definitions of the remaining variables are provided in the fifty-eighth embodiment and other embodiments described herein.

[0145] In a sixtieth embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-ninth embodiment, wherein at least one cooling system is a water cooling system. Definitions of the remaining variables are provided in the fifty-ninth embodiment and other embodiments described herein.

[0146] In the sixty-first embodiment, the present disclosure provides a one-pot pyrolysis system according to the fifty-eighth to sixtieth embodiments, wherein the condenser portion comprises at least one condenser. The definitions of the remaining variables are provided in any one of the fifty-eighth to sixtieth embodiments and other embodiments described herein.

[0147] In a sixty-second embodiment, the present disclosure provides a one-pot pyrolysis system according to any one of the forty-sixth to sixty-first embodiments, wherein the condenser portion is connected to a gas collection element and a liquid collection element. The definitions of the remaining variables are provided in any one of the forty-sixth to sixty-first embodiments and other embodiments described herein.

[0148] In a sixty-third embodiment, the present disclosure provides a one-pot pyrolysis system according to the sixty-second embodiment, wherein the gas collection element is a gas bag. Definitions for the remaining variables are provided in the sixty-second embodiment and other embodiments described herein.

[0149] In a sixty-fourth embodiment, the present disclosure provides a one-pot pyrolysis system according to the sixty-third embodiment, wherein the liquid collection element is a glass bottle. Definitions for the remaining variables are provided in the sixty-third embodiment and other embodiments described herein.

[0150] In a sixty-fifth embodiment, the present disclosure provides a one-pot pyrolysis system according to the sixty-fourth embodiment, wherein the glass bottle is immersed in an ice bath. Definitions for the remaining variables are provided in the sixty-fourth embodiment and other embodiments described herein.

[0151] 3. Use of solid acid in pyrolysis method

[0152] In the sixty-sixth embodiment, the present disclosure provides the use of a solid acid in a pyrolysis process for converting a plastic comprising a polyolefin polymer into olefins; wherein the solid acid is selected from the group consisting of P-SiO2, 15WZr, 25WZr, H-ZSM-5, Al-MCM-41, Al-SBA-15 and HY(30).

[0153] In a sixty-seventh embodiment, the present disclosure provides a use according to the sixty-sixth embodiment, wherein the pyrolysis method comprises contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350°C and about 500°C.

[0154] In a sixty-eighth embodiment, the present disclosure provides a use according to the sixty-seventh embodiment, wherein the one-pot pyrolysis system comprises a microwave-assisted slurry reactor. Definitions for the remaining variables are provided in the sixty-seventh embodiment and other embodiments described herein.

[0155] 4.Limited

[0156] For ease of understanding of the disclosure described herein, some terms are defined below. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the disclosure belongs. In the event of a conflict, the present application (including the limitations) shall prevail. Unless the context otherwise requires, singular terms include plural terms, and plural terms include singular terms. All publications, patents and other references mentioned herein are incorporated by reference in their entirety for all purposes, as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

[0157] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are for illustrative purposes only and are not intended to be limiting. Other features and advantages of the present disclosure will be apparent from the detailed description and claims.

[0158] In this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. The term "a" (or "an") and the terms "one or more" and "at least one" are used interchangeably herein. In some aspects, the term "a" or "an" means "single". In other aspects, the term "a" or "an" includes "two or more" or "plurality".

[0159] The term "about" is used herein to mean approximately, roughly, around, or in the region of. When the term "about" is used in conjunction with a numerical range, it modifies the range by expanding the boundaries above and below the listed numerical values. Generally speaking, the term "about" is used herein to modify a numerical value above and below the stated value by a difference of 10% above or below (higher or lower).

[0160] As used herein, the term "alkene" or "olefin" generally refers to a hydrocarbon derived from C 2-12 A straight chain or branched hydrocarbon is a monovalent group having at least one carbon-carbon double bond by removing a single hydrogen molecule. Examples of olefins include, but are not limited to, higher homologs and isomers of ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, and decene.

[0161] The term "plastic" as used herein generally refers to materials based on organic macromolecules mainly composed of carbon and hydrogen, such as polyolefins, or also containing oxygen, such as polyesters, polyethers, acrylic and methacrylic polymers, polyacetals, or macromolecules also containing nitrogen, such as polyamides and polyurethanes, or macromolecules also containing halogens, such as polyvinyl chloride and fluorinated polymers, or sulfur-containing macromolecules, such as polysulfides and polysulfones, or copolymers obtained by combining various monomers, such as acrylonitrile-butadiene copolymers (ABS) and the like. In one embodiment, the plastic used in the present disclosure is recycled plastic, that is, recovered from household and / or industrial waste by appropriate mechanical selection and grinding operations, as known in the art. Therefore, it can also include various additives and other components for the production of articles derived from recycled plastic. In one embodiment, the carbon content of the plastic used is greater than 45 weight %, greater than 60 weight % or greater than 70 weight %. In one embodiment, the hydrogen content of the plastic used is greater than 5 weight %, greater than 8 weight % or greater than 12 weight %. In one embodiment, the oxygen content is less than 20 weight %, less than 10 weight %, or less than 7 weight %. In one embodiment, the sum of the contents of nitrogen, halogens and sulfur is less than 3 wt%, less than 2 wt%, or less than 0.5 wt%.

[0162] The term "polyolefin polymer" as used herein generally refers to all polymers and copolymers (including high pressure low density polyethylene (LDPE), heterogeneous polymers, random, block and graft polymers, interpolymers and copolymers) containing one or more polymerized monomers selected from ethylene, alpha olefins having 3 to 20 carbon atoms (e.g., 1-propylene, 1-butene, 1-hexene, styrene, 1-heptene and 1-octene), 4-methyl-1-pentene and / or acetylenically unsaturated monomers having 2 to 20 carbon atoms and / or dienes having 4 to 18 carbon atoms and any other monomers used in the art to modify the density of the polymer. Heterogeneous polymers include Ziegler-Natta polymers such as LLDPE and HDPE, and include products such as DOWLEX manufactured by The Dow Chemical Company. TM Linear low density polyethylene (LLDPE). Random copolymers include copolymers polymerized using metallocene or constrained geometry catalyst technology and include polymers such as AFFINITY TM Polyolefin elastomers and ENGAGE TM Polyolefin elastomers and EXACT available from ExxonMobil TMPolyolefins. Methods for polymerizing these random copolymers are well known in the art and include those described in U.S. Pat. Nos. 5,272,236 and 5,278,272. Block copolymers include those polymerized using chain shuttling techniques and two catalyst species, such as disclosed in U.S. Pat. No. 7,355,089, and include polymers such as INFUSE manufactured by The Dow Chemical Company. TM Olefin block copolymers. In addition, the term "polyolefin polymer" in this disclosure is defined as a polymer having an average molecular weight greater than 1,000 g / mol (in one embodiment, 2,000 g / mol, greater than 4,000 g / mol, or up to 10 million g / mol) as determined by light scattering. Polyolefin polymers can be copolymers consisting primarily of polymerized ethylene monomers and polymerized alpha olefin monomers (e.g., 1-octene). Polyolefin polymers can be copolymers consisting primarily of polymerized propylene monomers and polymerized alpha olefin monomers (e.g., ethylene). Such propylene polymers include homopolymer polypropylene, impact propylene copolymers, and random propylene copolymers. Other more specialized polymers include ethylene / acrylic acid copolymers, ethylene / vinyl acetate copolymers, and ethylene / styrene interpolymers, halogenated polymers, and polymers containing maleic anhydride moieties.

[0163] The term "polypropylene" refers to a polyolefin containing more than 50.0% (by number) of repeating propylene-derived units. In one embodiment, at least 85% (by number) of the repeating units in the polypropylene homopolymer and / or polypropylene copolymer are propylene units. In one embodiment, the polypropylene used herein refers to a polymer composed of 100% repeating propylene units.

[0164] The term "isotactic polypropylene" as used herein generally refers to polypropylene in which the side chain groups (e.g., alkyl groups such as methyl groups) are positioned on one side of the carbon backbone, or at least 10%, 20%, 30%, 40%, 50%, 60%, 80%, 90% or more of all the methyl groups are positioned on one side of the carbon backbone, such that the isotactic polypropylene has a higher structural rigidity or crystallinity than non-isotactic polymers (e.g., polypropylene).

[0165] As used herein, the term "amorphous polypropylene" or "atactic polypropylene" generally refers to polypropylene having side chain groups (e.g., alkyl groups such as methyl groups) with random orientation along the polymer chain. "Amorphous" means non-crystalline, e.g., not having a definite shape and not having significant structural rigidity. Atactic polypropylene can be a random copolymer obtained or obtainable by polymerization of homopolypropylene with a comonomer selected from propylene, ethylene, butene and octene, or a block copolymer of polypropylene with ethylene-propylene.

[0166] As used herein, the term "syndiotactic polypropylene" generally refers to polypropylene in which substituents (e.g., alkyl groups such as methyl groups) have alternating positions along the polymer chain. In one embodiment, the term "syndiotactic polypropylene" is defined as having 10% or more syndiotactic pentads.

[0167] As used herein, the term "microwave susceptor" generally refers to a material that redirects electromagnetic material toward itself. As an example, a microwave susceptor may be made of a silicon carbide material, but any material having this property may be used. In some examples, a microwave susceptor may include a material that absorbs microwave energy (e.g., a microwave sponge). As an example, a microwave susceptor material may reach a temperature of 200+°C within 1 minute of microwave heating, but other variations and material properties are possible.

[0168] The term "lubricant" as used herein generally refers to a substance that can be introduced between two or more moving surfaces and reduces the friction level between two adjacent surfaces moving relative to each other. In one embodiment, it refers to a mixture of hydrocarbons having a carbon number distribution between about 13 and about 60.

[0169] As used herein, the term "carbon number distribution" generally refers to the range of compounds present in a composition, wherein each compound is defined by the number of carbon atoms present. Example

[0170] The following examples provide useful embodiments of the disclosed methods. It should be understood that the examples are given for illustrative purposes only.

[0171] General Materials and Methods

[0172] a. Materials

[0173] Low-density polyethylene (MW 4000Da), chloroplatinic acid (H2PtCl6, 8 wt% dissolved in H2O), ethanol (200 alcohol proof), zirconium oxychloride hydrate (ZrOCl2·xH2O, >99%), ammonium hydroxide (NH4OH), phosphoric acid (H3PO4), ammonium metatungstate hydrate (99.99% trace metal basis), silica (mesoporous SBA-15, particle size <150μm, pore size 6nm), silica gel (high purity grade, pore size 70–230 mesh) and aluminum chloride (AlCl3, >99%) were obtained from Sigma-Aldrich. n-Octacosane was obtained from Tokyo Chemical Industry. Zeolite-Y (CBV720, Si:Al=30, H type) was from Tokyo Chemical Industry. Al-MCM-41 (Si:Al=25) was obtained from ACS Materials. Dichloromethane was obtained from Fisher Scientific. Ultrapure water (Type 1) (Direct-Q 3UV-R) was used. All chemicals were used as received.

[0174] b. Catalyst preparation

[0175] b-1. Synthesis of 0.5Pt-HY(30)

[0176] Zeolite HY(30) was calcined at 550°C for 4 hours (heating rate of 2°C / min) in air before use. The Pt catalyst on HY(30) was synthesized by wet impregnation of the HY(30) support with a chloroplatinic acid (HPtCl6, 8 wt% in H2O; Sigma-Aldrich) solution. 2.0 g of HY(30) was impregnated with a 0.064 M chloroplatinic acid solution. The impregnated material was then dried at 110°C in air and then calcined at 550°C for 4 hours (heating rate of 2°C / min) in static air. The catalyst was loaded with 0.5 wt% Pt.

[0177] b-2. Synthesis of P-SiO2

[0178] Preparation of P-SiO2 catalyst (H3PO4, 10 wt%) by impregnation First, SiO2 (high purity, pore size 100 mm) was impregnated with H3PO4 aqueous solution. 70-230 mesh, Sigma-Aldrich). The solvent was evaporated on a hot plate at 75°C and then dried in an oven at 110°C for 12 hours, and the fine powder catalyst was calcined in a crucible at 500°C for 3 hours in air (2°C / min).

[0179] b-3. Synthesis of WO3 / ZrO2

[0180] First, zirconium (IV) hydroxide (Zr(OH)4) was prepared by precipitating ZrOCl2 with NH4OH. The precipitate was then aged in ultrapure deionized (UPDI) water for 24 h, adjusted to pH 10 by adding NH4OH, filtered, and then dried at 110°C overnight. The solid thus obtained was crushed and continuously redispersed in UPDI water (adjusted to pH 10 for 30 min) and then filtered to remove Cl - ions until the supernatant has background levels of Cl -ions. Use 0.1M AgNO3 solution to test Cl - Ion concentration.

[0181] The final filtered Zr(OH)4 was dried at 110°C overnight and then crushed to >230 mesh (<63μm). The xWZr support, where x corresponds to the weight percentage of WO3 loading on ZrO2, was prepared by wet impregnation of the synthesized Zr(OH)4 solid. 2.0g of Zr(OH)4 was impregnated with ammonium metatungstate hydrate solution (0.042M and 0.08M for 15% and 25% WO3 loading, respectively), dried in air at 110°C, and then calcined at 800°C for 3 hours in static air (heating rate of 2°C / min). Samples with 15 wt% and 25 wt% WO3 loading on ZrO2 were prepared.

[0182] b-4. Synthesis of Al-SBA-15

[0183] Al-SBA-15 (Si:Al=25) catalyst was prepared by impregnation. SBA-15 was calcined at 350°C for 4 hours (1°C / min heating rate) before use. Then 2.0 g of calcined SBA-15 was impregnated with a solution of 0.26M AlCl3 (>99%) in ethanol (200 proof) in a Petri dish. The impregnated material was dried in air at room temperature for 12 hours, then dried in air at 80°C for 12 hours, and then calcined at 540°C for 4 hours at a heating rate of 1°C / min.

[0184] c. Reactor device

[0185] c-1. Microwave cavity characterization and temperature measurement

[0186] A single-mode cylindrical microwave resonator with a diameter of 104.92 mm and a height of 85 mm, manufactured by the ITACA Institute in Valencia, was used. The microwave system was operated in TE111 mode with a constant output power of 132 W. The operating frequency was around 2.45 GHz with an adjustable frequency span (0.2-100 MHz). The sample temperature was controlled by changing the coupling position of the antenna and adjusting the frequency span. An almost uniform electromagnetic field was formed in an area of ​​15 mm height and 10 mm diameter in the center of the microwave cavity, where all samples were placed in a quartz tube (inner diameter 10 mm). A porous silicon carbide (SiC) monolith with millimeter-range channels was used as a microwave susceptor ( Figure 2C). A pyrometer (CT laser LT, Optris, -50–975 °C) and an infrared (IR) thermal imager (PI 1M, Optris, 450-1800 °C) were connected to the microwave cavity to achieve temperature measurement of the quartz reactor wall and axial temperature distribution, respectively. The infrared (IR) imager was also used to monitor the formation of any local hot spots during the reaction. In addition, a fiber optic temperature sensor (FISO Technologies Inc., -40-300 °C) was used to measure the internal temperature at the monolith wall and quantify the temperature difference between the reactor wall and the monolith. The pyrometer temperature readings were used as the primary reference temperature throughout the embodiments of the present disclosure.

[0187] c-2. Microwave pyrolysis

[0188] All reactions were carried out in a tubular reactor (diameter = 10 mm) with a porous quartz block ( Figure 1 B and Figure 2 A). A sample consisting of powdered LDPE mixed with solid acid was placed in and on the SiC monolith in the center of the tube ( Figure 1 B and Figure 2 A). Before the experiment, the reactor was purged with H2 or N2 to remove air. A mass flow controller (Brooks Instrument) was used to control the gas flow rate. The reactor was placed in the microwave cavity so that the entire piece was located in the center of the above-mentioned nearly uniform electromagnetic field region. The rest of the tube outside the microwave cavity was wrapped with heating tape and heated to 140°C to prevent condensation of the product inside the tube. Typically, 1.0 g of LDPE and 100 mg of catalyst were added to the reactor. For experiments using 0.5Pt-HY(30) and Pt-SiO2, the catalyst was reduced in 100 mL / min equimolar flow rates of H2 and He gases at 250°C for 2 hours (10°C / min heating rate) before use. The reactor was gradually heated to 190°C (<1°C / s) to ensure good mixing of the polymer melt, and quickly (heating rate = 2-2.5°C / s) to the reaction set point (375°C), and typically maintained for 200 seconds ( Figure 3 ). A distillation receiver cooled to 0°C using an ice bath was connected to the outlet end of the reactor. The distillation receiver was combined with a condenser section cooled to 6°C to separate the liquid product from the gaseous hydrocarbons. A Tedlar bag was connected to the rear end of the condenser section for online collection of the produced gaseous hydrocarbons. Upon completion, the reactor was quickly cooled to room temperature, and the liquid product was extracted from the distillation receiver and the reactor using dichloromethane (DCM).

[0189] c-3. Conventional pyrolysis

[0190] The apparatus used for conventional pyrolysis is almost the same as that for microwave pyrolysis, except that a high temperature heating belt is used instead of microwaves to heat the reaction zone ( Figure 2 B and Figure 4 ). Thermocouples measure the internal temperature and a PID controller is used to control the heating.

[0191] d. Catalyst Characterization

[0192] The crystal phase of the catalyst was identified by X-ray diffractometer (Bruker D8) using Cu Kα radiation. The voltage was 40 kV, the current was 40 mA, between 2θ = 10 and 70°, and the scan rate was 0.05 times / s. Xenocs SAXS / WAXS (Xenocs, Sassenage, France) was used in the range of 2θ = 0.02-8° using Cu Kα radiation. To record the small angle X-ray scattering pattern of the catalyst. The distance from the sample to the detector is 550 mm. The elemental composition is analyzed by X-ray fluorescence (XRF) spectroscopy on the Rigaku WDXRF. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis of the material were performed on an Auriga 60 microscope (Carl Zeiss NTS GmbH, Germany) equipped with a Schottky field emission gun (FEG). Transmission electron microscopy (TEM) analysis was performed at 200kV using a field emission transmission electron microscope JEM-2010F FasTEM. N2 physical adsorption was performed at -196°C using a Micromeritics ASAP 2020 instrument. CO chemical adsorption was performed in pulse mode on an Auto Chem II Micromeritics instrument. The pre-reduced sample was loaded into a quartz U-tube reactor and heated to 250°C in a 10% H2 / He flow for 2 hours (heating rate of 10°C / min). Fourier transform infrared (FTIR) spectra of adsorbed pyridine and subsequent thermal desorption of pyridine were recorded in transmission mode in a homemade Pyrex tubular flow cell equipped with a 32 mm KBr window. The sample was pressed into a self-supporting wafer (about 15 mg, 1.3 cm2 and 40 bar / cm2 pressure), placed in a quartz sample holder and heated to 300°C (heating rate of 10°C / min) in a pure argon flow and kept at this temperature for 1 hour. Then, the temperature was reduced to 150°C and the sample was treated with pyridine vapor by injecting liquid pyridine (5 μl, 99.8%; Sigma-Aldrich) through the septum port using a microsyringe. After saturation, the sample was flushed with pure helium for 30 min and the spectrum of the pyridine saturated sample was recorded. Finally, the temperature was increased to 300°C at a rate of 10°C / min under a constant argon flow and the spectrum was recorded every 1 min. Integration and peak deconvolution were performed using Omnic 8.2 software.

[0193] e. Product analysis

[0194] The gaseous products formed during the reaction were collected in a Tedlar gas sampling bag and analyzed by GC-FID (Agilent HP-PLOT / Q GC column). The residual oil mixture was extracted by adding about 20 mL of CH2Cl2. About 20 mg of n-octacosane was added as an internal standard, and the solution was mixed in a vortex mixer until the n-octacosane was completely dissolved. The resulting solution was analyzed by GC-FID (Agilent HP-1 column) for product quantification and GC-MS (Agilent DB-5 column) after filtration using a syringe filter for product identification. The C1–C 35 Calibration factors and retention times of all products measured by analytical standards ( Figure 5-7 ).

[0195] The conversion rate of LDPE is calculated as follows:

[0196]

[0197] Where W Rxtr,i is the initial weight of the reactor containing polymer, catalyst and monolith, W Rxtr,f is the final weight of the reactor, and W LDPE,i is the initial weight of LDPE used.

[0198] The alkane / alkene selectivity is calculated as follows:

[0199]

[0200] Quantification of C by GC-FID n Alkanes, C n Yields of olefins and aromatics.

[0201] f. Coke Characterization of Spent Catalyst

[0202] Coke samples were collected by flushing the reactor with DCM and then drying the samples in air at 70°C. TGA and DSC analysis were performed on a Q600SDT (TA Instruments). Raman spectra of coke samples were recorded under ambient conditions using a Horiba LabRam microscope equipped with a 15x objective and a 325nm UV laser. Spectra were deconvoluted using OMNIC software.

[0203] g. Temperature distribution measurement

[0204] Temperature measurements were performed at different flow conditions (3-150 mL / min) at the center of the monolith (using fiber optic temperature sensors) and at the wall (using pyrometers). Various filler materials (no filler, quartz, and LDPE) were used to eliminate the void space between the wall and the monolith. Figure 8 The experimental setup is described in . In addition, an infrared imager is used to scan the hot spots during microwave heating.

[0205] h. COMSOL simulation of microwave heating

[0206] Modeling a structured reactor in a microwave cavity requires studying a variety of coupling phenomena: the dissipation of electromagnetic energy in the electromagnetic field and solid, the fluid flow through the reactor, and the heat transfer within and between each phase. The thermal conductivity (about 100W / mK) and dielectric properties (9.8-1.1j) of SiC in the literature are used in the embodiments of the present disclosure (see A. Malhotra et al., Temperature Homogeneity under Selective and Localized Microwave Heating in Structured Flow Reactors, Industrial & Engineering Chemistry Research, 60 (18) (2021) 6835-6847; or H. Goyal et al., Scaleup of a Single-Mode Microwave Reactor, Industrial & Engineering Chemistry Research, 59 (6) (2019) 2516-2523). After solving the electric field, the steady-state heat transfer equation is obtained, in which the heat generation term (MW heating) generated by the electric field dissipation is given as:

[0207]

[0208] Where E is the electric field vector, f is the frequency of the microwave radiation, and ε o is the dielectric constant of vacuum, ε cIs the complex part of the relative dielectric constant, and σ is the conductivity. E is obtained by solving Maxwell's equations using the impedance boundary conditions of the metal cavity to minimize the computational load. Use a coaxial port to provide energy to the cavity. First-order scattering conditions are used at the inlet and outlet of the quartz tube to avoid reflection artifacts. The reactor tube is exposed to room temperature, where it dissipates heat to the environment according to Newton's law of cooling (see RBBird et al., Transport phenomena, 2nd, Wiley internationaled.ed., J.Wiley, New York, 2002). In order to determine the role of gas flow rate in temperature difference, the Navier-Stokes equations are solved to determine the flow field in the reactor under the laminar flow state established at the low flow rate analyzed in this paper. The flow distribution is solved by heat transfer iteration. The effect of different flow rates is determined by the average Nusselt number that increases with the increase in flow rate. A domain with effective thermal performance is simulated in the area between the wall and the monolith to determine the role of filler properties.

[0209] i. Process modeling, techno-economic and life cycle analysis

[0210] The economic potential of the MW slurry technology was evaluated for comparison with the market, considering the production of lubricants from olefins. An integrated process designed to produce lubricants from LDPE by pyrolysis was developed by Fig. 9 The method uses Modeled in v.11 and Figures 10 to 12 Representative compositions of paraffins and olefins are shown in Table 1.

[0211] Table 1.

[0212]

[0213] a – Assuming that the oligomerization stops in the first step of oligomerization reported by CS Hsia-Chean et al., Production of lubricant range hydrocarbons from light olefins, US 4,568,786 (709,143) (1986).

[0214] b– The most representative components of commercial lubricants analyzed in C. Yang et al., Oil fingerprinting analysis using gaschromatography-quadrupole time-of-flight (GC-QTOF), Standard Handbook Oil Spill Environmental Forensics: Fingerprinting and Source Identification, 2nd Edition (2016) 449-480.

[0215] Most of its features are obtained from the Aspen database. Only LDPE was characterized by using the Joback method to define the molecular structure and using reaction enthalpies (see PLSplitstone et al., The Enthalpies of Combustion and Formation of Linear Polyethylene, Journal of Research of the National Bureau of Standards-A. Physics and Chemistry, 78A(5)(1974)611-616), heat capacity (see SS Chang, Heat capacities of Polyethylene from 2 to 360 K. I Standard Samples of Linear and Branched Polyethylene Whole Polymer, Journal of Research of the National Bureau of Standards-A. Physics and Chemistry 77A(4)(1973)395-405), and the heat of fusion of branched polyethylene reported by the National Bureau of Standards (see Broadhurst, Thermodynamic Properties of Polyethylene Predicted from Paraffin Data, Journal of Research of the National Bureau of Standards-A. Physics and Chemistry 77A(4)(1973)395-405). Chemistry, 67A(3)(1963)233-240).

[0216] Techno-economic (TEA) and life cycle analysis (LCA) were performed to evaluate the economic potential and environmental impact of MW slurry technology. The plant operates 8,000 hours / year and processes 32,000 metric tons / year of clean LDPE. This capacity corresponds to 1% of the average annual LDPE produced in the United States over the past decade (3.208 million tons / year, see Tiseo, Y, Low density polyethylene production in the United States from 1990 to 2019). This value is also within the range of industrial recycling facilities reported in other works (see M. Larrain et al., Techno-economic assessment of mechanical recycling of challenging post-consumer plastic packaging waste, Resour Conserv Recy 170 (2021)). TEA and LCA were performed for the cases studied in Table 2 to determine the impact of traditional vs. MW slurry reactors and the effect of using catalysts with different selectivities for olefins.

[0217] Table 2. Cases evaluated in TEA and LCA studies.

[0218]

[0219]

[0220] Note that the use of hydrogen as a heat transfer carrier is not included because it is more expensive than nitrogen and gives lower olefin conversions. An LCA was performed to evaluate the environmental performance of MW slurry vs. conventional heating in lubricant production. The system expansion method was used to estimate the emissions of this method, simplifying Fig.13 One kilogram of lubricant was considered as one functional unit for analysis and comparison with oil-based lubricants in the Ecoinvent database v3.8 (see E. Santos et al., A catalytic reactive distillation approach to high density polyethylene pyrolysis–Part 1–Light olefin production, Chemical Engineering Journal 378 (2019) 122077).

[0221] Example 1: Reaction parameter optimization

[0222] The reaction temperature and bubbling gas flow rate were optimized ( Fig.14 ), at a temperature of 375 °C and N2 at 100 ml / min, the conversion rate on zeolite-Y (HY) reached >96% within 200 seconds. In the absence of HY, no activity was observed below 375 °C (according to TGA; Fig.14 A). Thus, solid acids significantly promoted extensive low-temperature cracking. Loading Pt on HY (Table 3) slightly increased the alkane yield because Pt has the ability to hydrogenate olefins; however, this effect was negligible (the difference in olefin selectivity <5%), probably due to the rapid coking of Pt. Catalytic pyrolysis on the Pt-SiO2 catalyst showed a negligible LDPE conversion rate (<7%), ruling out the possibility of a hydrocracking pathway on Pt-HY at these short contact times.

[0223] Table 3. Results of LDPE pyrolysis on 0.5Pt-HY, 1.0Pt-SiO2, and Al-SBA-15 under different gas flow conditions of MW heating and CH. Reaction conditions: temperature - 375 °C, gas flow rate - 100 ml / min, and time - 200 s.

[0224]

[0225]

[0226] Example 2: Evaluation of catalysts and reactivity

[0227] Microwave pyrolysis on several acid catalysts yielded C4-C 12 hydrocarbons (Figure 15B, D - E). The conversion rates followed the order: P-SiO2 < 15WZr < 25WZr < Al-MCM-41 < Al-SBA-15 < HY (Figure 15A). Reactive distillation narrowed the product molecular weight distribution and effectively separated products below C9 (>C 10The yield of hydrocarbons is lower). Heavier hydrocarbons are back-mixed and further cracked because the heating band only reaches 140 °C, which is below their boiling point. It is expected that this distribution can be adjusted by changing the distillation unit (reactor exhaust) temperature; the heating band is not required in large-scale systems where heat losses are small and the system can be operated nearly adiabatically. The catalytic activity arises from the interaction between acid site density, acid strength, and porosity. For example, the Brønsted acid site (BAS) density of P-SiO2 decreases sharply from 30 μmol / g (300 °C) to 4 μmol / g (375 °C), while Al-MCM-41 and Al-SBA-15 show a more gradual decrease from about 60 μmol / g to about 40 μmol / g. Therefore, the lower activity of P-SiO2 is related to its weak acid sites. On the other hand, Al-MCM-41 and Al-SBA-15 show higher activity because they have a higher BAS density and their acid sites have a higher intrinsic strength (Table 4).

[0228] Table 4. Structural properties of different catalyst samples.

[0229]

[0230] a – obtained from t-chart results; b – obtained from BJH desorption results; c – measured using FTIR of adsorbed pyridine; # – Spent catalyst calcined in static air at 550°C

[0231] The difference between Al-MCM-41 and Al-SBA-15 may be due to the difference in their pore sizes, about 3.4 nm for Al-MCM-41 vs. about 5.5 nm for Al-SBA-15 (obtained using N2 physical adsorption). Post characterization of the spent Al-SBA-15 catalyst further showed that the BAS density in the spent catalyst did not change after calcination at 550°C in static air (Table 4), indicating that the catalyst is robust and reusable.

[0232] The reaction on HY produced mainly singly and doubly branched alkanes (about 70%) as the main products (Figure 15B). In contrast, the mesoporous materials had larger pore sizes (about 2-50 nm) and low to moderate acid strength. Interestingly, they reacted with high selectivity (79-88%; Fig. 15C ) produced linear or singly branched olefins with internal C=C bonds. P-SiO2 and WZr produced C7-C 17The fraction is slightly higher. FTIR spectroscopy of adsorbed pyridine combined with thermal desorption confirms that P-SiO2 has fewer and weaker Brønsted acid sites. The olefin selectivity follows Al-SBA-15>Al-MCM-41>xWZr>P-SiO2>>HY(30).

[0233] Example 3: Transient LDPE MW Slurry Pyrolysis

[0234] The contact time experiments on HY and Al-SBA-15 showed about 96% and about 90% conversion within 200 seconds. The LDPE conversion increased monotonically with the reaction time, while the product distribution did not change much ( Fig.16 ). C4-C 12 Hydrocarbons are the main products; the longer chain hydrocarbons crack faster, resulting in secondary cracking to lighter products. Over time, Al-SBA-15 consumes the medium-sized fractions (C5-C7) to form lighter fractions (C1-C4), indicating that secondary cracking occurs ( Fig.16 C). HY does not show this phenomenon and results in a similar product distribution, which may be due to the rapid coking of its acid sites. This is further confirmed by the reduction of C4-C6 hydrocarbons after 15 seconds ( Fig.16 B).

[0235] Example 4: Conventional pyrolysis vs. microwave pyrolysis

[0236] MW and CH pyrolysis showed significant differences in LDPE conversion (96% vs. only 46%; Figure 17A-B ). In addition, pyrolysis of CH without the monolith resulted in an even lower conversion (13%), and the product contained mainly light C4-C6 alkanes (Figures 17A and 18). With the monolith, the distribution shifted to C6-C 12 , of which olefins are about 30% (Figure 18). Heat transfer (MW vs. CH) affects the thermal gradient in slurry pyrolysis. Excessive thermal gradients in CH caused by hot spots on the reactor sidewalls lead to coke formation (Figure 17C) and catalyst deactivation due to the formation of heavy aromatics due to rapid H transfer at these hot spots. These polycyclic aromatics can cause significant pore blockage, increase the residence time of hydrocarbons in the zeolite pores, and promote secondary cracking to light products ( Fig.19C). This effect has been previously reported in fixed-bed reactors for methanol-to-olefins reactions (see S.V. Konnov et al., Mechanism of SAPO-34 catalyst deactivation in the course of MTO conversion in a slurry reactor, Catalysis Science & Technology 8(6)(2018)1564 - 1577). In addition, CH pyrolysis exhibits higher alkane selectivity than microwave-assisted pyrolysis, further indicating that due to improved heat transfer in the slurry compared to the fixed bed, CH enhances the H-transfer reaction leading to coke (Table 3). Due to efficient heat transfer from the wall to the center of the reactor, the monolith can distribute gas and reduce the thermal gradient.

[0237] Although both heating modes produce coke, MW produces less coke on both HY and Al-SBA-15 catalysts (Figure 17C), which is reflected in the LDPE conversion. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) of coked HY indicate that there are two distinct bands for light coke (or organic residues; centered at approximately 295 °C), while there is a distinct band for heavy coke (centered at approximately 560 °C) ( Fig. 20 ). The maximum temperature shift for CH pyrolysis is approximately 10 °C ( Fig. 20 ). The order of the maxima of the differential thermal analysis (DTA) curves is MW-H2 < MW-N2 < CH-N2. Al-SBA-15 shows two light coke bands (centered at approximately 290 °C and 350 °C) and one heavy coke band (centered at approximately 500 °C) ( Fig.21 ). In addition, compared to Al-SBA-15 (approximately 500 °C), the center of the heavy coke band in HY is at approximately 560 °C, indicating that the polycyclic aromatic hydrocarbons in HY are heavier. The TGA weight loss (Figure 17G) shows that on the HY catalyst, MW pyrolysis exhibits approximately 49% reduction in heavy coke. On the other hand, only approximately 30% heavy coke is shown for MW and CH samples on Al-SBA-15; the rest is light coke ( Fig. 22 ). This result further explains the smaller difference in conversion of MW and CH on Al-SBA-15 compared to HY, indicating that the former is not as affected by heavy coke as the latter because it has larger pores, is less prone to H-transfer, and allows larger hydrocarbons to diffuse more quickly.

[0238] Figure 17D shows the Raman spectra of coke on the HY catalyst. The coke in CH-N2, MW-N2, and MW-H2 is graphitic carbon, indicated by a strong G band centered at 1600 cm -1 . The CH sample rich in coke ( Fig.23) has a larger D3 band intensity (higher I(D3) / I(G) ratio), corresponding to amorphous carbon caused by PAHs. The I(D3) / I(G) ratios of the MW samples in different gas streams show that the I(D3) / I(G) in H2 is lower, indicating that hydrogen hydrogenates the coke precursors in HY and reduces the PAH coke (Table 3). This is further confirmed by DTA analysis, where the MW-H2 sample corresponds to the lowest temperature among the three samples. Fig.17E-F and Fig.24 Raman spectra of coked Al-SBA-15 under CH and MW captured using a microscope at different spots on the same sample are shown. The CH sample has similar spectra ( Fig.17E-F ) is due to being evenly covered by graphite coke. For spot 1 ( Fig.17E-F ) MW samples (Figure 17F, Fig.24 ), the coke is similar to HY (Figure 17D), where the strong G band indicates that it is graphite coke. Fig.24 ), 1065, 1130, 1170, 1296, 1370, 1440cm -1 The characteristic features at correspond to unreacted polyethylene. This indicates that PE is slowly pyrolyzed in SBA-15 and the new peaks in TGA / DSC correspond to residual polymer rather than coke. The large pores of SBA-15 allow easy access of the polymer to the acid sites, resulting in a gentler depolymerization. In contrast, the formation of coke and light alkanes on HY is controlled by H transfer, resulting in rapid coke formation, which in turn blocks the pores.

[0239] Example 5: Thermal Gradient and Coke Formation

[0240] The non-isothermal operation of the reactor will accelerate the catalyst coking. The different behaviors of CH and MW pyrolysis are mainly due to the H transfer mediated coking ( Figure 17A-B ), which is more pronounced in zeolite than in Al-SBA-15. Volumetric microwave heating and mixing minimize thermal gradients. Figure 8 The temperature distribution during MW heating was evaluated using the apparatus described in . The temperature measurements showed that in the absence of any filler, there was a significant difference (about 60 °C) between the wall and the center of the monolith ( Fig.25). When quartz particles are used as fillers, this difference is reduced to about 20-30°C (Figure 17H, Figure 26), and this difference becomes smaller as the quartz particles become finer (Figure 17H, Figure 26). Using LDPE as a filler, the temperature difference is about 20-30°C (Figure 27), and the temperature difference is almost negligible (<5°C) at high gas flow rates (≥100mL / min). Similar behavior was also observed under reaction conditions for CH pyrolysis with a monolith, and significantly lower conversion was observed at low N2 flow rates (about 3ml / min) (Table 3), indicating the presence of transport limitations. This suggests that bubbling of gas through the melt can enhance heat and mass transfer and retard the formation of coke by reducing thermal gradients. COMSOL Multiphysics simulations show good qualitative agreement with the experimental data and demonstrate that a thermally uniform reaction domain can be established by increasing the thermal conductivity of the material or increasing the Nusselt number (by increasing the gas flow rate) ( Fig.17I ). Unlike microwaves that directly heat a SiC monolith, the walls of a CH reactor are hotter than the center, causing heat to flow inward, creating a temperature gradient. This inherent difference is critical to achieving a thermally uniform system and suppressing coke formation. In addition to facilitating selective heating, SiC is a high thermal conductivity material that disperses heat, and its porous structure facilitates the establishment of an effective slurry. These factors help maintain near-isothermal conditions. While laboratory-scale testing has been insightful and helpful in advancing the field, some challenges can arise when evaluating the value of treating real-life waste streams via pyrolysis. One of these challenges is related to the different properties of polymer waste streams, such as molecular weight, viscosity, thermal conductivity, etc., which often contain a mixture of different grades of plastics. Variations in properties can affect the choice of process parameters. COMSOL Multiphysics simulations show that using polymers with different thermal conductivities can result in significant thermal gradients ( Fig.17I ). In addition, a high Nusselt number (achievable by operating at high flow rates) can eliminate these gradients, even for heavier polymers ( Fig.17I ). In addition, the use of MW susceptors with enhanced penetration and heat transfer capabilities, such as foams or monoliths of good dielectric materials, and through small-scale modular operation, makes it possible to scale up MW reactors.

[0241] Example 6: Technical and economic feasibility and greenhouse gas emissions

[0242] For a techno-economic analysis of lubricant production from olefins, where the minimum selling price can be easily compared to available market prices, the minimum selling price for Al-SBA-11 is estimated to be $5.30 / gal vs. the highest selling price of $5.88 / gal for API Tier 1 lubricants over the past decade (see Synlube, Base Oil Prices in USA. Available from: http: / / www.synlube.com / BaseOilPrices.html (20th April) (2022)), and for 32,000 metric tons / year of LDPE, the price is $0.44 / kg (see The Recycler's Exchange, Clear LDPE Scrap (loose), USA BRITISH COLUMBIA Available from: https: / / www.recycle.net / Plastic / ldpe / xv100400.html (20th April) (2022)). Higher grade polyalphaolefin base oils are much more expensive and can be produced by oligomerization. CO2 emissions are estimated to be 1.07 kg CO2 / kilogram 润滑剂 , a reduction of 8% over the current petroleum-based route (see F. Brunner, Base oil production, petroleum refinery operation-RoW-base oil, Ecoinvent 3.8 Dataset (2021)). Due to the high proportion of fossil resources, the reduction in emissions is moderate under the current power structure in the United States. MW from renewable resources can reduce emissions by 0.57 kg CO2 / kilogram 润滑剂 , 51% less than petroleum-based lubricants. A more detailed description and sensitivity analysis are provided below.

[0243] Process Modeling

[0244] Pure LDPE is fed into the pyrolysis reactor ( Fig.10 ). Experimental yields were used. Mass and energy balances were performed in Aspen The energy demand obtained in the AspenPlus simulation is calculated by the energy efficiency of the power supply, ε 电源 = 95%, and the energy efficiency of the magnetron, ε 磁控管= 89% Offline correction is performed (see JM Serra et al., Hydrogen production via microwave-induced water splitting at low temperature, Nat Energy 5(11)(2020)910-919), see the following equation. Heat loss due to convection is not considered.

[0245]

[0246] When using a conventional heated reactor, consider a pyrolysis chamber using natural gas as fuel and having a heating efficiency of 90% (see HeatMatrix, Increase fired heater efficiency up to 95%, available from: https: / / heatmatrixgroup.com / thermal-processes / fired-heater / #:~:text=Fired%20Heaters%20are%20used%20in,around%2085%25%20%E2%80%93%2090%25.(2021)). The liquid and solid obtained from the pyrolysis are sent to a filter to remove unreacted LDPE. The liquid is then mixed with the gas and cooled to separate the liquid olefins.

[0247] The presence of nitrogen reduces the separation efficiency, and a high fraction of up to C8 can be obtained in a gas stream of 1 atm. This gas stream is sent to a debutanizer. Fig.10 The liquid product of the debutanizer is mixed with the liquid stream of S-1 and sent to Fig.12 The debutanizer distillate consists mainly of C3 and C4 fractions and is sent to the oligomerization reactor for light olefins, see Fig.11. In reactor R-2, light olefins are oligomerized at 70 bar and 473 K using HZSM-5 as a catalyst, with a conversion rate of 98% (see CS Hsia-Chean et al., Production of lubricantrange hydrocarbons from light olefins, US4568786 (709143) (1986)). The required high pressure is achieved using two compressors and an intermediate cooling step. Due to the limitations of the pressure ratio and operating temperature of the compressor, two steps are required. The intermediate cooling step results in the production of a liquid fraction, which cannot be sent to the compressor because it will damage the compressor. Therefore, a pump is used to bypass the liquid fraction via a bypass. The final gas-liquid mixture is heated to 473 K at 70 bar and then introduced into reactor R-2. Due to oligomerization, the pressure at the outlet is reduced to 17 bar. Under these conditions, a portion of the C8 olefin fraction obtained from the oligomerization is in the gas phase, so it needs to be cooled to minimize the loss of α-olefins generated in the flash separator and to avoid C4 and C3 paraffins from being obtained in the liquid phase. The liquid phase needs to be reduced in pressure and then sent to an alpha-olefin oligomerization reactor operating at 15 bar. The gas phase obtained from the flash separator is sent to a gas turbine with an integrated combustor where it is burned to produce power. The gas turbine operates at a pressure ratio of 16:1 and requires 300% excess air in metered quantities to avoid extreme temperatures that would damage the blades.

[0248] This liquid fraction obtained from the oligomerization of C2-C4 olefins is mixed with the liquid streams of the debutanizer and the flash separator S-1. The oligomerization of alpha-olefins is carried out with HZSM-5 to a conversion of 92% and occurs at 423 K, so a heat exchanger is placed before the mixture. The product consisting of lubricant, unreacted olefins and paraffins (assumed to be inert) is then depressurized to 1 bar and then introduced into the fractionation column. The fractionation column is modeled using the Petrofrac model and has three streams leaving the column: lubricant, diesel and gasoline fractions. The reflux ratio between the product streams and the number of trays are designed according to a simple method of separating C11 from C12 (separating the fractions of gasoline and diesel) and C19 from C20 (assuming the separation of the fractions of diesel and lubricants).

[0249] Techno-economic and life cycle analysis

[0250] Assumptions in TEA

[0251] The minimum selling price (MSP) of the lubricant is used to evaluate the economic feasibility of the technology. The payback period of the plant is expected to be 10 years, and the profits are also subject to a corporate tax of 21%. The estimation of the MSP requires the calculation of the capital cost (CAPEX) and operating costs (OPEX) of the process. The investment costs and installation of all units of the process except the MW slurry reactor and the oligomerization reactor were estimated using Aspen Process Economic Analyzer v.11. All costs estimated by Aspen Process Economic Analyzer v.11 are based on the first quarter of 2018, therefore, they were updated to 2021 values ​​based on the plant cost index from Chemical Engineering Magazine.

[0252] The capital cost of a MW slurry reactor is determined by the sum of the MW generator and reactor as shown in the following equation:

[0253] Cost MW reactor = Cost MW generator + Cost reactor

[0254]

[0255] Cost of MW generator C MW is a function of the power demand reported in JM Serra et al., Hydrogen production via microwave-induced water splitting at low temperature, Nat Energy 5(11)(2020)910-919. As a baseline case, an average reported value of $550 / kW for centralized power plants was used; a sensitivity analysis was also performed for a range of reported costs. The cost of the reactor was assumed to be the catalyst bed, as in JM Serra above. The bed consists of the zeolite and catalyst defined in the Materials section of this supplement. The price of the catalyst was estimated using the US Department of Energy's CatCost Tool. The Step Method available in the tool was used to estimate the catalyst cost. In all cases, a medium-sized plant of 10 Mt / d was used, based on the default version, with 1 day of production and 1 day of cleaning. The remaining economic inputs were also assumed to have default values. For the 0.5Pt-HY(30) catalyst, the following assumptions were considered:

[0256] 0.5Pt-HY(30) catalyst adopts the method applicable to zeolites with metal active sites. The material H2PtCl6 used to generate the active sites is not available in the database, so its price is obtained from an industrial supplier and is $100 / kg.

[0257] The amount of H2PtCl6 required per kg of zeolite is determined based on the mass percentage of Pt in the catalyst and the molecular weights of platinum and H2PtCl6 as shown in the following equation.

[0258]

[0259] The mass of HY-zeolite used as a support requires 20% alumina and 80% silica, based on the average values ​​of the following Y-zeolite patent US5785944.

[0260] Based on these inputs, the price comes out to be $33.46 / kg.

[0261] To estimate the cost of the Al-SBA-15, the following assumptions were considered when using CatCosttool:

[0262] • AlCl3 was used at the active sites at the concentrations given above.

[0263] Since SBA-15 or its precursors are not available in the tool’s database, a price of USD 400 / kg has been assumed. Sensitivity analysis has been performed over a range of USD 60 / kg to USD 400 / kg.

[0264] • The solvent ethanol is not included in the cost and is assumed to be fully recovered in the process.

[0265] • The method includes the units shown in Table 5, based on the description given above.

[0266] The price achieved under the base case (conservative price of $400 / kg for SBA-15) was $423.63 / kg.

[0267] Table 5. Inputs for 0.5Pt-HY(30) in CatCost.

[0268] Unit Type Number of units Reactor, simple (mixing) 1 Furnace continuous direct (300-1290℃) 2 Filters, Rotary Vacuum 1 Dryer Rotary 1

[0269] Since the MW slurry reactor operates in a semi-batch mode and the time to reload and regenerate the catalyst is assumed to be half the total time, the costs of the reactor and MW generator are multiplied by 2. In addition, a conservative installation factor IF is used with a value of 2.5.

[0270] The capital cost of the oligomerization reactor is determined by the catalyst cost plus the cost of the shell and tube unit. They are designed as fixed bed reactors, where the WHSV is reported in patent US4,568,786 and the LHSV is reported in JFKnifton et al., OlefinOligomerizationViaZeolite Catalysis, Catal Lett28(2-4)(1994)223-230, for designing the method. In order to ensure the same flow conditions as the reference, the flow used as a benchmark in the design is the total flow entering the reactor. The amount of HZSM-5 required in the reactor is calculated as shown in the following equation.

[0271]

[0272] In the case of α-olefin oligomerization (to provide LHSV), the mass of HZSM-5 was based on the desired zeolite volume and 2,300 kg / m was used. 3 The price of HZSM-5 was determined using the CatCost tool, with the same economic inputs as previous catalysts. The method used for the estimation is the method available in the tool for ZSM-5 zeolite. Based on patent US4,139,600, the materials used are 50% alumina block and 50% sodium silicate. The price obtained is $9.72 / kg, which is similar to the price of $10 / kg from online commercial suppliers (see Jiangxi Xiantao Technology Corporation, Molecular sieve Zeolite ZSM 5 for Petroleum Industry (20th April) (2022)).

[0273] The volume of the reactor is based on the required mass of HZSM-5 and the bulk density of HZSM-5 zeolite pellets, which is 720 kg / m 3 Calculated. The estimated volumes are used to design the reactor as a shell and tube unit. Multiple 1 inch and 20 foot long tubes (standard dimensions for shell and tube heat exchangers) are used in parallel. The number of tubes is determined by dividing the total volume required by the volume of each tube. The total number of tubes is ultimately used to estimate the cost of the shell and tube unit as a TEMA heat exchanger in Aspen Economic Analyzer v.11. The cost for this vessel as reported by Aspen Economic Analyzer has been updated to 2021 based on the Plant Cost Index from ChemicalEngineering Magazine.

[0274] The remaining capital expenditures (control equipment, piping, electrical installation, building, yard, services, land, project engineering costs, construction expenditures, contractor fees and contingency) used to estimate the total CAPEX were calculated using the average of the coefficients reported in M. Peters et al., Plant Design and Economics for Chemical Engineers, 5th Edition, 2002.

[0275] OPEX estimation includes the following:

[0276] Cost of raw materials. Consider the price of pure LDPE is $0.44 / kg. The price of nitrogen carrier gas is $0.177 CAD / m3, or $0.14 / m3.

[0277] Utility costs. Electricity price is assumed to be 7.3￠ / kWh. Natural gas price for heating is assumed to be $4.38 / MMBtu. Chilled water price is taken from Aspen Plus, 2.1·10 -7 $ / kJ.

[0278] · Labor costs for operators. The number of operators is 21, each working 8 hours per day, which is determined according to the factory shift situation and the given suggestions. The required salary for each operator is $70,200 / year.

[0279] Supervision costs are calculated at 15% of the operator’s total labor costs.

[0280] Annual maintenance costs are determined using a value of 4% of total CAPEX.

[0281] Operating expenses are the sum of laboratory product control expenses and insurance costs, local property taxes, rent, etc. Each of these expenses is estimated at an average of 15% of labor costs.

[0282] Factory overhead costs are determined to be 60% of the total cost of operating labor, supervision and maintenance.

[0283] Management costs are calculated at 25% of total labor costs.

[0284] · Assumption that the co-products obtained (gasoline and diesel) provide a discount to the estimated costs. The sales prices used (excluding taxes and distribution) are $3.31 / gallon for gasoline and $3.64 / gallon for diesel.

[0285] The MSP results of lubricants using different cases from Table 6 are reported in Table 7 and compared with the prices of API Class I lubricants over the past decade.

[0286] Table 6. Cases evaluated in TEA and LCA studies.

[0287]

[0288] Table 7. Minimum sales price and CAPEX of the facility to be built in each case studied.

[0289]

[0290] The cost distribution of each technology is given in Fig.28 and the details of the CAPEX required for each unit are provided in Fig.29 middle.

[0291] Sensitivity Analysis in TEA

[0292] The cost evaluation was enhanced by sensitivity analysis of different items with the aim of evaluating alternatives. The following components and scopes were considered in the evaluation:

[0293] The effect of LDPE price on MSP for all cases studied in Table 6. The prices reported by potential suppliers range widely (Greece: $0.24 / kg, Ohio: $0.35 / kg, and Florida: $0.77 / kg), with the highest price being $0.85 / kg. The results obtained for different LDPE prices are plotted in Fig.30 middle.

[0294] Since case MW-Al was determined to be the most profitable alternative obtained, the following sensitivity analysis was performed:

[0295] Different scales. The smallest scale is fixed at one-tenth of the existing plant, i.e. 3.2 thousand tons / year, slightly smaller than the two plastic pyrolysis plants currently operating in Europe (with a scale of 5 thousand tons / year). The largest scale is fixed at twice the size of the existing plant, i.e. 64 million tons / year, accounting for 2% of the total LDPE in the United States, and is three times the size of the largest plant in Europe (20,000 tons / year), and twice the size of the plant built by ExxonMobil and Plastic Energy in the Notre Dame de Gravenchon petrochemical complex (33,000 tons / year). The results are presented in Tables 8 and Fig.31 middle.

[0296] Table 8. Effect of scale on CAPEX and MSP of lubricants using MW-Al technology.

[0297]

[0298] The costs involved in the MW slurry reactor were also analyzed. These costs correspond to the investment costs required for the reactor, which is the largest contributor to the capital costs and the costs of electricity used to pyrolyze LDPE. The costs of the MW reactor were evaluated based on the ranges provided in the above-mentioned JMSerra. The upper value corresponds to the maximum reported for centralized plants and the lower value corresponds to the minimum expected in the future. The evaluation of electricity costs assumes a maximum residential electricity price of ￠12.6 / kWh and a minimum electricity price of half the current electricity price. The results are presented in Fig.32 middle.

[0299] The impact of SBA-15 price on catalyst price and lubricant MSP. SBA-15 has been studied over a range of prices given in "Zr Catalyst Co., Sba-15catalyst mesoporous silicapore size sba-15zeolite." Available from: https: / / www.alibaba.com / product-detail / sba-15-catalyst-mesoporous-silica-pore_1600225434897.html?spm=a2700.galleryofferlist.normal_offer.d_titl e.67d0441fUxrpk2(2022), the results of Table 9 were obtained.

[0300] Table 9. Effect of MW reactor installation factor.

[0301]

[0302] Effect of installation factor. A conservative scenario has been assumed as a base case with a value of 2.5. However, based on the range reported in JR Couper et al., Chemical Process Equipment Selection and Design, (2010), lower installation factors, up to 1.1, can be considered. The results of the study are provided in Table 10.

[0303] Table 10. Impact of SBA-15 price on catalyst, CAPEX and lubricant MSP.

[0304]

[0305] The lubricant price above the MSP is based on the internal rate of return (IRR) expected by the project investors. A base case for estimating the MSP has been studied, without considering any returns. However, the investors expect returns, so a price above the MSP is required. A sensitivity analysis has been conducted to evaluate the lubricant selling price based on the expected IRR. The evaluation ranges from zero to the highest value reported for specialty chemicals (17%). The results under different LDPE prices are shown in Fig.33 Given in.

[0306] Assumptions in LCA

[0307] The following assumptions were considered for the LCA:

[0308] Materials used in continuous manufacturing are considered. Other materials used in construction, infrastructure and catalysts should be recycled at the end of the process life cycle and are therefore not considered.

[0309] Take LDPE that needs to be recycled and assume it is provided by an external supplier 100 kilometers away from the factory.

[0310] Unconverted LDPE and coke are considered waste and sent to third-party companies for disposal.

[0311] The flue gas from the process contains only CO2. Other possible compounds (such as NO2) are not taken into account.

[0312] · Assume that the cooling water has a gradient of 5°C. This means that 1% of the total cooling water is discharged to the atmosphere, while the remaining 99% is recovered.

[0313] Electricity is supplied by a medium voltage grid based on average U.S. technology and losses.

[0314] Assume that natural gas is supplied at high pressure from a third party supplier.

[0315] • Gasoline and diesel are assumed to replace unleaded gasoline and diesel from a gasoline source.

[0316] The environmental impacts were calculated by the Traci method using Ecoinventv3.8 as the database. The results of the limited study cases in Table 2 are presented in Table 11.

[0317] Table 11. LCA results for each case study using the system expansion approach and emissions from the production of lubricants from petroleum.

[0318]

[0319] a –Acid. corresponds to (molar H + Eq. / kg 润滑剂) is the acidification potential, Ecotox. corresponds to (kg 2,4-DEq. / kg 润滑剂 ) corresponds to the ecotoxicity potential in kgN / kg 润滑剂 ) GW corresponds to the eutrophication potential in kg CO2 Eq. / kg 润滑剂 ) in terms of global warming potential, Ozone Dep. corresponds to (kg CFC-11-Eq / kg 润滑剂 ) is the amount of ozone depletion, Photox. corresponds to (kgNO x -Eq. / kg 润滑剂 ) in terms of photochemical oxidation potential, Carc. corresponds to (kg benzene-Eq / kg 润滑剂 ) carcinogenic potential, Non-Carc. corresponds to (kg toluene-Eq. / gk 润滑剂 ) of non-carcinogenic compounds, Resp. effect corresponds to (kg PM 2.5 Eq. / kg 润滑剂 ) meter's breathing effect.

[0320] The distribution of emissions between the different positive contributors is provided in the table for each case. Figure 34 to Figure 38 The results obtained in Table 11 show that some cases have negative indicators. These negative values ​​are due to the credits obtained by replacing the by-product gasoline and diesel of the current petroleum-based products using the system expansion approach. To better understand the results, the credits obtained are given in Table 12.

[0321] Table 12. Credits earned from fuel.

[0322]

[0323] It can be seen that these credits are mainly related to those cases with higher paraffin-to-olefin ratios (Conv, Monolith-Pt and MW-Pt). Although the "Conv" case shows the highest credit, this is not due to avoided emissions. This is because the mass of lubricant produced is very low, while the emissions per kg of lubricant are very high. Likewise, it is also important to note that having a higher credit does not ensure a lower impact, as all emissions are also divided by the mass of lubricant produced. This is particularly significant in terms of global warming potential, where MW-Al, with a higher lubricant production, shows better performance than the other technologies; see Table 11.

[0324] Sensitivity analysis of LCA

[0325] The most profitable and interesting technology is MW-Al due to its economic profitability. In addition to its economic profitability due to the selectivity of the catalyst and better heat distribution, the MW slurry reactor has the potential to integrate energy provided by renewable resources. A sensitivity analysis was performed assuming that the energy required in the process is obtained from two renewable resources: photovoltaic energy and wind energy. The results are presented in Table 13.

[0326] Table 13. LCA results for MW-Al supplied by conventional and renewable energy.

[0327]

[0328] Most indicators show that emissions are reduced when any of the renewable technologies replace the existing electricity mix in the U.S. This is particularly relevant for global warming potential, which shows a nearly 50 percent reduction in CO2 emissions.

[0329] The emissions obtained with the current method were compared with the reported results for petroleum-based lubricants. The difference between them was calculated as a percentage defined by the following equation and the results are provided in

[0330] Table 14.

[0331]

[0332] Table 14. Emissions comparison with petroleum-based lubricants.

[0333]

[0334]

[0335] Sensitivity analysis to the type of method used in LCA

[0336] For further comparison, the mass allocation and economic allocation methods were also used to evaluate the environmental indicators. The results obtained for the former are given in Table 15, while the reduction relative to petroleum-based lubricants is provided in Table 16. The results of the economic allocation method are reported in Tables 17 and 18.

[0337] Table 15. Environmental indicators obtained using the mass allocation method.

[0338]

[0339] Table 16. Comparison of potential relative to petroleum-based lubricants using the mass partitioning method.

[0340]

[0341]

[0342] Table 17. Environmental indicators obtained using the economic allocation method.

[0343]

[0344] Table 18. Comparison of potential relative to petroleum-based lubricants using the economic partitioning method.

[0345]

[0346]

[0347] In the economic allocation approach, prices defined in the TEA have been assumed for gasoline and diesel; and the average price of the reporting range for lubricants, 3.91 USD / gallon, was used. The emissions obtained for both approaches were compared with those obtained for the system expansion approach. In nearly half of the indicators, and especially with regard to global warming, the system expansion approach showed higher emissions than the economic and mass allocation approaches. Therefore, to be conservative and to avoid common allocations in multi-product systems, the CO2 emissions reported in the manuscript correspond to the system expansion approach.

[0348] The description of the foregoing specific embodiments will fully reveal the general nature of the present invention, and others can easily modify and / or adjust these specific embodiments for various applications by applying the technical knowledge in the art without excessive experimentation and without departing from the general concept of the present disclosure. Therefore, based on the teachings and guidance set forth herein, such adjustments and modifications are intended to be within the meaning and scope of the equivalents of the disclosed embodiments. It should be understood that the wording or terminology herein is for descriptive purposes, not for limitation, so that those skilled in the art can interpret the terms or wording in this specification according to the teachings and guidance.

[0349] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A pyrolysis method for converting a plastic comprising a polyolefin polymer into an olefin, comprising contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350°C and about 500°C; wherein the catalyst comprises a solid acid; and wherein the one-pot pyrolysis system comprises a microwave-assisted slurry reactor.

2. The method of claim 1, wherein the plastic comprises an olefin homopolymer, an olefin copolymer, or a mixture thereof.

3. The method according to claim 1 or 2, wherein the plastic comprises polyethylene, polypropylene, polybutylene, polyisobutylene, polypentene, polyhexene, polyoctene, polystyrene or a mixture thereof.

4. The method according to any one of claims 1 to 3, wherein the plastic comprises high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS) or a mixture thereof.

5. The method according to any one of claims 1 to 4, wherein the plastic is selected from isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, low molecular weight isotactic polypropylene, amorphous polypropylene, polypropylene bottles, polypropylene transparent bags, and mixtures thereof.

6. The method according to any one of claims 1 to 5, wherein the plastic is selected from isotactic polypropylene, low molecular weight isotactic polypropylene, amorphous polypropylene, polypropylene bottles, polypropylene transparent bags, and mixtures thereof.

7. The method according to any one of claims 1-6, wherein the pyrolysis process is carried out in a gas flow at a rate of about 5 ml / min to about 150 ml / min.

8. The method of claim 7, wherein the gas flow rate is about 15 ml / min to about 125 ml / min.

9. The method of claim 7 or 8, wherein the rate of the gas flow is about 25 ml / min to about 100 ml / min.

10. The method of any one of claims 7 to 9, wherein the gas flow rate is about 25 ml / min, about 50 ml / min, about 75 ml / min, or about 100 ml / min.

11. The method according to any one of claims 7 to 10, wherein the rate of the gas flow is about 100 ml / min.

12. The method of any one of claims 7 to 11, wherein the gas stream comprises nitrogen or hydrogen.

13. The method of claim 12, wherein the gas stream is a nitrogen stream.

14. The method of any one of claims 1-13, wherein the temperature is from about 350°C to about 475°C.

15. The method of any one of claims 1-14, wherein the temperature is from about 350°C to about 450°C.

16. The method of any one of claims 1-15, wherein the temperature is from about 350°C to about 400°C.

17. The method of any one of claims 1-16, wherein the temperature is about 375°C.

18. The method of any one of claims 1-17, wherein the pyrolysis process is performed for a period of less than 10 min.

19. The method of claim 18, wherein the time period is from about 10 seconds to about 400 seconds.

20. The method of claim 18 or 19, wherein the time period is from about 50 seconds to about 250 seconds.

21. The method of any one of claims 18-20, wherein the time period is about 200 seconds.

22. The process according to any one of claims 1 to 21, wherein the olefin is C4-C 12 A mixture of olefins.

23. The process according to any one of claims 1 to 22, wherein the olefin is selected from C4 olefins, C5 olefins, C7-C 12 Mixtures of olefins and mixtures thereof.

24. The method of any one of claims 1-23, wherein the weight ratio between plastic and catalyst is from about 40:1 to about 2:

1.

25. The method of any one of claims 1-24, wherein the weight ratio between plastic and catalyst is from about 30:1 to about 5:

1.

26. The method of any one of claims 1-25, wherein the weight ratio between plastic and catalyst is from about 20:1 to about 8:

1.

27. The method of any one of claims 1-26, wherein the weight ratio between plastic and catalyst is about 10:

1.

28. The method of any one of claims 1-27, wherein the conversion of the plastic is at least about 25%.

29. The method of any one of claims 1-28, wherein the conversion of the plastic is at least about 40%.

30. The method of any one of claims 1-29, wherein the conversion of the plastic is at least about 60%.

31. The method of any one of claims 1-30, wherein the conversion rate of the plastic is at least about 90%.

32. The process of any one of claims 1-31, wherein the yield of olefins is at least about 25%.

33. The process of any one of claims 1-32, wherein the yield of olefin is at least about 70%.

34. The process of any one of claims 1-33, wherein the yield of olefin is at least about 80%.

35. The method of any one of claims 1-34, wherein the catalyst is selected from P-SiO2, 15WZr, 25WZr, H-ZSM-5, Al-MCM-41, Al-SBA-15 and HY(30).

36. The method of any one of claims 1-35, wherein the method further comprises separating the resulting liquid pyrolysis products from the resulting gaseous pyrolysis products via a condenser section.

37. The method of any one of claims 1-36, wherein the microwave-assisted slurry reactor comprises a reaction vessel and a microwave source.

38. The method of claim 37, wherein the reaction vessel comprises A plastic inlet for adding plastic; and Gas inlet for injecting gas flow into the reaction vessel.

39. The process of claim 37 or 38, wherein the reaction vessel is a tubular reactor.

40. The method of any one of claims 37 to 39, wherein the reaction vessel further comprises a porous block.

41. The method of claim 40, wherein the porous block is a porous quartz block fixed in a reaction vessel.

42. The method of any one of claims 37-41, wherein the reaction vessel comprises a microwave susceptor.

43. The method of claim 42, wherein the microwave susceptor is a SiC monolith.

44. The method of any one of claims 37-43, wherein the microwave source emits microwaves to melt the plastic to form a slurry in the reaction vessel.

45. The method of any one of claims 37-44, further comprising a temperature probe for measuring the core temperature within the reactor vessel.

46. ​​One-pot pyrolysis system, comprising A microwave-assisted slurry reactor; and Condenser section; The microwave-assisted slurry reactor comprises a reaction container and a microwave source.

47. The one-pot pyrolysis system of claim 46, wherein the reaction vessel comprises plastic inlet for adding plastic; Gas inlet for injecting gas flow into the reaction vessel.

48. The one-pot pyrolysis system of claim 46 or 47, wherein the reaction vessel is a tubular reactor.

49. The one-pot pyrolysis system of any one of claims 46 to 48, wherein the reaction vessel further comprises a porous block.

50. The one-pot pyrolysis system of claim 49, wherein the porous block is a porous quartz block fixed in a reaction vessel.

51. The one-pot pyrolysis system of any one of claims 46-50, wherein the reaction vessel comprises a microwave susceptor.

52. The one-pot pyrolysis system of claim 51, wherein the microwave susceptor is a SiC monolith.

53. The one-pot pyrolysis system of any one of claims 46-52, wherein the microwave source emits microwaves to melt the plastic to form a slurry in the reaction vessel.

54. The one-pot pyrolysis system of any one of claims 46-53, further comprising a temperature probe for measuring the core temperature within the reaction vessel.

55. The one-pot pyrolysis system according to any one of claims 46-54, wherein the condenser section is connected to a microwave assisted slurry reactor via a connecting device.

56. The one-pot pyrolysis system of claim 55, wherein the connecting device is a glass tube.

57. The one-pot pyrolysis system of claim 56, wherein the glass tube is surrounded by a heating belt.

58. The one-pot pyrolysis system of any one of claims 46-57, wherein the condenser section separates liquid pyrolysis products from gaseous pyrolysis products.

59. The one-pot pyrolysis system of claim 58, wherein the condenser section comprises at least one cooling system.

60. The one-pot pyrolysis system of claim 59, wherein the at least one cooling system is a water cooling system.

61. The one-pot pyrolysis system of any one of claims 58 to 60, wherein the condenser section comprises at least one condenser.

62. The one-pot pyrolysis system of any one of claims 46-61, wherein the condenser portion is connected to a gas collection element and a liquid collection element.

63. The one-pot pyrolysis system of claim 62, wherein the gas collection element is a gas bag.

64. The one-pot pyrolysis system of claim 63, wherein the liquid collection element is a glass bottle.

65. The one-pot pyrolysis system of claim 64, wherein the glass bottle is immersed in an ice bath.

66. Use of a solid acid in a pyrolysis process for converting plastics containing polyolefin polymers into olefins; wherein the solid acid is selected from P-SiO2, 15WZr, 25WZr, H-ZSM-5, Al-MCM-41, Al-SBA-15 and HY(30).

67. The use of claim 66, wherein the pyrolysis process comprises contacting the plastic with a catalyst in a one-pot pyrolysis system at a temperature between about 350°C and about 500°C.

68. The use according to claim 67, wherein the one-pot pyrolysis system comprises a microwave-assisted slurry reactor.

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