Deconstruction of polyolefin plastic waste via a rapid joule heating process

Abstract

Disclosed herein are reactors and reactor systems designed to deconstruct a plastic waste feedstock that include one or more of a power supply, a plastic waste feedstock import line, and a reaction zone in communication with the power supply and the plastic waste feedstock import line, wherein the reaction zone contains a carbon-based heating element coated with a catalyst and a polymer. Method for deconstructing a plastic waste feedstock are also disclosed.

Description

[0001]2101715-001290 DECONSTRUCTION OF POLYOLEFIN PLASTIC WASTE VIA A RAPID JOULE HEATING PROCESS CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 63 / 575,988 filed on April 08, 2024, the contents of which are incorporated herein by reference in their entirety for all purposes. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH This invention was made with government support under Grant No. DE- EE0010838 awarded by the US Department of Energy. The government has certain rights in the invention. FIELD The present disclosure relates to systems and methods for deconstructing plastic waste feedstocks into hydrocarbon monomers that can be used in the production of other materials (e.g., polymers, chemicals, paints, rubbers and fuels). BACKGROUND Polyolefins, comprising low-density and high-density polyethylene (LDPE, HDPE) and polypropylene (PP), constitute about 60% of the plastic waste. While mechanical recycling is pivotal in managing some plastic waste, this recycling process falls short in producing high-quality materials, especially from polyolefins and mixed plastics. Consequently, there has been a surge in chemical upcycling and recycling technologies. However, the activation of C-C bonds in polyolefins remains challenging, thus rendering current upcycling and recycling technologies processes energy-intensive and unselective to high-value products. Though advancements in hydrocracking, hydrogenolysis, and catalytic pyrolysis have produced fuels, lubricants, and waxes with relatively high selectivity, these processes are not directly circular since their products need additional steps to produce monomers. An approach to synthesize monomers can entail producing naphtha via hydrocracking followed by steam cracking at high temperatures. Unfortunately, this two-step process is also extremely energy intensive. Alternatively, catalytic pyrolysis and ethenolysis have also been explored for direct monomer production. 2101715-001290 Ethenolysis employs ethylene as a reagent, the monomer of polyethylene, along with expensive noble metal catalysts, making it less circular and economically viable. Catalytic pyrolysis, while promising, entails high catalyst-to-polymer ratios (>>1), therefore lower selectivity to ethylene and propylene, and high energy intensity due to elevated reaction temperatures (especially when compared to mechanical recycling) along with slow penetration of the heat to the plastic. Process electrification can play a crucial role in decarbonizing the chemical industry by enabling the transition from traditional fossil fuel-based processes to more sustainable and energy-efficient alternatives. Utilizing renewable electricity as a clean energy source can replace carbon-intensive methods in producing key chemicals. As a result, electrified catalytic and non-catalytic processes using microwaves, induction heating, and Joule (or resistive) heating have gained traction. Though these processes have gained traction, there remains no process that can deconstruct plastic waste into hydrocarbon monomers with high selectivities and efficiencies. Thus, to address the foregoing issues with plastic waste upcycling and recycling technologies, the present disclosure provides novel approaches and systems that can, with high selectivities and efficiencies, upcycle and recycle plastic waste. SUMMARY One aspect of the present disclosure is a reactor or reactor system designed to deconstruct a plastic waste feedstock including (i.e., comprising) one or more of the following: a power supply, a plastic waste feedstock import line, and a reaction zone in communication with the power supply and the plastic waste feedstock import line, wherein the reaction zone contains a carbon-based heating element coated with a catalyst and a polymer. Another aspect of the present disclosure is a method for deconstructing a plastic waste feedstock including one or more of: obtaining the plastic waste feedstock; and deconstructing the plastic waste feedstock in a reactor, wherein the reactor contains a porous carbon fiber paper heating element coated with a catalyst and a polymer. 2101715-001290 BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the compositions, devices and methods disclosed herein will be apparent to those skilled in the art reading the following detailed description in conjugation with the exemplary embodiments illustrated in the drawings, wherein: FIG.1 depicts SEM images of (A) an exemplary fresh carbon fiber paper (1K X Mag) (CFP), (B) an exemplary CFP coated with H-ZSM-5 (500 X Mag), (C) an exemplary CFP coated with H-ZSM-5 and LDPE (1K X Mag), and (D) an exemplary post-reaction CFP after RPH of LDPE over H-ZSM-5 (1K X Mag). FIG.2 depicts a schematic of an exemplary Joule heating reactor. FIG.3 depicts the effect of DC voltage on the performance of thermal and catalytic RPH (60 pulses) on LDPE conversion to carbon products for various operating conditions. FIG.4 depicts an exemplary temperature profile for (A) Rapid Pulse Heating and (B) Continuous Joule heating of LDPE. FIG.5 depicts the product selectivity (left) and conversion (right) from an exemplary non-catalytic RPH of LDPE obtained using GC-FID. FIG.6 depicts the effect of the number of pulses on the performance of an exemplary RPH of LDPE over H-ZSM-5 catalyst at 42 V. FIG.7 depicts the effect of polymer-to-catalyst ratio on LDPE conversion of an exemplary RPH deconstruction process (42 V and 10 pulses). FIG.8 depicts a Raman spectrum of the polymer-to-catalyst ratios of spent catalysts and demonstrates that increased coking at higher polymer-to-catalyst ratios occurs in an exemplary RPH process. FIG.9 depicts (a) the weight loss (%) of coke on spent catalysts at different catalyst-to-polymer ratios (42 V and 10 pulses) from TGA; and (b) an example of TGA weight loss data for spent catalyst obtained from an exemplary PRH reaction performed at a catalyst-to-polymer ratio of 0.4. FIG.10 depicts the effect of He gas flow rate on the performance of an exemplary RPH of LDPE over H-ZSM-5 catalyst (42 V and 5 pulses). 2101715-001290 FIG.11 depicts the effect of pulsing frequency (controlled by varying cooling times) on the performance of an exemplary rapid pulse heating (RPH) process for LDPE deconstruction at constant energy consumption. The insets depict the pulses. FIG.12 depicts the effect of pulsing frequency (controlled by varying cooling times) on RPH-mediated LDPE conversion reactions when the peak temperature (Tmax ~720 °C) and the total exposure time (8 seconds) of the reactions are held constant. FIG.13 depicts the effect of heating time on the performance of an exemplary rapid pulse heating (RPH) process for LDPE deconstruction at constant energy consumption. FIG.14 depicts the effect of DC voltage on conversion and selectivity for an exemplary CJH-mediated deconstruction process of LDPE over H-ZSM-5 (reaction time = 500 ms). FIG.15 depicts the effect that used CFP, coated with H-ZSM-5, have on the conversion of LDPE for an exemplary RPH-mediated LDPE deconstruction process (42 V and 10 pulses). FIG.16 depicts the effect that used CFP, coated with H-ZSM-5, have on the conversion of LDPE for an exemplary CJH-mediated LDPE deconstruction process (26 V and 500 ms). FIG.17 depicts a Raman spectrum of spent H-ZSM-5 catalysts after 3 cycles of reuse in an RPH-mediated and a CJH-mediated LDPE deconstruction process. FIG.18 depicts the weight % of coke obtained from TGA of spent catalysts after 4 reuse cycles in an RPH-mediated and a CJH-mediated LDPE deconstruction process. FIG.19 depicts a comparison of DTA curves of spent catalysts from an RPH-mediated and a CJH-mediated LDPE deconstruction process after 3 cycles of reuse. FIG.20 depicts the effect of co-feeding steam during an RPH-mediated LDPE deconstruction process wherein a CFP coated with H-ZSM-5 catalyst was used (42 V, Tmax = 730 °C). 2101715-001290 FIG.21 depicts a Raman spectrum of spent catalysts from an RPH- mediated and CJH-mediated LDPE deconstruction process. The figure also depicts the Raman spectra of spent catalysts from an RPH-mediated and CJH-mediated LDPE deconstruction process involving the co-feeding of steam. FIG.22 depicts the effect that reused CFP, coated with H-ZSM-5, has on LDPE conversion for a CJH-mediated LDPE deconstruction process (26 V and 500 ms) with steam co-feeding. FIG.23 depicts a comparison of DTA curves of spent catalysts from an RPH-mediated LDPE deconstruction process with co-feeding steam, an RPH- mediated LDPE deconstruction process without co-feeding steam, and a CJH- mediated LDPE deconstruction process. FIG.24 depicts the performance of an exemplary rapid pulse heating (RPH) process on the deconstruction of real-life plastics. The exemplary RPH-mediated process uses a CFP coated with a H-ZSM-5 catalyst (42 V, 10 pulses and Tmax= 730 °C). DETAILED DESCRIPTION All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. One aspect of the present disclosure is a reactor designed to deconstruct a plastic waste feedstock including one or more of: a power supply, a plastic waste feedstock input line, and a reaction zone in communication with the power supply and the plastic waste feedstock input line, wherein the reaction zone contains a porous carbon-based, highly conductive heating element coated with a catalyst and a polymer. In exemplary embodiments, the carbon-based heating element is a porous carbon-fiber paper. The porous carbon-fiber paper can be, but is not limited to, a ToraycaTMcarbon-fiber paper (e.g., ToraycaTMCarbon Paper, ToraycaTMGDL), a 2101715-001290 FreudenbergTMcarbon-fiber paper (e.g., FreudenbergTMH23C8 CFP, FreudenbergTMH23C2, FreudenbergTMH24C5), or a TorayTMcarbon-fiber paper (e.g., TorayTMPaper 30, TorayTMPaper 60, TorayTMPaper 90, TorayTMPaper 120). In exemplary embodiments, the carbon-based heating element is a porous carbon-fiber felt. The porous carbon-fiber felt can be, but is not limited to, an AvCarbTMcarbon-fiber felt, a PAN-based carbon-fiber felts, or a RayonTMcarbon- fiber felt. In exemplary embodiments, the carbon-based heating element is a porous carbon-fiber foam sheet. The carbon-fiber foam sheet can be, but is not limited to, an ACP CompositesTMcarbon-fiber foam sheet, a KumairTMcarbon-fiber foam sheet, or a HexcelTMcarbon-fiber foam sheet. In exemplary embodiments, the carbon-based heating element is a porous 3D monolithic foam structure such as, but not limited to, poly(HIPE) foams, graphene foams, nickel foams, 3D printed mineral foams, and 3D monolithic composite foams. In exemplary embodiments, the carbon-based heating element is a carbon- fiber sheet. The carbon-fiber sheet can be, but is not limited to, a CHM Composites carbon-fiber sheet (e.g., Chemitex 20 carbon fiber veil), a PAN-based carbon-fiber sheet, a rayon-based carbon-fiber sheet, or a pitch-based carbon-fiber sheet. In exemplary embodiments, the carbon-based heating element is a monolithic carbon-fiber. The monolithic carbon-fiber can be, but is not limited to, a plain weave monolithic carbon fiber, a twill weave monolithic carbon-fiber, or a harness satin weave monolithic carbon fiber. In exemplary embodiments, the carbon-based heating element contains one or more conductive fibers. The conductive fibers can be selected from any conductive fiber known to have an electrical resistance of about 25,000 ohm / cm or lower, or about 25 to about 15,000 ohm / cm, and / or a melting point higher than about 500° C. The conductive fibers can also be selected from those known to be non-flammable, possess low water absorption, possess allergenic properties, and / or possess adhesive compatibility. Examples of conductive fibers that can be included within the carbon-based heating element are, but not limited to, nickel- coated carbon, silver-coated nylon, and aluminised glass. In exemplary embodiments, the carbon-based heating element include one or more conductive 2101715-001290 materials selected from, but not limited to, graphene, carbon nanotubes, carbon black, graphite, metal alloys, metal wires, 3D metal structures, silicon carbide and / or any other electrically conductive carbon-based structures known in the art. In exemplary embodiments, the carbon-based heating element is a woven or non-woven carbon-fiber web. The woven or non-woven carbon-fiber web can be made of or include carbon-fibers having a diameter between 5 to 20 microns and an average length of 3 to 9 mm. The woven or non-woven carbon-fiber web can also include electrically-conductive busbar strips. The woven or non-woven carbon- fiber web can be, but is not limited to, a PAN-based carbon-fiber web (e.g., those sold by Rock West Composites®), a rayon-based carbon-fiber web, or a pitch- based carbon-fiber web. The woven or non-woven carbon-fiber web can also include polyaramid fibers. In exemplary embodiments, the woven or non-woven carbon-fiber web contains 1-20 wt% or 5-10 wt% carbon fibers, and 80-99 wt% or 95-100 wt% polyaramid fibers. The woven or non-woven carbon-fiber webs disclosed herein can be formed by standard wet-laid manufacturing. Suitable wet- laying techniques are discussed, for example, in U.S. Pat. No.4,007,083, U.S. Pat. No.4,049,491, and U.S. Pat. No.4,200,488, which are herein incorporated by reference. In exemplary embodiments, the carbon-based heating element contains conductive fibers that are all either one length or a mixture of lengths. The minimum length of the conductive fibers can be about 1 / 8 of an inch and the maximum length can be 1 and a 1 / 2 or 2 inches. An advantage of using conductive fibers possessing a mixture of lengths is that the shorter fibers allow the carbon-based heating element to be more uniformly resistive while the longer fibers allow for use of less material to get substantial electrical contact, are more economical and also can increase the mechanical strength of the element. In exemplary embodiments, the average length of the conductive fibers is at least about 1 / 2 inch. The amount of conductive carbon fibers required within the carbon-based heating element will depend upon the type of conductive fiber chosen; the voltage at which the heating element is to be used; and the physical configuration of the heating element, which will determine the current path through it. Lower voltages and longer current paths require relatively more conductive fiber. 2101715-001290 In exemplary embodiments, the carbon-based heating element contains about 60 to about 99 wt%, about 70 to about 90 wt%, about 80 to about 85 wt%, or any wt% or range of wt%s falling within the range of about 60 to about 99 wt% of conductive carbon fibers. In exemplary embodiments, the carbon-based heating element possess a coating that contains a polymer-to-catalyst weight ratio of about 1.25 to about 50, about 1.25 to about 40, about 1.25 to about 30, about 1.25 to about 20, or any weight ratio or range of weight ratios falling within the range of about 1.25 to about 50. In exemplary embodiments, the carbon-based heating element has an exposed area of up to about 120 mm x 30 mm, up to about 100 mm x 20 mm, up to about 80 mm x 20 mm, or up to about 38 mm x 8 mm. As used herein, an “exposed area” is an area on the carbon-based heating element that is capable of interacting with the plastic waste feedstock and mediating the deconstruction of the plastic waste feedstock. In exemplary embodiments, the carbon-based heating element has an average pore size of about 0.1 to about 10 microns, about 0.1 to about 5 microns, about 0.1 to about 1 micron, or a pore size or range of pore sizes falling within the range of about 0.1 to about 10 microns. In exemplary embodiments, the catalyst coated on the carbon-based heating element is a zeolite catalyst. Examples of zeolite materials that can be used as the catalyst coating or can be present in the catalyst coating on the carbon-based heating element include, but are not limited to, silicate-based zeolites and amorphous materials such as faujasite, mordenite, or chabazite. Silicate-based zeolites can include those made of alternating SiO2and MOxtetrahedra, where M is an element selected from the Groups 1 through 16 of the Periodic Table. Other suitable zeolite materials that can be used as or present in the coating include zeolite beta, zeolite Y, ferrite (FER), Mobil-type Five (MFI or ZSM-5), SSZ-13 (Chabazite), MCM-22, SAPO-34, and ITQ-2. Likewise other zeolite morphologies including hierarchical zeolites (containing mesopores in addition to micropores), self-pillared zeolites, and zeolite nanosheets can also be used. 2101715-001290 In exemplary embodiments, the catalyst coated on the carbon-based heating element is a mesoporous aluminosilicate. Examples of mesoporous aluminosilicate materials that can be used as the coating or present in the coating include, but are not limited to, Al-MCM-41, Al-SBA-15, Al-MCM-48, Al-KIT-6, Al-HMS, hybrid mesoporous aluminosilicate (i.e., mesoporous aluminosilicate catalysts obtained by non-hydrolytic sol–gel), amorphous SiO2-Al2O3, and any other mesoporous aluminosilicate catalyst known in the art. In exemplary embodiments, the catalyst coated on the carbon-based heating element is a metal oxide catalyst. Examples of metal oxide materials that can be used as the coating or present in the coating include, but are not limited to, copper oxide, iron oxide, manganese dioxide, nickel oxide, chromium oxide, cobalt oxide, vanadium oxide, titanium dioxide, zinc oxide, molybdenum oxide, zirconium oxide, Tin Oxide, mixed metal oxides (e.g., SrTiO3, NiAl2O4, NiAl- and CoAl- layered double hydroxides (LDH)), and metal oxide nanoparticles (e.g., TiO2nanoparticles, ZnO nanoparticles, and Fe2O3 nanoparticles). In exemplary embodiments, the catalyst coated on the carbon-based heating element is a supported metal-acid catalyst. Examples of supported metal-acid catalyst materials that can be used as the coating or present in the coating include, but are not limited to, metals such as Pt, Ru, Ni, Co, Rh, Pd, Ir supported on solid acids (e.g., USY, HBEA, HZSM-5, WOx-ZrO2, Nb2O5, SiO2-Al2O3, Al-SBA-15), NiMo supported on Zeolites, (Ni, Co)MoSxsupported on Zeolites, and any supported metal-acid catalyst material used in processes involving the hydrocracking of plastics. In exemplary embodiments, the catalyst coated on the carbon-based heating element is a supported metal catalyst. Examples of supported metal catalysts that can be used as the coating or present in the coating include, but are not limited to, metals such as Pt, Ru, Ni, and Co supported on supports such as SiO2, TiO2, ZrO2, Al2O3, CeO2, Carbon, SBA-15, MCM-41, mixed metal oxides (e.g., SrTiO3, NiAl2O4, NiAl- and CoAl- layered double hydroxides (LDH)), and any supported metal catalyst material used in processes involving the hydrogenolysis of plastics. In exemplary embodiments, the polymer is selected from a low-density polyethylene polymer film, a high-density polyethylene polymer film, a linear low- 2101715-001290 density polyethylene polymer film, a polypropylene film, a polyethylene terephthalate film, a polyvinyl chloride film, a poly(ethylene-co-vinyl alcohol) film, a poly(ethylene-co-vinyl acetate) film, or combinations thereof. In exemplary embodiments, the polymer is a film having a thickness that is less than about 100 µm, less than about 20 µm, less than about 15 µm, less than about 10 µm, less than about 5 µm, less than about 1 µm, or any thickness or range of thicknesses falling within the range of 0.1 µm to 100 µm. In exemplary embodiments, the reactor is selected from a fixed-bed reactor or a slurry reactor. In exemplary embodiments, the reactor is a fixed-bed reactor that utilizes a carbon-based foam or a carbon-based monolith as a heating element. In exemplary embodiments, the reactor is a slurry reactor that utilizes a carbon-based foam or a carbon-based monolith as a heating element. In exemplary embodiments, the reactor is a fixed-bed reactor that utilizes a silicon-based foam or a silicon-based monolith, for example, SiC-based foams or monoliths. In exemplary embodiments, the reactor is a slurry reactor that utilizes a silicon-based foam or monolith. In exemplary embodiments, the reactor is configured to operate in a Rapid Pulse Joule Heating (RPH) mode and / or a Continuous Joule Heating (CJH) mode. In exemplary embodiments, the reactor is in communication with a solid state relay that is capable of transferring short bursts of energy (e.g., via a laser or electromagnetic pulses) to the reactor to quickly heat the carbon-based heating element in predetermined intervals. In exemplary embodiments, the solid state relay is also capable of transferring a continuous amount of energy to the reactor to continuously heat the carbon-based heating element to a predetermined temperature. In exemplary embodiments, the reactor includes a steam import line in communication with the reaction zone and a gas container. The steam import line can be configured to transfer steam into the reaction zone that has formed from a bubbler unit located between or within the steam import line and the gas container. In exemplary embodiments, the gas container contains a gas selected from, but not limited to, hydrogen, carbon dioxide, nitrogen, helium, and argon. 2101715-001290 In exemplary embodiments, the reactor is in communication with a power supply. In exemplary embodiments, the reactor includes a solid-state relay that is in communication with the power supply and the reaction zone. The power supply can be any component or machine known by those of ordinary skill in the art to be capable of supplying enough power to a reactor system, for example, a power grid, a generator, or a battery. In exemplary embodiments, the power supply is configured to supply a predetermined amount of energy or power to the reactor. In exemplary embodiments, the reactor is in communication with a programmable source measure unit. A programmable source measure unit can be any instrument capable of precisely sourcing a specific voltage or range of voltages to the reactor and simultaneously measure the voltage or range of voltages supplied to the reactor. In exemplary embodiments, the programmable source measure unit is a programmable sourcemeter. The programmable source measure unit can be in communication with a solid state relay and a data output device. The data output device can be any instrument or device capable of displaying data gathered on the reactor. In exemplary embodiments, the data output device is a computer monitor in communication with a processing unit. In exemplary embodiments, the processing unit contains one or more software programs capable of gathering data on the reactor. The data can include, but is not limited to, the temperature of the reaction zone, the amount of steam entering the reaction zone, the power being supplied to the reaction zone, the frequency of power being applied to the reaction zone, the amount of plastic waste feedstock entering the reaction zone, the status of the carbon-based heating element in the reaction zone, and / or the amount of product leaving the reaction zone. In exemplary embodiments, the reactor is configured to heat the carbon- based heating element by resistive heating. In exemplary embodiments, the reactor includes an output line in communication with the reaction zone. The output line can be configured to transport hydrocarbon monomers that are formed from the deconstruction of a plastic waste feedstock from the reaction zone to a storage container. In exemplary embodiments, the hydrocarbon monomers contain or consist essentially of C2-C4olefins. 2101715-001290 In exemplary embodiments, the reaction zone is a made of a material capable of converting electrical energy into heat. For example, the reaction zone can be made of quartz, fused silica, ceramics (e.g., silicon carbide and molybdenum disilicide), and certain alloys (e.g., NiChrome, FeCrAl). In exemplary embodiments, the reaction zone is a vertical tube containing one or more clamps and / or plates capable of interacting with the carbon-based heating element and transferring energy to the carbon-based heating element. The clamps and / or plates can be made of a material selected from, but not limited to, steel, copper, silver, aluminum, bronze, tungsten, zinc, aluminum nitride, and other metal alloys. In exemplary embodiments, the reactor includes a component capable of detecting and monitoring a temperature of the carbon-based heating element. The component can be, but is not limited to, an infrared camera, a thermometer and / or a pyrometer. Another aspect of the present disclosure is a method for deconstructing a plastic waste feedstock include one or more of: obtaining the plastic waste feedstock and / or deconstructing the plastic waste feedstock in a reactor, wherein the reactor contains a carbon-based heating element coated with a catalyst and a polymer. The reactor used in the method can be any reactor disclosed herein. The catalyst used in the method can be any catalyst disclosed herein. The polymer used in the method can be any polymer disclosed herein. The carbon-based heating element used in the method can be any carbon-based heating element disclosed herein. In exemplary embodiments, the deconstructing of the plastic waste feedstock in the reactor does not involve using a carbon-based heating element coated with a catalyst and a polymer but instead involves directly adding the catalyst and polymer into the reactor, which contains the carbon-based heating element, before and / or during the deconstructing. In these embodiments the catalyst and polymer can be, but are not required to be, in powdered form. In exemplary embodiments, the deconstructing of the plastic waste feedstock in the reactor includes resistively heating the carbon-based heating element by a rapid pulse joule heating process to a temperature ranging from about 2101715-001290 300°C to about 1200°C, from about 500 °C to about 800 °C or any temperature or temperature range falling within the range of 300°C to about 1200°C. In exemplary embodiments, the rapid pulse joule heating process includes pulsing the carbon-based heating element one or more times with a dual current (DC) voltage ranging from about 0 V to about 70 V, about 20 V to about 60 V, about 30 V to about 40 V or any voltage or range of voltages falling within the range of 0 V to about 70 V. Those of ordinary skill in the art will appreciate that the ideal range of voltages to conduct the rapid pulse joule heating process at will depend on a number of factors, for example the heating and cooling times, the pulse width and number of pulses used during the deconstructing reaction. Accordingly, those of ordinary skill in the art will appreciate that there are embodiments of the method wherein the rapid pulse joule heating process includes pulsing the carbon-based heating element one or more times with a dual current (DC) voltage above 70 V. For example, when the carbon-based heating element is a foam or a monolith the amount of power needed to heat the foam or monolith to an appropriate temperature for deconstruction of the plastic waste feedstock can be above 70 V. Another example involves the production of hydrogen from the plastic waste feedstock. Producing and recovering hydrogen from the plastic waste feedstock can require heating the carbon-based heating element to temperatures above 1000°C and, to achieve these temperatures, voltages above 70 V can be needed. In exemplary embodiments, the rapid pulse joule heating process includes pulsing the carbon-based heating element at least 5 times, at least 10 times, at least 50 times, at least 100 times, at least 200 times, at least 300 times, at least 500 times, at least 1000 times, at least 2000 times, or no more than 28,000 times. Those of ordinary skill in the art will appreciate that the ideal number of pulses to use during the rapid pulse joule heating process will depend on how long it takes to achieve full deconstruction of the plastic waste feedstock. Full deconstruction of the plastic waste feedstock can be determined via gravimetric methods. In exemplary embodiments, the pulsing of the carbon-based heating element includes heating the carbon-based heating element for about 10 ms to about 1000 ms, about 50 ms to about 500 ms, about 50 ms to about 200 ms, or any amount of time or range of times falling within the range of 10 ms to about 1000 ms. In 2101715-001290 exemplary embodiments, the pulsing of the carbon-based heating element includes cooling the carbon-based heating element for about 10 ms to about 1000 ms, about 50 ms to about 900 ms, about 100 ms to about 800 ms, about 800 ms to about 950 ms, or any amount of time or range of times falling within the range of 10 ms to about 1000 ms. In exemplary embodiments, the deconstructing of the plastic waste feedstock in the reactor includes resistively heating the carbon-based heating element by a continuous joule heating process to a temperature ranging from about 300°C to about 1200°C, from about 500 °C to about 800 °C or any temperature or temperature range falling within the range of 300°C to about 1200°C. In exemplary embodiments, the continuous joule heating process includes heating the carbon-based heating element for about 10 ms to about 3000 ms, about 10 ms to about 2000 ms, about 10 ms to about 1000 ms, about 10 ms to about 500 ms, about 500 ms, or about any amount of time or range of times falling within the range of about 10 ms to about 3000 ms. In exemplary embodiments, the continuous joule heating process includes subjecting the carbon-based heating element to a DC voltage of about 0 V to about 70 V, about 10 V to about 60 V, about 20 V to about 35 V, or any voltage or range of voltages falling within the range of 0 V to 70 V. Those of ordinary skill in the art will appreciate that the ideal range of voltages to conduct the continuous joule heating process at will depend on a number of factors, for example the heating time and the pulse width used during the deconstructing reaction. Accordingly, those of ordinary skill in the art will appreciate that there are embodiments of the method wherein the continuous joule heating includes subjecting the carbon-based heating element with a dual current (DC) voltage above 70 V. In exemplary embodiments, the method includes introducing a steam gas into the reactor during the deconstructing of the plastic waste feedstock. In exemplary embodiments, the method includes regenerating the catalyst on the carbon-based heating element after the carbon-based heating element has undergone at least three cycles of deconstructing the plastic waste feedstock. In exemplary embodiments, the regenerating of the catalyst on the carbon-based heating element occurs after the carbon-based heating element has undergone 2101715-001290 three cycles, four cycles, five cycles, six cycles, seven cycles, eight cycles, or ten cycles of deconstructing the plastic waste feedstock. In exemplary embodiments, the deconstruction of the plastic waste feedstock converts at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, 100 wt%, or any wt% or range of wt%s falling within the range of 75 wt% to 100 wt% of the plastic waste feedstock into hydrocarbon monomers. In exemplary embodiments, the hydrocarbon monomers include or consist essentially of C2-C4olefins. In exemplary embodiments, the deconstructing of the plastic waste feedstock in the reactor comprises operating the deconstructing reaction at condition that produce a catalyst ID / IG ratio of at most 0.40, at most 0.30, at most 0.20, at most 0.10, or at most 0.05. As used herein, a “ID / IGratio” is a weight ratio of the defected to graphitic carbon on the catalyst. In exemplary embodiments, the deconstructing of the plastic waste feedstock in the reactor includes producing no more than 20 wt%, no more than 15 wt%, no more than 10 wt%, no more than 5 wt%, or no more than 1 wt% coke based on the total weight of the deconstructed plastic waste feedstock products. In exemplary embodiments, the catalyst is wash coated onto the carbon- based heating element. In exemplary embodiments, the catalyst is a powder or a pellet and deposited onto the carbon-based heating element. In these embodiments, the catalyst material can be crushed or grounded into a finer particles before being deposited onto the carbon-based heating element. Examples The present disclosure will be described in more detail with reference to the following Examples, which shows exemplary embodiments in accordance with the present disclosure. The present disclosure is not limited to these exemplary embodiments. Example 1 Objective: This example demonstrates the efficiency and selectivity that the systems and methods disclosed herein possess when used to deconstruct a plastic 2101715-001290 wastes feedstock into C2-C4 olefins. In this example, exemplary methods that use a Rapid Pulse Joule Heating (RPH) process and a Continuous Joule Heating (CJH) process as the means to provide the energy for the deconstruction of plastic wastes were evaluated. Materials and Methods Materials LDPE (Mw = 4 kDa), PP (Mw = 12 kDa), ethanol (EtOH), toluene, xylene, and dichloromethane (DCM) were obtained from Sigma-Aldrich. H-ZSM-5 (CBV3024E, Si:Al = 30, NH4+-form) was obtained from Zeolyst International. Carbon fiber paper (CFP) - Freudenberg H23, thickness= 210 μm, was obtained from Freudenberg Performance Materials SE & Co. Polyethylene bottles were obtained from SP Scienceware. PE bags were obtained from Ziploc™. HOPE grocery bags were obtained from ULINE. Centrifuge tubes were obtained from Fisher Scientific. The Ocean plastic (HOPE fishnets) was provided by researchers at the Hawaii Pacific University. Heating Element Preparation Catalysts were coated on a CFP heating element with an exposed area of 38 mm by 8 mm. Prior to coating, the ZSM-5 was calcined in air at 550 °C (2 °C / min ramp) for 4 h to convert it to H+form (referred to as H-ZSM-5 henceforth). Typically, 10 mg of catalyst was sonicated in EtOH to form a uniform suspension before being drip-coated uniformly on both sides of the CFP. The suspension was self-distributed on the CFP by the capillary effect. Once the catalyst was coated, the CFP was dried in an oven at 70 °C in static air to remove excess solvent. A given amount of polymer and toluene (or xylene in the case of HOPE and PP) were mixed and heated to 130-180 °C to obtain a homogeneous solution of the polymer in the solvent (at a concentration of 5-20 wt%). Once the polymer was completely dissolved, the CFP was placed on a glass slide on a hotplate at about 150 °C. The polymer solution was then added dropwise to the CFP and left on the hot plate for 2 min to remove residual solvent. Any excess solvent was removed by further drying the CFP in a vacuum for 30 min at 70 °C. FIG.1 shows SEM images of fresh CFP, CFP coated with the catalyst, and the CFP uniformly coated with the polymer and the H-ZSM-5 catalyst. The bright regions represent the polymer's 2101715-001290 negative charging during SEM imaging. Given the porous structure of the CFP matrix, the polymer deposits on the fibers and within the inter-fiber gaps. SEM images reveal that the distance between adjacent fibers is typically < 20 μm. Consequently, the thickness of the polymer layer was expected to be <20 μm. Joule Heated (JH) Reactor Design The JH reactor used in this example was a vertical quartz tube (ID= 22 mm) with gas reactants flowing from top to bottom. The Joule heating element was fixed by two stainless steel clamps and four copper plates to ensure good electrical contact. A direct current (DC) power supply provided current for Joule heating (Volteq HY7520ex). A DC solid-state relay, a source meter (Keithley 2425), and a LabView program enabled programmable heating. The temperature of the heating element was monitored using an IR camera (Optris PI 1M or Pl640) through the quartz reactor with a frame rate of up to 1000 FPS (frames per second). The reactor was subjected to passive air cooling (20 °C) in a fume hood. A simplified schematic of the setup is shown in (FIG.2). A typical RPH had a cycle period of 1 s, with 5% of duty cycle (50 ms heating and 950 ms cooling). The pulsing parameters were adjusted accordingly for each of the experimental conditions discussed below. Alternatively, the heating element was also operated under steady state CJH. Reactivity Tests The conversion of the plastic wastes was conducted in the JH reactor containing a CFP impregnated with the zeolite coated with about 10-12 mg of plastic along with an upward He flow of 25 sccm (unless stated otherwise) regulated by a mass flow controller. The He gas flowing along the CFP acted as a carrier gas and removed the vaporized product. A Tedlar bag was connected to the rear end of the reactor section for online collection of the hydrocarbons produced. For steam co-feeding experiments, the He gas was bubbled through a bubbler containing water, resulting in a concentration of about 3-4% water in the gas stream. Catalyst Characterization The X-ray diffraction (XRD) pattern of the catalyst was recorded using an X- ray diffractometer (Bruker D8) with Cu Kα radiation (λ= 1.54056 Å) at 40 kV and 40 2101715-001290 mA and a scanning rate of 0.05 per second between 2θ = 10-70°. Elemental composition was obtained using X-ray fluorescence (XRF) spectroscopy on a Rigaku WDXRF. N2 physisorption at -196°C was performed on a Micromeritics ASAP 2020 instrument. Fourier transform infrared (FTIR) spectra of adsorbed pyridine followed by pyridine thermodesorption were recorded in transmission mode in a homemade Pyrex tubular flow cell equipped with 32 mm KBr windows. The sample was pressed in a self-supported wafer (about 15 mg, 1.3 cm2and 40 bar / cm2pressure), placed in a quartz sample holder, and heated in flow of pure Ar at 300 °C (ramping rate 10°C / min) with 1 h dwell at that temperature. 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) with a micro syringe through a septum port. After saturation, the sample was flushed with pure He for 30 min, and the spectrum of the pyridine-saturated sample was recorded. Finally, the temperature was increased at 10°C / min to 300 °C in a constant flow of Ar, and spectra were recorded every 1 min. Integration and peak deconvolution were done using the OMNIC 8.2 software. The coked catalyst samples were collected by sonicating the spent CFP in EtOH, followed by drying the samples in air at 70 °C. Thermogravimetric analysis was performed on a TGA5500 (TA instruments). Approximately about 5 mg of sample was loaded onto each pan and heated in 20 sccm of air at a ramp rate of 20 °C / min. Raman spectra of the coked catalyst samples were recorded under ambient conditions on a Horiba LabRam microscope with a 15x objective using a 325 nm UV laser. The analysis of the spectra was done using OMNIC 8.2 software. Product Analysis The products collected in the Tedlar gas sampling bag were analyzed with a GC-FID (Agilent HP-PLOT / Q GC column). Additionally, a solvent trap filled with CH2Cl2and cooled down to about 0 °C was used to extract products with a carbon number ≥ C4, and the species in the resulting mixture were analyzed using a GC- MS (Agilent DB-5 column). Calibration coefficients and retention times for all products were measured using C1 – C8 analytical standards. The conversion of LDPE was calculated as follows: 2101715-001290 where WCFP,iis the initial weight of the CFP, after coated with the polymer and the catalyst, WCFP,fis the final weight of the CFP, and WPOL,iis the weight of the polymer coated calculated by measuring the weight difference of CFP before and after coating the polymer. The calculated, theoretical conversion here does not consider the inevitable loss of polymer into coke (typically <10% based on TGA). Hence, the real, actual conversion would be expected to be slightly higher than the reported conversion. The product fraction of extractable products (gas and liquids) was calculated as follows: The carbon balances of the different reactivity tests can be found in Table 1. Table 1: Maximum and Average Temperatures at Different Pulsing Conditions Measured using an IR camera Operational Pulsing TmaxTavgVoltage Mode Parameters (°C) (°C) 60 pulses, 32 V RPH 540 <476 50 ms 60 pulses, 36 V RPH 630 495 50 ms 60 pulses, 42 V RPH 752 542 50 ms 10 pulses, 42 V RPH 730 510 50 ms 1 pulse, 20 V CJH 495 <475 500 ms 23 V CJH 1 pulse, 565 505 2101715-001290 500 ms 1 pulse, 25 V CJH 648 550 500 ms 1 pulse, 26 V CJH 748 625 500 ms 1 pulse, 27 V CJH 815 670 500 ms 1 pulse, 31 V CJH 1030 >700 500 ms 5 pulses, 42 V RPH 50 ms, <475 <475 0.25 Hz 5 pulses, 42 V RPH 50 ms, 490 <475 0.5 Hz 10 pulses, 59.4 V RPH 25 ms, 775 518 1 Hz 5 pulses, 59.4 V RPH 25 ms, 729 485 1 Hz 10 pulses, 21 V RPH 200 ms, 690 497 1 Hz 5 pulses, 21 V RPH 200 ms, 544 <476 1 Hz 5 pulses, 10.5 V RPH 800 ms, <476 <476 1 Hz 15 V CJH 1 pulse, 640 691 2101715-001290 10 s 1 pulse, 16 V CJH 744 810 10 s 4 pulses, 53 V RPH 50 ms, 720 490 0.5 Hz 2 pulses, 65 V RPH 50 ms, 716 485 0.25 Hz Results and Discussion Evaluation of Reaction Parameters The depolymerization of the plastic wastes was conducted in a Joule Heated reactor consisting of a carbon fiber paper (CFP) impregnated with an MFI zeolite (H-ZSM-5) and coated with the plastic. The polymer was in intimate contact with the CFP and the catalyst and was heated resistively very rapidly by the heating element. The flowing He gas, regulated by a mass flow controller, entrained the gas products and minimized their contact with the catalyst and secondary reactions. Reaction conditions were evaluated to determine which conditions afforded high conversions and selectivities to monomers (e.g., ethylene, propylene, and potentially butylene) under pulse heating. First, the DC voltage was adjusted to control the average and peak temperatures. The total pulsing time was 60 s, encompassing 60 pulses, with each pulse comprising 50 ms of heating and 950 ms of cooling and a polymer-to-catalyst ratio of about 1. Non-catalytic tests were also performed as a reference. The excellent electric conductivity and thermal conductivity of the CFP enabled rapid and uniform heating, respectively. FIG.3 demonstrated that the catalyst significantly increased (about 20% higher) activity at 32 V (Tmax= 540 °C) but gave comparable conversion at 42 V because of higher peak temperatures (Tmax= 750 °C). However, the product selectivity differed profoundly: non-catalytic cracking led to a broad distribution of alkanes and olefins ranging from C1-C31along with heavier wax products (see FIG.4 and FIG.5), whereas catalytic cracking resulted in complete conversion and produced C1 -C8 2101715-001290 range hydrocarbons, with an about 74% selectivity to C2-C4 products. A voltage of 42 V achieved the highest selectivity of C2-C3products (about 45%) and was selected for subsequent tests. We attributed the high selectivity of light olefins to the thin polymer film (<20 μm thick) and short contact times. This bears critical importance, as a thin polymer film (e.g., <100 μm at about 700 °C) ensured negligible heat and mass transport limitations (treaction> tconvection> tconduction, treaction> tdiffiusion), and short contact times are important to preclude slower secondary reactions leading to char formation. After evaluating the effect that voltage had on the conversion and selectivity of the plastic waste depolymerization reaction, the effect of the number of pulses used during the depolymerization was evaluated (FIG.6). About 10 pulses achieved full conversion, whereas ≤3 pulses exhibited significantly lower conversion. The lower conversion was attributed to lower peak and average temperatures (Tmax= 503 °C at 3 pulses vs.730 °C at ≥5 pulses), which resulted from the energy of the initial pulses being expended in heating the polymer to its melting point and facilitated the phase transition from solid to molten state. Additionally, the lower peak and average temperatures resulted in lower selectivity towards C2-C4 hydrocarbons. The effect of the polymer-to-catalyst ratio was studied next. All ratios (1.25-20) showed >90% conversion (FIG.7), but the amount of coke increased monotonically with increasing ratios, as depicted in FIG.8. Raman spectra of the spent catalyst indicated an intense graphitic band at about 1610 cm-1, along with two defected carbon bands at about 1395 cm-1and about 1210 cm-1, respectively. At catalyst-to-polymer ratios of <0.4, heavy coke exceeded 30 wt. % (see FIG.9). Hence, a ratio of about 0.8 (polymer-to-catalyst ratio of about 1.25) was used for subsequent tests. Lastly, varying the He gas flow rate led to no significant changes (FIG.10). Effect of Pulsing Parameters The effect that pulsing frequency had on the plastic waste depolymerization reaction was also evaluated through systematic variation of heating and cooling times. First, the frequency was modulated by varying the cooling time while keeping the heating time at 50 ms and maintaining a voltage of 42V for 5 pulses. FIG.11 illustrates notably lower conversions at 0.25 Hz and 0.5 Hz, attributed to the longer 2101715-001290 cooling times (3950 ms and 1950 ms, respectively) that lead to lower peak and average temperatures (FIG.11, Table 1). For example, at 0.25 Hz, the cooling time was about 4 s, causing the CFP to reach near room temperature upon cooling. Likewise, the conversion after two sequential experiments of 5 pulses each on the same sample at 1 Hz was about 20% lower than in a single sequence of 10 pulses. Similarly, at a given frequency, fewer pulses reduced the conversion significantly (see FIG.6). A similar phenomenon was reported by Dong et al. (Dong, Q. et al. “Depolymerization of plastics by means of electrified spatiotemporal heating”, Nature 616, 488-494), thus demonstrating that the non-catalytic process required a combination of melting, wicking, vaporization, and reaction to achieve good performance. However, with rapid joule heating alone without a bilayer structure, the non-catalytic depolymerization was unselective due to the lack of a temperature gradient that promoted wicking. Additionally, the effect of pulsing frequency was assessed under conditions of constant peak temperatures (Tmax= about 720 °C) and total exposure times (8 seconds). The evaluation of pulsing frequency was accomplished by adjusting the DC voltage and pulse sequences: 2 pulses at 0.25 Hz (65 V), 4 pulses at 0.5 Hz (53V), and 8 pulses at 1 Hz (42V). Again, the results suggested that the conversion of the plastic waste to monomers decreased with a decrease in frequency, primarily due to a lower Tavg(FIG.12). Alternatively, variations in the pulse width were investigated while maintaining a constant pulsing frequency of 1 Hz by adjusting the heating and cooling times. In these experiments, the energy consumption was held nearly constant by regulating the voltage and pulse width simultaneously (for example, a 50 ms pulse width at 42 V and a 200 ms pulse width at 21 V consume the same amount of energy due to the equation, E=t*U2 / R, where t is the pulse width, U is the voltage, and R is the resistance of the CFP).10 pulses gave no distinct change in conversion and selectivity, likely due to a similar Tmax(about 690-750 °C) (FIG.13). 5 pulses gave much lower conversions with heating times exceeding 200 ms, primarily due to significantly lower temperatures (Tmax= 544 °C at 21 V and Tmax< 476 °C at 10.5 V) (FIG.13). Similar trends were seen in selectivity, with an increase in heavier products at lower temperatures. The average and peak temperatures are 2101715-001290 discovered to be key process parameters, with high temperatures being an important parameter for achieving high conversions and selectivities. Continuous Joule Heating (CJH) vs. Rapid Pulse Joule Heating (RPH) Next, CJH as evaluated as an alternative heating strategy. To ensure a fair comparison, the DC power source was kept operational for 500 ms, which was equivalent to the total heating time (voltage on) of 10 pulses in RPH. The voltage was varied between 20-31 V, affecting Tavg. An increase in the voltage increased conversion, and a voltage of 31 V achieved full conversion (FIG.14). The selectivity to C2-C3 products also increased with voltage, plateauing around 26-27 V (FIG.14). Further increasing the voltage enhanced the selectivity of lighter products, including methane, acetylene, and propyne. These results demonstrated that CJH exhibits a slightly higher selectivity than RPH to C2-C4products, primarily due to the elevated Tavg at similar Tmax (Table 1). A voltage of 26 V (Tmax = about 730-750 °C) closely resembled the RPH conditions that produced high conversions and selectivities. Accordingly, this voltage was chosen for subsequent CJH experiments. While CJH exhibited slightly higher selectivity than RPH, pulsed operation often offers other co-benefits, for example, reduced coke due to shorter exposure at elevated temperatures. Thus, the reusability of the CFP was investigated in RPH and CJH modes of operation. Prior to each cycle, the CFP was coated with polymer following the procedure described in the Methods section of this Example without washing or regenerating the catalyst. FIG.15 illustrates that the conversion and selectivity remained unchanged in 3 cycles of reuse in RPH. In contrast, CJH exhibited a decline in conversion and selectivities (FIG.16). The diminishing activity is attributed to higher coking in CJH than in RPH mode. It is widely accepted that hydrocarbon reactions at higher temperatures over solid acids coke more due to alkylation, cyclization, and dehydrogenation. The higher Tavg in CJH (about 625 °C) led to more expedited catalyst deactivation than what was observed in RPH (about 540 °C). Raman spectra (FIG.17) corroborated significantly higher coking in CJH, demonstrating an ID / IGratio (the ratio of the Defected to Graphitic Carbon) of 0.44 (vs.0.38 for RPH). Consistently, TGA data (FIG.18 and FIG.19) showed nearly twice the amount of coke, with more heavy coke, ultimately rendering its performance inferior. 2101715-001290 Effect of Co-feeding Steam Next the impact of cofeeding steam on the plastic waste deconstruction process was investigated. Helium gas was introduced through a water-filled bubbler in these experiments, with the rest of the experimental setup unchanged. The results (FIG.20) demonstrated a substantial enhancement in the C2-C4 olefin selectivity when steam was co-fed in RPH (increases by about 16% over RPH), thus surpassing the performance of even the CJH configuration discussed above. No significant change in the conversion was observed. The combined yield to C2- C4 products (about 90wt%) was excellent. Similarly, a slight increase in the C2-C4 olefin selectivity was observed when steam was co-fed in CJH. However, this increase in selectivity was not as pronounced as in RPH, thus underscoring the importance of high-temperature pulsing. The enhanced performance was likely attributable to reduced coking. Raman spectra of the spent catalysts further illustrated the lowest amount of coke when steam was co-fed (FIG.21). The ID / IGratio was the lowest for RPH with steam (ID / IG = 0.358) followed by CJH with steam (ID / IG = 0.39) compared to RPH (ID / IG = 0.396) and CJH (ID / IG = 0.44) without steam. However, in CJH catalyst deactivation was still observed with steam co-feeding after the 2nd cycle of reuse (FIG.22, ID / IG of RHP = 0.4 < ID / IG of CJH with Steam = 0.42 < ID / IGof CJH = 0.44, after 3 cycles of reuse). TGA further demonstrated the least coke (about 10 wt%) when steam was co-fed. Further analysis revealed that co-feeding steam reduced the amount of heavy coke (about 16% with steam vs. about 20% in RPH and about 22% in CJH without steam). Differential Thermal Analysis (DTA) further illustrated significant changes in the maxima positions among samples, with the peaks shifting to lower temperatures by about 5-15 °C when steam was co-fed (FIG.23). Performance of RPH with Various Feedstocks and Real-world Plastics Real-world plastics contain additives and impurities that can hinder catalyst efficacy. Hence, the deconstruction of PE and PP feedstocks from diverse sources was investigated. FIG.24 illustrates that the conversion and selectivities remained largely unaffected, irrespective of source, highlighting the process's resilience. Notably, PP materials gave a higher selectivity to C2-C4range products, likely stemming from the easier activation of the tertiary carbons and faster β-scission 2101715-001290 rates of tertiary carbenium ion intermediates. In contrast, PE, predominantly composed of secondary carbons, necessitated isomerization before undergoing cracking. Strikingly, dyes in fishnets (cyan) and centrifuge tubes (black gradations) did not impact performance. The plastic grocery bags made of HDPE achieved a slightly lower “apparent conversion” of about 84%, possibly due to calcium carbonate (CaCO3), extensively used as a filler in plastic bags. TGA of the plastic bags indicated that CaCO3 constituted roughly 20 wt%. During the reaction, CaCO3 partly decomposed to CaO, which accounted for the remaining unconverted mass, i.e., the filler did not seem to impact the polymer conversion. Conclusions The results of Example 1 demonstrate that Rapid Pulse Joule Heating (RPH) for catalytic cracking of polyolefin waste exhibits significant promise in achieving high monomer selectivity and conversion. The ultra-fast reactor heating, enabled by the CFP, allowed plastic deconstruction in 500 ms (via 10, 50 ms pulses). The zeolite H-ZSM-5 catalyst enabled the effective breakdown of polymers into light hydrocarbons, with a remarkable >75% selectivity toward C2-C4 products at full conversion. The results surpass those seen in state-of-the-art studies in the literature, thus demonstrating that the methods and reactors disclosed herein can achieve remarkable productivity at about 50-200 times lower catalyst usage. While continuous Joule heating (CJH) offered higher selectivity toward light olefins than RPH, the heating technique did exhibit more catalyst deactivation than RPH. Co- feeding steam in RPH processes increased selectivity toward monomers by minimizing coke formation. Notably, an impressive >90% selectivity to C2-C4products at full conversion was demonstrated, thus highlighting the RPH's potential for monomer production. The high propylene-to-ethylene ratios (about 2.6 to 3.5) suggest that the technology is particularly well suited for propylene production. Compared to conventional catalytic pyrolysis, the thin-film structure of the polymer eliminated heat transfer limitations and the associated bulky reactors to enable modular systems. Furthermore, the methods evaluated in Example 1 demonstrate that the methods and systems disclosed herein can efficiently deconstruct various real-life feedstocks, thus offering new and sustainable avenues for monomer production from polyolefins while mitigating associated CO2 emissions. 2101715-001290 It will be appreciated by those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the disclosure is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.

Claims

2101715-001290 CLAIMS:

1. A reactor designed to deconstruct a plastic waste feedstock comprising: a power supply, a plastic waste feedstock input line, and a reaction zone in communication with the power supply and the plastic waste feedstock input line, wherein the reaction zone contains a porous carbon-based heating element coated with a catalyst and a polymer film having a thickness of less than 100 µm.

2. The reactor of claim 1, wherein the catalyst is a zeolite catalyst.

3. The reactor of claim 1, wherein the polymer film is a low-density polyethylene (LDPE) polymer film.

4. The reactor of claim 1, wherein the reactor is configured to operate in a Rapid Pulse Joule Heating (RPH) mode and / or a Continuous Joule Heating (CJH) mode.

5. The reactor of claim 1, comprising: a steam import line in communication with the reaction zone and a gas container.

6. The reactor of claim 1, comprising: a solid-state relay in communication with the power supply and the reaction zone.

7. The reactor of claim 6, comprising: a programmable sourcemeter in communication with the solid-state relay and a data output device.2101715-001290 8. The reactor of claim 1, wherein the reactor is configured to heat the porous carbon fiber paper heating element by resistive heating.

9. The reactor of claim 1, comprising: an output line in communication with the reaction zone, wherein the output line is configured to transport C2-C4olefins from the reaction zone to a storage container.

10. The reactor of claim 1, wherein the porous carbon fiber paper heating element has a polymer-to-catalyst weight ratio of about 1.25 to about 50.

11. The reactor of claim 1, wherein the porous carbon fiber paper heating element has an exposed area of at most about 120 mm by 30 mm.

12. The reactor of claim 1, wherein the porous carbon fiber paper heating element has a pore size of 0.1 to 10 microns.

13. The reactor of claim 1, wherein the reaction zone is a vertical quartz tube containing one or more steel clamps and / or copper plates.

14. The reactor of claim 1, comprising: an infrared camera configured to detect and monitor a temperature of the porous carbon fiber paper heating element.

15. The reactor of claim 1, wherein the polymer film has a thickness less than about 20 µm.2101715-001290 16. A method for deconstructing a plastic waste feedstock comprising: obtaining the plastic waste feedstock; and deconstructing the plastic waste feedstock in a reactor, wherein the reactor contains a porous carbon fiber paper heating element coated with a catalyst and a polymer film having a thickness of less than 100 µm.

17. The method of claim 16, wherein the deconstructing of the plastic waste feedstock in the reactor comprises: resistively heating the porous carbon fiber paper heating element by a rapid pulse joule heating process to a temperature ranging from about 300 °C to 1200 °C.

18. The method of claim 17, wherein the rapid pulse joule heating process comprises: pulsing the porous carbon fiber paper heating element one or more times with a dual current (DC) voltage ranging from about 0 V to about 70 V.

19. The method of claim 18, wherein the rapid pulse joule heating process comprises: pulsing the carbon fiber paper heating element at least 5 times to no more than 28,000 times.

20. The method of claim 18, wherein the pulsing of the carbon fiber paper heating element comprises:2101715-001290 heating the carbon fiber paper heating element for about 50 ms to about 1000 ms and cooling the carbon fiber paper heating element for about 50 ms to about 1000 ms.

21. The method of claim 16, wherein the deconstructing of the plastic waste feedstock in the reactor comprises: resistively heating the porous carbon fiber paper heating element by a continuous joule heating process to a temperature ranging from about 300 °C to 1200 °C.

22. The method of claim 21, wherein the continuous joule heating process comprises: heating the porous carbon fiber paper heating element for about 10 ms to about 3000 ms.

23. The method of claim 21, wherein the continuous joule heating process comprises: subjecting the porous carbon fiber paper heating element to a DC voltage of about 0 V to about 70 V.

24. The method of claim 16, comprising: introducing a steam gas into the reactor during the deconstructing of the plastic waste feedstock.2101715-001290 25. The method of claim 16, comprising: regenerating the catalyst on the porous carbon fiber paper heating element after the porous carbon fiber paper heating element has undergone at least three cycles of deconstructing the plastic waste feedstock.

26. The method of claim 16, wherein the deconstruction of the plastic waste feedstock converts at least 75 wt% of the plastic waste feedstock into a C2-C4 olefin carbon feed.

27. The method of claim 16, wherein the deconstructing of the plastic waste feedstock in the reactor comprises: producing no more than 20 wt% coke based on the total weight of the deconstructed plastic waste feedstock.

28. The method of claim 16, wherein the catalyst is a zeolite catalyst.

29. The method of claim 16, wherein the polymer film is a low-density polyethylene (LDPE) polymer film.

30. The method of claim 16, the porous carbon fiber paper heating element has a polymer-to-catalyst ratio of about 1.25 to about 20.

31. The method of claim 16, wherein the porous carbon fiber paper heating element has an exposed area of about 38 mm by 8 mm.2101715-001290 32. The method of claim 16, wherein the porous carbon fiber paper heating element has a pore size of 0.1 to 10 microns.

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