Synthesis of hydrogen gas by flash Joule heating

Abstract

A method and system for synthesizing hydrogen gas by flash Joule heating, for example, by flash Joule heating from waste plastic materials, other solid materials, or liquid materials.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to (1) U.S. Patent Application No. 63 / 452,069, filed on 14 March 2023, entitled "Methods And Systems For Catalyst-Free, High-Yield Production Of Hydrogen Gas From Waste By Flash Joule Heating," and (2) U.S. Patent Application No. 63 / 595,646, filed on 2 November 2023, entitled "Synthesis Of Hydrogen Gas From Waste Plastic Materials By Flash Joule Heating."

[0002] The methods and systems of the present invention are also related to PCT patent applications PCT / US21 / 52030, PCT / US21 / 52043, PCT / US21 / 52057, and PCT / US21 / 52070 filed with James M. Tour et al., each titled "Ultrafast Flash Joule Heating Synthesis Methods And Systems For Performing Same," filed on September 24, 2021, and each claiming priority to U.S. Patent Application No. 63 / 082,592, filed on September 24, 2020.

[0003] Each of these patent applications is commonly owned by the owner of the present invention, and the whole is incorporated herein.

[0004] The present invention relates to a method and system for synthesizing hydrogen gas by flash Joule heating, for example, the synthesis of hydrogen gas from waste plastic materials, other solid materials, or liquid materials by flash Joule heating.

[0005] Government subsidies This invention was made possible with government support under grant number FA9550-22-1-0526 from the U.S. Air Force Office of Scientific Research, grant number W912HZ-21-2-0050 from the U.S. Army Corps of Engineers, Center for Engineering Research and Development, and grant number 1842494 from the National Science Foundation. The U.S. Government has certain rights in this invention. [Background technology]

[0006] Hydrogen has emerged as a promising clean and environmentally friendly energy resource capable of powering a wide range of sectors, including transportation, industry, and power generation, particularly in the face of challenges such as climate change and the depletion of fossil fuel resources. More than 90 million tons (MMT) of hydrogen gas (H2) are used annually in petroleum refining and ammonia synthesis. [Velazquez 2017] H2 is also a key storable fuel in the global shift towards green, pollution-free, and efficient energy production, through its use in fuel cells to generate electricity and water, or through direct combustion to produce water. [Abe 2019]

[0007] Current hydrogen synthesis methods, including methane reforming, methane pyrolysis, and water electrolysis, suffer from low efficiency, high energy consumption, and high greenhouse gas emissions, often requiring precise metal catalysts, but failing to synthesize value-added by-products. [Grogoriev 2020; van Rennsen 2020]. Over 95% of the H2 produced globally is synthesized by metal-catalyzed steam methane reforming, which produces stoichiometric amounts of CO2 during H2 production while consuming non-renewable fossil fuel raw materials. [Nikolaidis 2017]. Steam methane reforming for H2 production, also known as "gray hydrogen" production, accounts for 800 MMT of CO2 production per year, equivalent to all CO2 emissions in the UK. [Holladay 2009]. As H2 demand is projected to increase rapidly over the next 30 years (Figure 1A), alternative production methods are needed to avoid further increases in CO2 production.

[0008] Electrolysis of water to produce H2 and O2 presents one such pathway that does not produce greenhouse gases even when powered by renewable energy. [Dincer 2012] Unfortunately, despite current emissions awareness, the proportion of H2 produced by electrolysis has not increased, and fossil fuels remain essential for H2 production (Figure 1B). One reason for the slow development of electrolytic production methods is the need for expensive metal catalysts such as Pt, Ir, or Ru, as well as the fresh water required for its electrochemical conversion to H2 and O2. [Shiva Kumar 2022] Nine kg of water are consumed for every 1 kg of H2 produced, limiting the implementation of electrolysis in some climates. [Besqick 2021] H2 produced by electrolysis typically costs 3 to 5 times more than H2 produced from steam methane reforming, making it economically difficult for electrolysis to gain a foothold in the market. [Hermesmann 2022] High-temperature methane pyrolysis, known as turquoise hydrogen, and steam methane reforming with associated CO2 capture, known as blue hydrogen, do not result in stoichiometric greenhouse gas emissions, but both face similarly high costs and still require fossil fuels as raw materials. [Timmerberg 2020]

[0009] Therefore, cost-effective methods for hydrogen synthesis are highly desirable for the widespread use of hydrogen. A method is needed for H2 production that produces little CO2, does not require expensive catalysts, and uses globally abundant raw materials. Co-production of H2 with expensive materials could provide economic competition to replace steam methane reforming (Figure 1C).

[0010] Plastic materials, including plastics and plastic-containing composites, are widely used worldwide, from beverage containers to building reinforcement components. Currently, 4.9 billion tons of plastic waste are generated annually, most of which have been directly landfilled. Furthermore, it is estimated that plastic waste will increase to approximately 12 billion tons by 2050, placing a tremendous strain on the environment. [Lopez 2017; Geyer 2017]. Considering that plastics often contain 0.5–15% by weight of hydrogen atoms, plastics offer a substantial resource for hydrogen production. [Jie 2020; Barbarias 2016]. However, 95% of the plastic waste generated each year is not recycled due to the high cost of separating different types of plastic. [Al-Salem 2017]. Therefore, some technologies view plastic waste as a potential source of H2. [Jie 2020]. Typically, a two-step process involving catalytic pyrolysis or gasification converts waste plastics into small hydrocarbons, followed by steam reforming to yield H2, CO, and approximately 12 kg of CO2 per kg of H2. [Williams 2021]

[0011] Therefore, there is also a need to recycle waste plastics, which are included as raw materials for hydrogen synthesis. [Overview of the Initiative]

[0012] The present invention relates to a method and system for synthesizing hydrogen gas from waste plastic materials by flash Joule heating.

[0013] In a typical embodiment, the present invention relates to a method for producing hydrogen gas from a solid material using flash Joule heating.

[0014] Implementations of the present invention may include one or more of the following features:

[0015] Solid materials can be treated as waste.

[0016] The solid material can be plastic.

[0017] The plastic can be one of the following: polyethylene, high-density polyethylene, low-density polyethylene, polyethylene terephthalate, polystyrene, polybutadiene, polyacrylonitrile, nylon, polyester, polypropylene, vinyl polymer, step-growth polymer, chain-growth polymer, thermoplastic resin, thermosetting resin, rubber, living polymer, ring-opening polymer, siloxane polymer, block polymer, block copolymer, inorganic polymer, and organic polymer, or a mixture thereof.

[0018] The solid material can be cellulose.

[0019] The cellulose material may be derived from any one or a combination of the following: wood, paper, cardboard, trees, plants, household waste, municipal waste, and industrial waste.

[0020] The cellulose material can be further thermally pretreated before the flash Joule heating reaction.

[0021] The thermally pretreated material can be biochar.

[0022] The material to be processed can be waste material.

[0023] This method can co-produce one or more of the following: graphene, carbon nanotubes, one-dimensional materials, amorphous carbon, graphite, nanodiamonds, and silicon carbide.

[0024] This method can co-produce silicon carbide in the form of 1D nanofibers, nanotubes, and / or nanowhiskers.

[0025] This method can co-produce 3D silicon carbide particles.

[0026] Graphene can be co-produced. Graphene can mainly be in the form of turbostratic or Bernal (AB stack), or a mixture of turbostratic and Bernal (AB stack).

[0027] Hydrocarbons can be co-produced.

[0028] Hydrocarbons can include one or more of methane, ethane, propane, butane, pentane, and hexane.

[0029] Hydrocarbons can include one or more of the branched isomers of butane, pentane, and hexane.

[0030] Hydrocarbons can include alkenes, alkynes, aromatics, or mixtures thereof.

[0031] Carbon monoxide, carbon dioxide, or mixtures thereof can be co-produced.

[0032] One or more of flash graphene, carbon nanotubes, one-dimensional materials, amorphous carbon, graphite, nanodiamonds, and silicon carbide can be co-produced.

[0033] Heteroatom-containing graphene can be co-produced.

[0034] The heteroatom can be one or a mixture of the following: B, N, O, F, S, Si, and P.

[0035] The heteroatom can be one or a mixture of metal atoms.

[0036] The solid material can be selected from the group consisting of coal, coal derivatives, petroleum derivatives, petroleum products, carbon-containing materials, glass mixed with plastic, glass fiber + plastic, glass fiber + carbon fiber, and combinations thereof.

[0037] Flash Joule heating can be performed without a catalyst.

[0038] Flash Joule heating can be performed using a catalyst.

[0039] The catalyst can be an Fe-containing catalyst.

[0040] The Fe-containing catalyst can be iron chloride.

[0041] The catalyst can be selected from the group consisting of iron chloride, ferrocene, iron chloride / nickel chloride mixtures, cobalt salts, cobalt oxides, and combinations thereof.

[0042] In a typical embodiment, the present invention relates to a method comprising producing hydrogen gas from a material using flash Joule heating. The material includes a liquid having chemically present hydrogen atoms.

[0043] Implementations of the present invention may include one or more of the following features:

[0044] The liquid may contain chemically present carbon and hydrogen.

[0045] The liquid can be selected from the group consisting of crude oil, oil, asphalt, and combinations thereof.

[0046] The liquid can be absorbed by the sponge.

[0047] The sponge can be selected from a group of materials including carbon-based sponges, carbohydrate sponges, glass-based sponges, ceramic-based sponges, and combinations thereof.

[0048] Flash Joule heating can be performed without a catalyst.

[0049] Flash Joule heating can be performed using a catalyst. [Brief explanation of the drawing]

[0050] [Figure 1A] This shows the current state and projected demand for hydrogen production. It also shows the historical and projected demand for H2 separated by use. [Figure 1B] This report outlines the current state of hydrogen production and projected demand. It also shows historical sources of hydrogen produced, separated by raw materials. [Figure 1C] This document outlines the current state of hydrogen production and projected demand. It also presents a scheme comparing current H2 production methods with hydrogen synthesis by flash Joule heating (FJH) as disclosed and described herein. [Figure 2A] This demonstrates the catalyst-free decomposition of polyethylene to obtain hydrogen and graphene. A schematic diagram shows a typical flash Joule heating process used. [Figure 2B] This paper demonstrates the non-catalytic decomposition of polyethylene to obtain hydrogen and graphene. The resistance of the plastic sample before treatment and the peak temperature reached during FJH treatment are shown as a function of conductive carbon mixed with waste polyethylene. [Figure 2C] This paper demonstrates the catalytic decomposition of polyethylene to obtain hydrogen and graphene. It also shows an investigation into how initial sample resistance affects hydrogen yield and hydrogen efficiency in FJH decomposition of polyethylene. [Figure 2D] This shows the catalytic decomposition of polyethylene to obtain hydrogen and graphene. It illustrates how the initial sample resistance affects the gaseous products and yields of H2 and graphene resulting from polyethylene decomposition. The bar graph corresponds to the partial pressure of the gases, while the line graph corresponds to the yield of H2 or graphene compared to the amounts of atoms H and C present in the starting mixture. [Figure 2E] This demonstrates the catalytic decomposition of polyethylene to obtain hydrogen and graphene. It also shows the complete mass balance of polyethylene decomposition as resistance fluctuates. [Figure 3]This shows the carbon and hydrogen content in different precursors. [Figure 4A] This shows the setup for hydrogen synthesis using FJH. A schematic diagram of the FJH process is also shown. [Figure 4B] This shows the setup for hydrogen synthesis using FJH. Images of the FJH jig and hydrogen capture device are shown. [Figure 5A] This study demonstrates the generality of processes for other waste polymers, mixtures, and low-cost conductive additives. It shows the hydrogen yield and efficiency when (a) polymer identity or (c) conductive additives vary. [Figure 5B] The generality of the process for other waste polymers, mixtures, and low-cost conductive additives is shown. (b) Polymer identity and (d) generated gaseous products with calculated hydrogen and graphene yields as the conductive additive varies. The bar graph corresponds to the partial pressure of the gas, while the line graph corresponds to the yield of H2 or graphene compared to the amounts of atoms H and C present in the starting mixture. [Figure 5C] This study demonstrates the generality of processes for other waste polymers, mixtures, and low-cost conductive additives. It shows the hydrogen yield and efficiency when (a) polymer identity or (c) conductive additives vary. [Figure 5D] The generality of the process for other waste polymers, mixtures, and low-cost conductive additives is shown. (b) Polymer identity and (d) generated gaseous products with calculated hydrogen and graphene yields as the conductive additive varies. The bar graph corresponds to the partial pressure of the gas, while the line graph corresponds to the yield of H2 or graphene compared to the amounts of atoms H and C present in the starting mixture. [Figure 5E] The generality of the process for other waste polymers, mixtures, and low-cost conductive additives is demonstrated. (e) polymer identity or (f) average Raman spectra (100 unique spectra over an area of ​​1 mm²) are shown as the conductive additive varies. [Figure 5F]The generality of the process for other waste polymers, mixtures, and low-cost conductive additives is demonstrated. (e) polymer identity or (f) average Raman spectra (100 unique spectra over an area of ​​1 mm²) are shown as the conductive additive varies. [Figure 6] The GC-TCD spectra of HDPE samples with different Fe loading contents are shown. [Figure 7] The GC-TCD spectra of HDPE samples with different catalyst loads are shown. [Figure 8A] The GC-TCD spectra of samples different from those used in graphene synthesis are shown. [Figure 8B] This shows the GC-TCD spectrum of a sample different from that used for CNT synthesis. [Figure 8C] This shows the GC-TCD spectrum of a sample different from amorphous carbon synthesis. [Figure 8D] This shows the GC-TCD spectrum of a sample different from the one used for SiC synthesis. [Figure 9A] Characterization of polyethylene-derived graphene. [Figure 9B] Characterization of polyethylene-derived graphene. [Figure 9C] Characterization of polyethylene-derived graphene. [Figure 9D] Characterization of polyethylene-derived graphene. [Figure 9E] Characterization of polyethylene-derived graphene. [Figure 9F] Characterization of polyethylene-derived graphene. [Figure 10A] This shows the characterization of graphene. It is a Raman spectrum. (Graphene PDF card: 00-056-0159). [Figure 10B] This shows the characterization of graphene. It is a Raman spectrum. (Graphene PDF card: 00-056-0159). [Figure 10C] This shows the characterization of graphene. It is an XRD pattern. (Graphene PDF card: 00-056-0159). [Figure 11A]This image shows the characteristics of flashed carbon nanotubes (CNTs) and is an SEM image. [Figure 11B] This image shows the characterization of flashed carbon nanotubes (CNTs) and is a TEM image. [Figure 11C] This shows the XPS spectrum for characterizing flashed carbon nanotubes. [Figure 11D] This shows the Raman spectrum for characterizing flashed carbon nanotubes. [Figure 12A] This shows the characterization of flash amorphous carbon. It is a Raman spectrum. [Figure 12B] This shows the characterization of flash amorphous carbon. It is an XRD pattern. (Paraffin PDF card: 00-040-1995) [Figure 12C] This shows the characterization of flash amorphous carbon. The image is a TEM image. [Figure 13A] This shows the properties of a flashed diamond. It is a Raman spectrum. [Figure 13B] This shows the characterization of a flashed diamond. It is an XRD pattern. (Graphite PDF card: 00-056-0159) [Figure 13C] This shows the characterization of a flashed diamond. It is a TEM image. [Figure 14A] This shows the characterization of flashed SiC. It is a Raman spectrum. [Figure 14B] This shows the characterization of flashed SiC. It is an XRD pattern. (Graphite PDF card: 00-056-0159) [Figure 14C] This shows the characterization of flashed SiC. It is a Si 1s XPS pattern. [Figure 14D] This shows the characterization of flashed SiC. It is a TEM image. [Figure 15] A schematic diagram of a flash Joule heating vessel connected to a gas capture vessel is shown. [Figure 16] This shows the gas container used for flash joule heating of the liquid reactants. [Figure 17]This shows GC-MS data of gases trapped from flash Joule heating reactions of both olive oil and crude oil. [Figure 18A] The mass spectra of fragments resulting from FJH of various polymers (polypropylene, polystyrene, and PET) are shown, demonstrating that fragments of the parent polymer can be observed. [Figure 18B] The mass spectra of fragments resulting from FJH of various polymers (polypropylene, polystyrene, and PET) are shown, demonstrating that fragments of the parent polymer can be observed. [Figure 18C] The mass spectra of fragments resulting from FJH of various polymers (polypropylene, polystyrene, and PET) are shown, demonstrating that fragments of the parent polymer can be observed. [Figure 18D] The mass spectra of fragments resulting from FJH of various polymers (polypropylene, polystyrene, and PET) are shown, demonstrating that fragments of the parent polymer can be observed. [Figure 19] This paper presents thermodynamic calculations (HSC Chemistry, Version 9) studying the catalyst-free reaction pathway of polyethylene adducts as a function of reaction temperature. [Figure 20] This describes a possible mechanism for the formation of graphene and H2 from HDPE. [Figure 21A] The following shows an atomic simulation of the FJH reaction: (a) A simplified representation of the atomic model of HDPE particles, mainly showing carbon spines of the polymer, where the colors indicate individual polymer strands. [Figure 21B] The following is an atomic simulation of the FJH reaction: (a) Individual polymer strands extracted from Figure 21A are shown in full atomic detail. [Figure 21C] The following atomic simulations of the FJH reaction are shown: (a) H2 production during simulations at 1,500 K and 3,000 K. [Figure 21D]The following atomic simulations of the FJH reaction are shown: (a) showing the formation of an aromatic network in the initial stages of HDPE degradation. [Figure 22A] This demonstrates the conversion of asphaltene to H2 and graphene (FJH), showing high yield, efficiency, and purity of the gas flow, as well as high-quality graphene. The sample was heated to 6 ohms. [Figure 22B] This demonstrates the conversion of asphaltene to H2 and graphene (FJH), showing high yield, efficiency, and purity of the gas flow, as well as high-quality graphene. The sample was heated to 6 ohms. [Figure 23A] This paper presents a life cycle assessment and technoeconomic analysis of FJH decomposition in comparison with recent literature, showing (a) cumulative energy demand, (b) greenhouse gas emissions, and (c) estimated production costs arising from the production of 1 kg of H2 using different methods. [Figure 23B] This paper presents a life cycle assessment and technoeconomic analysis of FJH decomposition in comparison with recent literature, showing (a) cumulative energy demand, (b) greenhouse gas emissions, and (c) estimated production costs arising from the production of 1 kg of H2 using different methods. [Figure 23C] This paper presents a life cycle assessment and technoeconomic analysis of FJH decomposition in comparison with recent literature, showing (a) cumulative energy demand, (b) greenhouse gas emissions, and (c) estimated production costs arising from the production of 1 kg of H2 using different methods. [Figure 23D] This paper presents a life cycle assessment and technoeconomic analysis of FJH degradation, compared with recent literature. It also shows a comparison of different methods for producing H2 from waste plastics, biomass, or hydrocarbons. Numbers indicate specified references. [Modes for carrying out the invention]

[0051] The present invention relates to a method and system for synthesizing hydrogen gas by flash Joule heating, for example, the synthesis of hydrogen gas from waste plastic materials, other solid materials, or liquid materials by flash Joule heating.

[0052] In embodiments, the flash Joule heating (FJH) method synthesizes hydrogen from waste plastics (or other household, industrial, or related cellulose waste, including wood, paper, and cardboard). Hydrogen can be effectively synthesized within seconds with high purity (>90 vol%) and high yield (20-60%) without the additional consumption of any catalysts or solvents. By adjusting the precursor type and flash parameters, value-added materials such as graphene, amorphous carbon, carbon nanotubes, and silicon carbide can be synthesized simultaneously, providing a secondary value stream to enhance the economic competitiveness of H2 (which can be referred to here as hydrogen or dihydrogen) production.

[0053] Therefore, if this is considered an H2 production process, high-purity turbostatic graphene is offered as a value-added by-product. The scalable process does not form stoichiometric CO2 when decomposing polyolefins, producing H2 with a purity of up to 93.8% and up to 46.6 mmol of H2g. -1 This results in a treated polymer, which accounts for 65% of the available hydrogen atoms on the plastic, which are generated as H2.

[0054] H 2 synthesis These methods and systems use a simple, one-step process to directly convert either virgin or post-consumer plastics (or solid or liquid materials) into high-purity H2 gas and expensive graphene in seconds. The process requires no catalysts, solvents, or water, and does not require the use of fossil fuels because waste materials are used as raw materials (although fossil fuels, solids like coal or coke, or liquids like oil can be used as raw materials). A highly scalable technology, FJH only requires the addition of conductive additives if the conductivity of the raw materials is too low. [Luong 2020; Wyss I 2022]. In some cases, such as anthracite, metallurgical coke from calcined coke, etc., they are sufficiently conductive and no conductive additives are needed. A schematic diagram illustrating the available methods is shown in Figure 2A.

[0055] As shown in Figure 2A, crushed mixed waste plastic 201 (no need to be washed or separated) mixed with a conductive additive (without the need for a catalyst) is used in the FJH process. The FJH apparatus may include, for example, an electrode 202, a quartz tube 203, copper wool 204, and a hollow electrode 205 that allows for gas capture. Interactive FJH discharge was performed (206). Graph 207 in the insert in Figure 2A shows the current discharge, which can be used as a function of time over four iterative FJH treatments of a 6Ω initial resistance sample to decompose the polymer. This resulted in rapid gas generation with high-purity H2 and high-value graphene (208). No CO2 was generated from polyolefins such as polyethylene (PE) and polypropylene (PP). Product characterization was performed for characterization and quantification (209) and is discussed below.

[0056] Examples: A typical example of catalyst-free decomposition of waste plastics into H2 and expensive graphene was performed as follows: The reaction precursor is prepared by grinding in mortar and pestle, mixing in a hammer mill, or mixing in a ball mill. The reaction precursor consists of (1) either virgin or post-consumer plastic, which is ground and filtered through a 2 mm sieve and used without any rinsing or pretreatment, and (2) a small amount of conductive additive, which may include graphite, graphene, metcoke, carbon black, etc. As demonstrated in Figure 2B (traces 211-212 are sample resistance and the temperature reached, respectively), the amount of conductive additive (in its plot, carbon black BP-2000, Cabot) determines the initial resistance of the sample, which affects the temperature of the FJH reaction. If other conductive additives are used, such as pyrolysis ash, metallurgical coke, calcined coke, or charcoal, also known as "metcoke," a larger wt% of the conductive additive may be required to reach a comparable resistance. Once the reaction precursor is completely mixed, the black / gray powder mixture can undergo a flash Joule heating process.

[0057] Flash Joule heating of the precursor mixture is shown in Figure 2A. The mixture (total 0.5 g, 0.08 g conductive additive, carbon black BP-2000 from Cabot and 0.42 g polymer) was loaded into a quartz tube and compressed to a resistance of 5-10 ohms. Two copper or graphite rods were applied to both sides to function as electrodes. Hollow electrodes were used to allow the release and capture of volatile substances into a Pyrex Schlenk flask that was flushed with Ar and evacuated to -28 kPa. The entire system was leak-proof, and after establishing a vacuum with a valve, the vacuum was maintained for at least about 15 minutes.

[0058] Next, flash Joule heating was induced by charging a capacitor bank (220mF) to 100-130V. This was then discharged through the sample at a very fast rate (typically less than 3 seconds) using either a full discharge or a variable frequency drive (VFD) type discharge pulse. A single sharp current discharge pulse was observed (Graph 207 shown in Figure 2A), as determined by a pressure gauge attached to the volatile trap, and this process was repeated 3-4 times until no further gas was generated. The interruption of current discharge in the first three pulses is a result of volatile substances being released from the system, temporarily increasing the resistance of the sample and thus reducing the amount of current that can pass through the sample. The amount of volatile substances generated was measured using a pressure gauge attached to the volatile trap. The partial pressure of H2 in the mixture was then measured using gas chromatography with a thermal conductivity detector (GC-TCD), which can then be used to determine the amount of H2 generated by the process, using the ideal gas equation as well as the experimentally determined pressure, temperature, and volume of gas generated. The GC-TCD can also detect methane and CO, if present. Syringe headspace sampling of the volatile trap was also analyzed by GC-MS, detecting the small hydrocarbons (up to C6 species) produced. The volatile trap can also be rinsed with various solvents to study oils, waxes, or aromatic species by injecting this rinse into the GC-MS. A standard analyte mixture (gas, oils, and aromatic compounds) allows for the quantification of substances produced by FJH degradation of plastics.

[0059] This graphene powder can be removed from a quartz tube, weighed, and characterized. Typically, Raman spectroscopy, powder X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy were used to characterize the graphene product for purity and quality, as discussed below.

[0060] Further Examples: Another representative example of hydrogen production from plastics using a flash Joule heating (FJH) process was performed as follows: Sample Preparation: Different waste plastic precursors, including high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyvinylidene fluoride (PVDF), and glass fiber reinforced plastic (GFRP), were ground using a hamper grinder (Wenling LINDA machinery Corporation, DF-15). The C and H content in each precursor was quantified elementally using the ECS 4010-CHNS-O_Hlk157351815 elemental combustion_Hlk157351815 system. Figure 3. The ground GFRP samples were further pulverized for 2 hours using a planetary ball mill (MSE Supplies, PMV1-0.4L). For carbon nanotube (CNT) synthesis, 3.0 mg of ferric chloride (FeCl3, 97%, Millipore-Sigma) was dissolved in 30 mL of a solvent consisting of an 80 / 20 v / v mixture of water (Millipore-Sigma, ACS reagent for ultratrace analysis) and ethanol (Millipore-Sigma, ACS reagent, >99.5%). Subsequently, 5.0 g of HDPE was dispersed in the FeCl3 solution in an ultrasonic bath (Cole-Parmer Ultrasonic Cleaner) for 15 minutes. The sample was then vacuum-dried overnight in a drying oven to remove the solvent, resulting in Fe-loaded HDPE.

[0061] Hydrogen production from plastics by flash Joule heating (FJH) process. Schematic diagrams of the FJH process for hydrogen production and collection, and photographs of the FJH apparatus are shown in Figures 4A-4B. Figure 4A shows a condenser bank 403 used in FJH, which is supplied to a quartz tube containing a mixture of plastic waste and carbon black 402 (carbon black is a conductive additive) used to synthesize a graphene electrode 403 and hydrogen gas 404. The graphite electrode 403 is loaded into the quartz tube, and two brass electrodes with O-rings 415 of a flash jig 416 are used to seal the sample inside the tube. The generated gas can flow through a hollow electrode 413 into a gas capture flask 412.

[0062] During the FJH process, the processed plastic sample was pre-mixed with carbon black (Cabot, Black Pearls 2000) in a mass ratio of 4:1 and then hand-milled for 5 minutes. The mixture was then loaded into a quartz tube with an inner diameter (ID) of 8 mm and an outer diameter (OD) of 12 mm. Two brass electrodes with O-rings were applied to compress and seal the sample. A spring wound around the surface of the tube was used to enhance the mechanical integrity of the tube and prevent breakage caused by the pressure accumulated during the FJH process. (The spring was wrapped around the surface of the tube and used to prevent explosions caused by gas generation during the FJH process). After purging the system with Ar to +75 kPa, the system was evacuated five times to -95 kPa before the FJH reaction to remove any residual air. Capacitor bank 403 was charged by a direct current (DC) supply.

[0063] The FJH input capacitance can be modulated from 60 to 114 mF by turning on different amounts of capacitors. The maximum voltage of the capacitor bank can reach 400 V. The discharge time was controlled by applying a programmable delay relay with millisecond controllability. Details of the experiment are shown in Table I. During the FJH, the generated gas can be vented from the quartz reaction tube through the hollow electrode 413 to a sealed gas collection flask 412 with a volume of 280 mL. The amount of volatile substances generated was measured using a pressure gauge 411 attached to the flask. [Table 1]

[0064] Control. Parameters and other factors can be used for the generation of H2 from waste plastics (and other materials) into FJH, and may include:

[0065] (i) The initial resistance of the precursor plastic / additive mixture can be used to control the overall reaction temperature reached. The initial resistance can be controlled by varying the amount of conductive additive (Figure 2B, traces 211-212 are sample resistance and temperature reached, respectively). Polyethylene was used as a model system. Lower resistance results in higher reaction temperatures, producing more H2 and higher purity (Figure 2C, traces 221-222 are H2 yield and hydrogen efficiency, respectively). Higher hydrogen efficiency, as defined herein as the total mass of atomic hydrogen contained in all gas-phase products compared to the atomic hydrogen content of the starting polymer, also increases as the initial resistance decreases (Figure 2C). Hotter and faster heating rates result in more H2 recovery and more atomic hydrogen being released from the solid polymer when an initial sample resistance of 6 ohms and high-density polyethylene (HDPE) raw material are used (Figure 2C), up to 46.6 mmol of H2 g. -1 It is made of plastic and boasts an efficiency of 92.7%.

[0066] (ii) Other gases, mainly consisting of methane and short alkenes, can be produced. However, as the reaction rate is accelerated and higher temperatures are reached, the purity of H2 increases (Figure 2D, bar graph). In an ideal system, all carbon atoms in polyethylene are converted to graphene and all hydrogen atoms are released as H2, yielding 100% compared to the theoretical maximum. The yield percentage relative to this ideal maximum is also plotted in Figure 2D (line graph, traces 231-232 are the gas composition produced and yield, respectively). The perfect mass balance can be used to understand how other products are produced during the decomposition process and how this is affected by the reaction kinetics. Figure 2E shows the mass yields of H2, graphene, other gases, liquids, solids, and aromatic residues produced by FJH decomposition. Similar to Figure 2D, faster and hotter reactions prefer more complete polymer decomposition, resulting in less oil and wax, as well as more graphene and H2 recovered with lower sample resistance.

[0067] (iii) Virgin or post-consumer polymers (polyvinyl chloride (PVC), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and low-density polyethylene (LDPE) as demonstrated to date) can each be converted to flash graphene with high H2 recovery rates (Figure 5A, plots 501-502 are H2 yield and hydrogen efficiency, respectively; Figure 5B, plots 511-512 are the generated gas composition and yield, respectively). The purity of H2 obtained from all polyolefins is >84%. Some CO and CO2 were produced when polyester was decomposed, arising from oxygen present in the ester bonds. Similarly, some N2 was produced when ABS was decomposed. These polymers contain fewer atomic hydrogens, so less H2 is recovered, but the overall efficiency and yield remain high (Figures 5A-5B). The yields of H2 and graphene were somewhat affected by polymer identity, with H2 yields of 52-68% and graphene yields of 46-63%, which are 5-10 times better than other non-catalytic decomposition methods.

[0068] (iv) This process was carried out using carbon black as a conductive additive, but this process can also be adapted to low-value carbon materials such as charcoal, metallurgical coke (methcoke), plastic pyrolysis ash, scrap tire carbon black, biochar, and calcined coke. The conductive additive (metallurgical coke) can be reused by simple sieving for many iterations, further reducing the cost burden associated with the required conductive additive (Figure 5C, traces 521-522 are H2 yield and hydrogen efficiency, respectively, and Figure 5D, traces 531-532 are the generated gas composition and yield, respectively). When the conductive additive had an atomic O content, a small amount of CO / CO2 was produced. Metcoke can be reused as a conductive additive by simple sieving separation, further reducing the cost associated with the conductive additive, with 91.7% recovered after 5 use cycles. Furthermore, after the first cycle, no CO or CO2 is produced because the O content is removed from the metcoke additive.

[0069] Catalyst selection for H2 and CNT synthesis. While catalysts are not required for FJH generation of H2 from waste plastics (and other materials), they can be utilized. Types and content of Fe-containing catalysts for hydrogen production. First, when iron chloride was used as the catalyst, the H2 yield increased from 29% to 46% (Figure 6), and the Fe-loaded content increased from 0% to 1% by weight. Furthermore, the catalyst was changed from FeCl3 to ferrocene and a mixture of FeCl3 / NiCl2, maintaining the metal content at 1% by weight (Figure 7). All of these catalysts were found to effectively promote H2 production. The same catalysts can be added to the decomposition of glass / plastic or carbon fiber / glass to obtain silicon carbide nanofibers and nanotubes.

[0070] Hydrogen detection Hydrogen detection was performed on the generated gases using gas chromatography-thermal conductivity detector (GC-TCD). The partial pressure of H2 in the mixtures was quantitatively analyzed using an Agilent 8890 GC with a 5977 B MSD and G4407 TCD equipped with an Agilent HP-5ms low bleeding column (30 m, 0.25 mm inner diameter, 0.25 μm film). Ar was used as the carrier gas for the TCD tests. The amount of H2 generated by the FJH process can be calculated using the ideal gas equation, as well as the experimentally determined pressure, temperature, and volume of the generated gas according to equation 1. A series of high-purity mixed gases with different hydrogen / argon ratios were tested by GC-TCD to obtain calibration curves between peak integrals and hydrogen concentration.

number

[0071] The H2 yield (y) can be further calculated according to equation (2):

number

[0072] Representative GC-TCD spectra for graphene, carbon nanotubes (CNTs), amorphous carbon, and SiC synthesis are shown in Figures 8A to 8D. The main peak with a retention time of approximately 1.8 minutes can be attributed to H2, while small amounts of N2 and O2 may originate from air. The H2 purity in the generated gas is over 90% by volume. The H2 yields were calculated to be 31.7%, 25.0%, 20.0%, and 60.1% for graphene, carbon nanotubes (CNTs), amorphous carbon, and SiC synthesis, respectively.

[0073] Characterization of residual materials Graphene and other residual materials were characterized.

[0074] Graphene produced by the FJH process was characterized by numerous techniques demonstrating its valuable by-product status. Raman spectroscopy is the most common technique, as it allows for the examination of graphene quality and purity. Under optimized conditions, purity of 96–100% is common, and high-quality turbostatic graphene was observed spectroscopically for all plastics and conductive additives studied (Figures 5E–5F).

[0075] Further graphene characterization of polyethylene-derived graphene produced by the methods described herein is shown in Figures 9A–9F, including a demonstration of dispersibility, which can be one of the most important aspects of graphene used in composite applications.

[0076] Figure 9A shows the average Raman spectrum (1 mm) of graphene produced as the initial polyethylene sample resistance. 2 Figure 9B shows that the 100 intrinsic spectra across the area vary. Graphene purity (trace 901) and I, as determined by Raman spectroscopy, are shown as a function of sample resistance. 2D / I GThe ratio is (trace 902). Figure 9C shows the bulk powder X-ray diffraction analysis of solid produced from a 6Ω sample of polyethylene by repeated FJH treatment, compared to the initial raw material mixture, demonstrating the bulk conversion of polyethylene to pure graphene. Figure 9D shows the X-ray photoelectron spectroscopy analysis (plot 911) of graphene produced from the 6Ω sample, with a high-resolution analysis of the C1s transition (plot 912) inserted. Figure 9E shows a scanning electron microscope (SEM) image of crystalline graphene produced from a 6Ω sample of polyethylene. Figure 9F shows high-resolution Raman spectra demonstrating the presence of TS1 and TS2 peaks in the FJH graphene sample (plot 921) showing turbostratic stacking, while the presence of the M peak in the commercially available graphene sample (plot 922) showing AB stacking. The inset photograph shows polyethylene-derived graphene 924 and commercially available graphene 923 dispersed in a water-Pullon (F-127) solution (1 wt%) by sonication and then centrifuged, demonstrating that turbostratic stacking significantly improves graphene dispersibility.

[0077] Furthermore, Raman spectra were acquired using a Renishaw Raman microscope system with a laser wavelength of 532 nm, laser power of 5 mW, and lens 50_Hlk130655978×_Hlk130655978. Separate 2D peaks and low-D peaks in the Raman spectrum revealed the formation of graphene in FJH (Figure 10A). Higher resolution Raman spectra also showed TS1 and TS2 peaks (Figure 10B), which indicated the turbostratic structure of flash graphene [Luong 2020]. Its graphite structure was further confirmed by X-ray diffraction (XRD) patterns (Figure 10C) performed using a Rigaku SmartLab system with filtered Cu Kα emission (λ=1.5406 Å). TEM images were obtained with a 200 kV JEOL 2100 field emission gun transmission electron microscope.

[0078] For the carbon nanotubes (CNTs), their nanotube structure was observed using SEM and TEM with an average diameter of several tens of nanometers obtained on the FEI Quanta 400 ESEM FEG system under a voltage of 20 kV and a working distance of 10 mm (Figures 11A-11B). X-ray photoelectron spectroscopy revealed the presence of catalyst iron and carbon with low oxygen content (<3 atomic%, Figure 11C), indicating the high purity of the CNT samples. XPS spectra were obtained using the PHI Quantera XPS system, at 5 × 10⁻⁶ -9 The spectra were obtained under Torrell pressure. Investigation spectra were collected with a step size of 0.5 eV and a pass energy of 140 eV, and elemental spectra were collected with a step size of 0.1 eV and a pass energy of 26 eV. All XPS spectra were calibrated using the C 1s peak at 284.8 eV as a reference. 200–300 cm⁻¹ -1 The Raman peak in this range is related to the radial breathing mode of CNTs (Figure 11D).

[0079] For the amorphous carbon sample, overlapping D and G peaks in the Raman spectrum indicated high defect levels (Figure 12A). The broad peak of approximately 25° in the XRD pattern (Figure 12B) and the amorphous structure in the TEM image (Figure 12C) reveal low crystallinity, although the paraffin signal may originate from HDPE degradation products.

[0080] Regarding the nanodiamond sample, the Raman spectrum at 1330 cm⁻¹ -1 The sharp peaks indicate its diamond structure (Figure 13A), which is also confirmed by its XRD pattern (Figure 13B) and lattice structure in the TEM image (Figure 13C).

[0081] For SiC, Raman spectroscopy revealed the presence of graphene with D, G, and 2D peaks, as well as SiC with TO and LO peaks (Figure 14A). XRD patterns further confirmed the coexistence of graphene and SiC (Figure 14B), and TEM images revealed the lattice structure of SiC (Figure 14C). Further XPS spectroscopy clearly showed that Si-C is the main peak of its Si 2p XPS spectrum, although the Si-O peak may originate from slight oxidation on the SiC surface (Figure 14D).

[0082] liquid raw material In addition to waste and other solid materials that can be used to synthesize hydrogen gas by flash Joule heating, liquid materials can also be utilized. If the liquid raw material contains both carbon and hydrogen chemically, such as most oils, the gaseous products of the flushing will be hydrogen gas and carbonaceous gases, such as butane or other alkanes. If the reaction is carried out in an inert environment, such as under argon, the only reactive elements present are those from the flash Joule heating raw material.

[0083] Figure 15 shows a schematic diagram of a flash Joule heating container 1501 connected to a gas capture container 1504 (with the liquid raw material absorbed into a sponge such as a carbon-based sponge, carbohydrate-based sponge, or glass-based sponge). When the flash Joule heating process occurs, gas 1502 escapes from container 1501, flows through pipe switch 1503, and is captured in capture container 1504. Figure 16 shows a gas container used for flash Joule heating of liquid reactants.

[0084] The gas confined in the gas capture vessel can contain argon (if present, from an inert flushing atmosphere), as well as hydrogen and any other gases formed during the flash Joule heating process. The composition of the confined gas was evaluated by an Agilent 8890 gas chromatography system with 5977 B MSD and G4407 TCD, and the latter was used to measure the hydrogen gas concentration. The GC chromatographs of the gas confined from two liquid flashes (olive oil and crude oil) are shown in Figure 17. The main products from these two reactions are carbonaceous gases composed of 4 to 6 carbon atoms per gas molecule. The large peak is H2.

[0085] Computational and experimental mechanistic studies of the FJH process Since a catalyst is not required to be present during rapid FJH, the production of flash H2 is thought to proceed through the homolysis of C-H bonds that break down the polymer chains into the observed volatile substances (Figures 18A - 18D). The ultra-high heating rate and high temperature (Figure 2B) allow for more complete decomposition to the most thermodynamically favorable products. Figure 19 (Plots 1901 - 1903 are ΔH, ΔS, and ΔG, respectively). (Note that in Figure 19, the enthalpy of the reaction does not become negative until above 1,000°C, explaining why H2 generation was not observed in conventional low-temperature, low heating rate pyrolysis processes). The reaction mechanism for the FJH or laser-vaporization-assisted conversion of amorphous or olefinic carbon to graphene has been thought to be due to mobile carbon nucleating sheets through a seed growth mechanism that can achieve a diffusion-controlled reaction rate at a sufficiently high energy density. [Stanford 2020; Beckham 2022; Kokai 2022].

[0086] As the sample resistance decreases, the growth of sheet-like graphene domains of semi-crystalline turbostratic stacks from small, wrinkled, and defective regions can be morphologically observed by SEM imaging. Approximately 10 -4Extensive sheet-like morphology was not observed until a temperature of >2,300 K was reached, corresponding to the atomic carbon vapor pressure of Pa. This low vapor pressure was maintained for only a few milliseconds, unlikely to enable micron-scale crystal growth, suggesting that the mobile carbon hypothesis requires another intermediate. [Lopes 2018] The FJH process formed 1,3-butadiene, ethylene, and benzene, which, when detected by GC-MS, can bond through aromatic polymerization to form graphite domains. Figure 20. As aromatic products were detected, resistance decreased, and higher temperatures were achieved, the overall amount and size of the aromatics increased. Polymerization of polycyclic aromatic hydrocarbons has been previously demonstrated under high-energy-density conditions such as in stellar or laser irradiation. [Webster 2022; Contreras 2013] The detected polycyclic aromatic hydrocarbons formed during FJH can be considered seeds for the final turbostatic graphene sheets that grow through aromatic coupling of other mobile carbon species.

[0087] These findings were also computationally analyzed by molecular dynamics (MD) simulations using AIREBO interatomic potentials [Stuart 2000; Brennar 2002]. Following the structural properties of HDPE, systems of long, highly entangled PE strands were constructed [Miao 2001]. Due to the high flexibility of polymer chains at temperatures observed during FJH, structures containing smaller structures or shorter chains showed rapid disintegration, necessitating the use of chains with at least 150 carbon atoms [Bets 2009]. The HDPE structure was generated by the repeated addition of carbon strands composed of a series of randomly oriented straight and curved segments, ensuring a highly woven structure (Figures 21A-21B). Following the experimental results, the system behavior was compared at 1500K and 3000K, representing samples with high resistance (225 ohms) and low resistance (30 ohms), respectively. In both cases, H2 generation was observed through simulations, and H2 production increased significantly at higher temperatures (Figure 21C). The synthesis of short-chain hydrocarbons was also observed. Dehydrogenated and partially dehydrogenated carbon chains were observed to form bonds that produced interconnected carbon networks and aromatic segments (Figure 21D), and further proceeded to the formation of graphite domains.

[0088] Use and Applications Hydrogen gas is a primary storable fuel for pollution-free energy production, with over 90 million tons consumed worldwide annually. Current H2 synthesis methods, including methane reforming, methane pyrolysis, and electrolysis, suffer from low efficiency, high energy consumption, high costs, and high greenhouse gas emissions, and have not synthesized value-added by-products. Here, we introduce the flash Joule heating (FJH) method for synthesizing hydrogen from waste plastics, as well as other solid and liquid materials. Without consuming any catalysts or solvents, H2 can be effectively synthesized within seconds with high purity (>60 vol%) and high yield (20-60%). By adjusting the precursor type and flash parameters, value-added materials such as graphene in the form of particles or one-dimensional fibers or tubes, amorphous carbon, carbon nanotubes, and SiC can be selectively synthesized simultaneously, providing a secondary value stream to improve the economic competitiveness of flash H2 production.

[0089] In the case of upcycling waste plastics into hydrogen and other materials using the flash Joule heating (FJH) method, applications include:

[0090] (i) Waste plastics can be converted into high-purity (>90 vol%) hydrogen gas by FJH, which can then be used as an energy source for fuel cells.

[0091] (ii) Different types of materials, including graphene, carbon nanotubes, amorphous carbon, graphite (through extended heating of graphene), and SiC, can be synthesized simultaneously by adjusting the type of precursor and flash parameters. Graphene formed by the FJH method has been utilized in many demonstrated applications, including composite materials, energy storage in Li batteries, and electrocatalytic activity. [Wyss III 2022; Wyss 2021]. In about three years, FJH production of graphene increased from 1 g per hour to >1 kg per hour on a laboratory scale, and industry achieved a rate of ton per day in a pilot plant. Raw materials other than waste plastics should also be considered, ideally with a high atomic H content and a low atomic O content to minimize CO2 emissions. Asphalt, bitumen, and asphaltene contain >11% H and <1% O, and they present large-scale, low-cost materials that can complement plastic decomposition for H2 production as needed. [Petersen 2000]. Asphaltene and gilsonite are also demonstrated here to produce high-purity H2 and graphene byproducts. Figure 22A (plots 2201-2202 are H2 yield and hydrogen efficiency, respectively), Figure 22B (plots 2211-2212 are the generated gas composition and yield, respectively).

[0092] (iii) Compared to other hydrogen synthesis methods such as steam methane reforming and methane pyrolysis, FJH saves time and energy and produces less greenhouse gas. Figures 23A to 23D.

[0093] Demand for H2 is projected to increase significantly as its use in fuel cells and as a combustion fuel source grows, and as the transportation sector seeks alternatives to green fuels. Production methods that do not generate large amounts of carbon dioxide are essential. When polyolefins undergo FJH, no CO2 is produced. If renewable energy sources are used to power the FJH system, no stoichiometric amounts of CO2 will be produced from the production of H2 from these plastics.

[0094] Because it does not require precious metal catalysts, membranes, or brine, the methods and systems described herein are far more scalable than current green hydrogen (electrolysis of water). Furthermore, the co-production and projected sale of graphene are estimated to result in a negative cost for H2 production, making this production method and waste upcycling economically viable and easily competitive even with the cheapest (and most environmentally degraded) production method, namely gray hydrogen production by steam methane reforming.

[0095] This technology is considered primarily as an H2 production method, and secondarily as a plastic upcycling method and a graphene production method. The methods disclosed herein are compared with existing H2 production methods through life cycle evaluation and preliminary estimated production costs. These analyses are shown in Figures 23A-23C, which show (a) cumulative energy demand, (b) greenhouse gas emissions, and (c) estimated production costs arising from the production of 1 kg of H2 using different methods. The main assumptions used here include that the power sources for all methods (electrolysis, FJH, pyrolysis, etc.) are green energy and that there are no emissions from supplying electricity to each method. Therefore, the amount of greenhouse gas emitted is a result of the procurement of materials (Pt, CH4, freshwater, catalyst, etc.) and any CO2 produced stoichiometrically by the process. In addition, the estimated production costs of the "FJH PE H2" and "FeAlOx PE H2" processes include the sale of expensive carbon by-products, graphene and MWCNTs, respectively. Significant purification is required to remove the reported approximately 10 wt% catalyst, so a selling price of US$16,000 per ton was assumed for MWCNTs. The "worst-case" scenario assumes a selling price of US$3,000 per ton for graphene, taking into account the possibility of market saturation. This assumed selling price of US$3,000 per ton for graphene is 95% lower than the actual current market value of multilayer graphene products (US$60,000 per ton).

[0096] FJH production of H2 through plastic decomposition is competitive with current methods in terms of cumulative energy demand and greenhouse gas emissions, and is the only method that has demonstrated negative estimated production costs. Currently, H2 is not produced from industrial-scale waste materials, only in academic papers, which typically use large amounts of metal catalysts. We compare the FJH decomposition method with other academic methods for producing H2 from waste materials (shown in Table II) in Figure 23D. This comparison shows that the FJH method produces significantly more H2 than most methods, while not using metal catalysts. [Table 2]

[0097] Therefore, the co-production of expensive graphene results in negative cost production of H2 fuel, even if graphene is sold at 5% of its current market value. The U.S. Department of Energy has committed to producing H2 at $1 per kilogram over the next decade. Here, it is shown that H2 can be produced at "negative dollars per kilogram." More specifically, if the price of graphene is artificially lowered to just $3,000 / ton, that would be $4.30 per kilogram. In other words, graphene, as a by-product, would have no cost to H2 production and would provide such value even at negative $4.30 / kg. And all this H2 can be derived from waste such as waste plastics, cellulose household waste, construction waste, or manufacturing waste such as asphaltene. The methods and systems disclosed herein provide a step towards the clean fuel needed for the rest of this century while removing waste from our landfills.

[0098] While embodiments of the present invention have been shown and described, modifications thereof can be made by those skilled in the art without departing from the spirit and teachings of the invention. The embodiments and examples provided herein are merely illustrative and not intended to limit. Many variations and modifications of the invention disclosed herein are possible and within the scope of the invention. The scope of protection is not limited by the above description but only by the following claims, which include all equivalents of the subject matter of the claims. When scaling a process from laboratory to manufacturing, many of the processes and materials need to be modified. For example, quartz tubes are changed to concrete or brick or mullite housings. Plastic tubing is changed to steel tubing. DC capacitors are changed to AC electric Joule heating. Gas capture and units are made of large steel resistant to H2 for capture and separation.

[0099] All patents, patent applications, and publication disclosures cited herein are incorporated herein by reference in their entirety, insofar as they provide exemplary, procedural, or other details that complement those described herein.

[0100] In this specification, quantities and other numerical data may be presented in range format. Such range format is used solely for convenience and brevity, and should be understood to be interpreted flexibly to include not only the numbers explicitly listed as range limits, but also all individual numbers or subranges contained within that range, as if each number and subrange were explicitly listed. For example, a numerical range of approximately 1 to approximately 4.5 should be interpreted to include not only the explicitly listed limits of 1 to approximately 4.5, but also individual numbers such as 2, 3, 4, and subranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges listing only one number, such as "less than approximately 4.5," which should be interpreted to include all of the above values ​​and ranges. Furthermore, such interpretation should apply regardless of the breadth of the range or the characteristics described.

[0101] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art in the field to which the subject matter of this disclosure pertains. Preferred methods, apparatus, and materials are described herein, even though any similar or equivalent methods, apparatus, and materials may be used in the practice or testing of the subject matter of this disclosure.

[0102] In accordance with long-standing patent law convention, the terms “a” and “an,” as used in this application, mean “one or more” including the claims.

[0103] Unless otherwise indicated, all numbers used herein and in the claims, such as quantities of raw materials and reaction conditions, should be understood in all examples to be modified by the term "approximately." Therefore, unless otherwise indicated, the numerical parameters described herein and in the appended claims are approximations that can vary depending on the desired properties required by the subject matter of this disclosure.

[0104] As used herein, the terms “about” and “substantially” mean, when referring to a value or quantity of mass, weight, time, volume, concentration or percentage, to include variations of ±20%, ±10%, ±5%, ±1%, ±0.5%, and ±0.1% in some embodiments, as appropriate for performing the disclosed method.

[0105] As used herein, the terms “substantially perpendicular” and “substantially parallel” mean, in some embodiments, variations within ±10° of the vertical and parallel directions, in some embodiments, within ±5° of the vertical and parallel directions, in some embodiments, within ±1° of the vertical and parallel directions, and in some embodiments, within ±0.5° of the vertical and parallel directions.

[0106] As used herein, the term "and / or," when used in the context of a list of entities, means that entities exist individually or in combination. Thus, for example, the phrase "A, B, C, and / or D" includes A, B, C, and D individually, but also any and all combinations of A, B, C, and D, as well as subcombinations of A, B, C, and D.

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Claims

1. It is a method, A method for producing hydrogen gas from solid materials using flash Joule heating.

2. The method according to claim 1, wherein the solid material is waste.

3. The method according to claim 1, wherein the solid material is plastic.

4. The method according to claim 3, wherein the plastic is one or a mixture thereof from the following: polyethylene, high-density polyethylene, low-density polyethylene, polyethylene terephthalate, polystyrene, polybutadiene, polyacrylonitrile, nylon, polyester, polypropylene, vinyl polymer, step-grow polymer, chain-grow polymer, thermoplastic resin, thermosetting resin, rubber, living polymer, ring-opening polymer, siloxane polymer, block polymer, block copolymer, inorganic polymer, and organic polymer.

5. The method according to claim 1, wherein the solid material is cellulose.

6. The method according to claim 5, wherein the cellulose material is derived from one or a combination thereof from: wood, paper, cardboard, wood, plants, household waste, municipal waste, and industrial waste.

7. The method according to claim 6, wherein the cellulose material is further thermally pretreated before the flash Joule heating reaction.

8. The method according to claim 7, wherein the thermally pretreated material is biochar.

9. The method according to any one of claims 3 to 8, wherein the material to be processed is waste material.

10. The method according to claim 1, wherein the method co-produces one or more of the following: graphene, carbon nanotubes, one-dimensional materials, amorphous carbon, graphite nanodiamonds, and silicon carbide.

11. The method according to claim 10, wherein the method co-produces silicon carbide which is 1D nanofibers, nanotubes, and / or nanowhiskers.

12. The method according to claim 10, wherein the method co-produces silicon carbide 3D particles.

13. (a) Graphene is co-produced, (b) The method according to claim 10, wherein the graphene is mainly a turbostratic or Bernal (AB stack) stack, or a mixture of a turbostratic and a Bernal (AB stack) stack.

14. The method according to claim 1, wherein hydrocarbons are co-produced.

15. The method according to claim 14, wherein the hydrocarbon comprises one or more of methane, ethane, propane, butane, pentane, and hexane.

16. The method according to claim 14, wherein the hydrocarbon comprises one or more branched isomers of butane, pentane, and hexane.

17. The method according to claim 14, wherein the hydrocarbon comprises an alkene, an alkyne, an aromatic, or a mixture thereof.

18. The method according to claim 1, wherein carbon monoxide, carbon dioxide, or a mixture thereof is co-produced.

19. The method according to claim 1, wherein one or more of flash graphene, carbon nanotubes, one-dimensional materials, amorphous carbon, graphite, nanodiamonds, and silicon carbide are co-produced.

20. The method according to claim 1, wherein heteroatom-containing graphene is co-produced.

21. The method according to claim 20, wherein the heteroatom is one of the following: B, N, O, F, S, Si, and P, or a mixture thereof.

22. The method according to claim 20, wherein the heteroatom is one of metal atoms or a mixture thereof.

23. The method according to claim 1, wherein the solid material is selected from the group consisting of coal, coal derivatives, petroleum derivatives, petroleum products, carbon-containing materials, glass mixed with plastic, glass fiber + plastic, glass fiber + carbon fiber, and combinations thereof.

24. The method according to claim 1, wherein the flash Joule heating is performed without a catalyst.

25. The method according to claim 1, wherein the flash Joule heating is performed using a catalyst.

26. The method according to claim 25, wherein the catalyst is an Fe-containing catalyst.

27. The method according to claim 26, wherein the Fe-containing catalyst is iron chloride.

28. The method according to claim 25, wherein the catalyst is selected from the group consisting of iron chloride, ferrocene, a mixture of iron chloride / nickel chloride, a cobalt salt, cobalt oxide, and combinations thereof.

29. It is a method, A method comprising producing hydrogen gas from a material using flash Joule heating, wherein the material includes a liquid having chemically present hydrogen atoms.

30. The method according to claim 29, wherein the liquid has chemically present carbon and hydrogen.

31. The method according to claim 29, wherein the liquid is selected from the group consisting of crude oil, oil, asphalt, and combinations thereof.

32. The method according to claim 29, wherein the liquid is absorbed by the sponge.

33. The method according to claim 32, wherein the sponge is selected from the group consisting of carbon-based sponges, cellulose-based sponges, glass-based sponges, ceramic-based sponges, and combinations thereof.

34. The method according to claim 29, wherein the flash Joule heating is performed without a catalyst.

35. The method according to claim 29, wherein the flash Joule heating is performed using a catalyst.

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