Porous composite material capable of generating an electric arc in a microwave field, method for preparing the same, and use thereof.

Abstract

This paper describes a porous composite material capable of generating an arc in a microwave field, its manufacturing method, and its use. The porous composite material comprises an inorganic porous skeleton and a carbon material loaded on the inorganic porous skeleton, and the inorganic porous skeleton has an average pore size of 0.2 to 1000 μm. The porous composite material has excellent mechanical properties and can rapidly generate high temperatures by generating an arc in a microwave field. This allows it to be used in a variety of applications, including microwave high-temperature heating, biomass pyrolysis, vegetable oil processing, waste polymer pyrolysis, petrochemical pyrolysis, carbon fiber composite material recovery, waste treatment, VOC waste gas treatment, COD wastewater treatment, high-temperature catalysis, recycling of all components in waste circuit boards, and hydrogen generation.

Description

Detailed Description of the Invention

[0001] Field of the Invention The present invention relates to the fields of microwave heating, microwave high-temperature pyrolysis, and waste resource utilization. Specifically, the present invention relates to a porous composite material capable of generating an arc in a microwave field, a preparation method therefor and its use, and a method for pyrolyzing and / or recycling substances containing organic compounds.

[0002] Background Art More than 90% of chemical raw materials are derived from fossil energies such as petroleum, shale gas, and coal. However, fossil energy is non-renewable and generates CO2 during its use. Therefore, currently, the development of environmentally friendly renewable energy has become one of the focuses in the energy field. For more sustainable economic and social development, it is urgent to replace fossil energy with renewable biomass energy. Among them, vegetable oil has been the subject of research due to its characteristics such as low price and large-scale cultivation. From 2012 to 2013, major vegetable oils such as palm oil, rapeseed oil, sunflower oil, and soybean oil were produced at 462 million tons worldwide. In recent years, due to the rapid development of pyrolysis technology, pyrolysis technology has become one of the relatively efficient and mature biomass utilization technologies.

[0003] In another context, since the 1950s, humanity has produced 8.3 billion tons of plastic, of which 6.3 billion tons have become waste. Of this 6.3 billion tons of waste plastic, only 9% is recycled, 12% is incinerated, and the remaining 79% (approximately 5.5 billion tons) is landfilled and accumulating in the natural environment. Humanity continues to accelerate the rate of plastic production. Currently, annual plastic production has reached 400 million tons. It is estimated that by 2050, there will be 12 billion tons of waste plastic in the world. More than 8 million tons of plastic are dumped into the ocean every year. Without restrictions, by 2050, there will be more plastic waste in the ocean than fish. In recent years, a number of top-tier international publications have been issued on the pollution of marine and river organisms and drinking water by plastic particles. The pollution of marine and river organisms and drinking water by plastic particles has raised societal awareness of plastic pollution. In 2018, the United Nations Environment Programme focused for the first time on the problem of single-use plastic pollution. Furthermore, the United Nations Environment Programme announced "Stop Plastic Pollution" as the theme for World Environment Day, calling for a "declaration of war" against plastic pollution worldwide.

[0004] Scientific researchers have made continuous efforts to solve the problem of plastic pollution. Since 1970, much research has been conducted toward the preparation of plastics that can be biodegraded in the natural environment. However, biodegradable plastics have important applications only in biomedicine, agricultural mulch films, and garbage bags, and when recycling is required, the presence of biodegradable plastics has a significant impact on the performance of recycled plastic items. Furthermore, biodegradable plastics take a relatively long time to decompose in less-than-ideal natural environments and therefore cannot effectively solve the problem of white pollution.

[0005] Currently, mechanical recycling is the only widely used technical solution for processing waste plastics. The main steps involve the continuous removal of organic residue, washing, crushing, and melting and reprocessing. In the melting and reprocessing process, it is generally necessary to blend in new materials to maintain performance. Different plastics react differently to the processing, which means that the technical solution of mechanical recycling is applicable to only a very small number of plastic types. Currently, only polyethylene terephthalate (PET) and polyethylene (PE) are recycled, accounting for 9% and 37% of annual plastic production, respectively. Temperature-sensitive plastics, composite materials, and plastics (such as thermosetting plastics) that do not melt and flow at high temperatures cannot be processed by this method.

[0006] Chemical recycling, which converts waste plastics into small molecule hydrocarbons (gases, liquid oils, or solid waxes) through chemical or thermal conversion, is considered a superior technological solution to mechanical recycling. The resulting products can then be used as fuel or chemical raw materials. However, this technological solution is not currently widely used, mainly due to its high cost. On the one hand, most chemical recycling processes require expensive catalysts. Also, the selectivity of the catalysts requires that the raw materials be pure polymers, which necessitates time-consuming and labor-intensive sorting of waste plastics. On the other hand, chemical recycling processes consume a lot of energy.

[0007] Furthermore, with the rapid development of the global economy, rubber materials are widely used in various industries, and the demand for rubber products is increasing. The advent of automobiles has brought great convenience to human production and life, and has promoted social development. At the same time, it has also brought about hidden dangers that cannot be ignored, namely the worsening of environmental and resource problems. As automobile production increases year by year, the consumption of resources and the amount of waste tires continue to increase. China, with its vast territory and population, is a major tire user. Waste tires occupy a large amount of land resources and environmental space, and furthermore, they are not only difficult to compress and purify during the unknown time required for decomposition, but also difficult to biodegrade. Because waste tires cause great harm to the environment and are difficult to dispose of, they are called "black pollution." The reuse of waste rubber resources is an urgent need.

[0008] In other aspects, carbon fiber composite materials possess excellent properties such as light weight, high strength, and good corrosion resistance. Carbon fiber composite materials are widely used in high-tech fields such as aerospace, new energy, the automotive industry, and sporting goods. With the proliferation of carbon fiber composite materials, the amount of carbon fiber composite waste generated is increasing daily. The large amount of carbon fiber composite waste is attracting attention, and this has a significant impact on environmental protection and economic interests. Amid growing concerns about environmental protection and international affairs, it is contributing to the energy and resource crisis. Furthermore, the carbon fibers in carbon fiber composite materials are expensive and possess excellent overall performance, making research into carbon fiber recycling technology an important development trend for the future.

[0009] Current carbon fiber recycling technologies mainly include physical and chemical recycling methods. Physical recycling involves crushing and melting carbon fiber composite waste, which is the raw material for new materials. However, this method impairs the properties of various components of the composite material, and in particular, it is not possible to obtain carbon fiber from it, thus failing to achieve recyclability. Chemical recycling is a method of recycling carbon fiber from carbon fiber composite waste using thermal decomposition or organic solvent decomposition. Reuse through organic solvent decomposition yields clean carbon fiber. However, a large amount of organic solvent is used for resource recovery, causing environmental pollution. Separation of used solvents (liquid separation, extraction, distillation, etc.) is a complex operation and results in high recycling costs. Furthermore, this method is selective in terms of the type of matrix resin and curing agent of the carbon fiber reinforced resin composite material and is not suitable for all matrix resins. The most industrially viable method disclosed in the prior art is the thermal decomposition of carbon fiber composite materials. However, conventional heating methods are generally inefficient and have excessively high energy costs.

[0010] Printed circuit boards (PCBs) are essential components of almost all electronic information products and are widely used in various industrial fields such as electronic components and electrical control. As a substrate material in PCB manufacturing, copper-clad laminates mainly consist of three parts: the substrate, copper foil, and adhesive. The substrate is composed of polymer synthetic resin and reinforcing materials. The adhesive is typically phenolic resin, epoxy resin, polyimide resin, cyanate ester resin, or polyphenylene ether resin. In 2000, the annual production of copper-clad laminates reached 160,100 tons. In 2006, China's printed circuit board output surpassed Japan's, making it the world's largest and most productive printed circuit board manufacturer. While approximately 40% of the world's PCBs are produced in China, the amount of waste printed circuit boards (WPCBs) is also enormous. Existing WPCB processing methods, such as mechanical processing and acid dissolution, mainly focus on recycling metals in the circuit boards, but rarely involve the effective recycling of non-metallic components. Furthermore, most of these methods pose a significant threat to environmental safety. Therefore, devising an efficient WPCB treatment method through washing is one of the important problems in current research.

[0011] Microwaves refer to electromagnetic waves with wavelengths between infrared and ultra-high frequency (UHF) radio waves, possessing very strong penetrating power, with wavelengths between 1 m and 1 mm, and corresponding frequencies between 300 GHz and 300 MHz. The magnetron of a microwave generator receives the output of a power source to generate microwaves. The microwaves are transmitted through a waveguide to a microwave heater. The material to be heated is then heated under the action of the microwave field. The microwave heating mode is completely different from normal heat transfer. The high-frequency electric field periodically changes the applied electric field and direction at a rate of hundreds of millions of units per second. As a result, polar molecules in the material vibrate at high frequencies due to the electric field, as well as due to intermolecular friction and squeeze action. The material is heated rapidly, thereby causing the internal and surface temperatures of the material to rise rapidly at the same time.

[0012] In recent years, microwave pyrolysis technology that does not use catalysts has been developed. It can simultaneously process and pyrolyze moderately contaminated waste plastics, such as polyethylene, polypropylene, polyester, polystyrene, and polyvinyl chloride, which are currently the most commonly used materials, into chemical raw materials. Furthermore, microwave pyrolysis is also used to pyrolyze waste rubber into monomers, which are then repolymerized for reuse. Therefore, microwave pyrolysis technology is expected to be key to solving the problem of plastic pollution and recycling rubber resources.

[0013] Numerous patents, including patent applications CN102585860A, CN103252226A, and CN106520176A, disclose pyrolysis techniques utilizing this property of microwaves. However, all of these use ordinary microwave-sensitive materials such as silicon carbide to generate heat in a microwave field and transfer that heat to the material to be pyrolyzed, thereby achieving the pyrolysis objective. Such methods cannot achieve high working temperatures, ideal efficiency, and product composition. Therefore, there is still a need to develop microwave heating materials that can rapidly generate high temperatures in a microwave field and transfer heat to the material. There is also still a need to develop efficient methods for microwave high-temperature pyrolysis of waste plastics, waste rubber, biomass, or vegetable oils. Furthermore, there is still a need to develop efficient methods for microwave high-temperature pyrolysis of carbon fiber composite materials and recycling of carbon fibers, as well as methods for microwave high-temperature pyrolysis of circuit boards to achieve effective resource recycling. The development of such materials and methods has great potential for application.

[0014] [Disclosure of the Invention] In view of the problems of the prior art, the object of the present invention is to provide porous composite materials, as well as methods for preparing and using the same. Porous composite materials can generate high temperatures (especially above 1000°C) rapidly (e.g., within tens of seconds to a few minutes) by generating an electric arc in a microwave field. This enables effective microwave high-temperature heating or microwave thermal decomposition of organic compound-containing materials (e.g., plastics such as polyethylene, polypropylene, and polystyrene; rubber; vegetable oils; biomass; carbon fiber composite materials; circuit boards), and recycling the beneficial substances in the thermal decomposition products as chemical raw materials or for application in other contexts. Furthermore, the porous composite materials themselves can withstand high temperatures and are suitable for industrial applications.

[0015] Another objective of the present invention is to provide a simple and easy method for manufacturing porous composite materials and to facilitate large-scale production.

[0016] Another object of the present invention is that efficient operation can be achieved by using porous composite materials to process organic compound-containing materials by microwave high-temperature heating or microwave thermal decomposition. The thermal decomposition products can achieve high added value, and in particular, are mainly light components (especially gaseous or small molecule gases).

[0017] Another object of the present invention is to provide a method for microwave high-temperature pyrolysis of circuit boards to achieve effective resource recycling. The pyrolysis gas products can be gases with high recycling value, and the solid residue can be easily separated into metallic and non-metallic components. Furthermore, the solid residue can be easily recovered efficiently, including metal and glass fibers. This enables the clean and efficient recovery of all components of waste circuit boards.

[0018] The above object of the present invention can be achieved by a porous composite material capable of generating an electric arc in a microwave field. The porous composite material capable of generating an electric arc in a microwave field comprises an inorganic porous framework and a carbon material supported on the inorganic porous framework.

[0019] Specifically, according to a first aspect of the present invention, a porous composite material is provided which can generate an electric arc in a microwave field, comprising an inorganic porous framework and a carbon material supported on the inorganic porous framework. The average pore size of the inorganic porous framework is 0.2 to 1000 μm.

[0020] Here, "supported" means that the carbon material is fixed to the surface and / or structure of the inorganic porous framework by specific bonding forces, where "surface" means all interfaces of the porous framework that can come into contact with the gas phase, and "fixed" means that it is embedded or fixed inside the porous framework itself rather than inside the pore channels.

[0021] An electric arc refers to a gas discharge phenomenon, a beam of high-temperature ionized gas, and is a type of plasma.

[0022] The carbon material is comprised of graphene, carbon nanotubes, carbon nanofibers, graphite, carbon black, carbon fibers, carbon dots, carbon nanowires, products obtained by carbonizing carbable organic materials, and products after carbonization of mixtures of carbable organic materials; preferably, it may be at least one selected from the group comprising graphene, carbon nanotubes, products obtained by carbonizing carbable organic materials, and products after carbonization of mixtures of carbable organic materials.

[0023] Carbonization is a process that involves treating organic matter under specific temperature and atmospheric conditions to volatilize all or most of the hydrogen, oxygen, nitrogen, sulfur, etc. contained in the organic matter, thereby obtaining synthetic raw materials with a high carbon content.

[0024] Carbonizable organic matter refers to organic polymer compounds that include synthetic organic polymer compounds and natural organic polymer compounds; The synthetic organic polymer compound is preferably at least one selected from the group consisting of rubber, plastics including thermosetting plastics and thermoplastic plastics, more preferably epoxy resin, phenolic resin, furan resin, polystyrene, styrene-divinylbenzene copolymer, polyacrylonitrile, polyaniline, polypyrrole, polythiophene, styrene-butadiene rubber and polyurethane rubber; The natural organic polymer compound is preferably at least one selected from the group consisting of starch, viscose fiber, lignin and cellulose.

[0025] The mixture containing carbonizable organic substances refers to a mixture of carbonizable organic substances and other metal-free organic substances and / or metal-free inorganic substances, and is preferably at least one selected from the group consisting of coal, natural pitch, petroleum pitch or coal tar pitch.

[0026] The proportion of the carbon material can be 0.001% - 99%, preferably 0.01% - 90%, more preferably 0.1% - 80% based on the total mass of the porous composite material.

[0027] The inorganic porous skeleton refers to an inorganic material having a porous structure. The average pore diameter of the inorganic porous skeleton is 0.2 - 1000 μm, preferably 0.2 - 500 μm, more preferably 0.5 - 500 μm, particularly preferably 0.5 - 250 μm, or 0.2 - 250 μm. The porosity of the inorganic porous skeleton may be 1% - 99.99%, preferably 10% - 99.9%, more preferably 30% - 99%.

[0028] Here, the average pore diameter is measured by a scanning electron microscope (SEM). First, the pore diameter of each individual pore is determined by the minimum value of the distance between two intersections of a straight line passing through the center of each individual pore and the contour of the pore in the SEM photograph. And the average pore diameter is determined by the number average value of the pore diameter values of all the pores shown in the SEM photograph.

[0029] The porosity is determined by referring to GB / T 23561.4-2009.

[0030] The inorganic material may be one or a combination of more than one of carbon, silicate, aluminate, borate, phosphate, germanate, titanate, oxide, nitride, carbide, boride, sulfide, silicide and halide, preferably one or a combination of more than one of carbon, silicate, titanate, oxide, carbide, nitride and boride. Here, the oxide may be at least one selected from the group consisting of aluminum oxide, silicon oxide, zirconium oxide, magnesium oxide, cerium oxide and titanium oxide. Also, the nitride may be at least one selected from the group consisting of silicon nitride, boron nitride, zirconium nitride, hafnium nitride and tantalum nitride. The carbide may be at least one selected from the group consisting of silicon carbide, zirconium carbide, hafnium carbide and tantalum carbide. The boride may be at least one selected from the group consisting of zirconium boride, hafnium boride and tantalum boride. The inorganic material of the inorganic porous framework is more preferably at least one selected from the group consisting of carbon, silicate, aluminum oxide, magnesium oxide, zirconium oxide, silicon carbide, boron nitride, and potassium titanate.

[0031] Preferably, the inorganic porous skeleton is at least one of the following skeletons: a carbon skeleton obtained after carbonization of a polymer sponge, a porous skeleton composed of inorganic fibers, an inorganic sponge skeleton, a skeleton composed of inorganic particles, a ceramic porous skeleton obtained after baking a ceramic porous skeleton precursor, and a ceramic fiber skeleton obtained after baking a ceramic fiber skeleton precursor; preferably, at least one of the following: a skeleton obtained after carbonization of a melamine sponge, a skeleton after carbonization of a phenolic resin sponge, a porous skeleton of aluminum silicate fibers (such as aluminum silicate rock wool), a porous skeleton of mullite fibers, a porous skeleton of alumina fibers (such as alumina fiberboard), a porous skeleton of zirconia fibers, a porous skeleton of magnesium oxide fibers, a porous skeleton of boron nitride fibers, a porous skeleton of boron carbide fibers, a porous skeleton of silicon carbide fibers, a porous skeleton of potassium titanate fibers, and a ceramic fiber skeleton obtained after baking a ceramic fiber skeleton precursor.

[0032] The porous structure of an inorganic porous skeleton may originate from the pore structure of the skeleton material itself, such as a sponge-like structure, or from the pore structure formed by filling with fibrous materials such as fibrous cotton, fibrous felt, fiberboard, and other structural forms, or from the pore structure formed by filling with granular materials such as sand pile structures, or from a combination of the above various forms. Preferably, the porous structure of an inorganic porous skeleton originates from the pore structure formed by filling with fibrous materials. Particular attention should be paid to porous skeletons composed of inorganic fibers as described above. In this context, "porous" refers to the pore structure in the skeleton formed by filling with fibrous materials, but does not mean that the fibers themselves are porous.

[0033] The porous composite material according to the present invention can generate a high-temperature electric arc in a microwave field, for example, in a microwave field of 900 watts. The porous composite material can generate an electric arc that can raise its temperature above 1000°C, and the porous composite material itself can withstand high temperatures up to 3000°C. This porous composite material, which can generate an electric arc in a microwave field according to the present invention, is an efficient microwave heating material.

[0034] <Preparation method> A second aspect of the present invention provides a method for preparing a porous composite material. The preparation method according to the present invention includes the following steps: Step (1): Immerse the inorganic porous skeleton or inorganic porous skeleton precursor in a solution or dispersion of carbon material and / or carbon material precursor so that the pores of the inorganic porous skeleton or inorganic porous skeleton precursor are filled with the solution or dispersion; Step (2): A step of heating and drying the porous material obtained in step (1) to precipitate or solidify a carbon material or carbon material precursor on an inorganic porous framework or inorganic porous framework precursor to provide support; Step (3): If at least one of a carbon material precursor or an inorganic porous skeleton precursor is used as a starting material, the following steps are further carried out: heating the porous material obtained in step (2) under an inert gas atmosphere to convert the inorganic porous skeleton precursor into an inorganic porous skeleton, and / or reducing or carbonizing the carbon material precursor.

[0035] The solution or dispersion of the carbon substance or its precursor in step (1) may contain a solvent selected from the following: benzene, toluene, xylene, trichlorobenzene, chloroform, cyclohexane, ethyl caproate, butyl acetate, carbon disulfide, ketone, acetone, cyclohexanone, tetrahydrofuran, dimethylformamide, water, and alcohol; where the alcohol is preferably at least one selected from the group consisting of propanol, n-butanol, isobutanol, ethylene glycol, propylene glycol, 1,4-butanediol, isopropanol, and ethanol.

[0036] The carbon material precursor for support used in the manufacturing method of the present invention is preferably a precursor that can be dissolved or dispersed in a human- and environmentally friendly solvent before support, so that the preparation process is "earth-friendly". The human- and environmentally friendly solvent is at least one selected from the group consisting of ethanol, water, and mixtures thereof. That is, the solvent in step a is more preferably a solvent containing water and / or ethanol, and even more preferably water and / or ethanol.

[0037] The solution or dispersion only needs to achieve sufficient dissolution or dispersion of the carbon material and / or carbon material precursor in the solvent. Generally, the concentration may be 0.001 to 1 g / mL, preferably 0.002 to 0.8 g / mL, and more preferably 0.003 g to 0.5 g / mL.

[0038] The heating and drying in step (2) can be carried out at a temperature of 50 to 250°C, preferably 60 to 200°C, more preferably 80 to 180°C, and microwave heating is preferred. The microwave output may be 1W to 100KW, preferably 500W to 10KW. The microwave heating time can be 2 to 200 minutes, preferably 20 to 200 minutes.

[0039] The inorganic porous skeleton precursor is a porous material that can be converted into an inorganic porous skeleton, and may be at least one selected from the group consisting of a ceramic precursor, a porous material of a carbable organic material, or a porous material of a mixture of carbable organic materials.

[0040] The carbon material precursor may be at least one of graphene oxide, modified carbon nanotubes, modified carbon nanofibers, modified graphite, modified carbon black, modified carbon fibers, and carbogenic organic matter or a mixture containing carbogenic organic matter. Modified carbon nanotubes, modified carbon nanofibers, modified graphite, modified carbon black, and modified carbon fibers refer to carbon materials that are pretreated to improve the dispersibility of these carbon materials in water or an organic solvent and to obtain a stable dispersion. For example, pretreatment may be performed with a dispersant and a surfactant, or by grafting hydrophilic groups. All of these pretreatment methods employ pretreatment methods for improving dispersibility in the prior art. Carbon materials that have undergone the above pretreatments, such as aqueous dispersion of graphene, ethanol dispersion of graphene, aqueous slurry of graphene, oil slurry of graphene, aqueous dispersion of oxide graphene, ethanol dispersion of oxide graphene, N-methylpyrrolidone dispersion of oxide graphene, aqueous dispersion of oxide graphene, aqueous dispersion of carbon nanotubes, aqueous dispersion of carboxylated carbon nanotubes, ethanol dispersion of carbon nanotubes, dimethylformamide dispersion of carbon nanotubes, and N-methylpyrrolidone slurry of carbon nanotubes, are all commercially available.

[0041] The heating temperature in step (3) can be 400 to 1800°C, preferably 600 to 1500°C, more preferably 800 to 1200°C, and microwave heating is preferred. The microwave output may be 100W to 100KW, preferably 700W to 20KW. The microwave heating time can be 0.5 to 200 minutes, preferably 1 to 100 minutes.

[0042] In one embodiment, the preparation method includes the following steps: a. Preparation of solutions or dispersions of supporting carbon material or carbon material precursors; b. A step of immersing an inorganic porous skeleton or inorganic porous skeleton precursor in the solution or dispersion of step a, wherein the solution or dispersion fills the pores of the inorganic porous skeleton or inorganic porous skeleton precursor, wherein the carbon material and / or carbon material precursor comprises 0.001% to 99.999%, preferably 0.01% to 99.99%, and more preferably 0.1% to 99.9% of the total mass of the inorganic porous skeleton material or inorganic porous skeleton material precursor and the carbon material and / or carbon material precursor; c. The porous material obtained in step b is removed, and then heated and dried to precipitate or solidify the carbon material or carbon material precursor and support it on the inorganic porous framework or inorganic porous framework precursor; the heating and drying temperature is 50 to 250°C, preferably 60 to 200°C, more preferably 80 to 180°C; If the starting materials are carbon material and an inorganic porous skeleton, the process after step c includes a step to obtain a porous composite material capable of generating an electric arc in a microwave field; Furthermore, if the starting material used includes at least one carbon material precursor or inorganic porous framework precursor, perform step d below; d. The porous material obtained in step c is heated under an inert gas atmosphere to convert the inorganic porous framework precursor into an inorganic porous framework and / or reduce or carbonize the carbon material precursor, thereby obtaining a porous composite material that can generate an electric arc in a microwave field; the heating temperature is 400 to 1800°C, preferably 600 to 1500°C, more preferably 800 to 1200°C.

[0043] In the manufacturing method of the present invention, when the carbon material supported on the inorganic porous framework is graphene, it is preferable to use an aqueous solution of graphene oxide in step (1) or step a.

[0044] When the carbon material supported on the inorganic porous framework is carbon nanotubes, it is preferable to use a dispersion of carbon nanotubes in step (1) or step a.

[0045] When a thermosetting plastic is selected as the carbon material precursor for support, in step (1) or step a, it is necessary to prepare an appropriate curing system according to the conventional curing agents for thermosetting plastics selected in the prior art. In the curing system, one or more additives selected from the following group may be added: curing accelerators, dyes, pigments, colorants, antioxidants, stabilizers, plasticizers, lubricants, flow regulators or auxiliary agents, flame retardants, anti-dripping agents, anti-solidification agents, adhesion accelerators, conductive agents, polyvalent metal ions, impact regulators, release aids, nucleating agents, etc. The amount of additives used may be a normal amount or can be adjusted according to the actual conditions. When a thermosetting plastic is selected as the carbon material precursor for support, after heating in step c, the thermosetting resin used as the carbon material precursor is cured and supported on the inorganic porous framework.

[0046] When a thermosetting plastic is selected as the carbon material precursor for support, in step (1) or step a, a suitable solvent from the prior art is selected to dissolve the thermosetting plastic and its curing system to obtain a carbon material precursor solution for support.

[0047] When a thermoplastic material is selected as the supporting carbon material precursor, the solution of the supporting carbon material precursor may contain antioxidants, co-antioxidants, heat stabilizers, light stabilizers, ozone stabilizers, processing aids, plasticizers, softeners, anti-blocking agents, foaming agents, dyes, pigments, waxes, fillers, organic acids, flame retardants, silane coupling agents, and other additives commonly used in the prior art during plastic processing. The amounts of additives used may be conventional amounts or may be adjusted according to the actual situation.

[0048] In the preparation method according to the present invention, the pores of the inorganic porous framework can be filled with a solution or dispersion of a supporting carbon material or carbon material precursor by compressing it several times or not compressing it at all.

[0049] In step (2) of the manufacturing method of the present invention, after removing the porous material obtained in step (1), means may or may not be taken to remove any excess solution or dispersion of carbon material or carbon material precursor to be supported in the porous material obtained in step (1). The above measurement includes, but is not limited to, one or two of the following: a compression operation and a centrifugal operation.

[0050] The heating in steps (2) and (3) of the preparation method according to the present invention may preferably be microwave heating, which is not only efficient but can also achieve uniform heating.

[0051] Specifically, in step (2), the microwave output may be 1W to 100KW, preferably 500W to 10KW, and the microwave irradiation time is 2 to 200 minutes, preferably 20 to 200 minutes.

[0052] In step (3), the microwave output may be 100W to 100KW, preferably 700W to 20KW, and the microwave irradiation time is 0.5 to 200 minutes, preferably 1 to 100 minutes.

[0053] The heating in step (3) of the manufacturing method of the present invention must be carried out under an inert gas atmosphere. The inert gas atmosphere is selected from inert gas atmospheres commonly used in the prior art, preferably nitrogen.

[0054] The apparatus used in the preparation method according to the present invention is all the same.

[0055] <Examples of application> The porous composite material according to the present invention exhibits unexpectedly excellent mechanical properties due to the combination of an inorganic porous framework and a carbon material. The porous composite material according to the present invention can generate an electric arc to rapidly generate high temperatures in a microwave field, for example, a 900W microwave field. The porous composite material according to the present invention can generate an electric arc that can raise the temperature of the porous composite material to over 1000°C. As a result, the porous composite material can be used in fields such as microwave high-temperature heating, biomass pyrolysis, vegetable oil treatment, waste polymer material pyrolysis, petrochemical pyrolysis, carbon fiber composite material recycling, waste treatment, VOC waste gas treatment, COD wastewater treatment, and high-temperature catalysts. At the same time, the porous composite material itself is resistant to high temperatures, its preparation process is simple and easy to implement, thereby easily enabling large-scale preparation.

[0056] Accordingly, according to a third aspect, the present invention provides for the use of porous composite materials according to the present invention for microwave high-temperature heating, pyrolysis and recycling in the fields of organic compounds (e.g., organic matter, mixtures containing organic matter or composite materials containing organic matter), high-temperature catalysts and other fields, and in particular for use in biomass pyrolysis, vegetable oil treatment, waste polymer material pyrolysis, petrochemical pyrolysis, carbon fiber composite material recycling, waste treatment, VOC waste gas treatment or COD wastewater treatment.

[0057] In petrochemical manufacturing processes, petroleum fractionation products (including petroleum gas) are commonly used as raw materials. Petrochemical pyrolysis methods, which use higher temperatures than thermal decomposition, are used to decompose long-chain hydrocarbon molecules into various short-chain gaseous hydrocarbons and small amounts of liquid hydrocarbons to provide organic chemical raw materials.

[0058] The porous composite material according to the present invention may be particularly suitable for the thermal decomposition and / or recycling of substances containing organic compounds.

[0059] Accordingly, according to a fourth aspect, the present invention provides a method for thermally decomposing and / or recycling a substance containing an organic compound. The substance containing the organic compound is brought into contact with a porous composite material according to the present invention under an inert atmosphere or vacuum, and a microwave field is applied to the substance containing the organic compound and the porous composite material. The porous composite material generates an electric arc in the microwave field, thereby rapidly reaching a high temperature and thermally decomposing the substance containing the organic compound.

[0060] Organic compound-containing materials include organic materials, mixtures containing organic materials, and composite materials containing organic materials, which may be selected from, for example, the following: -Waste plastics; here, waste plastics refer to plastics and mixtures thereof that have been used for consumer, industrial, and other purposes. Examples of waste plastics include, but are not limited to, the following: Specifically, at least one of polyolefins, polyesters (polyesters and mixtures thereof, such as at least one of polyethylene terephthalate, polybutylene terephthalate, and polyarylate), polyamides, acrylonitrile-butadiene-styrene terpolymers, polycarbonates, polylactic acid, polyurethanes, polymethyl methacrylate, polyoxymethylene, polyoxymethylene ether, and polyphenylene sulfide; preferably, polyethylene and mixtures thereof (containing, but not limited to, at least one of low-density polyethylene, medium-density polyethylene, high-density polyethylene, and ultra-high molecular weight polyethylene), polypropylene and mixtures thereof, polyvinyl chloride and mixtures thereof, polyethylene terephthalate, polystyrene and mixtures thereof (containing, but not limited to, ordinary polystyrene, expanded polystyrene, high-impact polystyrene, and syndiotactic polystyrene), polyamides, acrylonitrile-butadiene-styrene terpolymers, polycarbonates, polylactic acid, polymethyl methacrylate, and polyoxymethylene; more preferably, at least one of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, polycarbonate, and polyamides. The waste plastics can be mixed together and processed directly without sorting, thereby simplifying the waste plastic processing procedure, except that if there are special requirements for the decomposition products, the waste plastics must be processed according to their type.

[0061] -Waste rubber; here, waste rubber refers to rubber and mixtures thereof for civilian, industrial and other purposes that have been used and ultimately discarded or replaced, preferably at least one of natural rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, isoprene rubber, ethylene propylene rubber, butyl rubber, neoprene, styrene-based block copolymer and silicone rubber, more preferably at least one of natural rubber, butadiene rubber, styrene-butadiene rubber, isoprene rubber and ethylene propylene rubber. The waste rubber can be mixed together and processed directly without sorting, thereby simplifying the waste rubber processing procedure; however, if there are special requirements for the decomposition products, the waste rubber needs to be processed according to type.

[0062] -Biomass; here, biomass refers to various animals, plants, and algae produced by photosynthesis, mainly composed of cellulose, hemicellulose, and lignin, and includes, but is not limited to, at least one of straw, bagasse, twigs, leaves, wood chips, rice husks, rice stalks, straw, peanut shells, coconut shells, palm seed husks, walnut shells, macadamia nut shells, pistachio shells, wheat straw, corn stalks, and corn cobs.

[0063] - Vegetable oil; Hereinafter, vegetable oil means oils and fats obtained from the fruits, seeds and embryos of plants, and mixtures thereof. Examples of oils and fats obtained from the fruits, seeds and embryos of plants include, but are not limited to, at least one of palm oil, rapeseed oil, sunflower oil, soybean oil, peanut oil, linseed oil, and castor oil, preferably at least one of palm oil, rapeseed oil, sunflower oil, and soybean oil.

[0064] -Carbon fiber composite material; here, the carbon fiber composite material is preferably a carbon fiber reinforced polymer composite material in the prior art. The polymer matrix composited with carbon fibers includes, but is not limited to, at least one of polyethylene, polypropylene, nylon, phenolic resin, and epoxy resin.

[0065] - Circuit board; here, the circuit board can be any type of circuit board manufactured with the current technological capabilities.

[0066] In the case of carbon fiber composite materials, a microwave field is applied to the carbon fiber composite and porous composite materials in an inert atmosphere or vacuum. The porous composite material generates an electric arc in the microwave field, thereby rapidly reaching a high temperature to thermally decompose the polymer matrix in the carbon fiber composite material, while the carbon fibers remain and are recycled.

[0067] In the case of a circuit board, the circuit board is in contact with a porous composite material, and a microwave field is applied to the circuit board and the porous composite material under an inert atmosphere or vacuum. The porous composite material generates an electric arc under microwaves and rapidly reaches a high temperature, thermally decomposing organic materials such as polymer synthetic resins in the circuit board, yielding large amounts of gas products, which are highly flammable gases, and solid residues. The solid residues consist of metal components with a loose structure that are easily separated, and non-metallic components, mainly glass fiber mixtures.

[0068] The weight ratio of the substance containing the organic compound to the porous composite material may be 1:99 to 99:1, preferably 1:50 to 50:1, more preferably 1:30 to 30:1, and more preferably 1:10 to 10:1.

[0069] The microwave output of the microwave field can be 1W to 100KW, more preferably 100W to 50KW, more preferably 200W to 50KW, more preferably 500W to 20KW, most preferably 700W to 20KW, and especially 700W, 900W, or 1500W. The microwave irradiation time can be 0.1 to 200 minutes, more preferably 0.5 to 150 minutes, and most preferably 1 to 100 minutes. An electric arc is generated in the microwave field and can rapidly reach 700 to 3000°C, preferably 800 to 2500°C, more preferably 800 to 2000°C. This causes the organic compounds in the material containing the organic compounds to be thermally decomposed.

[0070] For example, the microwave output for thermal decomposition of palm oil can be 200W to 80KW, preferably 300W to 50KW, and the microwave irradiation time can be 0.2 to 200 minutes, preferably 0.3 to 150 minutes. The microwave output for thermal decomposition of rapeseed oil can be 100W to 50KW, preferably 200W to 30KW, and the microwave irradiation time can be 0.1 to 150 minutes, preferably 0.2 to 130 minutes. The microwave output for thermal decomposition of sunflower oil can be 80W to 60KW, preferably 200W to 40KW, and the microwave irradiation time can be 0.3 to 120 minutes, preferably 0.4 to 100 minutes. The microwave output for thermal decomposition of soybean oil can be 120W to 40KW, preferably 200W to 30KW, and the microwave irradiation time can be 0.2 to 100 minutes, preferably 0.5 to 90 minutes. For thermal decomposition of peanut oil, the microwave output can be 100W to 10KW, preferably 300W to 8KW, and the microwave irradiation time can be 0.3 to 100 minutes, preferably 0.5 to 90 minutes. For thermal decomposition of linseed oil, the microwave output can be 150W to 80KW, preferably 300W to 50KW, and the microwave irradiation time can be 0.1 to 80 minutes, preferably 0.3 to 70 minutes. For thermal decomposition of castor oil, the microwave output can be 200W to 50KW, preferably 300W to 40KW, and the microwave radiation time can be 0.5 to 70 minutes, preferably 0.6 to 60 minutes. For thermal decomposition of straw, the microwave output can be 100W to 70KW, and the microwave irradiation time can be 0.2 to 150 minutes. For thermal decomposition of bagasse, the microwave output can be 80W to 50KW, and the microwave irradiation time can be 0.2 to 120 minutes. For thermal decomposition of tree branches, the microwave output can be 120W to 100KW, and the microwave irradiation time can be 0.5 to 200 minutes. For thermal decomposition of leaves, the microwave output can be 50W to 40KW, and the microwave irradiation time can be 0.1 to 80 minutes. For thermal decomposition of wood chips, the microwave output can be 100W to 10KW, and the microwave irradiation time can be 0.2 to 100 minutes.For thermal decomposition of rice husks, a microwave output of 80W to 80KW and a microwave irradiation time of 0.2 to 120 minutes are possible. For thermal decomposition of rice stalks, a microwave output of 100W to 70KW and a microwave irradiation time of 0.2 to 100 minutes are possible. For thermal decomposition of rice straw, a microwave output of 50W to 60KW and a microwave irradiation time of 0.2 to 60 minutes are possible. For thermal decomposition of peanut shells, a microwave output of 100W to 50KW and a microwave irradiation time of 0.3 to 70 minutes are possible. For thermal decomposition of coconut shells, a microwave output of 200W to 80KW and a microwave irradiation time of 0.5 to 150 minutes are possible. For thermal decomposition of palm seed husks, a microwave output of 100W to 50KW and a microwave irradiation time of 0.3 to 100 minutes are possible. For thermal decomposition of corn cobs, the microwave output can be 80W to 50KW, and the microwave irradiation time can be 0.2 to 70 minutes. For thermal decomposition of natural rubber, the microwave output can be 100W to 50KW, and the microwave irradiation time can be 0.5 to 150 minutes. For thermal decomposition of butadiene rubber, the microwave output can be 120W to 60KW, and the microwave irradiation time can be 0.5 to 120 minutes. For thermal decomposition of styrene-butadiene rubber, the microwave output can be 150W to 80KW, and the microwave irradiation time can be 0.6 to 200 minutes. For thermal decomposition of isoprene rubber, the microwave output can be 100W to 60KW, and the microwave irradiation time can be 0.5 to 150 minutes. For thermal decomposition of ethylene-propylene rubber, the microwave output can be 200W to 70KW, and the microwave irradiation time can be 0.2 to 100 minutes.

[0071] Microwave fields can be generated by various conventional microwave devices, such as household microwave ovens and industrialized microwave equipment (microwave pyrolysis reactors, etc.).

[0072] The inert atmosphere is a conventionally used inert gas atmosphere such as nitrogen, helium, neon, argon, krypton, or xenon, preferably nitrogen.

[0073] Organic compound-containing substances and porous composite materials can be brought into contact in various ways. If the organic compound-containing substance is a solid such as waste plastic, the substance can be placed on a porous composite material, placed in a cavity formed by the porous composite material, or covered by the porous composite material, preferably the solid substance (e.g., circuit board) is crushed and then brought into contact with the porous composite material. If the organic compound-containing substance is a liquid such as vegetable oil, one useful mode is the batch mode, where the vegetable oil is first added to the porous composite material. In this case, the porous composite material automatically absorbs the vegetable oil into its pores. Next, microwave thermal decomposition is performed. Another useful mode is the continuous mode, where, during microwave thermal decomposition, a pump (such as a peristaltic pump) is used to continuously add the vegetable oil to the surface of the porous material through a quartz pipe. The pumping speed only needs to ensure the residence time of the mixture of vegetable oil and porous composite material in the microwave field. If the organic compound-containing substance is a mixture of solid and liquid, the mixing forms of the above contact modes can be adopted accordingly.

[0074] In the method of the present invention, the apparatus used for placing or transporting organic compound-containing substances and porous composite materials is capable of transmitting microwaves and withstanding temperatures exceeding 1200°C. The apparatus can be various containers or pipes such as quartz crucibles, quartz reactors, quartz tubes, alumina crucibles, alumina reactors, and alumina tubes.

[0075] In the method of the present invention, the organic compound-containing substance is gasified after pyrolysis. The gas obtained after pyrolysis can be collected for subsequent processing or recycling. For example, after separation, the gas can be used as fuel for subsequent reactions and production, or as a raw material for the chemical industry. The residue after pyrolysis is discarded as waste or for carbon fiber composite materials. The residue after pyrolysis is mainly carbon fiber, which can be recovered and reused after removal of impurities, or, for circuit boards, the solid residue obtained from the pyrolysis of circuit boards can be processed to separate the metallic and non-metallic components, which can then be recycled. Various separation methods and apparatuses in the prior art can be employed for the above separation of the solid residue.

[0076] Gas collection is a common method in the prior art and can be carried out using a gas collection device, preferably under an inert atmosphere. For example, when using a household microwave oven, a quartz crucible filled with a substance consisting of an organic compound and a porous composite material is placed in a vacuum bag and sealed inside a nitrogen-protected glove box. After the reaction is carried out under microwaves, the crucible is opened across the vacuum bag, and a syringe is pushed into the vacuum bag for sampling. When an industrial microwave oven with a gas inlet and gas exhaust port (such as a microwave pyrolysis reactor) is used, the gas collection mode is such that nitrogen purging is performed during the reaction process, and sampling and collection by the gas collection bag is performed at the gas exhaust port.

[0077] The present invention utilizes a porous composite material to generate an electric arc in a microwave field, thereby rapidly generating high temperatures to thermally decompose a substance containing organic compounds. The thermal decomposition products can be used as chemical raw materials for recycling, or valuable residues such as carbon fibers or metals remaining after thermal decomposition can be recycled, achieving complete recycling of waste circuit boards in particular. This method is efficient, and the resulting compositions have high added value.

[0078] [Examples] The present invention will be further described with reference to the following examples, but the scope of the present invention is not limited to these examples.

[0079] The experimental data in the examples were measured using the following equipment and measurement methods: 1. Determination of the mass percentage of carbon material supported in porous composite material: 1) When an inorganic porous skeletal material was used as the starting material, the weight of the inorganic porous skeletal material was measured first, and then the weight of the resulting porous composite material was measured. The difference in weight between the two was taken as the weight of the supporting carbon material, and the mass percentage of the carbon material supported within the porous composite material was determined.

[0080] 2) When an inorganic porous skeleton precursor was used as the starting material, two samples of the same weight of inorganic porous skeleton precursor were used. One of these was used in the example of the present invention, and the other was used in a reference example in which only steps c and d of the above preparation method were carried out. After the experiment was completed, the weight of the porous composite material obtained in the example was weighed, and the final weight of the sample obtained in the reference example was weighed. The difference in weight between the two was taken as the weight of the supported carbon material, and the mass percentage of the carbon material supported in the porous composite material was determined. 2. In the following examples and comparative examples, chromatographic analysis of the pyrolyzed gases was performed using an Agilent 6890N gas chromatograph manufactured by Agilent Corporation (USA), unless otherwise specified. The Agilent 6890N gas chromatograph used was equipped with an FID detector, an HP-PLOT AL2O3 capillary column (50 m × 0.53 mm × 15 μm) as the chromatographic column, He as the carrier gas, a linear velocity of 41 cm / sec, an inlet temperature of 200 °C, a detector temperature of 250 °C, a splitting ratio of 15:1, an injection sample volume of 0.25 ml (gas), and a heating program. The initial temperature was maintained at 55 °C for 3 minutes, then increased at 4 °C / min to 120 °C and maintained for 4 minutes, and then further increased at 20 °C / min to 170 °C and maintained for 10 minutes. 3. The average pore diameter of inorganic porous frameworks and porous composite materials was determined as follows: The pore diameter of individual pores was determined by the minimum distance between two intersections of lines passing through the center of each pore and the contour of the pore in the scanning electron microscope (SEM) image. The average pore diameter was then calculated by averaging the pore diameter values ​​of all pores shown in the SEM image. The SEM used was a Hitachi S-4800 (Hitachi, Japan) with a magnification of 200x. 4. Porosity was determined by referring to GB / T 23561.4-2009.

[0081] All starting materials used in the examples were commercially available.

[0082] <Preparation of Porous Composite Materials> [Example 1] (1) Weigh 500 ml of an aqueous dispersion of graphene oxide (JCGO-95-1-2.6-W, 10 mg / ml, Nanjing Ji Cang Nano Tech Co, LTD.) and place it in a beaker; (2) 2 g of a porous skeleton made of phenolic resin (phenolic foam, average pore size 300 μm, porosity 99%, Changshu Smithers-Osys Floral Foam Co., Ltd.) was immersed in an aqueous dispersion of graphene oxide. As a result, the dispersion penetrated sufficiently into the pore channels of the porous skeleton. (3) Remove the immersed porous material and place it on a stainless steel tray, then place it in an oven at 180°C and heat it for 1 hour to dry and pre-reduce the material; (4) The dried porous material was placed in a household microwave oven (700W, M1-L213B model, Midea) and microwaved at high power for 2 minutes to reduce the pre-reduced graphene oxide back to graphene and carbonize the phenolic resin skeleton into a carbon skeleton (average pore size 200 μm, porosity 99%). This yielded a porous composite material in which graphene was supported on a carbon porous skeleton, capable of generating an electric arc in a microwave field. Graphene constituted 10% of the total mass of the porous composite material.

[0083] [Example 2] (1) 500 ml of a dispersion of carbon nanotubes (XFWDM, 100 mg / ml, Nanjing XFNANO Materials Tech Co, Ltd.) was measured and placed in a beaker; (2) 2 g of a porous skeleton made of phenolic resin (phenolic foam, average pore size 200 μm, porosity 99%, Changshu Smithers-Osys Floral Foam Co., Ltd.) was immersed in a carbon nanotube dispersion. As a result, the carbon nanotube dispersion penetrated sufficiently into the pore channels of the porous skeleton. (3) Remove the immersed porous material, place it on a stainless steel tray, and heat it in an 80°C oven for 5 hours to dry the material; (4) The dried porous material was placed in a tubular furnace and carbonized at 800°C for 1 hour under a nitrogen atmosphere to obtain a porous composite material in which carbon nanotubes were supported on a porous carbon skeleton (average pore size of the carbon skeleton was 140 μm, and porosity was 99%), on which an electric arc could be generated in a microwave field. The carbon nanotubes accounted for 30% of the total mass of the porous composite material.

[0084] [Example 3] (1) Weigh 500 ml of a dispersion of carbon nanotubes (XFWDM, 100 mg / ml, Nanjing XFNANO Materials Tech Co, Ltd.) and place it in a beaker; (2) 5 g of a fibrous, cotton-like porous skeleton composed of silicate (average pore size 150 μm, porosity 90%, Shandong Luyang Energy-Saving Materials Co., Ltd.) was immersed in a carbon nanotube dispersion and compressed several times to ensure that the dispersion was sufficiently absorbed into the pore channels of the porous skeleton; (3) The immersed porous material was removed, placed on a stainless steel tray, and heated in a 150°C oven for 2 hours to dry it, thereby obtaining a porous composite material in which carbon nanotubes were supported on a silicate fiber porous framework, and an electric arc could be generated in a microwave field. The carbon nanotubes accounted for 10% of the total mass of the porous composite material.

[0085] [Example 4] (1) Weigh 30g of powdered phenolic resin (2123, Xinxiang Bomafengfan Industry Co, Ltd.) and 3.6g of hexamethylenetetramine curing agent, place them in a beaker, pour in 500ml of ethanol, and stir with a magnetic stirrer for 1 hour until all components are dissolved; (2) 5 g of a fibrous, cotton-like porous skeleton made of silicate (average pore size 150 μm, porosity 90%, Shandong Luyang Energy-saving Materials Co., Ltd.) was immersed in the compounding solution and squeezed several times. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton; (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 1000°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbides were supported on a silicate fiber porous framework, and an electric arc could be generated in a microwave field. The carbon material constituted 5% of the total mass of the porous composite material.

[0086] [Example 5] (1) Weigh 50 g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 500 ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 8 g of a plate-shaped porous skeleton made of alumina (average pore size 100 μm, porosity 85%, Shandong Luyang Energy-Saving Materials Co., Ltd.) was immersed in the formulated solution. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 900°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbides were supported on an alumina fiber porous framework, and an electric arc could be generated in a microwave field. The carbon material constituted 6% of the total mass of the porous composite material.

[0087] [Example 6] (1) Weigh 30g of water-soluble starch (pharmaceutical grade, product code: S104454, Shanghai Aladdin Biochemical Technology Co., Ltd.), place it in a beaker, pour in 500ml of deionized water, and stir with a magnetic rotor for 1 hour to dissolve it; (2) 8 g of a fibrous mat-like porous skeleton made of alumina (average pore size 100 μm, porosity 85%, Shandong Luyang Energy-Saving Materials Co., Ltd.) was immersed in the formulated solution. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed in a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.), and microwaved at a power of 10KW for 2 minutes to dry the porous material; (4) The dried porous material was placed in a tubular furnace and carbonized at 1200°C for 1 hour under a nitrogen atmosphere to carbonize the water-soluble starch and obtain a porous composite material in which starch carbides were supported on an alumina fiber porous framework, and an electric arc could be generated in a microwave field. The carbon material constituted 0.1% of the total mass of the porous composite material.

[0088] [Example 7] (1) Weigh 50g of water-soluble starch (pharmaceutical grade, product code: S104454, Shanghai Aladdin Biochemical Technology Co., Ltd.), place it in a beaker, pour in 500ml of deionized water, and stir with a magnetic rotor for 1 hour to dissolve it; (2) 8 g of a fibrous, cotton-like porous skeleton made of alumina (average pore size 100 μm, porosity 85%, Shandong Luyang Energy-Saving Materials Co., Ltd.) was immersed in the compounding solution and squeezed several times. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed in a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.), and treated with microwaves at a power of 500W for 2 hours to dry the porous material; (4) A porous material was placed in a tubular furnace and carbonized at 1000°C for 1 hour under a nitrogen atmosphere to carbonize the starch, thereby obtaining a porous composite material in which starch carbides were supported on an alumina fiber porous framework, which could generate an electric arc in a microwave field. The carbon material constituted 0.2% of the total mass of the porous composite material.

[0089] [Example 8] (1) Weigh 2 kg of liquid phenolic resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 4 L of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 2 g of a porous skeleton made of phenolic resin (phenolic foam, average pore size 500 μm, porosity 99%, Changshu Smithers-Osys Floral Foam Co., Ltd.) was immersed in the compounding solution. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton; (3) Remove the immersed porous material, place it on a stainless steel tray, and heat it in an oven at 150°C for 2 hours to dry the material; (4) The dried porous material was placed in a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.) and microwaved at a power output of 20 kW for 100 minutes under a nitrogen atmosphere to obtain a porous composite material in which phenolic resin carbides were supported on a porous carbon framework (the carbon framework had an average pore size of 350 μm and a porosity of 99%) that could generate an electric arc in the microwave field. The carbon material supported on the inorganic carbon framework constituted 80% of the total mass of the porous composite material.

[0090] [Example 9] (1) Weigh 0.3 g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 100 ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 300 g of activated alumina (average pore size 0.05 μm, porosity 30%, Shandong Marine Chemical Industry Co., Ltd.) was immersed in the formulated solution. As a result, the solution penetrated sufficiently into the pore channels of the activated alumina; (3) Remove the immersed porous material, place it on a stainless steel tray, and heat it in an oven at 150°C for 2 hours to dry the material; (4) The dried porous material was placed in a tubular furnace and carbonized at 1000°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbides were supported on an activated alumina (porous framework) that could generate an electric arc in a microwave field. The carbon material constituted 0.05% of the total mass of the porous composite material.

[0091] [Example 10] (1) Weigh 30 g of powdered phenol resin (2123, Xinxiang Bomafengfan Industry Co, Ltd.) and 3.6 g of hexamethylenetetramine curing agent, place them in a beaker, pour in 500 ml of ethanol, and stir with a magnetic rotor for 1 hour until dissolved; (2) 8 g of a fibrous plate-like porous skeleton made of magnesium oxide (average pore size 100 μm, porosity 80%, Jinan Huolong Thermal Ceramics Co, Ltd.) was immersed in the formulated solution. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 1000°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin and obtain a porous composite material in which phenolic resin carbide was supported on a magnesium oxide fiber porous framework, and an electric arc could be generated in a microwave field. The carbon material constituted 3% of the total mass of the porous composite material.

[0092] [Example 11] (1) Weigh 100g of water-soluble starch (pharmaceutical grade, Shanghai Aladdin Biochemical Technology Co., Ltd.), place it in a beaker, pour in 500ml of deionized water, and stir with a magnetic rotor for 1 hour to dissolve it; (2) 8 g of a fibrous plate-like porous skeleton made of zirconia (average pore size 150 μm, porosity 80%) was immersed in the formulated solution (Jinan Huolong Thermal Ceramics Co, Ltd.). As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton; (3) The immersed porous material was removed and placed in a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.), and treated with microwaves at a power of 3 kW for 20 minutes to dry the porous material; (4) The dried porous material was placed in a tubular furnace and carbonized at 900°C for 2 hours under a nitrogen atmosphere to carbonize the starch, thereby obtaining a porous composite material in which starch carbides were supported on a zirconia fiber porous framework, which could generate an electric arc in a microwave field. The carbon material constituted 0.5% of the total mass of the porous composite material.

[0093] [Example 12] (1) Weigh 50 g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 500 ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 8 g of a fibrous plate-like porous skeleton composed of boron nitride (average pore size 100 μm, porosity 80%, Jinan Huolong Thermal Ceramics Co, Ltd.) was immersed in the prepared solution. As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 900°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbides were supported on a boron nitride fiber porous framework, which could generate an electric arc in a microwave field. The carbon material constituted 5% of the total mass of the porous composite material.

[0094] [Example 13] (1) Weigh 100g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 500ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 8 g of a fibrous plate-like porous skeleton made of silicon carbide (average pore size 100 μm, porosity 80%) was immersed in the formulated solution (Jinan Huolong Thermal Ceramics Co, Ltd.). As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton. (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 800°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbides were supported on a porous silicon carbide fiber framework, and an electric arc could be generated in a microwave field. The carbon material constituted 10% of the total mass of the porous composite material.

[0095] [Example 14] (1) Weigh 100g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 500ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 8 g of a porous fibrous skeleton made of potassium titanate (average pore size 100 μm, porosity 80%) was immersed in the compounded solution (Jinan Huolong Thermal Ceramics Co, Ltd.). As a result, the solution penetrated sufficiently into the pore channels of the porous skeleton; (3) The immersed porous material was removed and placed on a stainless steel tray, and the material was heated in a 180°C furnace for 2 hours to dry the material, remove the solvent, and cure the phenolic resin; (4) The dried and cured porous material was placed in a tubular furnace and carbonized at 800°C for 1 hour under a nitrogen atmosphere to carbonize the phenolic resin, thereby obtaining a porous composite material in which phenolic resin carbide was supported on a potassium titanate fibrous porous framework capable of generating an electric arc in a microwave field. The carbon material constituted 10% of the total mass of the porous composite material.

[0096] <Microwave thermal decomposition of waste plastics>: [Example 15] 0.5g each of beverage bottle body (PET), beverage bottle cap (HDPE), greenhouse membrane (LLDPE), PP pellets, PP lunch box fragments, packaging polystyrene (PS) foam, acrylonitrile-butadiene-styrene terpolymer tray (ABS), nylon pipe fragment (PA6), and clear water cup (PC), as well as 0.5g of polyvinyl chloride (PVC) hose, were cut with scissors or weighed and placed on 1g of the porous composite material obtained in Example 1. After being protected with nitrogen, they were thermally decomposed by high-power microwaves in a household microwave oven (700W) for 30 seconds. Using the porous composite material obtained in Example 1, all materials were thermally decomposed and gasified after short-time microwave treatment of 30 seconds in a household microwave oven (700W). There was almost no residue, and only a small amount of black substance remained on the polyvinyl chloride (PVC) hose. Intense arc discharge phenomena were observed throughout the process. The porous composite material generated an electric arc in a microwave field, which rapidly generated high temperatures, transferring heat to the material and causing rapid thermal decomposition.

[0097] Using the samples obtained in Examples 2-14, experiments similar to those described above were conducted, and similar experimental phenomena and results were obtained. All porous composite materials obtained in Examples 2-14 were able to generate an electric arc in a microwave field, thereby rapidly generating high temperatures and transferring heat to the material, causing rapid thermal decomposition of the material.

[0098] [Example 16] 50g of beverage bottle cap (HDPE), 50g of PP lunch box fragments, 50g of acrylonitrile-butadiene-styrene terpolymer tray (ABS), 50g of nylon tube fragments (PA6), 50g of clear water cup (PC), 3g of packaging foam (PS), 10g of house film (LLDPE), 50g of beverage bottle body (PET), 50g of disposable clear plastic cup (PS) fragments, and 50g of polyvinyl chloride (PVC) hose fragments were cut with scissors and placed in cavities made of 30g of porous composite material obtained in Example 1. Then, using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atopio Equipment Manufacturing Co., Ltd.), the materials were protected with nitrogen and processed for 5 minutes at an output of 1500W. Furthermore, in the case of the polyvinyl chloride hose, almost no residue was observed in any of the materials, and only a small amount of black substance remained.

[0099] The placement of the material to be pyrolyzed into a cavity made of porous composite material that generates an electric arc in microwaves was carried out as follows: First, a portion of the porous composite material was placed at the bottom and around the quartz reactor to form a cavity with an upper opening. Next, the material was placed inside the cavity. Finally, the top of the material was covered with the remaining porous composite material.

[0100] Using the samples obtained in Examples 2-14, experiments similar to those described above were conducted, and similar experimental phenomena and results were obtained. All porous composite materials obtained in Examples 2-14 were able to generate an electric arc in microwaves, thereby rapidly generating high temperatures, transferring them to the material, and rapidly thermally decomposing the material.

[0101] [Comparative Example 1] 0.5g of beverage bottle cap (HDPE) fragments, 0.5g of PP lunchbox fragments, 0.5g of PET bottle body fragments, and 0.5g of PS foam and PVC hose were each placed on 1g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.), protected with nitrogen, and then subjected to high-power microwave treatment in a household microwave oven (700W) for 30 seconds. No sparks were observed in any of the materials during the microwave process. After microwave treatment, the HDPE bottle cap, PP lunchbox fragments, PET fragments, PS foam, and PVC hose all remained unchanged, and only the bottom of the quartz crucible was slightly warmed.

[0102] [Comparative Example 2] A 0.5g fragment of a beverage bottle cap (HDPE) was placed on 1g of activated carbon powder (AR, ≥200 mesh, item number C112223, Shanghai Aladdin Bio-Chem Technology Co., LTD.), protected with nitrogen, and then subjected to high-power microwave treatment in a household microwave oven (700W) for 30 seconds. Electric arcs occasionally appeared during the microwave process. After microwave treatment, the HDPE bottle cap melted but did not completely disappear. The weight loss of the HDPE was found to be 25% after weighing.

[0103] [Example 17] Except for the following parameters, the other parameters and steps were the same as in Example 15: Using 1 g of the sample obtained in Example 1, 0.5 g of HDPE, 0.5 g of PP, and 0.5 g of LLDPE were thermally decomposed using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.) at a power output of 700 W for 30 seconds (or a household microwave oven (700 W) at high power for 30 seconds). The resulting gases were chromatographically analyzed, and the main components detected are shown in Table 1-1.

[0104] Using 1 g of the sample obtained in Example 1, 0.5 g of PET was thermally decomposed using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.) at a power output of 700 W for 30 seconds (or a household microwave oven (700 W) at high power for 30 seconds). The resulting gas was chromatographically analyzed, and the main components detected are shown in Table 1-2.

[0105] Using 1 g of the sample obtained in Example 1, 0.5 g of PS was thermally decomposed using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.) at a power output of 700 W for 30 seconds (or a household microwave oven (700 W) at high power for 30 seconds). The resulting gas was chromatographically analyzed, and the detected main components are shown in Table 1-3.

[0106] Using 1 g of the sample obtained in Example 1, 0.5 g of PVC was thermally decomposed at high power for 30 seconds using a household microwave oven (700 W), and the resulting gas was subjected to chromatographic analysis. The main components detected are shown in Table 1-4.

[0107] [Table 1-1]

[0108] [Table 1-2]

[0109] [Table 1-3]

[0110] [Table 1-4]

[0111] [Example 18] Except for the following parameters, the other parameters and steps were the same as in Example 15: 30 g of the sample obtained in Example 6 was thermally decomposed in a microwave pyrolysis reactor with 50 g of HDPE, 50 g of PP, and 50 g of LLDPE at an output of 1500 W for 10 minutes, and the resulting gas was subjected to chromatographic analysis. The main components detected are shown in Table 2-1.

[0112] 30 g of the sample obtained in Example 6 was used to thermally decompose 50 g of PET in a microwave pyrolysis reactor at an output of 1500 W for 20 minutes, and the resulting gas was then subjected to chromatographic analysis. The main components detected are shown in Table 2-2.

[0113] Using 30 g of the sample obtained in Example 6, 3 g of PS was thermally decomposed in a microwave pyrolysis reactor at an output of 1500 W for 40 minutes, and the resulting gas was subjected to chromatographic analysis. The main components detected are shown in Table 2-3.

[0114] 30 g of the sample obtained in Example 6 was used to thermally decompose 50 g of disposable transparent plastic cup (PS) fragments in a microwave pyrolysis reactor at an output of 1500 W for 15 minutes, and the resulting gas was then subjected to chromatographic analysis. The main components detected are shown in Table 2-4.

[0115] 30 g of the sample obtained in Example 6 was used to thermally decompose 50 g of a PVC hose fragment using a microwave pyrolysis reactor at an output of 1500 W for 15 minutes, and the resulting gas was then subjected to chromatographic analysis. The main components detected are shown in Table 2-5.

[0116] [Table 2-1]

[0117] [Table 2-2]

[0118] [Table 2-3]

[0119] [Table 2-4]

[0120] [Table 2-5]

[0121] [Comparative Example 3] (1) Weigh 50 g of liquid phenol resin (2152, Jining Baiyi Chemicals), place it in a beaker, pour in 500 ml of ethanol, and stir with a magnetic stirrer for 1 hour to dissolve it; (2) 8 g of a fibrous plate-like porous skeleton made of alumina (average pore size 100 nm, Pu-Yuan Nanotechnology Limited Company, Hefei, China) was immersed in the formulation solution so that the solution would sufficiently penetrate the pore channels of the porous skeleton; (3) The immersed porous material was removed and placed on a stainless steel tray, which was then placed in a furnace at 180°C and heated for 2 hours to remove the solvent and cure the phenolic resin; (4) The dried and hardened porous material was placed in a tubular furnace and carbonized at 900°C for 1 hour in a nitrogen atmosphere to carbonize the phenolic resin.

[0122] A 0.5g fragment of a beverage bottle cap (HDPE) was placed on 1g of the material obtained in step (4), and then, after being protected with nitrogen, it was subjected to high-power microwave treatment in a household microwave oven (700W) for 30 seconds. No sparks were observed during the microwave treatment, and the HDPE bottle cap remained unchanged after the microwave treatment. It was found that when the pore size of the inorganic porous framework is small, a porous composite material capable of generating an electric arc in the microwave field to achieve effective thermal decomposition could not be obtained.

[0123] <Microwave thermal decomposition of vegetable oil>: [Example 19] 0.5g each of palm oil, rapeseed oil, sunflower oil, and soybean oil were placed on 1g of the porous composite material obtained in Example 1. The oils were automatically absorbed by the porous composite material, protected with nitrogen, and then subjected to high-power microwave thermal decomposition for 30 seconds in a household microwave oven (700w) (or thermal decomposition for 30 minutes at 700W using a microwave thermal decomposition reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.)). After weighing, it was confirmed that there was almost no material residue in the porous composite material. When the porous composite material obtained in Example 1 was treated with microwaves (700w) for a short time of 30 seconds, all the materials were thermally decomposed and gasified, and a violent arc discharge phenomenon was observed. The porous composite material generated an electric arc in the microwave field, which rapidly generated high temperatures, transferred heat to the material, and rapidly thermally decomposed the material. The gas obtained after thermal decomposition was subjected to chromatographic analysis, and the main components detected are shown in Table 3-1.

[0124] [Table 3-1]

[0125] [Example 20] Palm oil, rapeseed oil, sunflower oil, and soybean oil were each placed in 100g beakers. 30g of the porous composite material obtained in Example 1 was placed in a quartz reactor purged with 500ml / min of nitrogen for 10 minutes. After adjusting the flow rate to 100ml / min, a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atopio Industrial Co., Ltd.) was started at an output of 1500W. The above vegetable oils were continuously added to the surface of the porous composite material inside the quartz reactor at a rate of approximately 2g / min through a quartz capillary using a peristaltic pump (LongerPump BT100-2J precision peristaltic pump), and the material was continuously pyrolyzed into the gas. After the operation was completed, almost no material remained.

[0126] When experiments similar to the above process were performed using the porous composite materials obtained in Examples 2 to 14, similar experimental phenomena and results were obtained.

[0127] [Comparative Example 4] 0.5 g of palm oil was dropped onto 1 g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.), and after nitrogen protection, it was subjected to high-power microwave treatment in a household microwave oven (700 W) for 30 seconds. No sparks were observed during microwave treatment, and only the bottom of the quartz crucible became slightly warm. After microwave treatment, gravimetric measurements showed that the mass of the palm oil had not significantly changed.

[0128] [Example 21] Except for the following parameters, the other parameters and steps were the same as in Example 19: 30 g of the sample obtained in Example 6 was used to pyrolyze 100 g each of palm oil, rapeseed oil, sunflower oil, and soybean oil at a supply rate of 2 g / min using a microwave pyrolysis reactor with an output of 1500 W. The resulting gases were analyzed by chromatography. The main components detected are shown in Table 3-2.

[0129] [Table 3-2]

[0130] <Microwave thermal decomposition of biomass> [Example 22] 1 g of the porous composite material obtained in Example 1 was placed on top of 0.5 g each of straw, bagasse, tree branches, leaves, wood chips, rice husks, rice straw, peanut shells, coconut shells, coconut husks, and corn cobs. After protecting with nitrogen, the materials were thermally decomposed using high-power microwaves in a household microwave oven (700 W) for 30 seconds. When the porous composite material obtained in Example 1 was subjected to short-time microwave treatment of 30 seconds in a household microwave oven (700 W), all the materials were thermally decomposed and gasified, leaving only a black substance. A vigorous arc discharge phenomenon was observed during this process. The porous composite material generated an electric arc in the microwave, which rapidly generated a high temperature, transferring heat to the material and rapidly thermally decomposing it.

[0131] 50g each of straw, bagasse, twigs, leaves, wood chips, rice husks, rice straw, peanut shells, coconut shells, coconut seed husks, corn husks, and corn cobs were placed in cavities composed of 30g of the porous composite material obtained in Example 1. After being protected with nitrogen, they were treated for 5 minutes at 1500W using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.). For all materials, only a black substance remained.

[0132] The placement of the material to be pyrolyzed into the cavity, which is composed of porous composite material, was carried out in the following manner: First, a portion of the porous composite material was placed at the bottom and around the quartz reactor to form a cavity with an upper opening. Next, the material was placed inside the cavity. Finally, the top of the material was covered with the remaining porous composite material.

[0133] Using the samples obtained in Examples 2 to 14, the same experiments as described above were carried out, and similar experimental phenomena and results were obtained.

[0134] [Comparative Example 5] 0.5g of rice husks was placed on 1g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.), protected with nitrogen, and then subjected to high-power microwave treatment in a household microwave oven (700W) for 30 seconds. No sparks occurred during the microwave process. After microwave treatment, the rice husks remained unchanged, and only the bottom of the quartz crucible was slightly warmed.

[0135] [Example 23] Except for the following parameters, the other parameters and steps were the same as those in Example 22: One g of the sample obtained in Example 1 was used to thermally decompose 0.5 g each of straw and rice husks using a household microwave oven (700 W) at high power for 30 seconds. Next, the resulting gases were subjected to chromatographic analysis. The main components detected other than CO and CO2 are shown in Table 4-1.

[0136] 30 g of the sample obtained in Example 6 was used to pyrolyze 50 g of straw and rice husks using a microwave pyrolysis reactor with an output of 1500 W for 15 minutes. Next, the resulting gases were subjected to chromatographic analysis. The main components detected other than CO and CO2 are shown in Table 4-2.

[0137] [Table 4-1]

[0138] [Table 4-2]

[0139] <Thermal decomposition of waste rubber by microwaves> [Example 24] 1 g of the porous composite material obtained in Example 1 was placed on top of 0.5 g each of samples: a fragment of an automobile tire (Hankook), styrene-butadiene rubber (Beijing Rubber Products Factory), and ethylene-propylene rubber (Beijing Rubber Products Factory). After being protected with nitrogen, the materials were thermally decomposed using high-power microwaves in a household microwave oven (700 W) for 30 seconds. Using the porous composite material obtained in Example 1, after short-time microwave treatment for 30 seconds in a household microwave oven (700 W), all materials were thermally decomposed and gasified; for the automobile tire fragment, only a black substance crushed into one pinch remained; and for the styrene-butadiene rubber and ethylene-propylene rubber samples, no residue remained. A vigorous arc discharge phenomenon was observed during this process. The porous composite material generated an electric arc in the microwave, which rapidly generated high temperatures, transferring heat to the material and rapidly thermally decomposing it.

[0140] In Example 1, 50 g each of samples were placed in a cavity consisting of 30 g of porous composite material, which had been arc-generated in a microwave. These samples included a fragment of an automobile tire (Hankook), styrene-butadiene rubber (Beijing Rubber Products Factory), and ethylene-propylene rubber (Beijing Rubber Products Factory). After nitrogen protection, the samples were treated for 5 minutes at 1500 W using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co, Ltd.). In contrast, all materials were pyrolyzed and gasified after being treated with microwaves for a short period of 30 seconds using a household microwave oven (700 W). For the automobile tire fragment, only a black substance crushed into one pinch remained; for the styrene-butadiene rubber and ethylene-propylene rubber samples, no residue remained.

[0141] The placement of the material to be pyrolyzed into the cavity, which is composed of porous composite material, was carried out in the following manner: first, a portion of the porous composite material was placed at the bottom and around the quartz reactor to form a cavity with an upper opening; then, the material was placed inside the cavity; and finally, the top of the material was covered with the remaining porous composite material.

[0142] When experiments similar to the above process were performed using the porous composite materials obtained in Examples 2 to 14, similar experimental phenomena and results were obtained.

[0143] [Comparative Example 6] A 0.5 g sample of styrene-butadiene rubber was placed on 1 g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.), protected with nitrogen, and then treated with high-power microwaves in a household microwave oven (700 W) for 30 seconds. No sparks were observed during the microwave treatment process. After microwave treatment, the styrene-butadiene rubber sample remained unchanged, and only the bottom of the quartz crucible was slightly warmed.

[0144] [Example 25] 0.5 g each of samples of automobile tire (Hankook) fragments, styrene-butadiene rubber (Beijing Rubber Products Factory), and ethylene-propylene rubber (Beijing Rubber Products Factory) were placed on 1 g of the porous composite material obtained in Example 1. After nitrogen protection, the materials were thermally decomposed by high-power microwaves in a household microwave oven (700 w) for 30 seconds, and chromatographic analysis was performed. The main components other than CO and CO2 are shown in Tables 5-1, 5-2, and 5-3.

[0145] Using the same procedure as described above, 30 g of the sample obtained in Example 6 was used to thermally decompose 50 g each of samples of automobile tire (Hankook), styrene-butadiene rubber (Beijing Rubber Products Factory), and ethylene-propylene rubber (Beijing Rubber Products Factory) in a microwave pyrolysis reactor at an output of 1500 W for 15 minutes. The resulting gases were subjected to chromatographic analysis. The main components other than CO and CO2 are shown in Tables 5-4, 5-5, and 5-6.

[0146] [Table 5-1]

[0147] [Table 5-2]

[0148] [Table 5-3]

[0149] [Table 5-4]

[0150] [Table 5-5]

[0151] [Table 5-6]

[0152] <Microwave thermal decomposition of carbon fiber composite materials>: [Example 26] 1 g of the porous composite material obtained in Example 1 was placed on top of 2 g of carbon fiber reinforced epoxy resin composite material (Choshu Hanada Fiber Composite Materials Co., Ltd.), and thermal decomposition was performed for 40 seconds using high-power microwaves in a household microwave oven (700 W). When the carbon fiber composite material was removed and weighed, weight loss was observed, and the carbon fibers could be easily peeled off. Active arc discharge phenomena were observed during microwave treatment. The porous composite material generated an electric arc in the microwave, which rapidly generated a high temperature, transferring heat to the material and rapidly thermally decomposing it.

[0153] In Example 1, 50 g of carbon fiber reinforced epoxy resin composite material (Changzhou Huada Fiber Composite Material Co., Ltd.) was placed in a cavity consisting of 30 g of porous composite material that generates an arc in microwaves. After nitrogen protection, the material was treated for 5 minutes at 1500 W of electricity using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co., Ltd.). When the carbon fiber composite material was removed and weighed, weight loss was observed, and the carbon fibers could be easily peeled off the nonwoven fabric.

[0154] The placement of the material to be pyrolyzed into a cavity made of porous composite material that generates an electric arc in microwaves was specifically carried out as follows: First, a portion of the porous composite material that has generated an electric arc in microwaves was placed at the bottom and around the quartz reactor to form a cavity with an upper opening. Next, the material was placed inside the cavity. Finally, the top of the material was covered with the remaining porous composite material.

[0155] Using the samples obtained in Examples 2-14, experiments similar to those described above were conducted, and similar experimental phenomena and results were obtained. All porous composite materials obtained in Examples 2-14 were able to generate an electric arc in microwaves, thereby rapidly generating high temperatures, transferring them to the material, and rapidly thermally decomposing the material.

[0156] [Comparative Example 7] 1 g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.) was placed on top of 2 g of carbon fiber reinforced epoxy resin composite material (Changzhou Huatan Fiber Composite Co., Ltd.). After nitrogen protection, it was subjected to high-power microwave treatment in a household microwave oven (700 W) for 30 seconds. No sparks occurred during the microwave treatment process. After microwave treatment, the material remained unchanged, and only the bottom of the quartz crucible was slightly warmed.

[0157] [Example 27] In Example 1, 1 g of porous composite material was prepared by generating an arc with microwaves. 2 g of carbon fiber reinforced epoxy resin composite material (Choshu Hanada Fiber Composite Materials Co., Ltd.) was placed on top of this composite material, and thermal decomposition was performed for 40 seconds using high-power microwaves in a household microwave oven (700 watts). After that, the carbon fiber composite material was removed. After weighing, a weight loss of 36% was observed, and the carbon fibers could be easily peeled off the nonwoven fabric. The collected gas was subjected to chromatographic analysis, and the main components detected are shown in Table 6.

[0158] In Example 6, 30 g of carbon fiber reinforced polypropylene composite material (Changzhou Huada Fiber Composite Material Co., Ltd.) was placed in a cavity consisting of 30 g of porous composite material obtained by generating an arc in microwaves. After nitrogen protection, the material was treated for 5 minutes at an output of 1500 W using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Atpio Instrument Manufacturing Co., Ltd.). After weighing, a weight loss of 38% was observed, and the carbon fibers could be easily peeled off the nonwoven fabric. The collected gas was subjected to chromatographic analysis, and the main components detected are shown in Table 6.

[0159] In Example 7, 50 g of carbon fiber reinforced nylon composite material (Changzhou Huada Fiber Composite Material Co., Ltd.) was placed in a cavity consisting of 30 g of porous composite material that generates an arc in microwaves. After nitrogen protection, the material was treated for 10 minutes at an output of 2000 W using a microwave pyrolysis reactor (XOLJ-2000N, Nanjing Thermal Equipment Manufacturing Co., Ltd.). After weighing, a 39% weight reduction was observed, and the carbon fibers could be easily peeled off the nonwoven fabric. The collected gas was subjected to chromatographic analysis, and the main components detected are shown in Table 6.

[0160] The placement of the material into the cavity, which is composed of a porous composite material that generates an electric arc using microwaves, was performed as follows: First, a portion of the porous composite material that generates an electric arc using microwaves was placed at the bottom and around the quartz reactor to form a cavity with an upper opening. Next, the material was placed inside the cavity. Finally, the top of the material was covered with the remaining porous composite material.

[0161] [Table 6]

[0162] <Microwave thermal decomposition of circuit boards>: In the following examples, the collected gases were chromatographically analyzed as follows: The gas products collected after pyrolysis were analyzed using a purified gas analyzer (HP Agilent 7890 A, consisting of three channels including one FID and two TCDs (thermal conductivity detectors)) according to the ASTM D1945-14 method. Hydrocarbons were analyzed on the FID channel. Hydrogen content was determined using one TCD with nitrogen as the carrier gas because there was a slight difference in conductivity between the hydrogen and helium carrier gases. Other TCDs using helium as the carrier gas were used for the detection of CO, CO2, N2, and O2. For quantitative analysis, the response coefficient was determined by using RGA (Purified Gas Analysis) calibration gas standards.

[0163] [Example 28] A cavity made of 50g of the porous composite material obtained in Example 1 contains a waste circuit board (the waste circuit board has an area of ​​approximately 1cm²). 2 The circuit board was pre-crushed into irregular pieces; 10g of (brand name, gigabytes) was taken from a discarded computer motherboard and placed in a microwave pyrolysis reactor (Qingdao Makewave Instrument Manufacturing Co., Ltd., model MKX-R1C1B). The reactor was protected with nitrogen and treated in the microwave pyrolysis reactor at a power of 900W for 5 minutes. The porous composite material was subjected to a microwave to generate an electric arc, which rapidly generated high temperatures that were transferred to the material, causing rapid thermal decomposition. The recovered gaseous components were subjected to gas chromatography analysis.

[0164] Table 7-1 shows the main components of the pyrolysis gas products. The mass of the solid residue after the reaction was 30% of the mass before pyrolysis, including metal components with a loose structure that were easily separated, and non-metallic components mainly consisting of glass fiber mixtures. After simple grinding, the metal and non-metallic components (mainly glass fibers) could be separated and recovered.

[0165] The placement of the thermally decomposed circuit boards into the cavity made of porous composite material was carried out as follows: First, a portion of the porous composite material was placed inside the quartz reactor, and then the porous composite material was arranged sequentially to form a hollow cavity with an opening at the top. Then, the waste circuit boards were placed inside the cavity. Finally, the top of the material was covered with the remaining porous composite material.

[0166] Using the samples obtained in Examples 2-14, experiments similar to the above procedure were conducted, and similar experimental phenomena and results were obtained. The mass of the solid residue after the reaction was approximately 28-35% of the mass before thermal decomposition. All porous composite materials obtained in Examples 2-14 were able to generate an electric arc in a microwave field, thereby rapidly generating high temperatures, which were then transferred to the material, causing rapid thermal decomposition of the material.

[0167] [Comparative Example 8] 10g of waste circuit board and 50g of silicon carbide powder (98.5%, Sinopharm Chemical Reagent Beijing Co., Ltd.) were uniformly mixed and placed in a quartz reaction vessel. This mixture was then placed in a microwave reactor (MKX-R1C1B, Qingdao Makewave Instrument Manufacturing Co., Ltd.), protected with nitrogen, and treated in the microwave pyrolysis reactor at 900W for 5 minutes. No sparks were observed during the microwave treatment, the waste circuit board remained unchanged after the treatment, and only the bottom of the quartz reaction tank was slightly warmed.

[0168] [Example 29] Except for the following parameters, the other parameters and steps were the same as in Example 28: 30 g of the multilayer composite material obtained from the waste circuit board 10 and Example 6, which had been subjected to an electric arc in microwaves, was uniformly mixed and placed in a quartz reaction vessel. The entire mixture was then placed in a microwave pyrolysis reactor, protected with nitrogen, and treated in the microwave pyrolysis reactor at an output of 1,200 W for 10 minutes. The porous composite material was subjected to a rapid thermal decomposition by generating a high temperature through an electric arc in microwaves, which was then transferred to the material. The recovered gas components were subjected to gas chromatography analysis. The main components of the pyrolysis gas products are shown in Table 7-2. The mass of the solid residue after the reaction was 32% of the mass before pyrolysis. Furthermore, the metal and the substrate had a loose structure, and the metal and non-metal components could be separated and recovered by simple grinding.

[0169] [Example 30] Except for the following parameters, the other parameters and steps were the same as in Example 28: In Example 2, 15 g of porous composite material obtained by generating an arc in microwaves and 10 g of waste circuit board were uniformly mixed and placed in a quartz reaction vessel. The entire mixture was then placed in a microwave pyrolysis reactor, protected with nitrogen, and treated in the microwave pyrolysis reactor at an output of 900 W for 20 minutes. The porous composite material was rapidly heated by generating an electric arc in microwaves, which transferred to the material and rapidly pyrolyzed it. The recovered gas components were subjected to gas chromatography analysis. The main components of the pyrolysis gas products are shown in Table 7-3. The mass of the solid residue after the reaction was 30% of the mass before pyrolysis. Furthermore, the metal and the substrate had a loose structure, and the metal and non-metal parts could be separated and recovered by simple grinding.

[0170] [Example 31] Except for the following parameters, the other parameters and steps were the same as in Example 28: In Example 11, 60 g of porous composite material obtained by generating an arc in microwaves and 2 g of waste circuit board were uniformly mixed and placed in a quartz reaction vessel. The entire mixture was then placed in a microwave pyrolysis reactor, and after nitrogen protection, it was treated in the microwave pyrolysis reactor at an output of 900 W for 5 minutes. The porous composite material was rapidly heated by generating an electric arc in microwaves, which transferred to the material and rapidly pyrolyzed it. The recovered gas components were subjected to gas chromatography analysis. The main components of the pyrolysis gas products are shown in Table 7-4. The mass of the solid residue after the reaction was 30% of the mass before pyrolysis. Furthermore, the metal and the substrate had a loose structure, and the metal and non-metal parts could be separated and recovered by simple grinding.

[0171] [Example 32] Except for the following parameters, the other parameters and steps were the same as in Example 28: In Example 8, 5 g of multilayer composite material in an electric arc generated by microwaves and 20 g of waste circuit board were uniformly mixed and placed in a quartz reaction vessel. The entire mixture was then placed in a microwave pyrolysis reactor, protected with nitrogen, and treated in the microwave pyrolysis reactor at an output of 1000 W for 30 minutes. The porous composite material was rapidly decomposed by generating a high temperature in a microwave electric arc, which was then transferred to the material. The recovered gas components were subjected to gas chromatography analysis. The main components of the pyrolysis gas products are shown in Table 7-5. The mass of the solid residue after the reaction was 31% of the mass before pyrolysis. Furthermore, the metal and the substrate had a loose structure, and the metal and non-metal parts could be separated and recovered by simple grinding.

[0172] [Table 7-1]

[0173] [Table 7-2]

[0174] [Table 7-3]

[0175] [Table 7-4]

[0176] [Table 7-5]

[0177] The data in the table also shows that the pyrolysis products contain a relatively high proportion of hydrogen, and therefore, they can be collected and used as fuel.

Claims

1. A porous composite material comprising an inorganic porous framework and a carbon material supported on the inorganic porous framework, which can generate an arc in a microwave field, The average pore size of the inorganic porous framework is 0.2 to 1000 μm. The aforementioned inorganic porous skeleton is an inorganic material having a porous structure. The inorganic porous skeleton is at least one selected from the group consisting of a carbon skeleton after carbonization of a melamine sponge, a carbon skeleton after carbonization of a phenolic resin sponge, a porous skeleton composed of inorganic fibers, and a ceramic fiber skeleton obtained after firing a ceramic fiber skeleton precursor. The porous skeleton composed of the inorganic fibers is selected from a porous skeleton of aluminum silicate fibers, a porous skeleton of mullite fibers, a porous skeleton of alumina fibers, a porous skeleton of zirconia fibers, a porous skeleton of magnesium oxide fibers, a porous skeleton of boron nitride fibers, a porous skeleton of boron carbide fibers, a porous skeleton of silicon carbide fibers, and a porous skeleton of potassium titanate fibers. The carbon material supported on the inorganic porous framework is selected from the group consisting of graphene, carbon nanotubes, graphite, carbon black, carbon fibers, carbon dots, carbon nanowires, carburable organic matter, or products obtained by carbonizing a mixture containing carburable organic matter, and combinations thereof. Porous composite material.

2. The average pore size of the inorganic porous framework is 0.2 to 500 μm, and / or The porosity of the inorganic porous framework is 1% to 99.99%. The porous composite material according to feature 1.

3. The proportion of the carbon material is 0.001% to 99% of the total mass of the porous composite material. A porous composite material according to claim 1 or 2, characterized by the above.

4. The porous composite material, by an electric arc generated in a microwave field, reaches a temperature exceeding 1000°C. A porous composite material according to any one of claims 1 to 3.

5. The carbon material is selected from the group consisting of graphene, carbon nanofibers, carbon nanotubes, carbable organic matter, or products obtained by carbonizing a mixture containing carbable organic matter, and combinations thereof. A porous composite material according to any one of claims 1 to 4.

6. The carbonizable organic material is selected from synthetic organic polymer compounds and natural organic polymer compounds. The porous composite material according to feature 1.

7. The aforementioned synthetic organic polymer compound is rubber or plastic. The aforementioned plastics include thermosetting plastics and thermoplastics. The aforementioned natural organic polymer compound is at least one selected from the group consisting of starch, viscose fiber, lignin, and cellulose. The porous composite material according to feature 6.

8. The synthetic organic polymer compound is selected from the group consisting of epoxy resins, phenolic resins, furan resins, polystyrene, styrene-divinylbenzene copolymers, polyacrylonitrile, polyaniline, polypyrrole, polythiophene, styrene-butadiene rubber, polyurethane rubber, and combinations thereof. The porous composite material according to feature 7.

9. The mixture containing the carbonizable organic matter is a mixture of a carbonizable organic substance and other metal-free organic substances and / or metal-free inorganic substances. The porous composite material according to feature 1.

10. The mixture containing carbonizable organic matter is selected from the group consisting of coal, natural pitch, petroleum pitch or coal tar pitch and combinations thereof. The porous composite material according to feature 9.

11. A method for preparing a porous composite material according to any one of claims 1 to 10, Step (1): Immerse an inorganic porous skeleton or inorganic porous skeleton precursor in a solution or dispersion of a carbon material and / or carbon material precursor to fill the pores of the inorganic porous skeleton or inorganic porous skeleton precursor with the solution or dispersion; Step (2): A step of heating and drying the porous material obtained in step (1) to precipitate or solidify and support a carbon material or carbon material precursor on the inorganic porous framework or inorganic porous framework precursor; Step (3): When at least one of a carbon material precursor or an inorganic porous skeleton precursor is used as a starting material, the porous material obtained in step (2) is heated in an inert gas atmosphere to convert the inorganic porous skeleton precursor into an inorganic porous skeleton and / or reduce or carbonize the carbon material precursor; including, A preparation method characterized by the above.

12. The solution or dispersion of the carbon material or carbon material precursor in step (1) comprises a solvent selected from the group consisting of benzene, toluene, xylene, trichlorobenzene, chloroform, cyclohexane, ethyl caproate, butyl acetate, carbon disulfide, ketone, acetone, cyclohexanone, tetrahydrofuran, dimethylformamide, water, and alcohol, as well as combinations thereof. and / or, The concentration of the solution or dispersion in step (1) is 0.001 to 1 g / mL; and / or, In step (1), the carbon material and / or carbon precursor material is contained in an amount of 0.001% to 99.999% of the total mass of the inorganic porous framework material or inorganic porous framework material precursor and the carbon material and / or carbon material precursor combined. The preparation method according to feature 11.

13. The solvent in the solution or dispersion of the carbon material or carbon material precursor in step (1) is water and / or ethanol. The preparation method according to feature 12.

14. In step (2), heating and drying are carried out at 50 to 250°C. The preparation method according to any one of claims 11 to 13.

15. In step (2), heating and drying are carried out by microwave heating. The output power of the microwave is 1W to 100KW. The heating time using microwaves is 2 to 200 minutes. The preparation method according to feature 14.

16. The inorganic porous skeleton precursor is selected from the group consisting of ceramic precursors, melamine sponges, phenolic resin sponges, and / or combinations thereof. The carbon material precursor is selected from the group consisting of graphene oxide, modified carbon nanotubes, modified carbon nanofibers, modified graphite, modified carbon black, modified carbon fibers, a mixture containing carbogenic organic matter or carbogenic organic matter, and / or, The heating in step (3) above is carried out at a temperature of 400 to 1800°C. The preparation method according to any one of claims 11 to 15.

17. The heating in step (3) is microwave heating, The output power of the microwave is 100W to 100KW. The heating time using microwaves is 0.5 to 200 minutes. The preparation method according to feature 16.

18. Use of a porous composite material according to any one of claims 1 to 10 in the thermal decomposition and reuse of materials containing organic compounds.

19. A method for thermally decomposing and / or recycling materials containing organic compounds, The organic compound-containing material is brought into contact with the porous composite material according to any one of claims 1 to 10. In an inert atmosphere or under vacuum, a microwave field is applied to the organic compound-containing material and the porous composite material, causing the porous composite material to generate an electric arc in the microwave field, rapidly reaching a high temperature, and thermally decomposing the organic compound contained in the organic compound-containing material. A method for thermally decomposing and / or recycling an organic compound-containing material, characterized by the above.

20. The aforementioned organic compound-containing material is an organic substance, a mixture containing an organic substance, or a composite material containing an organic substance. A method for thermally decomposing and / or recycling an organic compound-containing material according to claim 19.

21. The method according to 19, characterized in that the organic compound-containing material is selected from the group consisting of (i) to (vi); (i) Waste plastic; (ii) Waste rubber; (iii) Biomass; (iv) vegetable oil; (v) Carbon fiber composite materials containing a polymer matrix selected from the group consisting of polyethylene, polypropylene, nylon, phenolic resins, and epoxy resins; And, (vi) Circuit board.

22. The weight ratio of the organic compound-containing material to the porous composite material is 1:99 to 99:1; and / or, The microwave output of the microwave field is 1W to 100KW; and / or, The microwave irradiation time is 0.1 to 200 minutes. The method according to claim 19.

23. The aforementioned organic compound-containing material is a carbon fiber composite material. After thermally decomposing the polymer matrix in the carbon fiber composite material, the remaining carbon fibers are recycled. The method according to claim 19.

24. The aforementioned organic compound-containing material is a circuit board, The solid residue obtained by thermally decomposing the circuit board is processed to separate the metallic and non-metallic components for recycling, and / or, The gas products obtained by thermally decomposing the circuit board are collected. The method according to claim 19.

25. Hydrogen contained in the pyrolysis products is collected. The method according to claim 24.

Images