CN115123999A - Method for producing hydrogen by carbon-containing solid - Google Patents

Abstract

The invention belongs to the technical field of energy regeneration, and specifically discloses a method for producing hydrogen from carbon-containing solids. The method uses carbon-containing solids as raw materials, and includes two stages of microwave catalytic treatment which are carried out continuously. The high-efficiency and low-carbon hydrogen production method based on microwave technology provided by the present invention can realize high-selectivity, high-efficiency and complete dehydrogenation treatment through the interaction of catalyst and microwave, and realize the preparation of high-purity hydrogen from carbon-containing solids, It does not produce harmful substances and has low emissions. It is a green and low-carbon hydrogen production method.

Description

A kind of method for producing hydrogen from carbonaceous solid

technical field

The invention belongs to the field of energy regeneration, and in particular relates to a method for producing hydrogen by using carbon-containing solids as raw materials.

Background technique

For the future demand for hydrogen energy, scientists have been looking for hydrogen storage materials with high hydrogen content and stability. Carbonaceous solid is a solid raw material rich in hydrogen, including but not limited to polyolefin plastics, biomass, artificial organic polymers, biochar, coal, pitch, coke, paraffin, chemical fibers, tires, medical waste items, household waste, etc. The selective extraction of hydrogen from carbonaceous solids is a great challenge.

For example, polypropylene plastic is a kind of plastic waste that is difficult to degrade and has a high abandonment rate. At present, the treatment methods of polypropylene plastics are incineration or landfill, which are both high-emission and high-polluting treatment methods. Therefore, environmentally friendly and efficient innovative process methods are urgently needed to deal with polypropylene plastics. For the method of hydrogen production from polypropylene plastic, researchers have developed a multi-step reaction process of reforming and thermal cracking-reforming, but both reforming and thermal cracking require higher reaction temperatures, and the hydrogen produced is mostly A synthesizer of hydrogen and carbon monoxide; and produces significant carbon dioxide emissions.

For another example, the current treatment of urban domestic waste mainly focuses on the treatment of harmless and reduced quantities. The most common domestic waste disposal method in my country is the sanitary landfill method. However, most of these domestic wastes have not been classified or harmless, and are often mixed with toxic substances and other recyclable substances. These wastes are directly landfilled without treatment, which will not only cause serious secondary pollution, but also cause waste of some available resources. Economic losses.

Although biomass waste has the characteristics of being environmentally friendly, its degradation takes time, and its disposal will have an impact on the environment and cause waste of biomass resources. How to utilize these waste resources is an urgent problem to be solved. At present, the methods of biomass treatment mainly include chemical conversion-based methods such as gasification method and pyrolysis reforming method. In addition, hydrogen production from biomass waste can also be achieved by biological methods such as photo-splitting water for hydrogen production, photo-fermentation for hydrogen production, dark fermentation for hydrogen production, and light-dark coupled fermentation for hydrogen production. However, due to the complexity of the biomass structure, hydrogen production from biomass usually requires a multi-step complex reaction path, and then the intermediate product is reformed to produce hydrogen. With the development of microwave pyrolysis technology in recent years, researchers have developed a technology to treat biomass waste using microwave pyrolysis technology, and also proved that compared with traditional pyrolysis technology, microwave pyrolysis has a fast and high hydrogen yield. Features. However, the simple microwave pyrolysis treatment will produce a large amount of biomass oil and the by-products are widely distributed, which greatly reduces the hydrogen yield and is difficult to utilize.

Therefore, there is an urgent need to develop a high-yield method for producing hydrogen from carbonaceous solids while avoiding a large amount of carbon dioxide emissions.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the defects of the prior art and provide a method for producing hydrogen from carbonaceous solids by microwave catalytic dehydrogenation. The method is based on microwave catalytic dehydrogenation technology, and high-purity hydrogen is prepared from the decomposition of carbon-containing solids, and no carbon dioxide emission or other harmful substances are emitted during the process, thereby providing a green hydrogen production method and a clean method for treating carbon-containing solids.

Specifically, the present invention provides a method for producing hydrogen from a carbon-containing solid. The method uses the carbon-containing solid as a raw material and includes two-stage microwave catalytic treatment, wherein:

The first stage of microwave catalysis is to perform a microwave treatment on the carbon-containing solid raw material under the action of catalyst A to generate mixed gas;

The second stage of microwave catalysis is to perform secondary microwave treatment on the mixed gas obtained by the first stage of microwave catalysis under the action of catalyst B to generate hydrogen-containing gas;

The catalyst A and/or the catalyst B are selected from carbon materials, transition metal materials and transition metal materials supported by carbon materials; the catalyst A and the catalyst B have the same or different compositions.

In some embodiments, the carbon material is selected from carbon black, activated carbon, and silicon carbide.

In some embodiments, the transition metal material includes at least one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, and tungsten-based metal materials.

In some preferred embodiments, the transition metal material is selected from iron-nickel-based metal materials, molybdenum-based compounds or chromium-based compounds.

Wherein, the iron-nickel-based metal material is selected from one or more of metallic iron, ferrous oxide, iron oxide, iron carbide, iron tetroxide, metallic nickel, nickel oxide, iron-nickel alloy and mixed iron-nickel oxide kind. The molybdenum-based compound is selected from molybdenum oxide or molybdenum carbide. The chromium-based compound is selected from chromium oxide compounds or chromium carbides.

In some embodiments, the catalyst A is an iron-nickel-based metal material or an iron-nickel-based metal material supported by a carbon material.

Preferably, the catalyst A is metal iron, iron oxide, iron-nickel alloy or metal iron, iron oxide or iron-nickel alloy supported by carbon material.

In some embodiments, the catalyst B is a carbon material, an iron-nickel-based metal material, or an iron-nickel-based metal material supported by a carbon material.

Preferably, the catalyst B is carbon material, metallic iron, iron oxide, iron-nickel alloy or metallic iron, iron oxide or iron-nickel alloy supported by carbon material.

In some embodiments, the carbon-containing solids include polyolefin plastics, biomass, man-made organic polymers, biochar, coal, pitch, coke, paraffin, chemical fibers, tires, medical waste, and domestic waste. at least one.

In some preferred embodiments, the carbonaceous solids are selected from polypropylene plastics, household waste and biomass.

Wherein, the domestic garbage includes humus, metal articles, plastic articles, paper articles, glass, leather products, cloth articles, slag and wood articles, preferably the content of humus is in the range of 5-50wt%, and the content of metal articles is in the range of 0-10wt%, plastic products content range is 5-50wt%, paper products content range is 0-30wt%, glass content range is 0-10wt%, leather products content range is 0-10wt%, cloth products content range is 0-10wt% It is 0-10 wt %, the content of lime-soil slag is 0-30 wt %, and the content of wood products is 0-30 wt %.

The biomass includes all plants, microorganisms, animals that take plants and microorganisms as food, and their wastes. Representative biomass includes crops, crop waste, wood, wood waste and animal manure. Biomass includes, but is not limited to: bioenergy crops, agricultural residues, sludge from the paper industry, yard waste, wood and forestry waste. Examples of biomass include, but are not limited to: corn kernels, corn cobs, crop residues such as straw, corn husks, corn fiber, grass, wheat, hay, rice straw, switchgrass, waste paper, bagasse, sorghum stalk, soybean husks or stalks , A component obtained from the grind of grains, trees, branches, roots, leaves, wood chips, sawdust, shrubs and underbrush, vegetables, fruits, flowers and ruminant manures.

Preferably, the biomass raw material is selected from straw, wood chips, fallen leaves, starch and paper scraps.

In some embodiments, the mass ratio of the carbon material as the carrier to the metal material supported thereon is (0.1-10):1, preferably (0.1-5):1.

In some embodiments, the mass ratio of the carbonaceous solid to the catalyst A in the method is (0.5-10):1.

In some embodiments, the mass ratio of catalyst A to catalyst B used is (1-5):(1-2).

In some embodiments, the power of the first stage of microwave catalytic treatment is 500-8000W, preferably 1000-6000W;

The power of 500-8000W is used in the second stage of microwave catalytic treatment, preferably the power is 1000-6000W, or the temperature of the second stage of microwave catalytic treatment is 600-1000°C.

In some embodiments, the frequency of the first stage and/or the second stage of microwave catalytic treatment is 0.3-3 GHz, preferably 2.45 GHz or 915 MHz.

In some embodiments, the time of the first stage of microwave catalytic treatment is 20-60 min, and/or the time of the second stage of microwave catalytic treatment is 20-60 min.

In some embodiments, the first-stage microwave catalytic treatment and the second-stage microwave catalytic treatment are performed in an inert environment with standard atmospheric pressure and an oxygen content of less than 5000 ppm.

In some embodiments, the method further includes: after the first stage of microwave catalysis and/or the second stage of microwave catalysis is completed, separating and purifying the product;

Preferably, the separation and purification includes gas scrubbing and/or pressure swing adsorption treatment.

In some embodiments, the method further includes the step of purging the mixture of carbonaceous solids and catalyst A in the microwave reactor under nitrogen conditions prior to the first stage of microwave catalysis.

Preferably, the purging is carried out under nitrogen conditions for 5 to 20 minutes.

The microwave catalysis used in the present invention, or called microwave-induced catalysis, is different from the so-called reaction accelerated by the microwave thermal effect. The microwave thermal effect usually does not involve a catalyst. induction. The present invention realizes the efficient preparation of hydrogen through the two-stage microwave catalytic treatment under the action of the catalyst.

The catalyst used in the present invention can be prepared by chemical preparation methods such as impregnation method, precipitation method, and combustion method known in the art. For transition metal materials supported by carbon materials or iron-based metal materials supported by carbon materials, metals can be mixed with the support materials in the form of precursors, including but not limited to nitrates, Chlorates, organometallic compounds, etc. In order to better ensure the effect of the catalyst to absorb microwaves, the particle size of the catalyst used in the present invention is less than 50 μm, and preferably the particle size of the catalyst is 50 nm˜10 μm.

The two-stage microwave catalytic treatment of the present invention can be carried out in a microwave reactor equipped with a conventional microwave source (including a magnetron or a solid-state source). In actual operation, when the first stage of microwave catalytic treatment is started, the catalyst B of the second stage of microwave catalytic treatment should be preheated.

In the present invention, in order to realize the characteristics of instantaneous heating and cooling of microwaves and improve the interaction between microwaves and catalysts, the furnace body of the reactor for microwave catalytic dehydrogenation (ie, the first stage of microwave catalytic treatment) is not equipped with wave-absorbing materials. In order to increase the efficiency of the microwave reactor, the microwave reactor used for the second stage of microwave catalytic treatment is equipped with silicon carbide material for absorbing waves on the periphery of the furnace body, and the maximum working temperature is 1100°C.

In the method provided by the invention, after the reaction is completed, the catalyst is cooled and collected, so as to realize the recycling of the catalyst.

Compared with the prior art, the method provided by the present invention is based on microwave catalysis technology, and the interaction between microwave and catalyst realizes in-situ heating of the catalyst and activates the active sites on the catalyst. Unlike the catalyst, the carbonaceous solid itself is completely penetrated by microwaves without heating. Therefore, the side reactions of the carbonaceous solid due to pyrolysis are minimized, so that the catalyst can selectively achieve carbon-hydrogen bond cleavage. produce hydrogen. It is found through a lot of practice in the present invention that a small amount of small molecular hydrocarbons mainly composed of methane, ethylene and propylene are mixed in the hydrogen produced by the primary microwave catalysis. In the process, a preheated dehydrogenation catalyst is used, and the hydrogen-rich gas is dehydrogenated again by utilizing the characteristics of instantaneous microwave heating, which effectively improves the yield and purity of hydrogen, and prepares high-purity hydrogen.

Description of drawings

Fig. 1 is the process flow diagram of the method provided by Embodiment 1-11 of the present invention;

Fig. 2 is the process flow diagram of the method provided by Embodiment 12-21 of the present invention;

FIG. 3 is a process flow diagram of the method provided in Embodiments 22-35 of the present invention.

Detailed ways

The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

The method provided by the present invention firstly performs rapid and selective catalytic dehydrogenation treatment on the raw material to be treated, such as polypropylene plastic polymer, through the interaction of microwave and catalyst A under the environment of standard atmospheric pressure and oxygen-free/poor oxygen, A mixed gas product containing hydrogen, etc. is generated; after the mixed gas product is collected by washing, it is passed into the fixed bed of catalyst B heated by microwave, and the mixed gas product is dehydrogenated and purified again to obtain high-purity hydrogen.

The present invention relates to the treatment of domestic garbage. Due to the high water content of the urban domestic garbage, the domestic garbage is first dried and pretreated, and then mixed with a catalyst for catalytic dehydrogenation treatment, which has a better effect. The domestic waste is selectively dehydrogenated through the interaction of microwaves and catalysts to produce a mixed gas of composite hydrogen (which contains small gas molecules such as hydrogen, hydrocarbons, carbon oxides, etc.). The mixed gas is subjected to secondary catalytic dehydrogenation to obtain crude hydrogen. After the crude hydrogen product is scrubbed, it is purified by pressure swing adsorption (PSA) method to obtain high-purity hydrogen. Specifically, the domestic garbage is dried and pulverized, mixed with catalyst A, and subjected to a catalytic dehydrogenation reaction on the garbage in a standard atmospheric pressure, oxygen-free/low-oxygen environment; the product gas obtained from the reaction is passed into the next stage of the microwave reactor. , Under standard atmospheric pressure and oxygen-free/low-oxygen environment, the mixed product is subjected to secondary dehydrogenation treatment through the interaction of microwave and catalyst B, and the small molecular hydrocarbons in the mixed gas are removed to obtain hydrogen-rich gas. Finally, the crude hydrogen product is purified by scrubbing and pressure swing adsorption to obtain high-purity hydrogen. The method provided by the invention realizes a low-cost, high-efficiency and low-carbon clean hydrogen production process method from domestic waste.

Example 1

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst supported by carbon black, wherein the mass ratio of metal iron, metal nickel and carbon is 3:1:1) are fully mixed physically and mechanically, Put into microwave reactor (1), carry out purging for 10 minutes under nitrogen conditions (100ml/min), and microwave reaction under the conditions of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; Collect gaseous products and take samples for analysis;

(2) get 20g catalyst B (same as catalyst A in step (1)) and load it in microwave reactor (2), set reaction temperature to be 800 ℃, start heating preheating from room temperature, and heating rate is 20 ℃/min, When the microwave reactor (1) is opened, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 800° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after washing. ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gas products obtained after the two-step microwave catalysis are shown in Table 1;

Table 1: Gas Product Analysis

In this embodiment, the iron-nickel metal catalyst supported by carbon black is prepared by the following method: fully mixing carbon black with iron nitrate and nickel nitrate in distilled water; calcining at 350° C. for 3 hours under an inert atmosphere of argon; calcining After completion, the catalyst was subjected to reduction treatment in a 5% H2/Ar environment, and the reduction treatment condition was 650°C for 6 hours. The black powder of the iron-nickel catalyst supported by carbon black was finally collected, and the mass ratio of metal iron, metal nickel and carbon in the catalyst finally obtained was 3:1:1.

Example 2

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst supported by carbon black, the mass ratio of iron, nickel and carbon is 3:1:1) are fully physically and mechanically mixed, and put into microwave reaction In the device (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; after gas cleaning, the gas products were collected , and sample analysis;

(2) get 10g catalyst B (activated carbon) and load it in microwave reactor (2), set reaction temperature to be 800 ℃, start heating preheating from room temperature, heating rate is 20 ℃/min, after opening microwave reactor (1) At the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 800° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after washing. ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gas products obtained after the two-step microwave catalysis are shown in Table 2;

Table 2: Gas Product Analysis

Example 3

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst supported by carbon black, the mass ratio of iron, nickel and carbon is 3:1:1) are fully physically and mechanically mixed, and put into microwave reaction In the device (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; after gas cleaning, the gas products were collected , and sample analysis;

(2) get 20g catalyst B (same as catalyst A in step (1)) and load it in microwave reactor (2), set reaction temperature to be 750 ℃, start warming up preheating from room temperature, and heating rate is 20 ℃/min, When the microwave reactor (1) is opened, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 750° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gaseous products obtained after the two-step microwave catalysis are shown in Table 3;

Table 3: Gas Product Analysis

Example 4

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron oxide catalyst supported by carbon black, wherein the mass ratio of iron and carbon is 4:1) are fully physically and mechanically mixed, and put into microwave reactor (1) In the process, purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; ;

(2) get 50g catalyst B (silicon carbide powder) and load it in the microwave reactor (2), set the reaction temperature to be 900 ° C, start heating and preheating from room temperature, the heating rate is 20 ° C/min, after opening the microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 900° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after washing. ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gaseous products obtained after the two-step microwave catalysis are shown in Table 4;

Table 4: Gas Product Analysis

In this embodiment, the iron oxide catalyst supported by carbon black is prepared by the following method: dissolving ferric nitrate in distilled water, and then mixing with carbon black powder to make a suspension; repeating and fully stirring the obtained suspension, placing The samples were dried in an oven, and the dried samples were ground to obtain powder. The obtained powder was calcined at 350° C. for 3 hours in an inert atmosphere of argon, and black powder was collected, which was an iron oxide catalyst supported by carbon black, wherein the mass ratio of iron and carbon was 4:1.

Example 5

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (metal iron catalyst supported by carbon black, the mass ratio of iron and carbon is 5:1) are fully physically and mechanically mixed, and put into microwave reactor (1) , carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction for 30 minutes under the conditions of power 2000W, frequency 2.45GHz, and generate mixed gas products; after gas cleaning, collect gas products, and sample analysis;

(2) get 20g of catalyst B (identical to catalyst A) and load it in microwave reactor (2), set reaction temperature to be 850 ° C, start heating and preheating from room temperature, and heating rate is 20 ° C/min, after opening the microwave reactor (1), the microwave reactor (2) is opened at the same time, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gas products obtained after the two-step microwave catalysis are shown in Table 5;

Table 5: Gas Product Analysis

The metallic iron catalyst supported by carbon black in this example was prepared by the following method: fully mixing carbon black and ferric nitrate in distilled water; calcining at 350°C for 3 hours under an inert atmosphere of argon; after calcining, The catalyst was subjected to reduction treatment in a 5% H2/Ar environment, and the reduction treatment temperature was 650°C for 6 hours. Finally, the black powder of the metal iron catalyst supported by carbon black was collected, and the mass ratio of iron and carbon was 5:1.

Example 6

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (metal iron catalyst supported by carbon black, the mass ratio of iron and carbon is 5:1) are fully physically and mechanically mixed, and put into microwave reactor (1) , carry out purging for 10 minutes under nitrogen conditions (100ml/min), and microwave reaction for 30 minutes under the conditions of power 4000W and frequency 2.45GHz to generate mixed gas products; after gas cleaning, collect gas products, and sample and analyze;

(2) get 10g catalyst B (carbon black powder) and load it in microwave reactor (2), set reaction temperature to be 850 ℃, start heating preheating from room temperature, and heating rate is 20 ℃/min, after opening microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gaseous products obtained after the two-step microwave catalysis are shown in Table 6;

Table 6: Gas Product Analysis

Example 7

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst supported by carbon black, the mass ratio of metal iron, metal nickel and carbon is 3:1:1) are fully physically and mechanically mixed, put into In the microwave reactor (1), purging was carried out under nitrogen conditions (100ml/min) for 10 minutes, and the microwave reaction was carried out under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; Gas products, and sampling for analysis;

(2) get 20g of catalyst B (identical to catalyst A) and load it in microwave reactor (2), set reaction temperature to be 850 ° C, start heating and preheating from room temperature, and heating rate is 20 ° C/min, after opening the microwave reactor (1), the microwave reactor (2) is opened at the same time, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gas products obtained after the two-step microwave catalysis are shown in Table 7;

Table 7: Gas Product Analysis

Example 8

In this example, polypropylene plastic is used as a raw material for hydrogen production reaction. The process flow is shown in Figure 1. The specific reaction conditions are the same as those in Example 7. And the mass ratio of carbon is 3:1:1.

After mixing 83.2 g of the recovered carbon black-supported iron-nickel metal catalyst with 80 g of pulverized polypropylene plastic, put it into the microwave reactor (1), and carry out purging for 10 minutes under nitrogen conditions (100 ml/min). Set microwave power to be 3000W, frequency 2.45GHz, react for 30 minutes, the gained gas is collected and sampled and analyzed after the gas scrubbing treatment; The collected gas is passed into the microwave reactor (2), and the secondary catalytic dehydrogenation is carried out Treated, reacted for 30 minutes, collected hydrogen and sampled for analysis.

The analysis results of the gas products obtained after the two-step microwave catalysis after the catalyst is recovered and reused are shown in Table 8; from the following data, it can be seen that the recovered catalyst can also efficiently catalyze dehydrogenation to prepare high-purity hydrogen.

Table 8: Gas Product Analysis

Example 9

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst, the mass ratio of iron and nickel is 3:1) are fully physically and mechanically mixed, put into microwave reactor (1), under nitrogen conditions (100ml/min), carry out purging for 10 minutes, under the condition of power 4000W, frequency 2.45GHz, microwave reaction for 30 minutes to generate mixed gas product; after gas cleaning treatment, collect gas product, and sample analysis;

(2) get 20g catalyst B (the iron-nickel metal catalyst supported by carbon black, the mass ratio of metallic iron, metallic nickel and carbon is 3:1:1) and load in microwave reactor (2), set reaction temperature to be 850 ℃ ℃, start to heat up and preheat from room temperature, and the rate of temperature rise is 20 ℃/min, when opening the microwave reactor (1), the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analytical results of the gaseous products obtained after the two-step microwave catalysis are shown in Table 9;

Table 9: Gas Product Analysis

The iron-nickel metal catalyst in this embodiment is prepared by the following method: ferric nitrate, nickel nitrate and citric acid are fully mixed in distilled water; calcined at 450° C. for 3 hours; A reduction treatment was performed, and the reduction treatment conditions were 650° C. for 6 hours. The mass ratio of iron and nickel in the finally obtained iron-nickel alloy catalyst is 3:1.

Example 10

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (carbon black powder) were fully mixed physically and mechanically, put into microwave reactor 1, and purged for 10 minutes under nitrogen conditions (100ml/min), Microwave reaction under the conditions of power 4000W and frequency 2.45GHz for 30 minutes to generate mixed gas products; after gas scrubbing, the gas products are collected and sampled for analysis;

(2) get 20g catalyst B (the iron-nickel metal catalyst supported by carbon black, the mass ratio of metallic iron, metallic nickel and carbon is 3:1:1) and load in microwave reactor (2), set reaction temperature to be 850 ℃ ℃, start to heat up and preheat from room temperature, and the rate of temperature rise is 20 ℃/min, when opening the microwave reactor (1), the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analysis results of the gas products obtained after the two-step microwave catalysis are shown in Table 10;

Table 10: Gas Product Analysis

Example 11

In this embodiment, polypropylene plastic is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 1, which specifically includes the following steps:

(1) 50g of pulverized polypropylene plastic and 50g of catalyst A (iron-nickel metal catalyst, the mass ratio of iron and nickel is 3:1) are fully physically and mechanically mixed, put into microwave reactor 1, under nitrogen conditions (100ml /min), carry out purging for 10 minutes, microwave reaction for 30 minutes under the condition of power 4000W, frequency 2.45GHz, generate mixed gas product; after gas cleaning treatment, collect gas product, and sample and analyze;

(2) get 20g catalyst B (carbon black powder) and be loaded in microwave reactor (2), set reaction temperature to be 850 ℃, start heating up preheating from room temperature, heating rate is 20 ℃/min, after opening microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) Passing the mixed gas product obtained in step (1) into the microwave reactor (2) for secondary dehydrogenation and purification treatment, and microwave reaction at 850° C. for 30 minutes to generate a hydrogen-containing gas product, which is collected and sampled for analysis after gas washing ;

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The analysis results of the gas products obtained after the two-step microwave catalysis are shown in Table 11;

Table 11: Gas Product Analysis

Example 12

In this example, straw is used as the biomass raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of broken straw and 50g of catalyst A (iron oxide catalyst) were fully physically and mechanically mixed, put into the microwave reactor (1), and purged under nitrogen conditions (100ml/min) for 10 minutes at a power of 2000W , microwave reaction under the condition of frequency 2.45GHz for 30 minutes to generate mixed gas product;

(2) Take 50g of catalyst B (metal iron catalyst supported by activated carbon) and load it in the microwave reactor (2), set the microwave power to 3000W, the frequency of 2.45GHz, and start the microwave reaction when the microwave reactor (1) is opened. device (2), preheating the loaded catalyst B;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 12;

Table 12: Gas Product Analysis

H₂ 53.5% CH₄ 3.4% C₂₊ 0.8% CO 36.1% CO₂ 6.2%

(4) The hydrogen-containing gas obtained in step (3) is subjected to pressure swing adsorption (PSA) treatment after being scrubbed, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

The catalyst A in this example was prepared by the following method: after mixing ferric nitrate and citric acid in a mass ratio of 1:1, calcined at 450° C. for 3 hours to obtain orange iron oxide powder.

Catalyst B in this example was prepared by the following method: fully mixing activated carbon and ferric nitrate in distilled water, calcining in an argon atmosphere at 350°C for 3 hours, and then reducing it in a 5% H2/Ar environment at 650°C for 6 hours hours, the black powder of the activated carbon-supported metallic iron catalyst is obtained, and the mass ratio of iron and carbon in the activated carbon-supported metallic iron catalyst is 1:1.

Example 13

The present embodiment uses wood chips as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of wood chips and 50g of catalyst A (iron oxide catalyst prepared by combustion method) are fully physically and mechanically mixed, put into microwave reactor (1), and purged under nitrogen conditions (100ml/min) for 10 minutes , microwave reaction under the condition of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(2) Take 50g of catalyst B (the activated carbon-supported metal iron catalyst prepared by the impregnation method, the mass ratio of carbon and iron is 1:1) and load it into the microwave reactor (2), set the microwave power to 2000W and the frequency to 2.45GHz , the microwave reactor (2) is opened while the microwave reactor (1) is opened, and the loaded catalyst B is preheated;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 2000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 13;

Table 13: Gas Product Analysis

H₂ 54.4% CH₄ 2.9% C₂₊ 1.1% CO 32.9% CO₂ 8.7%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and then subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 14

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) After crushing 100g of maple leaves and 50g of catalyst A (iron oxide catalyst prepared by combustion method), carry out sufficient physical and mechanical mixing, put it into microwave reactor (1), and carry out 10 under nitrogen conditions (100ml/min). 10 minutes of purging, microwave reaction for 30 minutes under the condition of power 2000W and frequency 2.45GHz to generate mixed gas products;

(2) Take 50g of catalyst B (the activated carbon-supported metal iron catalyst prepared by the impregnation method, the mass ratio of carbon and iron is 1:1) and load it into the microwave reactor (2), set the microwave power to 2000W and the frequency to 2.45GHz , the microwave reactor (2) is opened while the microwave reactor (1) is opened, and the loaded catalyst B is preheated;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 2000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 14;

Table 14: Gas Product Analysis

H₂ 52.9% CH₄ 4.6% C₂₊ 2.2% CO 31.6% CO₂ 8.7%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 15

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) After crushing 100g of maple leaves and 50g of catalyst A (iron oxide catalyst prepared by combustion method), carry out sufficient physical and mechanical mixing, put it into microwave reactor (1), and carry out 10 under nitrogen conditions (100ml/min). 10 minutes of purging, microwave reaction for 30 minutes under the conditions of power 3000W and frequency 2.45GHz to generate mixed gas products;

(2) Take 50g of catalyst B (iron oxide catalyst prepared by combustion method) and load it in the microwave reactor (2), set the microwave power to 2000W, the frequency of 2.45GHz, and turn on the microwave when the microwave reactor (1) is turned on. Reactor (2), preheating the loaded catalyst B;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 2000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 15;

Table 15: Gas Product Analysis

H₂ 43.3% CH₄ 6.9% C₂₊ 4.2% CO 36.7% CO₂ 8.9%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 16

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of maple leaves are pulverized and 50g of catalyst A (a metal iron catalyst supported by activated carbon, wherein the mass ratio of carbon and iron is 1:1) is fully physically and mechanically mixed, and put into the microwave reactor (1), Purging under nitrogen conditions (100ml/min) for 10 minutes, microwave reaction under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(2) Take 50g of catalyst B (a metal iron catalyst supported by activated carbon, wherein the mass ratio of carbon and iron is 1:1) and load it in the microwave reactor (2), set the microwave power to 2000W, the frequency of 2.45GHz, and turn it on. The microwave reactor (2) is opened at the same time as the microwave reactor (1), and the loaded catalyst B is preheated;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 2000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 16;

Table 16: Gas Product Analysis

H₂ 60.5% CH₄ 2.6% C₂₊ 0.8% CO 33.2% CO₂ 2.9%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 17

In this example, straw is used as the biomass raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of broken straw and 50g of catalyst A (activated carbon catalyst) were fully mixed physically and mechanically, put into the microwave reactor (1), and purged for 10 minutes under nitrogen conditions (100ml/min), at a power of 2000W , microwave reaction under the condition of frequency 2.45GHz for 30 minutes to generate mixed gas product;

(2) Take 100g of catalyst B (a metal iron catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 4:1) and load it in the microwave reactor (2), set the microwave power to 3000W, the frequency of 2.45GHz, When the microwave reactor (1) is opened, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(3) the mixed gas product obtained in step (1) is passed into the microwave reactor (2), and the microwave reaction is carried out for 30 minutes under the condition of power 3000W and frequency 2.45GHz to generate hydrogen-containing gas product, which is collected and sampled for analysis after washing. , the results are shown in Table 17;

Table 17: Gas Product Analysis

H₂ 44.9% CH₄ 7.4% C₂₊ 3.2% CO 41.3% CO₂ 3.2%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Catalyst B in this example was prepared by the following method: fully mixing silicon carbide and ferric nitrate in distilled water, calcining in an argon atmosphere at 450°C for 3 hours, and then reducing it in a 5% H2/Ar environment at 750°C After 6 hours, a black powder of the silicon carbide-supported metallic iron catalyst was obtained. The mass ratio of iron and silicon carbide in the finally obtained catalyst powder was 1:4.

Example 18

In this example, straw is used as the biomass raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) Fully physically and mechanically mix 100g of broken straw and 50g of catalyst A (activated carbon catalyst), put it into the microwave reactor (1), and carry out purging for 10 minutes under nitrogen conditions (100ml/min), at a power of 3000W , microwave reaction under the condition of frequency 2.45GHz for 30 minutes to generate mixed gas product;

(2) get 100g catalyst B (the metal iron catalyst supported by silicon carbide prepared by impregnation method, the mass ratio of silicon carbide and iron is 4:1) and load it in microwave reactor (2), set microwave power to be 4000W, The frequency is 2.45GHz, the microwave reactor (2) is opened while the microwave reactor (1) is opened, and the loaded catalyst B is preheated;

(3) the mixed gas product obtained in step (1) is passed into the microwave reactor (2), and the microwave reaction is carried out for 30 minutes under the condition of power 4000W and frequency 2.45GHz to generate hydrogen-containing gas product, which is collected and analyzed by sampling after gas washing , the results are shown in Table 18;

Table 18: Gas Product Analysis

H₂ 51.1% CH₄ 4.6% C₂₊ 1.2% CO 40.2% CO₂ 2.9%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Catalyst B in this example was prepared by the following method: fully mixing silicon carbide and ferric nitrate in distilled water, calcining in an argon atmosphere at 450°C for 3 hours, and then reducing it in a 5% H2/Ar environment at 750°C After 6 hours, a black powder of the silicon carbide-supported metallic iron catalyst was obtained. The mass ratio of iron and silicon carbide in the finally obtained catalyst powder was 1:4.

Example 19

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) After crushing 100g of maple leaves and 100g of catalyst A (a silicon carbide-supported metal iron catalyst prepared by impregnation method, wherein the mass ratio of silicon carbide and iron is 4:1), carry out sufficient physical-mechanical mixing, and put into microwave reaction In the device (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was performed for 30 minutes under the conditions of power 3000W and frequency 2.45GHz to generate mixed gas products;

(2) get 100g catalyst B (the metal iron catalyst supported by silicon carbide prepared by impregnation method, the mass ratio of silicon carbide and iron is 4:1) and load it in microwave reactor (2), set microwave power to be 3000W, The frequency is 2.45GHz, the microwave reactor (2) is opened while the microwave reactor (1) is opened, and the loaded catalyst B is preheated;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 19;

Table 19: Gas Product Analysis

H₂ 49.3% CH₄ 4.8% C₂₊ 1.5% CO 37.6% CO₂ 6.8%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 20

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of maple leaves are pulverized and 50g of catalyst A (a metal iron catalyst supported by activated carbon, wherein the mass ratio of carbon and iron is 1:1) is fully physically and mechanically mixed, and put into the microwave reactor (1), Purging under nitrogen conditions (100ml/min) for 10 minutes, microwave reaction under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(2) get 50g catalyst B (activated carbon) and load it in microwave reactor (2), set microwave power to be 3000W, frequency 2.45GHz, open microwave reactor (1) while opening microwave reactor (2), Preheat the loaded catalyst B;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 20;

Table 20: Gas Product Analysis

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

Example 21

The present embodiment uses maple leaves as biomass raw materials to carry out hydrogen production reaction, and the process flow is shown in Figure 2, which specifically includes the following steps:

(1) 100g of maple leaves are crushed and mixed with 50g of catalyst A (activated carbon) for sufficient physical and mechanical mixing, put into microwave reactor (1), purged for 10 minutes under nitrogen conditions (100ml/min), Microwave reaction under the conditions of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(2) get 50g catalyst B (activated carbon) and load it in microwave reactor (2), set microwave power to be 3000W, frequency 2.45GHz, open microwave reactor (1) while opening microwave reactor (2), Preheat the loaded catalyst B;

(3) pass the mixed gas product obtained in step (1) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 21;

Table 21: Gas Product Analysis

H₂ 31.8% CH₄ 16.7% C₂₊ 21.4% CO 16.5% CO₂ 13.6%

(4) The hydrogen-containing gas product obtained in step (3) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen with a purity of 99.9% is collected.

After the reaction is completed, the catalyst (solid) sample is collected by cooling and recycled.

In the following examples, the compositions of the domestic waste samples involved are shown in Table 22 below.

Table 22 (unit: wt%)

sample Humus (food residue/green waste) Metal plastic paper Glass Leather product cloth Ash, dirt, slag wood A 32.3 1.2 10.3 23.1 0.9 3.4 0 9.9 18.9 B 17.2 0.7 30.9 26.1 5.4 1.2 3.1 5.7 9.7 C 27.9 5.2 27.5 15.6 7.8 0.1 0.2 15.7 0

Example 22

In this embodiment, the domestic waste sample A is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample A, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (an activated carbon-supported iron-nickel alloy catalyst), put it into the microwave reactor (1), and under nitrogen conditions (100 ml/min) ), carry out purging for 10 minutes, microwave reaction for 30 minutes under the condition of power 2000W, frequency 2.45GHz, generate mixed gas product;

(3) get 100g catalyst B (iron oxide catalyst) and load it in microwave reactor (2), set microwave power to 4000W, frequency 2.45GHz, open microwave reactor (1) while opening microwave reactor (2) ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 23;

Table 23: Gas Product Analysis

H₂ 48.3% CH₄ 2.4% C₂₊ 1.1% CO 42.3% CO₂ 5.9%

(5) The hydrogen-containing gas product obtained in step (4) is subjected to pressure swing adsorption (PSA) treatment after being scrubbed, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Catalyst A in this example was prepared by the following method: fully mixing activated carbon with ferric nitrate and nickel nitrate in distilled water; calcining at 350° C. for 3 hours under an inert atmosphere of argon; after calcining, at 5% The reduction treatment was carried out in an H2/Ar environment, and the reduction treatment conditions were 650°C for 6 hours. Finally, the activated carbon-supported iron-nickel alloy catalyst was collected, and the mass ratio of carbon, iron and nickel of the catalyst finally obtained was 7:2:1.

The catalyst B in this example was prepared by the following method: after mixing ferric nitrate and citric acid in a mass ratio of 1:1, calcined at 350° C. for 3 hours to obtain orange iron oxide powder.

After the reaction is completed, the catalyst (solid) is collected by cooling and can be recycled.

Example 23

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (an iron-nickel alloy catalyst supported by activated carbon; the mass ratio of carbon, iron and nickel is 7:2:1), and put into In the microwave reactor (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(3) Get 100g catalyst B (iron oxide catalyst) and load it in the microwave reactor (2), set the microwave power to 4000W, the frequency of 2.45GHz, and open the microwave reactor (2) while opening the microwave reactor (1). ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 24;

Table 24: Gas Product Analysis

H₂ 65.7% CH₄ 3.1% C₂₊ 0.7% CO twenty four% CO₂ 6.5%

(5) The hydrogen-containing gas product obtained in step (4) is subjected to pressure swing adsorption (PSA) treatment after being scrubbed, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 24

In this embodiment, the domestic waste sample C is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample C, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (an iron-nickel alloy catalyst supported by activated carbon; the mass ratio of carbon, iron and nickel is 7:2:1), and put into In the microwave reactor (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(3) Get 100g catalyst B (iron oxide catalyst) and load it in the microwave reactor (2), set the microwave power to 4000W, the frequency of 2.45GHz, and open the microwave reactor (2) while opening the microwave reactor (1). ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 25;

Table 25: Gas Product Analysis

H₂ 56.5% CH₄ 2.4% C₂₊ 1.1% CO 33.1% CO₂ 6.9%

(5) The hydrogen-containing gas product obtained in step (4) is subjected to pressure swing adsorption (PSA) treatment after being scrubbed, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 25

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (an iron-nickel alloy catalyst supported by activated carbon; the mass ratio of carbon, iron and nickel is 7:2:1), and put into In the microwave reactor (1), purging was carried out for 10 minutes under nitrogen conditions (100ml/min), and the microwave reaction was carried out under the conditions of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas products;

(3) get 50g catalyst B (same as catalyst A, it is the iron-nickel alloy catalyst supported by activated carbon; the mass ratio of carbon, iron and nickel is 7:2:1) and load it in microwave reactor (2), set The microwave power is 3000W, the frequency is 2.45GHz, and the microwave reactor (2) is opened while the microwave reactor (1) is opened, and the loaded catalyst B is preheated;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 26;

Table 26: Gas Product Analysis

H₂ 68.8% CH₄ 2.3% C₂₊ 0.9% CO 20.3% CO₂ 7.7%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 26

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 50 g of catalyst A (activated carbon), put it into the microwave reactor (1), and blow it for 10 minutes under nitrogen conditions (100 ml/min). Scanning, microwave reaction under the condition of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(3) Get 100g catalyst B (iron oxide catalyst) and load it in the microwave reactor (2), set the microwave power to 4000W, the frequency of 2.45GHz, and open the microwave reactor (2) while opening the microwave reactor (1). ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 27;

Table 27: Gas Product Analysis

H₂ 59.2% CH₄ 7.5% C₂₊ 2.3% CO 24.5% CO₂ 6.5%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 27

In this embodiment, the domestic waste sample C is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample C, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 50 g of catalyst A (activated carbon), put it into the microwave reactor (1), and blow it for 10 minutes under nitrogen conditions (100 ml/min). Scanning, microwave reaction under the condition of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(3) Get 100g catalyst B (iron oxide catalyst) and load it in the microwave reactor (2), set the microwave power to 4000W, the frequency of 2.45GHz, and open the microwave reactor (2) while opening the microwave reactor (1). ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 28;

Table 28: Gas Product Analysis

H₂ 53.9% CH₄ 8.1% C₂₊ 1.8% CO 31.9% CO₂ 4.3%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 28

In this embodiment, the domestic waste sample A is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample A, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 50 g of catalyst A (activated carbon), put it into the microwave reactor (1), and blow it for 10 minutes under nitrogen conditions (100 ml/min). Scanning, microwave reaction under the condition of power 2000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(3) Get 100g catalyst B (iron oxide catalyst) and load it in the microwave reactor (2), set the microwave power to 4000W, the frequency of 2.45GHz, and open the microwave reactor (2) while opening the microwave reactor (1). ), preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), and microwave reaction under the condition of power 4000W and frequency 2.45GHz for 30 minutes to generate hydrogen-containing gas product, which is collected and sampled for analysis after washing , the results are shown in Table 29;

Table 29: Gas Product Analysis

H₂ 43.8% CH₄ 3.7% C₂₊ 1.5% CO 46.3% CO₂ 4.7%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 29

In this embodiment, the domestic waste sample A is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample A, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physico-mechanical mixing of the dried and pulverized household garbage sample with 100 g of catalyst A (iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1), put into a microwave reactor ( 1) in, carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate mixed gas product;

(3) get 100g catalyst B (iron-nickel alloy, the mass ratio of iron and nickel is 4:1) and load it in microwave reactor (2), set microwave power to be 3000W, frequency 2.45GHz, open microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 30;

Table 30: Gas Product Analysis

H₂ 49.5% CH₄ 4.3% C₂₊ 0.9% CO 37.6% CO₂ 7.7%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Catalyst A in this example was prepared by the following method: fully mixing silicon carbide and ferric nitrate in distilled water; calcining at 350° C. for 3 hours under an inert atmosphere of argon; The catalyst was subjected to reduction treatment in the environment, and the reduction treatment conditions were 650° C. for 6 hours. The black powder of the metal iron catalyst supported by silicon carbide was finally collected, and the mass ratio of silicon carbide and iron in the finally obtained catalyst was 5:1.

Catalyst B in this example was prepared by the following method: ferric nitrate, nickel nitrate and citric acid were fully mixed in distilled water; calcined at 450°C for 3 hours; after calcination was completed, the catalyst was reduced in a 5% H2/Ar environment Treatment, reduction treatment conditions are 650 ° C, 6 hours. The iron-nickel mass ratio of the finally obtained iron-nickel alloy catalyst is 4:1.

Example 30

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physico-mechanical mixing of the dried and pulverized household garbage sample with 100 g of catalyst A (iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1), put into a microwave reactor ( 1) in, carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate mixed gas product;

(3) get 100g catalyst B (iron-nickel alloy, the mass ratio of iron and nickel is 4:1) and load it in microwave reactor (2), set microwave power to be 3000W, frequency 2.45GHz, open microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 31;

Table 31: Gas Product Analysis

H₂ 61.3% CH₄ 3.3% C₂₊ 1.7% CO 24.8% CO₂ 8.9%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 31

In this embodiment, the domestic waste sample C is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample C, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physico-mechanical mixing of the dried and pulverized household garbage sample with 100 g of catalyst A (iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1), put into a microwave reactor ( 1) in, carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate mixed gas product;

(3) get 100g catalyst B (iron-nickel alloy, the mass ratio of iron and nickel is 4:1) and load it in microwave reactor (2), set microwave power to be 3000W, frequency 2.45GHz, open microwave reactor ( 1) at the same time, the microwave reactor (2) is opened, and the loaded catalyst B is preheated;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 32;

Table 32: Gas Product Analysis

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 32

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (iron-nickel alloy, the mass ratio of iron and nickel is 4:1), put it into the microwave reactor (1), and put it into the microwave reactor (1). Purging under the condition (100ml/min) for 10 minutes, microwave reaction under the condition of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(3) get 50g catalyst B (same catalyst A, iron-nickel alloy, the mass ratio of iron and nickel is 4:1) and load it in microwave reactor (2), set microwave power to be 4000W, frequency 2.45GHz, turn on The microwave reactor (2) is opened at the same time as the microwave reactor (1), and the loaded catalyst B is preheated;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 33;

Table 33: Gas Product Analysis

H₂ 66.7% CH₄ 2.1% C₂₊ 1.1% CO 17.4% CO₂ 12.7%

(5) The hydrogen-containing gas product obtained in step (4) is subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, hydrogen gas with a purity of 99.9% is collected.

Example 33

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physico-mechanical mixing of the dried and pulverized household garbage sample with 100 g of catalyst A (iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1), put into a microwave reactor ( 1) in, carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate mixed gas product;

(3) get 50g catalyst B (same as catalyst A, it is the iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1) and load it in microwave reactor (2), set microwave power to be 4000W , frequency 2.45GHz, open microwave reactor (2) while opening microwave reactor (1), carry out preheating to the catalyst B of loading;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 34;

Table 34: Gas Product Analysis

H₂ 64.3% CH₄ 3.3% C₂₊ 1% CO 21.6% CO₂ 9.8%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 34

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physico-mechanical mixing of the dried and pulverized household garbage sample with 100 g of catalyst A (iron metal catalyst supported by silicon carbide, the mass ratio of silicon carbide and iron is 5:1), put into a microwave reactor ( 1) in, carry out purging for 10 minutes under nitrogen conditions (100ml/min), microwave reaction under the condition of power 3000W, frequency 2.45GHz for 30 minutes, generate mixed gas product;

(3) Take 100g of catalyst B (silicon carbide) and load it in the microwave reactor (2), set the microwave power to 4000W and the frequency to 2.45GHz, and open the microwave reactor (1) at the same time as the microwave reactor (2) , preheating the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 35;

Table 35: Gas Product Analysis

H₂ 41.2% CH₄ 18.9% C₂₊ 9.1% CO 21.1% CO₂ 9.7%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

Example 35

In this embodiment, the domestic waste sample B is used as the raw material to carry out the hydrogen production reaction, and the process flow is shown in Figure 3, which specifically includes the following steps:

(1) Take 300g of household waste sample B, set a temperature of 110°C and a heating rate of 20°C/min in a microwave drying reactor, carry out drying treatment for 1 hour to reduce the water content to below 10%, and then pulverize;

(2) Fully physically and mechanically mix the dried and pulverized household garbage sample with 100 g of catalyst A (activated carbon), put it into the microwave reactor (1), and carry out purging for 10 minutes under nitrogen conditions (100 ml/min). , microwave reaction under the condition of power 3000W and frequency 2.45GHz for 30 minutes to generate mixed gas product;

(3) get 100g catalyst B (activated carbon) and load it in microwave reactor (2), set microwave power to be 4000W, frequency 2.45GHz, open microwave reactor (2) while opening microwave reactor (1), Preheat the loaded catalyst B;

(4) pass the mixed gas product obtained in step (2) into the microwave reactor (2), microwave reaction under the condition of power 4000W, frequency 2.45GHz for 30 minutes, generate hydrogen-containing gas product, collect and sample analysis after gas washing , the results are shown in Table 36;

Table 36: Gas Product Analysis

H₂ 31.8% CH₄ 15.1% C₂₊ 22.4% CO 12.6% CO₂ 18.1%

(5) The hydrogen-containing gas product obtained in step (4) is scrubbed and subjected to pressure swing adsorption (PSA) treatment, and after separation and purification, the hydrogen with a purity of 99.9% is collected.

The percentages in the above gas product analysis tables are all mole percentages.

Although the present invention has been described in detail above with general description, specific embodiments and tests, some modifications or improvements can be made on the basis of the present invention, which is obvious to those skilled in the art . Therefore, these modifications or improvements made without departing from the spirit of the present invention fall within the scope of the claimed protection of the present invention.

Claims (10)

1. a method for producing hydrogen from carbon-containing solids, characterized in that the method takes carbon-containing solids as raw materials, comprising two stages of microwave catalytic treatment, wherein: The first stage of microwave catalysis is to perform a microwave treatment on the carbon-containing solid raw material under the action of catalyst A to generate mixed gas; The second stage of microwave catalysis is to perform secondary microwave treatment on the mixed gas obtained by the first stage of microwave catalysis under the action of catalyst B to generate hydrogen-containing gas; The catalyst A and/or the catalyst B are selected from carbon materials, transition metal materials and transition metal materials supported by carbon materials; the catalyst A and the catalyst B have the same or different compositions. 2. The method according to claim 1, wherein the carbon material is selected from carbon black, activated carbon and silicon carbide; and/or, The transition metal material includes at least one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum and tungsten series metal materials; Preferably, the transition metal material is selected from iron-nickel-based metal materials, molybdenum-based compounds or chromium-based compounds; Wherein, the iron-nickel-based metal material is selected from one or more of metallic iron, ferrous oxide, iron oxide, iron carbide, iron tetroxide, metallic nickel, nickel oxide, iron-nickel alloy and mixed iron-nickel oxide kind; And/or, the molybdenum-based compound is selected from molybdenum oxide or molybdenum carbide; And/or, the chromium-based compound is selected from chromium oxide compounds or chromium carbides. 3. The method according to claim 1 or 2, wherein the catalyst A is an iron-nickel-based metal material or an iron-nickel-based metal material supported by a carbon material, preferably metal iron, iron oxide, iron-nickel Alloys or metallic iron, iron oxide or iron-nickel alloys supported by carbon materials; The catalyst B is a carbon material, an iron-nickel-based metal material or an iron-nickel-based metal material supported by a carbon material, preferably a carbon material, metallic iron, iron oxide, iron-nickel alloy or metallic iron supported by a carbon material, Iron oxide or iron-nickel alloy. 4. The method according to any one of claims 1 to 3, wherein the carbon-containing solids comprise polyolefin plastics, biomass, artificial organic polymers, biochar, coal, pitch, coke, and paraffin , at least one of chemical fibers, tires, medical waste, and domestic waste; Preferably, the carbonaceous solids are selected from polypropylene plastics, household waste and biomass. 5 . The method according to claim 1 , wherein the mass ratio of the carbon material as the carrier to the metal material supported thereon is (0.1-10): 1, preferably (0.1-5) 5 . :1. 6 . The method according to claim 1 , wherein the mass ratio of the carbonaceous solid to the catalyst A in the method is (0.5-10): 1; 6 . And/or, the mass ratio of catalyst A to catalyst B used is (1-5):(1-2). 7. The method according to any one of claims 1 to 6, wherein the power of the first stage of microwave catalytic treatment is 500-8000W, preferably 1000-6000W; The power of 500-8000W is used in the second stage of microwave catalytic treatment, preferably the power is 1000-6000W, or the temperature of the second stage of microwave catalytic treatment is 600-1000°C. 8. The method according to claim 1, wherein the frequency of the first stage and/or the second stage of microwave catalytic treatment is 0.3-3 GHz, preferably 2.45 GHz or 915 MHz; Preferably, the time for the first stage of microwave catalytic treatment is 20-60 min, and/or the time for the second stage of microwave catalytic treatment is 20-60 min. 9 . The method according to claim 1 , wherein the first stage of microwave catalytic treatment and the second stage of microwave catalytic treatment are carried out in an inert environment with standard atmospheric pressure and an oxygen content of less than 5000 ppm. 10 . 10. The method according to any one of claims 1 to 9, wherein the method further comprises: separating and purifying the product after the first stage of microwave catalysis and/or the second stage of microwave catalysis is completed; Preferably, the separation and purification includes gas scrubbing and/or pressure swing adsorption treatment.

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