Method for preparing hydrogen-rich synthesis gas by microwave co-pyrolysis of biomass and plastics

Abstract

The present application relates to the field of biomass and polyolefin plastic resource utilization, especially under relatively mild conditions, microwave co-pyrolysis of biomass and plastic to prepare hydrogen-rich syngas. First, take Fe / Beta catalyst, rice husk and LDPE 1.5g, 1.0g, 0.5g respectively, stir evenly and place in a quartz tube, react under microwave environment at 600 DEG C for 15min. Through a series of water gas shift reaction and catalytic reforming reaction to prepare high purity hydrogen-rich syngas. The gas yield is 55.7-86.5% in the whole process, and the volume content of hydrogen-rich syngas is 62.9-89.5vol%. The present application aims to overcome the problems in the prior art such as harsh reaction conditions, dependence on noble metal catalyst and low selectivity of target product, and has important practical application value.

Description

Technical Field

[0001] This invention relates to the field of biomass and plastic resource utilization technology, and in particular to a method for preparing hydrogen-rich syngas by microwave co-pyrolysis of biomass and plastics. Background Technology

[0002] As a significant component of solid waste, biomass is the only carbon-containing renewable energy source, characterized by abundant reserves, environmental friendliness, and zero carbon dioxide emissions, making it a key candidate to replace traditional fossil fuels. However, biomass pyrolysis technology faces challenges: the quality of its produced products, such as bio-oil, is currently difficult to match that of fossil fuels. This is due to factors including the lower calorific value of bio-oil and the high oxygen content, strong corrosivity, and poor stability resulting from the cellulose / hemicellulose conversion reaction, which limits its further application. On the other hand, plastics, another important type of solid waste, have seen rapid production growth over the past 50 years due to their low cost and durability, with a global annual production of approximately 400 million tons. Current waste treatment strategies include landfill, incineration, gasification, and mechanical recycling, but these methods all have significant limitations. Compared to these methods, pyrolysis technology can effectively convert plastics into liquid fuels and high-value gases without producing large amounts of carbon dioxide or toxic pollutants. Notably, biomass and plastics exhibit significant complementarity in elemental composition and pyrolysis behavior. Biomass pyrolysis produces a large number of hydrogen-deficient oxygen-containing free radical intermediates, while plastics pyrolysis can serve as abundant hydrogen donors. This characteristic provides a chemical basis for the co-pyrolysis of biomass and plastics.

[0003] Co-pyrolysis of biomass and plastics is a promising method. Studies have shown that co-pyrolysis makes a positive contribution to syngas production. During co-pyrolysis, hydrogen-rich plastics can provide hydrogen to biomass through hydrogen transfer reactions, while co-pyrolysis intermediates can react at the active sites of the catalyst via Diels-Alder reactions, thereby synergistically forming high-quality hydrogen-rich syngas (H2+CO).

[0004] Catalysts can significantly improve the selectivity and yield of pyrolysis products. In the current field of microwave co-pyrolysis of biomass and plastics, iron-based catalysts are widely used. Chen et al. synthesized a highly efficient Fe@C catalyst, achieving a 51.62 vol.% H2 yield and a 27.13% aromatic hydrocarbon yield. Beta molecular sieves, with their three-dimensional twelve-membered ring cross-channel structure (0.66 × 0.67 nm) and tunable acidity, exhibit highly efficient catalytic performance in the microwave co-pyrolysis of biomass and plastics. The Brønsted acid sites of Beta can promote C–O bond breaking, catalyzing biomass deoxygenation (decarboxylation, dehydration) and plastic pyrolysis. The combination of Fe-based catalysts and Beta molecular sieves, through the strong microwave absorption of Fe species and the synergistic effect of Beta's shape-selective acid catalysis, can effectively address these challenges. Summary of the Invention

[0005] This invention proposes a method for preparing hydrogen-rich syngas through microwave co-thermolysis of biomass and plastics. Under the action of an Fe / Beta catalyst, the system undergoes free radical cross-reactions, with LDPE providing active hydrogen as a rice husk-derived intermediate, significantly enhancing deoxygenation, reforming, and water-gas shift reactions.

[0006] The technical solution of this invention is a method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics, characterized by the following specific steps: 1.5g Fe / Beta catalyst, 0.5-1g rice husk, and 0.5-1g LDPE are mixed uniformly and encapsulated in a quartz tube, both ends are sealed with quartz wool, and connected to the reaction system. An appropriate amount of CH2Cl2 is added to a cold trap gas washing bottle. After the system is purged with N2 (20mL / min, 15min) to remove air, the N2 flow rate is adjusted to 5mL / min, and a gas bag is connected. The microwave reaction temperature is adjusted to 500-700℃ and the reaction is started. After 15 minutes, hydrogen-rich syngas is obtained.

[0007] In the above-mentioned method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics, preferably, 1g of rice husk and 0.5g of LDPE are used, and the reaction temperature is 600℃.

[0008] In the above-mentioned method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics, preferably, the Fe / Beta catalyst is prepared by impregnation, and the Fe loading is 5-15%; Fe exists in the form of nanoparticles on the Beta surface, and the Fe / Beta catalyst has weak acid and moderate acid sites.

[0009] The preparation method of the above Fe / Beta catalyst is as follows: 7.2 g Fe(NO3)3·9H2O and 50 mL deionized water were added to a 100 mL beaker and stirred at 600 r / min for 20 min on a multi-heated magnetic stirrer while heating to 40 °C to completely dissolve the catalyst. Then, 10.0 g of Beta zeolite was accurately weighed and slowly added to the solution. After it was fully dispersed, the beaker was sealed with paraffin film, and stirring was continued at 60 °C until homogeneous. The resulting mixture was dried in an oven at 105 °C, and then transferred to a muffle furnace and calcined at a programmed temperature increase of 10 °C / min to 550 °C. Finally, the calcined sample was ground and sieved to obtain a 10% Fe / Beta catalyst with a particle size of 100 mesh. Based on the mass of the catalyst, catalysts with different Fe loadings were prepared by adjusting the molar ratio of the catalyst precursor metal salt.

[0010] In the above-mentioned method for preparing Fe / Beta catalyst, preferably, the Fe loading in the catalyst is 5-15%.

[0011] In the above-mentioned method for preparing hydrogen-rich syngas by microwave co-pyrolysis of biomass and plastics, preferably, the Fe / Beta catalyst has both microwave absorption and catalytic activity functions.

[0012] In the above-mentioned method for preparing hydrogen-rich syngas by microwave co-pyrolysis of biomass and plastics, preferably, the distribution of gaseous products is regulated by the synergistic effect of Fe / Beta and microwave field.

[0013] In the above-mentioned method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics, preferably, the system provides active hydrogen as a rice husk-derived intermediate through free radical cross-reaction.

[0014] After the reaction of biomass and plastics in microwave catalytic co-pyrolysis to prepare hydrogen-rich syngas in this invention is completed, the gas in the gas bag is collected; then, the gas products are quantitatively analyzed: 250 μL of sample is injected for each test; the temperature program for gas phase analysis is set as follows: first, the temperature is kept constant at 80℃ for 8 minutes, then the temperature is increased to 190℃ at 30℃ / min and held for 5 minutes; the component analysis of the gas obtained from the reaction shows that the volume yields of various gases are as follows: hydrogen 41.2-60.4 vol%; carbon monoxide 18.3-33.0 vol%; methane 3.8-11.8 vol%; carbon dioxide 3.0-18.2 vol%; of which hydrogen-rich syngas (H2+CO) is 62.9-89.5 vol%.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] This invention proposes a method for producing hydrogen-rich syngas from biomass and plastics via microwave co-pyrolysis, which has the advantages of a relatively mild reaction temperature and short reaction time. The mild reaction conditions help delay catalyst deactivation and extend its lifespan, thereby improving the overall economic efficiency of the process. The system produces high-purity hydrogen-rich syngas through free radical cross-reaction. The catalyst used is an inexpensive Fe-based metal catalyst, resulting in low catalytic cost. This achievement is of great significance for promoting the industrial application of microwave-assisted co-pyrolysis technology and the sustainable resource utilization of waste. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0018] Figure 2 The image shows the characterization results (XRD pattern) of the Fe / Beta catalyst. Detailed Implementation

[0019] The technical solutions of the present invention are not limited to the specific embodiments listed below, but also include any combination of various specific embodiments.

[0020] like Figure 1 As shown, 1.5 g of Fe / Beta catalyst, 1.0 g of rice husk, and 0.5 g of LDPE were weighed out, stirred evenly, and placed in a quartz tube. The mixture was then reacted in a microwave environment at 600 °C for 15 min. High-purity hydrogen-rich syngas was obtained through a series of water-gas shift reactions and catalytic reforming reactions. The gas yield was 55.7-86.5% throughout the process, with the volume content of hydrogen-rich syngas being 62.9-89.5 vol%.

[0021] like Figure 2 As shown, the crystal structure of the catalyst sample was analyzed using a Bruker D8 ADVANCE X-ray diffractometer with Cu target Kα radiation in the range of 2θ from 10° to 80°, and the XRD diffraction pattern was obtained by scanning at a rate of 2°–4° / min. The results show that the main crystal framework structure of Beta zeolite was well preserved after loading iron species by the impregnation method and subsequent calcination. With increasing iron loading, weak, broadened peaks began to appear near 2θ ≈ 33.2° and 35.6°. Comparison with standard PDF cards showed that these peak positions (33.2°, 35.6°) perfectly matched the characteristic diffraction peaks of hematite (α-Fe₂O₃). This trend indicates successful iron loading.

[0022] Unless otherwise specified, all chemical reagents involved in this invention are commercially available products.

[0023] The Fe / Beta catalyst used in the following implementation example was prepared according to the following method: 7.2 g Fe(NO3)3·9H2O and 50 mL deionized water were added to a 100 mL beaker and stirred at 600 r / min for 20 min on a multi-heated magnetic stirrer while heating to 40 °C to completely dissolve the catalyst. Then, 10.0 g of Beta zeolite was accurately weighed and slowly added to the solution. After sufficient dispersion, the beaker was sealed with paraffin wax and stirred at 60 °C until homogeneous. The resulting mixture was dried in an oven at 105 °C and then transferred to a muffle furnace for calcination at a programmed temperature increase of 10 °C / min to 550 °C. Finally, the calcined sample was ground and sieved to obtain a 10% Fe / Beta catalyst with a particle size of 100 mesh. Based on the mass of the catalyst, catalysts with different Fe loadings were prepared by adjusting the molar ratio of the catalyst precursor metal salt.

[0024] Implementation Case 1

[0025] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 500℃ and allow it to react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). 250μL of sample was injected for each test. The temperature program was set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 51.6 vol; carbon monoxide 31.0 vol; methane 3.8 vol; carbon dioxide 4.6 vol, of which hydrogen-rich synthesis gas (H2+CO) was 82.6 vol.

[0026] Implementation Case 2

[0027] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 550℃ and react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products is performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample is injected for each test. The temperature program is set as follows: first, hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 53.1 vol; carbon monoxide 31.1 vol; methane 5.4 vol; carbon dioxide 6.5 vol, of which hydrogen-rich synthesis gas (H2+CO) was 84.2 vol.

[0028] Implementation Case 3

[0029] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 600℃ and react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products is performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). 250μL of sample is injected for each test. The temperature program is set as follows: first, hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 56.4 vol; carbon monoxide 33.1 vol; methane 4.8 vol; carbon dioxide 3.1 vol, of which hydrogen-rich synthesis gas (H2+CO) was 89.5 vol.

[0030] Implementation Case 4

[0031] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 650℃ and allow it to react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample was injected for each test. The temperature program was set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 58.9 vol; carbon monoxide 30.8 vol; methane 4.8 vol; carbon dioxide 3.4 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 89.7 vol.

[0032] Implementation Case 5

[0033] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 700℃ and allow it to react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample was injected for each test. The temperature program was set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 51.7 vol; carbon monoxide 36.4 vol; methane 5.1 vol; carbon dioxide 3.9 vol, of which hydrogen-rich synthesis gas (H2+CO) was 88.1 vol.

[0034] Implementation Case 6

[0035] 1.5g of 10% Fe / Beta catalyst and 1.5g of rice husk were encapsulated in a quartz tube, sealed at both ends with quartz wool, and connected to the reaction system. An appropriate amount of CH2Cl2 was placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, the N2 flow rate was adjusted to 5mL / min, and a gas bag was connected. The microwave reaction temperature was adjusted to 600℃, and the reaction was started for 15 minutes. After the reaction, the gas in the gas bag was collected. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample was injected for each test. The temperature program was set as follows: first, a constant temperature of 80℃ for 8 minutes, then an increase in temperature of 30℃ / min to 190℃ and a holding time of 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 46.9 vol; carbon monoxide 26.8 vol; methane 3.2 vol; carbon dioxide 21.81 vol, of which hydrogen-rich synthesis gas (H2+CO) accounted for 73.7 vol.

[0036] Implementation Case 7

[0037] Mix 1.5g of 10% Fe / Beta catalyst, 0.75g of rice husk, and 0.75g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. Fill a cold trap washing bottle with CH2Cl2. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect a gas bag. Start the reaction at 600℃ and allow it to proceed for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 58.4 vol; carbon monoxide 26.1 vol; methane 7.7 vol; carbon dioxide 3.3 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 84.5 vol.

[0038] Implementation Case 8

[0039] Mix 1.5g of 10% Fe / Beta catalyst, 0.5g of rice husk, and 1g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 600℃ and react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products is performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample is injected for each test. The temperature program is set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 54.6 vol; carbon monoxide 26.2 vol; methane 11.8 vol; carbon dioxide 3.0 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 80.8 vol.

[0040] Implementation Case 9

[0041] Mix 1.5g of 10% Fe / Beta catalyst and 1.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. Fill a cold trap washing bottle with an appropriate amount of CH2Cl2. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to a gas bag. Start the reaction at 600℃ and allow it to proceed for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields for each gas: hydrogen 59.0 vol%; carbon monoxide 0 vol%; methane 21.3 vol%; carbon dioxide 0 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 59.0 vol%.

[0042] Implementation Case 10

[0043] Mix 1g of rice husk and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. Fill a cold trap gas washing bottle with an appropriate amount of CH2Cl2. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to a gas bag. Start the reaction at 600℃ and allow it to proceed for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 41.2 vol; carbon monoxide 21.7 vol; methane 8.9 vol; carbon dioxide 18.2 vol, of which hydrogen-rich synthesis gas (H2+CO) was 62.9 vol.

[0044] Implementation Case 11

[0045] Mix 1.5g Beta molecular sieve, 1g rice husk, and 0.5g LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. Fill a cold trap gas washing bottle with an appropriate amount of CH2Cl2. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to a gas bag. Start the reaction at 600℃ and allow it to proceed for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 50.1 vol; carbon monoxide 26.2 vol; methane 5.9 vol; carbon dioxide 4.2 vol, of which hydrogen-rich synthesis gas (H2+CO) was 76.3 vol.

[0046] Implementation Case 12

[0047] Mix 1.5g of 5% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 600℃ and react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products is performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample is injected for each test. The temperature program is set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 57.3 vol; carbon monoxide 29.6 vol; methane 5.1 vol; carbon dioxide 4.8 vol, of which hydrogen-rich synthesis gas (H2+CO) was 86.9 vol.

[0048] Implementation Case 13

[0049] Mix 1.5g of 15% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. A suitable amount of CH2Cl2 is placed in the cold trap gas washing bottle. After purging the system with N2 (20mL / min, 15min) to remove air, adjust the N2 flow rate to 5mL / min and connect to the gas bag. Start the reaction by adjusting the microwave reaction temperature to 600℃ and react for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products is performed using an Agilent 7890B gas chromatograph (50m*530um*15um) equipped with an HP-PLOTAI203 capillary column. 250μL of sample is injected for each test. The temperature program is set as follows: first, hold at 80℃ for 8 minutes, then increase the temperature at 30℃ / min to 190℃ and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 54.3 vol; carbon monoxide 28.0 vol; methane 7.0 vol; carbon dioxide 6.8 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 82.3 vol.

[0050] Implementation Case 14

[0051] Mix 1.5g Fe₂O₃, 1g rice husk, and 0.5g LDPE thoroughly, encapsulate in a quartz tube, seal both ends with quartz wool, and connect to the reaction system. Fill a cold trap gas washing bottle with an appropriate amount of CH₂Cl₂. After purging the system with N₂ (20mL / min, 15min) to remove air, adjust the N₂ flow rate to 5mL / min and connect to a gas bag. Start the reaction at 600℃ and allow it to proceed for 15 minutes. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 60.4 vol; carbon monoxide 18.3 vol; methane 5.1 vol; carbon dioxide 2.3 vol, of which hydrogen-rich synthesis gas (H2+CO) was 78.7 vol.

[0052] Implementation Case 15

[0053] Mix 1.5g of 10% Fe / Beta catalyst, 1g of rice husk, and 0.5g of LDPE thoroughly, place the mixture in a porcelain boat, and insert a quartz tube. Add an appropriate amount of CH2Cl2 to a three-necked flask in the cold trap, connect the system, and purge with N2 (20mL / min) for 15min. Then adjust the N2 flow rate to 5mL / min, increase the temperature to the target temperature of 600℃ at 10℃ / min, and hold for 40min to ensure complete pyrolysis. Collect the gas in the gas bag after the reaction. Quantitative analysis of the gaseous products was performed using an Agilent 7890B gas chromatograph (GC) equipped with an HP-PLOTAI203 capillary column (50m*530um*15um). Inject 250μL of sample for each test. The temperature program was set as follows: hold at 80℃ for 8 minutes, then increase to 190℃ at 30℃ / min and hold for 5 minutes. Component analysis of the gases obtained from the reaction revealed the following volume yields: hydrogen 45.5 vol; carbon monoxide 32.5 vol; methane 8.5 vol; carbon dioxide 9.0 vol%, of which hydrogen-rich synthesis gas (H2+CO) was 78.0 vol.

[0054] The above examples provide a detailed description of specific embodiments of the present invention. The present invention is not limited to the above embodiments. Any person skilled in the art can make various modifications, alterations, or equivalent substitutions to the embodiments without departing from the spirit and scope of protection defined by the claims. All such modifications, alterations, or substitutions fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics, characterized in that, Includes the following steps: Fe / Beta catalysts were prepared using an impregnation method. Add 7.2g Fe(NO3)3·9H2O and 50ml deionized water to a 100mL beaker, stir at 600r / min for 20min on a multi-heated magnetic stirrer, and heat to 40℃ to completely dissolve; then accurately weigh 10.0g Beta zeolite and slowly add it to the solution. After it is fully dispersed, the beaker is sealed with paraffin film and stirred at 60°C until it is evenly mixed. The resulting mixture is dried in an oven at 105°C and then transferred to a muffle furnace and calcined at 550°C at a rate of 10°C / min. Finally, the calcined sample is ground and sieved to obtain a 10% Fe / Beta catalyst with a particle size of 100 mesh. Preparation of hydrogen-rich syngas from microwave-catalyzed co-pyrolysis of biomass and plastics: In a rectangular single-mode microwave reactor, a co-pyrolysis experiment of rice husk and LDPE was carried out: rice husk, LDPE and Fe / Beta catalyst were mixed evenly at a mass ratio of 2:1:3 (the ratio of rice husk and LDPE raw materials to catalyst was kept at 1:1), encapsulated in a quartz tube, sealed at both ends with quartz wool, and connected to the reaction system. A suitable amount of CH2Cl2 was placed in the cold trap washing bottle; after the system was purged with N2 (20 mL / min, 15 min) to remove air, the N2 flow rate was adjusted to 5 mL / min and the gas bag was connected; the microwave reaction temperature was adjusted to 500~750℃ and the reaction was started. After 15 minutes of reaction, hydrogen-rich synthesis gas was obtained through free radical cross-reaction.

2. The method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics according to claim 1, characterized in that: Based on the mass of the Fe / Beta catalyst being 100%, catalysts with different Fe loadings were prepared by adjusting the molar ratio of the catalyst precursor metal salt; the Fe / Beta catalyst was prepared by impregnation.

3. The method for preparing hydrogen-rich syngas by microwave co-pyrolysis of biomass and plastics according to claim 1, characterized in that: The Fe / Beta catalyst is in powder form with an Fe loading of 5-15%. Fe exists on the Beta surface in the form of nanoparticles, and the Fe / Beta catalyst has weak acid and moderate acid sites.

4. The method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics according to claim 1, characterized in that: The Fe / Beta catalyst possesses both microwave absorption and catalytic activity.

5. The method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics according to claim 1, characterized in that: The microwave catalytic reactor has a microwave frequency of 2.45 GHz, a power range of 0.5-5 kW, and the reaction temperature can be precisely controlled between 300-800℃, ensuring rapid heating of the reaction system.

6. The method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics according to claim 1, characterized in that: The distribution of gaseous products was regulated by the synergistic effect of Fe / Beta and microwave field.

7. The method for preparing hydrogen-rich syngas by microwave co-pyrolysis of biomass and plastics according to claim 1, characterized in that: The specific parameters in the step of preparing hydrogen-rich syngas by microwave catalytic co-pyrolysis of biomass and plastic are as follows: 1.5g Fe / Beta catalyst, 0.5-1g rice husk and 0.5-1g LDPE are mixed evenly and packaged in a quartz tube, both ends are sealed with quartz wool and connected to the reaction system.

8. The method for preparing hydrogen-rich syngas by microwave co-thermolysis of biomass and plastics according to claim 1, characterized in that: After the reaction of biomass and plastics undergoing microwave catalytic co-pyrolysis to prepare hydrogen-rich syngas, the gas in the gas bag was collected. Quantitative analysis of the gas products was then performed: 250 μL of sample was injected for each test. The temperature program for gas phase analysis was set as follows: first, a constant temperature of 80℃ for 8 minutes, then a rate of 30℃ / min increase to 190℃ and a holding time of 5 minutes. Component analysis of the gas obtained from the reaction revealed the following volume yields: hydrogen 41.2-60.4 vol%; carbon monoxide 18.3-33.0 vol%; methane 3.8-11.8 vol%; carbon dioxide 3.0-18.2 vol%, of which hydrogen-rich syngas (H2+CO) accounted for 62.9-89.5 vol%.

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