Method for producing green ammonia alcohol by directly combusting biomass to prepare carbon dioxide and nitrogen coupled green hydrogen

Abstract

The invention discloses a method for producing green ammonia alcohol by directly combusting biomass to produce carbon dioxide and nitrogen coupled green hydrogen, which comprises a combustion boiler, the exhaust end of the combustion boiler is connected with the gas inlet end of a dust removal heat exchanger through a pipeline, and the output end of the dust removal heat exchanger is sequentially connected with a spray washing purifier, an electrostatic dust collector and an adsorption filter. The output end of the adsorption filter is connected with a carbon dioxide and nitrogen storage cabinet through a Roots blower, and the output end of the carbon dioxide and nitrogen storage cabinet is connected with a carbon dioxide and nitrogen separator; and the output ends of the carbon dioxide storage cabinet and the nitrogen storage cabinet are respectively connected with the green methanol catalytic synthesis reactor and the green ammonia catalytic synthesis reactor. According to the biomass direct-combustion oxidation method, only biomass fuel needs to be simply crushed and then directly combusted, a series of complex reactions such as pyrolysis, oxidation and reduction of biomass are promoted without the help of a complex gasification medium, and a special gasification furnace and complex equipment for follow-up gas treatment do not need to be arranged.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass energy utilization, and specifically to a method for directly burning biomass to produce carbon dioxide and coupling green hydrogen to produce green ammonia and alcohol. Background Art

[0002] Biomass energy is the fourth largest resource on Earth, second only to coal, oil, and natural gas, and is also the largest renewable energy source in terms of reserves. Biomass has the characteristics of wide distribution, rich reserves, renewability, and low pollution, and is one of the most potential alternative energy sources to fossil fuels. At present, the energy utilization methods of biomass mainly include fermentation to produce fuel, biogas, gasification, fast pyrolysis, and carbonization.

[0003] During the process of pyrolyzing biomass raw materials in a biomass gasifier, the initial stage is high-temperature gas, the temperature in the furnace is 700 - 800 degrees Celsius, and the gas is mixed with tar (the tar is in a gaseous state at this time). In order to effectively use this green gas to replace fossil fuels, the high-temperature gas needs to be cooled to room temperature before it can be transported to user equipment through pipelines.

[0004] Restricted by the technical ideas of traditional coal-to-methanol technology, current biomass-to-green-methanol is mostly limited to pyrolyzing and gasifying biomass to produce carbon monoxide, carbon dioxide, hydrogen, etc., and then coupling green hydrogen catalytic synthesis of green methanol after reforming to change the component ratio. This method relies on a complex pyrolysis and gasification process, with large equipment investment and cumbersome operation.

[0005] Although some explorations use biomass gasification to produce carbon dioxide and green hydrogen to synthesize green methanol, they still first gasify biomass and then oxidize it to produce carbon dioxide, with a long process, resulting in an increase in production links and costs. Some people have also tried to directly burn biomass to produce carbon dioxide, but use oxygen and other substances as gasifying agents, greatly increasing the reaction cost and being significantly limited in large-scale applications. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for directly burning biomass to produce carbon dioxide and coupling green hydrogen to produce green ammonia and alcohol, so as to solve the problems raised in the above background art.

[0007] To solve the above technical problems, the present invention provides the following technical solution: a method for producing green ammonia and alcohol by coupling carbon dioxide and nitrogen produced by direct combustion of biomass with green hydrogen production, which includes a combustion boiler. The exhaust end of the combustion boiler is connected to the intake end of a dust removal heat exchanger through a pipeline. The output end of the dust removal heat exchanger is successively connected with a spray water washing purifier, an electrostatic precipitator, and an adsorption filter. The output end of the adsorption filter is connected to a carbon dioxide and nitrogen gas storage tank through a Roots blower. The output end of the carbon dioxide and nitrogen gas storage tank is connected to a carbon dioxide and nitrogen separator. The output end of the carbon dioxide and nitrogen separator is respectively connected to a carbon dioxide gas storage tank and a nitrogen gas storage tank through pipelines. The output ends of the carbon dioxide gas storage tank and the nitrogen gas storage tank are respectively connected to a green methanol catalytic synthesis reactor and a green ammonia catalytic synthesis reactor. The output ends of the green methanol catalytic synthesis reactor and the green ammonia catalytic synthesis reactor are respectively connected to a green methanol storage tank and a green ammonia storage tank.

[0008] In a preferred embodiment, the dust removal heat exchanger adopts a two-stage cyclone dust removal heat exchanger, and the two-stage cyclone dust removal heat exchanger has a good dust removal and heat exchange effect on high-temperature flue gas.

[0009] In a preferred embodiment, the waste heat of the combustion boiler, the dust removal heat exchanger, and the spray water washing purifier is recovered for thermoelectric cooling supply and cooling of the carbon dioxide and nitrogen separator. The waste heat in the combustion boiler, the dust removal heat exchanger, and the spray water washing purifier is recovered, and then the heat is used for cooling the carbon dioxide and nitrogen separator, heating during green ammonia synthesis, and green alcohol synthesis, which can realize the reuse of heat and save resources.

[0010] In a preferred embodiment, the carbon dioxide and nitrogen separator is a pressure swing adsorption separation, a membrane separation, or a cryogenic distillation separation.

[0011] In a preferred embodiment, the input ends of the green methanol catalytic synthesis reactor and the green ammonia catalytic synthesis reactor are connected to a green hydrogen gas storage tank through pipelines. Green hydrogen is added to the green methanol catalytic synthesis reactor to synthesize green methanol, and green hydrogen is added to the green ammonia catalytic synthesis reactor to synthesize green ammonia.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0013] 1. The present invention simplifies the production process: For direct combustion oxidation of biomass, the biomass fuel only needs to be simply crushed and then directly burned, with simple operation and low technical requirements. Compared with biomass gasification, it does not require complex gasification media (such as air, oxygen, or steam) to promote a series of complex reactions such as pyrolysis, oxidation, and reduction of biomass, nor does it require special gasification furnaces and complex equipment for subsequent treatment of the gas.

[0014] 2. Cost reduction advantages of the present invention: In the production of carbon dioxide, considering only the upfront equipment investment and fuel costs, direct combustion oxidation has prominent cost advantages in distributed green hydrogen, ammonia, and alcohol application scenarios. It does not require, like biomass gasification, a large amount of capital investment in gasification equipment, gas purification devices, and subsequent treatment equipment;

[0015] 3. Optimization of gasifying agent selection in the present invention: Using air as the gasifying agent enables the full combustion of biomass to obtain the maximum amount of carbon dioxide, providing sufficient raw materials for synthesizing green methanol with green hydrogen;

[0016] 4. Expansion of profit channels in the present invention: Making full use of the nitrogen remaining after the reaction of oxygen in the gasifying agent with carbon, synthesizing green ammonia with green hydrogen, increasing the profit channels of the project, and enhancing the project's returns;

[0017] 5. Purification of gas products in the present invention: After the direct combustion of biomass, the method of spray washing with water can thoroughly remove a large amount of dust in the carbon dioxide gas, meeting the stringent conditions for synthesizing green ammonia and alcohol with green hydrogen;

[0018] 6. Improvement of safety performance in the present invention: The mixed gas of carbon dioxide and nitrogen produced is easier to separate than carbon monoxide. Moreover, both carbon dioxide and nitrogen are non-flammable and non-explosive gases, facilitating storage and transportation, and significantly enhancing the safety factor of ammonia and alcohol production;

[0019] 7. Efficient utilization of waste heat in the present invention: A large amount of heat is released during the oxidation of biomass. Recovering this heat fully and converting it into cold, heat, and electricity. The cold produced is used for gas separation, the heat is used for catalytic synthesis, and the electricity is used for system operation, realizing the efficient recycling of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0021] Figure 1 is a schematic diagram of the system structure of the present invention.

[0022] In the figure: 1. Combustion boiler; 2. Dust removal heat exchanger; 3. Spray washing purifier; 4. Electrostatic precipitator; 5. Adsorption filter; 6. Roots blower; 7. Carbon dioxide and nitrogen gas storage tank; 8. Carbon dioxide and nitrogen separator; 9. Carbon dioxide gas storage tank; 10. Nitrogen gas storage tank; 11. Green methanol catalytic synthesis reactor; 12. Green ammonia catalytic synthesis reactor; 13. Green methanol storage tank; 14. Green ammonia storage tank. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Please refer to Figure 1 , the present invention provides a method for directly burning biomass to produce carbon dioxide and coupling green hydrogen production to produce green ammonia and alcohol, including a combustion boiler 1. The exhaust end of the combustion boiler 1 is connected to the intake end of a dust removal heat exchanger 2 through a pipeline. The output end of the dust removal heat exchanger 2 is successively connected with a spray water washing purifier 3, an electrostatic precipitator 4, and an adsorption filter 5. The output end of the adsorption filter 5 is connected to a carbon dioxide and nitrogen gas storage tank 7 through a Roots blower 6. The output end of the carbon dioxide and nitrogen gas storage tank 7 is connected to a carbon dioxide and nitrogen separator 8. The output end of the carbon dioxide and nitrogen separator 8 is respectively connected to a carbon dioxide gas storage tank 9 and a nitrogen gas storage tank 10 through pipelines. The output ends of the carbon dioxide gas storage tank 9 and the nitrogen gas storage tank 10 are respectively connected to a green methanol catalytic synthesis reactor 11 and a green ammonia catalytic synthesis reactor 12. The output ends of the green methanol catalytic synthesis reactor 11 and the green ammonia catalytic synthesis reactor 12 are respectively connected to a green methanol storage tank 13 and a green ammonia storage tank 14.

[0025] In a preferred embodiment, the dust removal heat exchanger 2 adopts a two-stage cyclone dust removal heat exchanger, and the two-stage cyclone dust removal heat exchanger has a good dust removal and heat exchange effect on high-temperature flue gas.

[0026] In a preferred embodiment, the waste heat of the combustion boiler 1, the dust removal heat exchanger 2, and the spray water washing purifier 3 is recovered for thermoelectric cooling supply and cooling of the carbon dioxide and nitrogen separator 8. A large amount of heat is released during the oxidation process of biomass. These heats are fully recovered and converted into cold, heat, and electricity. The generated cold is used for gas separation, the heat is used for catalytic synthesis, and the electricity is used for system operation, realizing the efficient recycling of energy.

[0027] In a preferred embodiment, the carbon dioxide and nitrogen separator 8 is a pressure swing adsorption separation, membrane separation, or cryogenic distillation separation.

[0028] In a preferred embodiment, the input ends of the green methanol catalytic synthesis reactor 11 and the green ammonia catalytic synthesis reactor 12 are connected to a green hydrogen gas storage tank through pipelines. Green hydrogen is added to the green methanol catalytic synthesis reactor 11 to synthesize green methanol, and green hydrogen is added to the green ammonia catalytic synthesis reactor 12 to synthesize green ammonia.

[0029] The working principle of the present invention:

[0030] 1. Combustion stage: After being simply crushed, the biomass raw materials are transported to the combustion boiler 1 and burned sufficiently with air as the combustion aid, generating carbon dioxide, nitrogen, water vapor, etc. There will also be a small amount of nitrogen oxides, sulfur dioxide, etc.;

[0031] 2. Dust removal and purification: The burned gas first passes through the cyclone dust removal heat exchanger 2 for preliminary dust removal and heat exchange, then is cooled by spraying water through the spray water washing purifier 3, and then successively passes through the electrostatic precipitator 4 and the adsorption filter 5 to further remove impurities, obtaining a relatively pure mixed gas of carbon dioxide and nitrogen;

[0032] 3. Gas separation: The purified mixed gas enters the ultra-clean carbon dioxide and nitrogen storage tank 7, and then technologies such as pressure swing adsorption separation, membrane separation or cryogenic distillation separation are used to separate carbon dioxide and nitrogen, while removing impurities such as nitrogen oxides and sulfur dioxide;

[0033] 4. Synthesis stage: The separated carbon dioxide and nitrogen respectively react with green hydrogen in the reactor under the action of a specific catalyst to carry out catalytic synthesis reactions, generating green methanol and green ammonia, and the products are stored in the green alcohol storage tank and the green ammonia storage tank; During the whole process, the waste heat generated by biomass combustion is recycled to provide the required cold, heat and electricity for gas separation and catalytic synthesis.

[0034] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for producing green ammonia by direct combustion of biomass to produce carbon dioxide and nitrogen coupled with green hydrogen, characterized in that: The invention comprises a combustion boiler (1), wherein the exhaust end of the combustion boiler (1) is connected to the air inlet end of a dust removal heat exchanger (2) through a pipeline, the output end of the dust removal heat exchanger (2) is connected to a spray water purifier (3), an electrostatic precipitator (4) and an adsorption filter (5) in sequence, the output end of the adsorption filter (5) is connected to a carbon dioxide and nitrogen gas storage cabinet (7) through a Roots blower (6), the output end of the carbon dioxide and nitrogen gas storage cabinet (7) is connected to a carbon dioxide and nitrogen separator (8), the output end of the carbon dioxide and nitrogen separator (8) is connected to a carbon dioxide gas storage cabinet (9) and a nitrogen gas storage cabinet (10) through pipelines, the output ends of the carbon dioxide gas storage cabinet (9) and the nitrogen gas storage cabinet (10) are connected to a green methanol catalytic synthesis reactor (11) and a green ammonia catalytic synthesis reactor (12), respectively, and the output ends of the green methanol catalytic synthesis reactor (11) and the green ammonia catalytic synthesis reactor (12) are connected to a green methanol storage tank (13) and a green ammonia storage tank (14) respectively.

2. The method for producing green ammonia by direct combustion of biomass to produce carbon dioxide and nitrogen coupled with green hydrogen according to claim 1, characterized in that: The dust removal heat exchanger (2) is a two-stage cyclone dust removal heat exchanger.

3. The method for producing green ammonia by direct combustion of biomass to produce carbon dioxide and nitrogen coupled with green hydrogen according to claim 1, characterized in that: The waste heat recovered from the combustion boiler (1), the dust removal heat exchanger (2) and the spray water washing purifier (3) is used for heat, electricity and cooling supply and cooling supply for the carbon dioxide and nitrogen separator (8).

4. The method for producing green ammonia by direct combustion of biomass to produce carbon dioxide and nitrogen coupled with green hydrogen according to claim 1, characterized in that: The carbon dioxide and nitrogen separator (8) is a pressure swing adsorption separation, a membrane separation or a low temperature deep cold separation.

5. The method for producing green ammonia by direct combustion of biomass to produce carbon dioxide and nitrogen coupled with green hydrogen according to claim 1, characterized in that: The input ends of the green methanol catalytic synthesis reactor (11) and the green ammonia catalytic synthesis reactor (12) are connected to the green hydrogen gas storage cabinet through pipelines; green hydrogen is added to the green methanol catalytic synthesis reactor (11) to synthesize green methanol; and green hydrogen is added to the green ammonia catalytic synthesis reactor (12) to synthesize green ammonia.

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