Biomass biogas purification coupling carbon capture and conversion integrated system and device

Abstract

The invention provides a biomass biogas purification coupling carbon capture and conversion integrated system and device. The biomass biogas purification coupling carbon capture and conversion integrated system comprises a purification unit and a conversion unit. The purification unit comprises one or more trapping reactors, a trapping material is used for trapping carbon dioxide in the biomass biogas, the biogas purified by the single trapping reactor enters the conversion unit, and a high-added-value product is further synthesized; the biomass biogas purified by the plurality of trapping reactors can be used as biogas to enter a gas pipeline or be sold. The conversion unit comprises an in-situ conversion reactor or a combination of the in-situ conversion reactor and a Fischer-Tropsch synthesis reactor, and regeneration of a trapping material and high-value utilization of carbon dioxide are simultaneously realized in a catalytic conversion manner. The system simultaneously realizes integration of biomass biogas purification and carbon dioxide capture and utilization, improves the energy utilization efficiency of biomass biogas, co-produces high-added-value products, remarkably reduces the emission of carbon dioxide, and is a novel green, low-carbon and sustainable system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of renewable energy, more specifically, relates to a biomass biogas purification coupled carbon capture and conversion integrated system and device. BACKGROUND

[0002] With the increasing depletion of oil resources, the continuous growth of global population and the urgent need to reduce greenhouse gas emissions, the use of renewable energy is increasing. Wind energy, solar energy and biomass energy, as the three major renewable energy sources, are expected to dominate the global energy supply in the future and gradually replace fossil fuels. Unlike wind energy and solar energy, which have intermittent characteristics, biomass energy is abundant, widely used, and can achieve sustainable power generation on the premise of ensuring a reliable supply chain. Currently, biomass energy accounts for 10% of the total global primary energy supply. As a renewable resource, biomass biogas has been proven to significantly promote social and economic development. Biomass biogas is mainly derived from the anaerobic fermentation of organic waste (livestock and poultry manure, crop straw, industrial organic wastewater, etc.), composed of 40%-75% methane (CH4), 25%-60% carbon dioxide (CO2) and some trace gases such as hydrogen sulfide (H2S). Traditional biomass biogas utilization methods (such as power generation, direct combustion) have low energy conversion efficiency and poor economic performance. The alternative solution developed over the past few decades is to upgrade and upgrade biomass biogas to increase its methane content. Purified biomethane can be used locally as compressed gas, or directly injected into the natural gas pipeline as a renewable fuel.

[0003] In recent years, to improve the utilization potential of biomass biogas, technologies for purifying it to natural gas quality have attracted much attention. The presence of high concentrations of carbon dioxide in raw biomass biogas not only significantly reduces its calorific value, but also restricts its application potential in distributed energy systems. Traditional carbon dioxide removal technologies (pressure swing adsorption, chemical absorption and membrane separation, etc.) are mature, but have obvious defects: on the one hand, these technologies have high energy consumption and high operating costs, and CH4 can easily escape during the separation process; on the other hand, CO2 is not effectively utilized, resulting in resource waste and secondary pollution. In contrast, carbon capture and in-situ conversion technology not only has high CO2 capture efficiency, but also can convert captured CO2 into value-added chemicals (methane, syngas and olefins, etc.) on site, reducing compression and transportation costs and the corresponding equipment, with higher environmental and economic feasibility, realizing the innovation of the biomass biogas purification process. Therefore, it is of great significance to propose an integrated system that simultaneously realizes biomass biogas purification and biogas CO2 capture and conversion. SUMMARY

[0004] The present application overcomes the above-mentioned defects of the prior art and provides a biomass biogas purification coupled carbon capture and conversion integrated system and device.

[0005] In a first aspect, the present application provides a biomass biogas purification coupled carbon capture and conversion integrated system, having the following technical features: comprising a purification unit and a conversion unit.

[0006] The purification unit comprises one or more capture reactors, which use capture materials to capture carbon dioxide in the biomass biogas. The biogas purified by the single capture reactor enters the conversion unit for further synthesis of high value-added products. The biogas purified by the multiple capture reactors can be used as bio-gas to enter the gas pipeline or be sold.

[0007] The conversion unit comprises an in-situ conversion reactor or a combination of an in-situ conversion reactor and a Fischer-Tropsch synthesis reactor, which realizes the regeneration of the capture materials and the high-value utilization of carbon dioxide through catalytic conversion.

[0008] Preferably, the capture materials used are usually a combination of adsorbents and catalysts. The adsorbents are mainly alkali metal oxides, alkaline earth metal oxides and their combinations, including Na2O, K2O, CaO and MgO, etc. The catalysts are mainly metal-based catalysts and their combinations, including Ru, Ni, Fe, Pt, etc.

[0009] In the present application, the capture materials before and after capturing carbon dioxide are distinguished. The material without adsorbing carbon dioxide is referred to as capture material, and the material after adsorbing carbon dioxide is referred to as carbonated capture material.

[0010] The conversion unit converts carbon dioxide into high value-added products through in-situ conversion reactions such as methanation, reverse water gas shift, methane reforming, and low-carbon alkane dehydrogenation; or through in-situ conversion reactions and Fischer-Tropsch synthesis reactions, carbon dioxide is converted into high value-added downstream products.

[0011] Preferably, when the conversion unit involves reactions such as methanation, reverse water gas shift, and low-carbon alkane dehydrogenation, the purification unit needs multiple capture reactors to make the bio-gas meet the national standard requirements; when it involves the reaction of methane reforming to synthesize gas, the purification unit only needs a single capture reactor. The purified gas is fed into the conversion unit as a gas raw material to react with the released carbon dioxide to produce synthesis gas or as a raw gas for the Fischer-Tropsch synthesis reactor to further synthesize high value-added chemicals.

[0012] Preferably, the products of the biomass biogas purification coupled carbon capture and conversion integrated system can be bio-gas, high value-added products, and bio-gas and high value-added products.

[0013] In a second aspect, the present application provides a device for biomass biogas purification coupled with carbon capture and conversion, which comprises a capture reactor and an in-situ conversion reactor or a Fischer-Tropsch synthesis reactor, which are connected to each other, and the capture material is recycled by the cycle of carbonation and decarbonization; the biomass biogas to be purified is introduced into the capture reactor, and the conversion gas is introduced into the in-situ conversion reactor, and the carbon dioxide is directly converted into high-value-added products or the generated products are further introduced into the Fischer-Tropsch synthesis reactor to be converted into high-value-added chemicals.

[0014] Preferably, the high-value-added products can be methane, carbon monoxide, synthesis gas (CO, H2), olefins, etc., and more preferably, the synthesis gas can be further produced into high-value-added downstream products such as methanol, aviation kerosene, gasoline, diesel, etc. by Fischer-Tropsch synthesis.

[0015] Preferably, the conversion gas introduced into the in-situ conversion reactor is hydrogen, methane, low-carbon alkanes, etc.

[0016] Preferably, the pressure in the reactor is 1 atm or above.

[0017] Preferably, the temperature in the capture reactor is 300-800℃, the temperature in the in-situ conversion reactor is 300-850℃, and the temperature in the Fischer-Tropsch synthesis reactor is 300-1000℃.

[0018] Preferably, the reactor type can be in the form of a fixed bed, a single fluidized bed, a serial fluidized bed, etc.

[0019] Specifically, compared with the prior art, the present application has the following technical innovations and advantages:

[0020] (1) The biomass biogas purification coupled with carbon capture and conversion system and device provided by the present application simultaneously realizes the integration of biomass biogas purification and CO2 capture and conversion, and provides a new scheme for the efficient utilization of biomass biogas;

[0021] (2) The present application removes the carbon dioxide in the biomass biogas by the carbon dioxide capture and in-situ conversion technology, improves the energy density of the biomass biogas, and turns the waste carbon dioxide into treasure to produce high-value-added chemicals;

[0022] (3) The biomass biogas purification coupled with carbon capture and conversion system and device provided by the present application, the carbonated capture material obtained by the purification unit is introduced into the conversion unit, and the decarbonized capture material returns to the purification unit, realizing the recycling of the capture material.

[0023] In summary, the system provided by the present application realizes the integration of biomass biogas purification and CO2 capture and conversion through the purification unit and the conversion unit, improves the energy utilization efficiency of biomass biogas, co-produces high value-added products, and significantly reduces CO2 emissions, and is a green, low-carbon and sustainable new system. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Process flow block for the integration of biomass biogas purification and carbon capture and conversion;

[0025] Figure 2 Process flow diagram of the integration of biomass biogas purification and carbon capture and conversion-methanation system.

[0026] Figure 3 Process flow diagram of the integration of biomass biogas purification and carbon capture and conversion-methane reforming system.

[0027] Figure 4 Process flow diagram of the integration of biomass biogas purification and carbon capture and conversion-reverse water gas shift system. DETAILED DESCRIPTION

[0028] The present application will be further described below with reference to examples.

[0029] Example 1

[0030] This example provides a system for realizing the integration of biomass biogas purification and carbon dioxide capture and conversion by coupling calcium cycle and methanation reaction. Taking Ca-Ni capture material as an example, the specific process is as follows: a stream of biomass biogas from an agricultural industry park with an annual output of 210 million cubic meters is introduced into capture reactor 1, and the gas content is: 60% CH4, 40% CO2. The solid components are fresh Ca-Ni capture material feed and recycled Ca-Ni capture material, the temperature of capture reactor 1 is 550℃, and the operating pressure is ~1atm. The H2 feed of the methanation reactor is 180.06kmol / h, and the solid feed is the solid component after gas-solid separation of capture reactor 1 and capture reactor 2, the temperature of the methanation reactor is 550℃, and the operating pressure is ~1atm. The solid component obtained after gas-solid separation after the methanation reaction is introduced into capture reactor 1 and capture reactor 2, and the gas component is introduced into capture reactor 2 together with the gas component of capture reactor 1. The fresh Ca-Ni capture material feed of capture reactor 2 is 0.55kmol / h, the temperature of capture reactor 2 is 550℃, and the operating pressure is ~1atm. At equilibrium, the purity of the biogas is 98.8%.

[0031] Example 2

[0032] The embodiment provides a system for coupling calcium cycle and methane reforming reaction to realize integration of biomass biogas purification and carbon dioxide capture and conversion. Taking Ca-Ni capture material as an example, the specific process is as follows: a biomass biogas from an agricultural industrial park with an annual output of 2100 million cubic meters is introduced into a capture reactor, the gas content is 60% CH4 and 40% CO2. The solid component is fresh Ca-Ni capture material and recycled Ca-Ni capture material, the temperature of the capture reactor is 650 DEG C, and the operating pressure is about 1 atm. The water feed of the reforming reactor is 96.16 kmol / h, the solid feed of the capture reactor is the solid component after gas-solid separation of the capture reactor, and the gas component after gas-solid separation of the capture reactor is also introduced into the reforming reactor, the temperature of the reforming reactor is 850 DEG C, and the operating pressure is about 1 atm. The discharge of the reforming reactor is introduced into a methanol synthesis reactor after dehydration, the temperature of the methanol synthesis reactor is 250 DEG C, the operating pressure is 50 bar, and methanol is obtained after dehydration in a rectifying column. At equilibrium, the purity of the methanol is 99.3%.

[0033] Embodiment 3

[0034] The embodiment provides a system for coupling calcium cycle and reverse water gas shift reaction to realize integration of biomass biogas purification and carbon dioxide capture and conversion. Taking Ca-Ni capture material as an example, the specific process is as follows: a biomass biogas from an agricultural industrial park with an annual output of 2100 million cubic meters is introduced into a capture reactor 1, the gas content is 60% CH4 and 40% CO2. The solid component is fresh Ca-Ni capture material and recycled Ca-Ni capture material, the temperature of the capture reactor 1 is 650 DEG C, and the operating pressure is about 1 atm. The solid feed of the capture reactor 2 is also fresh Ca-Ni capture material and recycled Ca-Ni capture material, the gas feed is the gas component after gas-solid separation of the capture reactor 1, the temperature of the capture reactor 2 is 650 DEG C, and the operating pressure is about 1 atm. The hydrogen feed of the reverse water gas shift reactor is 135.06 kmol / h, the solid feed is the solid component after gas-solid separation of the capture reactor 1 and the capture reactor 2, the temperature of the reverse water gas shift reactor is 650 DEG C, and the operating pressure is about 1 atm. The discharge of the reverse water gas shift reactor is introduced into a methanol synthesis reactor after dehydration, the temperature of the methanol synthesis reactor is 250 DEG C, the operating pressure is 50 bar, and methanol is obtained after dehydration in a rectifying column. At equilibrium, the purity of the biogas is 99.3%, and the purity of the methanol is 99.0%.

Claims

1. A biomass biogas purification coupled carbon capture conversion integrated system, characterized in that, The application relates to a purification unit and a conversion unit. The purification unit comprises single or multiple capture reactors, carbon dioxide in biogas is captured by using a capture material, biogas purified by the single capture reactor enters the conversion unit, and is further synthesized into high-value-added products; biogas purified by the multiple capture reactors can enter a gas pipeline or be sold as bio-gas. The conversion unit comprises an in-situ conversion reactor or a combination of the in-situ conversion reactor and a Fischer-Tropsch synthesis reactor, and regeneration of the capture material and high-value utilization of carbon dioxide are realized by catalytic conversion. The capture material is generally a combination of an adsorbent and a catalyst, the adsorbent mainly being alkali metal oxides, alkaline earth metal oxides and combinations thereof, including Na2O, K2O, CaO and MgO, and the catalyst mainly being metal-based catalysts and combinations thereof, including Ru, Ni, Fe and Pt.

2. The system of claim 1, wherein, The conversion unit converts carbon dioxide into high-value-added products by in-situ conversion reactions such as methanation, reverse water gas shift, methane reforming and low-carbon alkane dehydrogenation; or converts carbon dioxide into high-value-added downstream products by in-situ conversion reactions and Fischer-Tropsch synthesis reactions.

3. The system of claim 1, wherein, When the conversion unit involves reactions such as methanation, reverse water gas shift and low-carbon alkane dehydrogenation, the purification unit needs multiple capture reactors to make the bio-gas meet the national standard requirements; when the conversion unit involves a reaction of synthesizing syngas by methane reforming, the purification unit only needs a single capture reactor, and the purified gas is introduced into the conversion unit to react with the released carbon dioxide, so as to synthesize syngas or to be used as raw gas of the Fischer-Tropsch synthesis reactor to further synthesize high-value-added chemicals.

4. The system of claim 1, wherein, The application relates to a capture reactor and an in-situ conversion reactor or a combination of the in-situ conversion reactor and a Fischer-Tropsch synthesis reactor which are in communication with each other, and the capture material is recycled by carbonation and decarbonization; the capture reactor is used to introduce biogas to be purified, the in-situ conversion reactor is used to introduce conversion gas, and carbon dioxide is directly converted into high-value-added products or the generated products are further introduced into the Fischer-Tropsch synthesis reactor to be converted into high-value-added chemicals.

5. The integrated device for biomass biogas purification coupled with carbon capture and conversion, characterized in that, The conversion gas comprises hydrogen, methane, low-carbon alkane and the like.

6. The apparatus of claim 5, wherein, The high-value-added products can be methane, carbon monoxide, syngas, olefin and the like, and the syngas can be further used to produce high-value-added downstream products such as methanol, aviation kerosene, gasoline and diesel by Fischer-Tropsch synthesis.

7. The apparatus of claim 5, wherein, The pressure in the reactors is 1 atm or above.

8. The apparatus of claim 5, wherein, The temperature in the capture reactor is 300-800 DEG C, the temperature in the in-situ conversion reactor is 300-850 DEG C, and the temperature in the Fischer-Tropsch synthesis reactor is 300-1000 DEG C.

9. The apparatus of claim 5, wherein, The reactor types can be fixed bed, single fluidized bed, serial fluidized bed and the like.

10. The apparatus of claim 5, wherein, ​

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