A carbon-negative electricity-heat-hydrogen trigeneration device and method based on biomass gasification

Abstract

The application discloses a kind of based on biomass gasification's negative carbon emission electric-heat-hydrogen triple supply device and method, the device includes: biomass gasification unit, chemical chain hydrogen production-oxygen production unit, gas turbine power generation unit, steam turbine power generation-heat supply unit and pipeline.The application is relative to traditional solid fuel gasification hydrogen production device, process is simple, only need to pass through gasification, combustion and water decomposition hydrogen production three stages, and H2Purity is as high as 99% or more;Through high-purity CO2 capture realizes negative carbon emission;Through bypass control valve control H2 And the generation amount of O2 In hydrogen-oxygen production unit;By adjusting the proportion of syngas entering chemical chain hydrogen production-oxygen production unit and gas turbine unit to adjust the proportion of hydrogen amount and power generation amount, by adjusting steam turbine extraction amount or extraction point position to meet the heating demand and adjust the proportion of power generation amount and heating amount;So as to realize negative carbon emission while flexibly adjusting the proportion among power generation, heating and hydrogen production of device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of distributed energy supply based on biomass as energy source, in particular to a carbon-negative electric-thermal-hydrogen trigeneration device and method based on biomass gasification. BACKGROUND

[0002] China is a large agricultural country, and the vast arable land and economic forest area will produce a large amount of agricultural and forestry biomass waste every year; biomass energy is a CO2 zero-emission renewable energy, which can not only realize the effective disposal of biomass waste, but also help to reduce the dependence on fossil fuels.

[0003] Biomass resources have the characteristics of diverse sources, low energy density and scattered distribution, which determine that it is necessary to develop biomass energy industry according to local conditions and distributed utilization. Industrial parks have the characteristics of large energy density, various energy forms and relatively stable energy demand, which is one of the best application scenarios for distributed energy application. Electricity and heat are the most widely demanded energy forms in industrial parks; in addition, hydrogen is an ideal fuel, its main combustion product in air is water, which will not cause environmental pollution, and greatly reduce greenhouse gas emissions. Hydrogen is an important raw material for modern industry, mainly used in petroleum refining and petrochemical industry such as synthetic ammonia and methanol, also used as rocket fuel in the aviation industry and reducing gas in the metallurgical industry, and plays an important role in modern society. Hydrogen energy is an energy carrier that will be developed in China in the future, which will play an important role in the green and low-carbon transformation of energy terminal. Therefore, it is of great significance to develop hydrogen-containing multi-generation system based on biomass as energy source. Biomass gasification technology is a process of converting biomass into valuable gas products and solid products through thermochemical methods, and is also an effective process for producing electricity and heat, hydrogen and second-generation biofuels. Combined with the diversified energy demand of industrial parks, it has good application prospect to develop electric-thermal-hydrogen trigeneration device and method based on biomass gasification.

[0004] In addition, considering that CO2 is a major greenhouse gas, it is necessary to capture and store CO2 during fuel utilization to achieve CO2 emission reduction. Therefore, it is of great significance to capture CO2 while utilizing biomass as energy.

[0005] The existing biomass gasification technology needs a high-energy-consuming cryogenic air oxygen production process, and the biomass gasification for high-purity hydrogen needs to go through gasification, desulfurization, reforming, shift, acid gas removal and pressure swing adsorption processes. Although the technology is relatively mature, the process is complex, high in energy consumption and low in hydrogen production efficiency. In addition, the multi-combined supply technology based on biomass gasification is currently mainly limited to electric-thermal combined supply, and less considers CO2 capture and storage. There is no mature technology for hydrogen-containing multi-combined supply systems based on biomass as an energy source, especially for hydrogen-containing multi-combined supply systems with flexible adjustment of output proportions among various energy forms. SUMMARY

[0006] The present application is characterized in that the biomass gasification-based negative carbon emission electric-thermal-hydrogen triple-combined supply device and method can avoid high-energy-consuming air separation oxygen production, produce hydrogen with a purity of up to 99% using a simple process, effectively adjust the output proportions among electricity, heat and hydrogen, and realize negative carbon emission of biomass.

[0007] Technical scheme: In order to achieve the above-mentioned purpose, the present application provides a biomass gasification-based negative carbon emission electric-thermal-hydrogen triple-combined supply device and method, which comprises a biomass gasification unit, a chemical chain hydrogen-oxygen production unit, a gas turbine power generation unit, a steam turbine power generation-heat supply unit and a pipeline.

[0008] The biomass gasification unit is composed of a gasification furnace, a first waste heat boiler syngas side, a dust and desulfurization device and a flow divider. The first waste heat boiler syngas side is connected in series at the outlet of the gasification furnace and connected with the dust and desulfurization device. The flow divider is connected in series at the outlet of the dust and desulfurization device, and the outlet pipeline of the flow divider is divided into two, one of which is connected with the fuel reactor of the chemical chain hydrogen-oxygen production unit, and the other is connected with the fuel compressor of the gas turbine power generation unit.

[0009] The chemical chain hydrogen-oxygen unit is composed of a fuel reactor, a flow divider, a steam reactor, a bypass control valve, an air reactor, a first waste heat boiler cold side, a first heat exchanger, an oxygen production reactor, a bypass control valve, a second waste heat boiler CO2 side, a CO2 compressor, a first cooler, a third waste heat boiler H2 side, an H2 compressor and a second cooler; the fuel reactor is connected in series with one of the outlets of the flow divider and a solid outlet of the oxygen production reactor, and is connected in series with a solid outlet of the air reactor through the bypass control valve; an outlet pipeline of the fuel reactor is divided into two, one of which is connected with the steam reactor and the air reactor through the bypass control valve, and the other of which is connected with the flow divider; an outlet pipeline of the flow divider is divided into two, one of which is connected with the chemical chain oxygen production reactor, and the other of which is connected with the second waste heat boiler; the second waste heat boiler CO2 side pipeline is connected in series with one of the outlets of the flow divider and the CO2 compressor; the CO2 compressor is connected in series with the second waste heat boiler CO2 side outlet and the first cooler; the first cooler CO2 side is connected in series with the CO2 compressor outlet, and a water side outlet of the first cooler is connected with a water side of the second cooler; the steam reactor is connected in series with the fuel reactor solid outlet and a steam side outlet of the first heat exchanger, and an outlet pipeline of the steam reactor is divided into two, one of which is connected with the air reactor, and the other of which is connected with the third waste heat boiler; the third waste heat boiler H2 side is connected in series with a gas outlet of the steam reactor and the H2 compressor; the H2 compressor is connected in series with the third waste heat boiler H2 side outlet and the second cooler; a H2 side of the second cooler is connected in series with the H2 compressor outlet, and a water side of the second cooler is connected in series with a water side outlet of the first cooler and a water side of the first waste heat boiler; the air reactor is connected in series with a first waste heat boiler air side outlet and a solid outlet of the steam reactor, and is connected in series with the fuel reactor solid outlet through the bypass control valve; an outlet pipeline of the air reactor is divided into two, one of which is connected with the oxygen production reactor and the fuel reactor through the bypass control valve, and the other of which is connected with a first heat exchanger air side; the first heat exchanger steam side is connected in series with a water side outlet of the first waste heat boiler and the steam reactor, and the first heat exchanger air side is connected in series with the air reactor outlet; the oxygen production reactor is connected in series with a solid side outlet of the air reactor and one of the outlets of the flow divider, and an outlet pipeline of the oxygen production reactor is divided into two, one of which is connected with the fuel reactor, and the other of which is connected with a gasification furnace; air and water from the second cooler are heated by the first waste heat boiler and then enter the air reactor and the first heat exchanger steam side respectively;

[0010] The gas turbine power generation unit consists of a fuel compressor, an air compressor, a combustion chamber, a gas turbine, and a waste heat boiler flue gas side; the fuel compressor is connected in series to one of the outlets of the splitter and is connected to the combustion chamber; the air compressor is connected to the combustion chamber; the combustion chamber is connected in series to the outlets of the fuel compressor and the air compressor and is connected to the gas turbine; the gas turbine is connected in series to the outlet of the combustion chamber and is connected to the fourth waste heat boiler flue gas side.

[0011] The steam turbine power generation and heating unit consists of a steam turbine, a second heat exchanger, a condenser, a feedwater pump, a fourth waste heat boiler (water side), a second waste heat boiler (steam side), and a third waste heat boiler (steam side). The steam turbine is connected in series at the outlet of the third waste heat boiler (steam side). The steam turbine outlet pipeline is split into two: one connected to the second heat exchanger, and the other connected to the condenser (steam side). The hot side of the second heat exchanger is connected in series to the steam turbine extraction port and to the feedwater pump; the cold side of the second heat exchanger serves as the heating medium. The condenser is connected in series to the steam turbine exhaust port and to the feedwater pump. The feedwater pump is connected in series to the outlet of the second heat exchanger (hot side) and the outlet of the condenser (steam side), and to the fourth waste heat boiler (water side). The fourth waste heat boiler (water side) is connected in series to the feedwater pump outlet and to the second waste heat boiler (steam side). The second waste heat boiler (steam side) is connected in series to the outlet of the fourth waste heat boiler (water side) and to the third waste heat boiler (steam side). The third waste heat boiler (steam side) is connected in series to the outlet of the second waste heat boiler (steam side) and to the steam turbine.

[0012] Preferably, the gasification medium of the biomass gasifier is a mixture of O2, H2O and CO2.

[0013] Preferably, the solid recycled material in the chemical loop hydrogen-oxygen production unit is a hydrogen-oxygen decoupling bifunctional oxygen carrier. This oxygen carrier is composed of a metal active oxide and an inert carrier, and the metal active oxide is a mixture of iron oxide with hydrogen production function and metal oxide with oxygen decoupling function; wherein, the metal oxide with oxygen decoupling function can be copper, cobalt, manganese metal oxide or perovskite.

[0014] Preferably, the distributor and the distributor can control the gas flow rate in the two outlet branches separately.

[0015] Preferably, the fuel reactor is a moving bed reactor, while the steam reactor, air reactor, and oxygen generator reactor are fluidized bed reactors.

[0016] Preferably, the fluidizing air of the oxygen generator comes from CO2 and H2O generated by the complete oxidation of syngas in the fuel reactor, thereby obtaining a mixture of O2, H2O and CO2 as a biomass gasification medium.

[0017] Preferably, negative carbon emissions from biomass are achieved by capturing a portion of the CO2 produced by the fuel reactor.

[0018] Preferably, the steam reactor and the oxygen production reactor are each equipped with a bypass control valve and a bypass control valve, respectively. The bypass control valve can adjust the bypass flow of solid materials by controlling the opening degree.

[0019] Preferably, the steam turbine is an extraction condensing steam turbine.

[0020] Based on the above-mentioned device, the present invention also provides a negative carbon emission combined heat and power (CHP) method for biomass gasification, comprising the following steps:

[0021] S1: Biomass and a mixture of O2, H2O and CO2 are fed into a gasifier to produce syngas through a biomass gasification reaction. The biomass gasifier uses atmospheric pressure gasification and the reaction temperature is 750 ~ 950 °C. The syngas enters the first waste heat boiler and exchanges heat with air and water from the second cooler. After being treated by a dust removal and desulfurization device, it enters a distributor. One part of it enters the fuel reactor of the chemical loop hydrogen-oxygen production unit, and the other part enters the gas turbine power generation unit.

[0022] S2: The fuel reactor is a moving bed reactor, with the temperature controlled at 800-850 °C. The syngas entering the fuel reactor undergoes a redox reaction with high-valence iron oxides and an oxygen-decoupled oxygen carrier, where Fe₂O₃ is deeply reduced to Fe / FeO. The reduced oxygen carrier then enters either a steam reactor or an air reactor, while the syngas is completely oxidized into a mixture of H₂O and CO₂ and enters a distributor. A portion of this mixture is sent to the oxygen generator reactor as fluidizing air, while the other portion first enters the second waste heat boiler for cooling, then is compressed using a CO₂ compressor. Further cooling and condensate removal by the first cooler yields high-purity compressed CO₂. The steam reactor is in a bubbling fluidized bed state, with the temperature controlled at 825-875 °C. At °C, the reduced oxygen carrier (containing a high amount of Fe / FeO) entering the steam reactor reacts with steam to produce a mixture of H2 and steam. The oxygen carrier is then sent to the air reactor for further oxidation. The H2 and steam mixture first enters the third waste heat boiler for cooling, then is compressed by an H2 compressor, and further cooled and decondensed by the second cooler to obtain high-purity compressed H2. Cooling water is heated by the first and second coolers and then enters the first waste heat boiler and the first heat exchanger to form high-temperature steam, which is then sent to the steam reactor to participate in the hydrogen production reaction. Air is heated by the first waste heat boiler and then sent to the air reactor to participate in the reaction. The air reactor is in a rapid fluidized bed, with the temperature controlled at 1000~1050 °C. The low-valence oxygen carrier entering the air reactor reacts with the air to become a high-valence oxygen carrier and releases a large amount of heat. The oxygen-deficient air after the reaction is cooled by the first heat exchanger and then discharged. The oxygen production reactor is in a bubbling fluidized bed, with the temperature controlled at 950~1000 °C. At °C, the oxygen in the high-valence oxygen carrier entering the oxygen generator reactor releases O2 at high temperature. The resulting mixture of O2, H2O and CO2 is sent to the gasifier as a gasifying agent. The oxygen carrier after oxygen release is sent to the fuel reactor to undergo a redox reaction with the syngas.

[0023] S3: One of the synthesis gas outlets of the splitter is compressed by the fuel compressor and then reacts with the air compressed by the air compressor in the combustion chamber. The generated high-temperature flue gas enters the gas turbine to do work and is then sent to the fourth waste heat boiler for cooling before being discharged into the air.

[0024] S4: After being pressurized by the feedwater pump, the feedwater enters the fourth, second and third waste heat boilers in sequence to become high-temperature and high-pressure steam, which then enters the steam turbine to do work. The exhaust steam after doing work enters the condenser to condense and then enters the feedwater pump for pressurization. The steam for heating releases heat and condenses after passing through the second heat exchanger before entering the feedwater pump.

[0025] Preferably, by adjusting the ratio of reduced oxygen carrier entering the steam reactor and the air reactor through a bypass control valve, the amount of hydrogen can be controlled while ensuring that the oxygen production remains constant.

[0026] Preferably, by adjusting the ratio of oxidized oxygen carrier entering the oxygen production reactor and the fuel reactor through a bypass control valve, the oxygen quantity can be controlled while ensuring that the hydrogen production quantity remains unchanged.

[0027] Preferably, the ratio of hydrogen to power generation is controlled by adjusting the ratio of syngas entering the chemical loop hydrogen-oxygen production unit and the gas turbine unit through a splitter.

[0028] Preferably, the heating demand is met by adjusting the steam extraction rate of the steam turbine or the location of the steam extraction point, and the ratio of power generation to heating is controlled.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0030] 1. This invention utilizes zero-carbon biomass as an energy source, which helps reduce carbon emissions; it eliminates the need for a high-investment, high-energy-consuming cryogenic air separation oxygen production unit, thus improving system efficiency.

[0031] 2. Compared with traditional solid fuel gasification hydrogen production equipment, the process is simple, requiring only three stages: gasification, combustion, and water decomposition to produce hydrogen. This not only improves hydrogen production efficiency but also achieves H2 purity of over 99%.

[0032] 3. It can achieve negative carbon emissions through high-purity CO2 capture;

[0033] In this invention, the biomass gasification gas from the gasifier, after dust removal and desulfurization, mainly consists of CO, H2, CO2, H2O, and a small amount of CH4; the oxidized oxygen carrier from the oxygen generator or air reactor can use its own lattice oxygen to oxidize the gaseous fuel into CO2 and H2O, thereby avoiding the mixing of N2; the H2O can be removed by condensation to obtain high-purity CO2, thereby achieving CO2 capture, i.e., negative carbon emissions.

[0034] 4. The amount of H2 and O2 generated in the hydrogen-oxygen production unit is controlled by the bypass control valve; the ratio of hydrogen and power generation is controlled by adjusting the ratio of syngas entering the chemical loop hydrogen-oxygen production unit and the gas turbine unit; the amount of steam extracted from the steam turbine or the location of the steam extraction point is adjusted to meet the heating demand and regulate the ratio of power generation and heating; thus, while achieving negative carbon emissions, the ratio between power generation, heating and hydrogen production in the unit can be flexibly controlled. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall device structure of the present invention.

[0036] The components include: 1. Gasifier; 2. First waste heat boiler; 3. Dust removal and desulfurization unit; 4. Diverter; 5. Fuel reactor; 6. Diverter; 7. Steam reactor; 8. Bypass control valve; 9. Air reactor; 10. First heat exchanger; 11. Bypass control valve; 12. Hydrogen production reactor; 13. Fuel compressor; 14. Air compressor; 15. Combustion chamber; 16. Gas turbine; 17. Fourth waste heat boiler; 18. Second waste heat boiler; 19. CO2 compressor; 20. First cooler; 21. Third waste heat boiler; 22. CO2 compressor; 23. Second cooler; 24. Second heat exchanger; 25. Steam turbine; 26. Condenser; 27. Feedwater pump. Detailed Implementation

[0037] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading this invention, any modifications of the invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0038] like Figure 1 As shown, the present invention provides a negative carbon emission combined heat and power (CHP) device based on biomass gasification, including a biomass gasification unit, a chemical looping hydrogen-oxygen production unit, a gas turbine power generation unit, a steam turbine power generation-heating unit, and pipelines;

[0039] The biomass gasification unit consists of a gasifier 1, a first waste heat boiler 2 (syngas side), a dust collector and desulfurizer 3, and a distributor 4. The first waste heat boiler 2 (syngas side) is connected in series to the outlet of the gasifier 1 and to the dust collector and desulfurizer 3. The distributor 4 is connected in series to the outlet of the dust collector and desulfurizer 3. The outlet pipeline of the distributor 4 is divided into two parts: one is connected to the fuel reactor 5 of the chemical loop hydrogen-oxygen production unit, and the other is connected to the fuel compressor 13 of the gas turbine power generation unit. The gasification medium of the biomass gasifier 1 is a mixture of O2, H2O, and CO2. The distributor 4 can control the gas flow rate in the two outlet branches separately.

[0040] The chemical loop hydrogen-oxygen production unit consists of a fuel reactor 5, a splitter 6, a steam reactor 7, a bypass control valve 8, an air reactor 9, a first waste heat boiler 2 (cold side), a first heat exchanger 10, an oxygen production reactor 12, a bypass control valve 11, a second waste heat boiler 18 (CO2 side), a CO2 compressor 19, a first cooler 20, a third waste heat boiler 21 (H2 side), an H2 compressor 22, and a second cooler 23. The fuel reactor 5 is connected in series with one outlet of the splitter 4 and the solid outlet of the oxygen production reactor 12, and is also connected in series with the solid outlet of the air reactor 9 via the bypass control valve 11. The outlet pipe of the fuel reactor 5 is split into two: one is for solids and connected to the steam reactor 16, and the other is connected to the air reactor 9 via the bypass control valve 8. One path is connected to reactor 9, and the other path is for gas and connected to distributor 6. The outlet pipe of distributor 6 is split into two: one path is connected to chemical loop oxygen generator 12, and the other path is connected to the second waste heat boiler 18. The CO2 side pipe of the second waste heat boiler 18 is connected in series to one of the outlets of distributor 6 and is connected to CO2 compressor 19. The CO2 side outlet of the second waste heat boiler 18 is connected in series and is connected to the first cooler 20. The CO2 side outlet of the first cooler 20 is connected in series to the outlet of CO2 compressor 19, and the water side outlet of the first cooler 20 is connected to the water side of the second cooler 23. Steam reactor 7 is connected in series to the solid outlet of fuel reactor 5 and the steam side outlet of the first heat exchanger 10. The outlet pipe of steam reactor 7 is split into two. One pipeline is for solids and connected to air reactor 9, and the other is for gas and connected to the third waste heat boiler 21. The H2 side of the third waste heat boiler 21 is connected in series to the gas outlet of steam reactor 7 and to H2 compressor 22. The H2 compressor 22 is connected in series to the outlet of the H2 side of the third waste heat boiler 21 and to the second cooler 23. The H2 side of the second cooler 23 is connected in series to the outlet of H2 compressor 22, and the water side of the second cooler 23 is connected in series to the water side outlet of the first cooler 20 and to the water side of the first waste heat boiler 2. Air reactor 9 is connected in series to the air side outlet of the first waste heat boiler 2 and the solid outlet of steam reactor 7, and is connected in series to the solid outlet of fuel reactor 5 through bypass control valve 8. The outlet pipeline of air reactor 9 is divided into two, one of which is... One path is solid and connected to the oxygen generator 12, and connected to the fuel reactor 5 via the bypass control valve 11. The other path is gas and connected to the air side of the first heat exchanger 10. The steam side of the first heat exchanger 10 is connected in series to the water side outlet of the first waste heat boiler 2 and connected to the steam reactor 7. The air side of the first heat exchanger 10 is connected in series to the outlet of the air reactor 9. The oxygen generator 12 is connected in series to the solid side outlet of the air reactor 9 and one of the outlets of the splitter 6. The outlet pipeline of the oxygen generator 12 is split into two, one path is solid and connected to the fuel reactor 5, and the other path is gas and connected to the gasifier 1. Air and water from the second cooler are heated by the first waste heat boiler 2 and then enter the air reactor 9 and the steam side of the first heat exchanger 10, respectively.The solid recycled material in the chemical loop hydrogen-oxygen production unit is a hydrogen-oxygen decoupling bifunctional oxygen carrier. This oxygen carrier is composed of active metal oxides and inert supports (including Al2O3, ZrO2, MgAl2O4, YSZ, SiO2, TiO2, etc., which can be one of them or a mixture of several). The active metal oxides are a mixture of iron oxides with hydrogen production function (including Fe2O3, Fe3O4, FeO, and Fe, four different valence states of iron oxides) and metal oxides with oxygen decoupling function. Among them, the metal oxides with oxygen decoupling function can be copper (CuO / Cu2O), cobalt (Co3O4 / CoO), manganese (Mn2O3 / Mn3O4) metal oxides or perovskite (Ba). x Sr 1-x Co y Fe 1-y O 3-δ Series of perovskites, such as Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (etc.); the splitter 6 can independently control the gas flow rate in the two outlet branches; the fuel reactor 5 is a moving bed reactor, and the steam reactor 7, air reactor 9 and oxygen generator 12 are fluidized bed reactors; the fluidizing air of the oxygen generator 12 comes from CO2 and H2O generated by the complete oxidation of syngas in the fuel reactor 5, thereby obtaining a mixture of O2, H2O and CO2 as the biomass gasification medium; negative carbon emissions of biomass are achieved by capturing part of the CO2 generated by the fuel reactor 5; the steam reactor 7 and the oxygen generator 12 are respectively equipped with bypass control valve 8 and bypass control valve 11, and the bypass control valve can adjust the bypass flow of solid materials by controlling the opening degree.

[0041] The gas turbine power generation unit consists of a fuel compressor 13, an air compressor 14, a combustion chamber 15, a gas turbine 16, and a waste heat boiler 17 on the flue gas side. The fuel compressor 13 is connected in series to one of the outlets of the distributor 4 and is connected to the combustion chamber 15. The air compressor 14 is connected to the combustion chamber 15. The combustion chamber 15 is connected in series to the outlets of the fuel compressor 13 and the air compressor 14 and is connected to the gas turbine 16. The gas turbine 16 is connected in series to the outlet of the combustion chamber 15 and is connected to the fourth waste heat boiler 17 on the flue gas side.

[0042] The steam turbine power generation and heating unit consists of a steam turbine 25, a second heat exchanger 24, a condenser 26, a feedwater pump 27, a fourth waste heat boiler 17 (water side), a second waste heat boiler 18 (steam side), and a third waste heat boiler 21 (steam side). The steam turbine 25 is connected in series to the steam outlet of the third waste heat boiler 21. The outlet pipe of the steam turbine 25 is split into two: one connected to the second heat exchanger 24, and the other connected to the steam side of the condenser 26. The hot side of the second heat exchanger 24 is connected in series to the steam extraction port of the steam turbine 25 and to the feedwater pump 27. The cold side of the second heat exchanger 24 serves as the heating medium. The condenser 26 is connected in series to... The steam turbine 25 has an exhaust port connected to the feedwater pump 23; the feedwater pump 27 is connected in series to the hot side outlet of the second heat exchanger 24 and the steam side outlet of the condenser 26, and is connected to the water side of the fourth waste heat boiler 17; the water side of the fourth waste heat boiler 17 is connected in series to the outlet of the feedwater pump 27 and is connected to the steam side of the second waste heat boiler 18; the steam side of the second waste heat boiler 18 is connected in series to the water side outlet of the fourth waste heat boiler 17 and is connected to the steam side of the third waste heat boiler 21; the steam side of the third waste heat boiler 21 is connected in series to the steam side outlet of the second waste heat boiler 18 and is connected to the steam turbine 25; the steam turbine 21 is an extraction condensing steam turbine.

[0043] This embodiment applies the above-mentioned device to provide a negative carbon emission combined heat and power (CHP) method based on biomass gasification, including the following steps:

[0044] S1: Biomass and a mixture of O2, H2O and CO2 are fed into gasifier 1 to produce syngas through a biomass gasification reaction. The biomass gasifier uses atmospheric pressure gasification and the reaction temperature is 750 ~ 950 °C. The syngas enters the first waste heat boiler 2 and exchanges heat with air and water from the second cooler 23. After being treated by the dust removal and desulfurization device 3, it enters the distributor 4. One part of it enters the fuel reactor 5 of the chemical loop hydrogen-oxygen production unit, and the other part enters the gas turbine power generation unit.

[0045] S2: Fuel reactor 5 is a moving bed reactor with a temperature controlled at 800-850 °C. The syngas entering fuel reactor 5 undergoes a redox reaction with high-valence iron oxides and an oxygen-decoupled oxygen carrier, where Fe2O3 is deeply reduced to Fe / FeO. The reduced oxygen carrier then enters steam reactor 7 or air reactor 9, while the syngas is completely oxidized into a mixture of H2O and CO2 and enters splitter 6. A portion of this mixture is sent to oxygen generator 12 as fluidizing air, while the other portion first enters the second waste heat boiler 18 for cooling, then is compressed by CO2 compressor 18, and further cooled by the first cooler 20 to remove condensate, yielding high-purity compressed CO2. Steam reactor 7 is in a bubbling fluidized bed state, with a temperature controlled at 825-875 °C. At °C, the reduced oxygen carrier (containing a high amount of Fe / FeO) entering the steam reactor 7 reacts with steam to produce a mixture of H2 and steam. The oxygen carrier is then sent to the air reactor 9 for further oxidation. The H2 and steam mixture first enters the third waste heat boiler 21 for cooling, then is compressed by the H2 compressor 22, and further cooled by the second cooler 23 to remove condensate, yielding high-purity compressed H2. Cooling water is heated by the first cooler 20 and the second cooler 23 before entering the first waste heat boiler 2 and the first heat exchanger 10 to form high-temperature steam, which is then sent to the steam reactor 7 to participate in the hydrogen production reaction. Air is heated by the first waste heat boiler 2 and then sent to the air reactor 9 to participate in the reaction. The air reactor 9 is in a rapid fluidized state, with the temperature controlled between 1000 and 1050 °C. At °C, the low-valence oxygen carrier entering the air reactor 9 reacts with the air to become a high-valence oxygen carrier and releases a large amount of heat. The oxygen-deficient air after the reaction is cooled by the first heat exchanger 10 and then discharged. The oxygen generating reactor 12 is in a bubbling fluidized bed, and the temperature is controlled at 950~1000 °C. The oxygen decoupled oxygen carrier contained in the high-valence oxygen carrier entering the oxygen generating reactor 12 releases O2 at high temperature. The generated O2, H2O and CO2 mixture is sent to the gasifier 1 as a gasifying agent. The oxygen carrier after oxygen release is sent to the fuel reactor 5 to undergo a redox reaction with the syngas.

[0046] S3: One of the synthesis gas outlets of the splitter 4 is compressed by the fuel compressor 13 and then reacts with the air compressed by the air compressor 14 in the combustion chamber 15. The generated high-temperature flue gas enters the gas turbine 16 to do work and is then sent to the fourth waste heat boiler 17 to cool down and then discharged into the air.

[0047] S4: After being pressurized by the feedwater pump 27, the feedwater enters the fourth waste heat boiler 17, the second waste heat boiler 18 and the third waste heat boiler 21 in sequence, and becomes high-temperature and high-pressure steam, which then enters the steam turbine 25 to do work. The exhaust steam after doing work enters the condenser 26 to condense and then enters the feedwater pump 27 for pressurization. The steam for heating releases heat and condenses after passing through the second heat exchanger 24 before entering the feedwater pump 27.

[0048] By adjusting the ratio of reduced oxygen carrier entering the steam reactor 7 and the air reactor 9 through the bypass control valve 8, the amount of hydrogen can be controlled while ensuring that the amount of oxygen produced remains unchanged.

[0049] By adjusting the ratio of oxidized oxygen carrier entering the oxygen production reactor 12 and the fuel reactor 5 through the bypass control valve 11, the oxygen quantity can be controlled while ensuring that the hydrogen production quantity remains unchanged.

[0050] The ratio of hydrogen to power generation is controlled by adjusting the proportion of syngas entering the chemical loop hydrogen-oxygen production unit and the gas turbine unit through the splitter 4.

[0051] The heating demand is met by adjusting the steam extraction rate or extraction point of the steam turbine 21, and the ratio of power generation to heating is controlled.

Claims

1. A carbon-negative combined heat and power (CHP) device based on biomass gasification, characterized in that, include: Biomass gasification unit, chemical loop hydrogen-oxygen production unit, gas turbine power generation unit, steam turbine power generation-heating unit, and pipelines; The biomass gasification unit consists of a gasifier (1), a first waste heat boiler (2) on the syngas side, a dust removal and desulfurization unit (3), and a distributor (4). The first waste heat boiler (2) on the syngas side is connected in series to the outlet of the gasifier (1) and connected to the dust removal and desulfurization unit (3). The distributor (4) is connected in series to the outlet of the dust removal and desulfurization unit (3). The outlet pipeline of the distributor (4) is divided into two parts: one part is connected to the fuel reactor (5) of the chemical loop hydrogen-oxygen production unit, and the other part is connected to the fuel compressor (13) of the gas turbine power generation unit. The chemical loop hydrogen-oxygen production unit consists of a fuel reactor (5), a splitter (6), a steam reactor (7), a bypass control valve (8), an air reactor (9), a first waste heat boiler (2) cold side, a first heat exchanger (10), an oxygen production reactor (12), a bypass control valve (11), a second waste heat boiler (18) CO2 side, a CO2 compressor (19), a first cooler (20), a third waste heat boiler (21) H2 side, an H2 compressor (22), and a second cooler (23); the fuel reactor (5) is connected in series to one outlet of the splitter (4) and the solid outlet of the oxygen production reactor (12), and is connected in series to the solid outlet of the air reactor (9) through the bypass control valve (11); the fuel reactor (5) outlet The outlet pipeline is divided into two: one is solid and connected to the steam reactor (7), and connected to the air reactor (9) through the bypass control valve (8); the other is gas and connected to the splitter (6); the outlet pipeline of the splitter (6) is divided into two: one is connected to the chemical loop oxygen generator (12), and the other is connected to the second waste heat boiler (18); the CO2 side pipeline of the second waste heat boiler (18) is connected in series to one outlet of the splitter (6) and connected to the CO2 compressor (19); the CO2 compressor (19) is connected in series to the CO2 side outlet of the second waste heat boiler (18) and connected to the first cooler (20); the CO2 side of the first cooler (20) is connected in series to the outlet of the CO2 compressor (19), and the first cooler (20) water... The side outlet is connected to the water side of the second cooler (23); the steam reactor (7) is connected in series to the solid outlet of the fuel reactor (5) and the steam side outlet of the first heat exchanger (10). The outlet pipeline of the steam reactor (7) is divided into two, one is solid and connected to the air reactor (9), and the other is gas and connected to the third waste heat boiler (21); the H2 side of the third waste heat boiler (21) is connected in series to the gas outlet of the steam reactor (7) and connected to the H2 compressor (22); the H2 compressor (22) is connected in series to the H2 side outlet of the third waste heat boiler (21) and connected to the second cooler (23); the H2 side of the second cooler (23) is connected in series to the outlet of the H2 compressor (22), and the water side of the second cooler (23) is connected in series to the first cooler. The water outlet of the cooler (20) is connected to the water side of the first waste heat boiler (2); the air reactor (9) is connected in series to the air outlet of the first waste heat boiler (2) and the solid outlet of the steam reactor (7), and is connected in series to the solid outlet of the fuel reactor (5) through the bypass control valve (8); the outlet pipeline of the air reactor (9) is divided into two, one is solid and connected to the oxygen generator (12), and connected to the fuel reactor (5) through the bypass control valve (11), and the other is gas and connected to the air side of the first heat exchanger (10); the steam side of the first heat exchanger (10) is connected in series to the water outlet of the first waste heat boiler (2) and connected to the steam reactor (7), and the air side of the first heat exchanger (10) is connected in series to the outlet of the air reactor (9);The oxygen generator (12) is connected in series to the solid side outlet of the air reactor (9) and one of the outlets of the splitter (6). The outlet pipeline of the oxygen generator (12) is split into two: one is solid and connected to the fuel reactor (5), and the other is gas and connected to the gasifier (1). The air and water from the second cooler are heated by the first waste heat boiler (2) and then enter the air reactor (9) and the steam side of the first heat exchanger (10) respectively. The gas turbine power generation unit consists of a fuel compressor (13), an air compressor (14), a combustion chamber (15), a gas turbine (16), and a fourth waste heat boiler (17) on the flue gas side; the fuel compressor (13) is connected in series to one outlet of the splitter (4) and is connected to the combustion chamber (15); the air compressor (14) is connected to the combustion chamber (15); the combustion chamber (15) is connected in series to the outlets of the fuel compressor (13) and the air compressor (14) and is connected to the gas turbine (16); the gas turbine (16) is connected in series to the outlet of the combustion chamber (15) and is connected to the flue gas side of the fourth waste heat boiler (17); The steam turbine power generation and heating unit consists of a steam turbine (25), a second heat exchanger (24), a condenser (26), a feedwater pump (27), a fourth waste heat boiler (17) water side, a second waste heat boiler (18) steam side, and a third waste heat boiler (21) steam side. The steam turbine (25) is connected in series to the steam side outlet of the third waste heat boiler (21). The outlet pipeline of the steam turbine (25) is divided into two parts, one of which is connected to the second heat exchanger (24), and the other is connected to the steam side of the condenser (26). The hot side of the second heat exchanger (24) is connected in series to the steam extraction port of the steam turbine (25) and to the feedwater pump (27). The cold side of the second heat exchanger (24) is the heating medium. The condenser (26) is connected in series to the exhaust port of the steam turbine (25) and to the feedwater pump (27); the feedwater pump (27) is connected in series to the hot side outlet of the second heat exchanger (24) and the steam side outlet of the condenser (26) and to the water side of the fourth waste heat boiler (17); the water side of the fourth waste heat boiler (17) is connected in series to the outlet of the feedwater pump (27) and to the steam side of the second waste heat boiler (18); the steam side of the second waste heat boiler (18) is connected in series to the water side outlet of the fourth waste heat boiler (17) and to the steam side of the third waste heat boiler (21); the steam side of the third waste heat boiler (21) is connected in series to the steam side outlet of the second waste heat boiler (18) and to the steam turbine (25).

2. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, The gasification medium of the biomass gasifier (1) is a mixture of O2, H2O and CO2.

3. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, The solid recycled material in the chemical loop hydrogen-oxygen production unit is a hydrogen-oxygen decoupling bifunctional oxygen carrier. This oxygen carrier is composed of active metal oxides and an inert support, and the active metal oxides are a mixture of iron oxides with hydrogen production function and metal oxides with oxygen decoupling function.

4. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, The flow divider (4) and flow divider (6) can control the gas flow rate in the two outlet branches separately.

5. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, The fluidizing air of the oxygen generator (12) comes from CO2 and H2O generated by the complete oxidation of syngas in the fuel reactor (5), thereby obtaining a mixture of O2, H2O and CO2 as a biomass gasification medium.

6. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, Biomass negative carbon emissions are achieved by capturing part of the CO2 produced by the fuel reactor (5).

7. The negative carbon emission combined heat and power (CHP) device based on biomass gasification according to claim 1, characterized in that, The steam reactor (7) and the oxygen generator (12) are respectively equipped with a bypass control valve (8) and a bypass control valve (11). The bypass control valve can adjust the bypass flow of solid materials by controlling the opening degree.

8. A carbon-negative combined heat and power (CHP) method based on biomass gasification, characterized in that, Includes the following steps: S1: Biomass and a mixture of O2, H2O and CO2 are fed into a gasifier (1) to produce syngas through a biomass gasification reaction. The biomass gasifier is used for atmospheric gasification, and the reaction temperature is 750 ~ 950 °C. The syngas enters the first waste heat boiler (2) and exchanges heat with air and water from the second cooler (23). After being processed by the dust removal and desulfurization device (3), it enters the distributor (4). One part of it enters the fuel reactor (5) of the chemical loop hydrogen-oxygen production unit, and the other part enters the gas turbine power generation unit. S2: The fuel reactor (5) is a moving bed with a temperature controlled at 800 ~ 850 °C. The syngas entering the fuel reactor (5) undergoes a redox reaction with high-valence iron oxides and oxygen decoupled oxygen carriers. Fe2O3 is deeply reduced to generate Fe / FeO. The reduced oxygen carrier enters the steam reactor (7) or the air reactor (9), while the syngas is completely oxidized into a mixture of H2O and CO2 and enters the splitter (6). Part of it is sent to the oxygen generator (12) as fluidizing air, and the other part first enters the second waste heat boiler (18) for cooling, and then is compressed by the CO2 compressor (19). After further cooling and removal of condensate by the first cooler (20), high-purity compressed CO2 is obtained. The steam reactor (7) is in a bubbling fluidized bed with a temperature controlled at 825 ~ At 875°C, the reduced oxygen carrier entering the steam reactor (7) reacts with steam to generate a mixture of H2 and steam. The oxygen carrier is then sent to the air reactor (9) for further oxidation. The H2 and steam mixture first enters the third waste heat boiler (21) for cooling, and then is compressed by the H2 compressor (22). After being further cooled by the second cooler (23) and having condensate removed, high-purity compressed H2 is obtained. The cooling water is heated by the first cooler (20) and the second cooler (23) and then enters the first waste heat boiler (2) and the first heat exchanger (10) to be heated to form high-temperature steam, which is then sent to the steam reactor (7) to participate in the hydrogen production reaction. The air is heated by the first waste heat boiler (2) and then sent to the air reactor (9) to participate in the reaction. The air reactor (9) is in a rapid fluidized state, and the temperature is controlled between 1000 and 1050°C. °C, the low-valence oxygen carrier entering the air reactor (9) reacts with the air to become a high-valence oxygen carrier and releases a large amount of heat. The oxygen-deficient air after the reaction is cooled by the first heat exchanger (10) and then discharged. The oxygen generator (12) is in a bubbling fluidized state and the temperature is controlled at 950 ~ 1000 °C. The oxygen decoupled oxygen carrier contained in the high-valence oxygen carrier entering the oxygen generator (12) releases O2 at high temperature. The generated O2, H2O and CO2 mixture is sent to the gasifier (1) as a gasifying agent. The oxygen carrier after oxygen release is sent to the fuel reactor (5) to undergo a redox reaction with the syngas. S3: One of the synthesis gas outlets of the splitter (4) is compressed by the fuel compressor (13) and then reacts with the air compressed by the air compressor (14) in the combustion chamber (15). The generated high-temperature flue gas enters the gas turbine (16) to do work and is then sent to the fourth waste heat boiler (17) to cool down and then discharged. S4: After being pressurized by the feedwater pump (27), the feedwater enters the fourth waste heat boiler (17), the second waste heat boiler (18) and the third waste heat boiler (21) in sequence, and becomes high-temperature and high-pressure steam, which enters the steam turbine (25) to do work; the exhaust steam after doing work enters the condenser (26) to condense and then enters the feedwater pump (27) to be pressurized. The steam for heating releases heat and condenses after passing through the second heat exchanger (24) and then enters the feedwater pump (27).

9. A carbon-negative combined heat and power (CHP) method based on biomass gasification according to claim 8, characterized in that, By adjusting the ratio of reduced oxygen carrier entering the steam reactor (7) and the air reactor (9) through the bypass control valve (8), the amount of hydrogen can be controlled while ensuring that the amount of oxygen produced remains unchanged. By adjusting the ratio of oxidized oxygen carrier entering the oxygen production reactor (12) and the fuel reactor (5) through the bypass control valve (11), the oxygen quantity can be adjusted while ensuring that the hydrogen production quantity remains unchanged. The ratio of hydrogen to electricity generation is controlled by adjusting the ratio of syngas entering the chemical loop hydrogen-oxygen production unit and the gas turbine unit through the splitter (4).

10. A carbon-negative combined heat and power (CHP) method based on biomass gasification according to claim 8, characterized in that, The heating demand is met by adjusting the steam extraction volume or extraction point of the steam turbine (25), and the ratio of power generation to heating is controlled.

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