Biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device and method

Abstract

The invention relates to a device and method for coupling biomass tar steam gasification hydrogen production with waste heat boiler power generation, and belongs to the fields of chemical industry and power generation. A circulating fluidized bed is connected to a high-efficiency cyclone separator 1, which is connected to a differential fluidized bed steam gasifier, which is connected to the circulating fluidized bed; a high-efficiency cyclone separator 1 is connected to a waste heat boiler, which is connected to a back-pressure steam turbine generator set, which is connected to the differential fluidized bed steam gasifier via a superheater; a differential fluidized bed steam gasifier is connected to a circulating fluidized bed catalytic bed via a high-efficiency cyclone separator 2, which is connected to a superheater, a third air preheater, a dust collector, a high-temperature steam shift reactor, a second air preheater, a low-temperature steam shift reactor, a first air preheater, a condenser, an organic amine scrubber, a compressor, and a pressure swing adsorption system. The invention is used for coupling biomass tar steam gasification hydrogen production with waste heat boiler power generation.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical industry and power generation, and particularly relates to a device and method for generating hydrogen through the gasification of biomass tar with steam coupled with a waste heat boiler for power generation. Background Art

[0002] Biomass tar is a complex liquid mixture produced during biomass gasification or pyrolysis, containing alcohols, phenols, aldehydes, and aromatic compounds. Due to its extremely complex composition, it is currently not well utilized. The treatment of biomass tar has become an international challenge and a major obstacle to the large-scale application of biomass gasification or pyrolysis. The industrial analysis of typical biomass tar after dehydration is: C = 39.8%, H = 10.7%, O = 49.1%, N = 0.22%, S = 0.15%, and other components 0.03. The present invention proposes a biomass tar steam gasification hydrogen production process to achieve high-value biomass tar. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem of tar produced in the current biomass gasification or pyrolysis process, and further provide a biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device and method.

[0004] The present invention utilizes high-temperature circulating ash from a circulating fluidized bed as a heat source and high-temperature water vapor as a gasification medium to gasify biomass tar in a differential fluidized bed to produce hydrogen, thereby achieving high-value utilization of biomass tar, and further providing a biomass tar water vapor gasification hydrogen production coupled with a waste heat boiler power generation device and method.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] Option 1: Biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device, including screw feeder 1, screw feeder 2, screw feeder 3, circulating fluidized bed, high-efficiency cyclone separator 1, differential fluidized bed steam gasifier, superheater, circulating fluidized bed catalytic bed, high-efficiency cyclone separator 2, air preheater 3, air preheater 2, air preheater 1, dust collector, high-temperature steam shift reactor, low-temperature steam shift reactor, condenser, organic amine scrubber, pressure swing adsorption system and compressor;

[0007] Screw feeder 1 is a biomass feeder, screw feeder 2 is a material feeder, and the material consists of limestone and dolomite. Screw feeder 3 is a Ni-based catalyst feeder. The discharge ports of screw feeder 1 and screw feeder 2 are both connected to the circulating fluidized bed. A Ni-based catalyst inlet is provided at the upper end of screw feeder 3, and the discharge port of screw feeder 3 is connected to the catalytic bed of the circulating fluidized bed. The flue gas outlet at the top of the circulating fluidized bed is connected to the flue gas inlet of the high-efficiency cyclone separator 1, and the discharge port at the lower end of the high-efficiency cyclone separator is connected to the feed port 1 of the differential fluidized bed steam gasification furnace through a return valve 1, and the discharge port of the differential fluidized bed steam gasification furnace is connected to the return port of the circulating fluidized bed through a return valve 2. The flue gas outlet at the top of the high-efficiency cyclone separator 1 is connected to the flue gas inlet of the waste heat boiler, and the steam outlet of the waste heat boiler is connected to the steam inlet of the back-pressure steam turbine generator set, and the exhaust outlet of the back-pressure steam turbine generator set is connected to the exhaust outlet of the back-pressure steam turbine generator set. It is connected to the superheated steam inlet of the superheater, and the superheated steam outlet of the superheater is connected to the superheated steam inlet at the bottom of the differential fluidized bed steam gasifier; the synthesis gas outlet at the top of the differential fluidized bed steam gasifier is connected to the synthesis gas inlet of the high-efficiency cyclone separator No. 2, the discharge port at the bottom of the high-efficiency cyclone separator No. 2 is connected to the feed port No. 2 at the bottom of the differential fluidized bed steam gasifier, the synthesis gas outlet at the top of the high-efficiency cyclone separator No. 2 is connected to the synthesis gas inlet at the bottom of the circulating fluidized bed catalytic bed, the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed is connected to the synthesis gas inlet of the superheater, the synthesis gas outlet of the superheater is connected to the air preheater No. 3, the dust collector, the high-temperature steam shift reactor, the air preheater No. 2, the low-temperature steam shift reactor, the air preheater No. 1, the condenser, the organic amine scrubber, the compressor and the pressure swing adsorption system in sequence, and the exhaust port of the pressure swing adsorption system is connected to the air inlet at the bottom of the circulating fluidized bed through a pipeline.

[0008] Furthermore, the feed water outlet of the condenser is connected to the feed water inlet of the waste heat boiler, and the feed water of the waste heat boiler enters the waste heat boiler after entering the condenser for heat exchange.

[0009] Furthermore, the outlet of the return valve 3 at the bottom of the circulating fluidized bed catalyst bed and the outlet at the lower end of the dust collector are connected to the inlet of the Ni-based catalyst regeneration bed through pipelines respectively.

[0010] A method for producing hydrogen by gasifying biomass tar with steam and coupling it with a waste heat boiler for power generation, the method comprising the following steps:

[0011] Step 1: Biomass is fed into a circulating fluidized bed for combustion via screw feeder 1, while limestone and dolomite are fed into the circulating fluidized bed for calcination via screw feeder 2. The calcined product serves as the circulating material of the circulating fluidized bed. The high-temperature flue gas from the top of the circulating fluidized bed carries the circulating material into a high-efficiency cyclone separator 1. The circulating material is separated by the high-efficiency cyclone separator 1 and fed into a differential fluidized bed steam gasifier through a return valve 1. Simultaneously, biomass tar is sprayed into the differential fluidized bed steam gasifier under steam atomization and reacts with the fed high-temperature steam at 500-550°C to generate synthesis gas at a bed temperature of 780-850°C.

[0012] Step 2: The high-temperature flue gas from the flue gas outlet at the top of the high-efficiency cyclone separator enters the waste heat boiler. The steam generated by the waste heat boiler is sent to the back-pressure steam turbine generator set to generate electricity. The steam discharged from the back-pressure steam turbine generator set enters the superheater and is heated to 500-550°C. The superheated steam then enters the differential fluidized bed steam gasifier from the bottom of the differential fluidized bed steam gasifier.

[0013] Step 3: In the differential fluidized bed steam gasifier, the high-temperature circulating material and high-temperature superheated steam heat the differential fluidized bed steam gasifier to 780-850℃, with a steam: tar mass ratio of 0.5-2.5:1, and react to produce synthesis gas H2, CO, CO2, CH4 and trace H2S. The volume of synthesis gas produced per kg of tar is 1.6-2.0Nm 3 , where H2=60-65%, CO=10-15%, CO2=18-20%, CH4≤5%, H2S<100mg / Nm 3 At the same time, the CaO formed after calcining limestone and dolomite reacts with H2S. The reaction time in the differential fluidized bed steam gasifier is not less than 10s, and more than 90% of H2S is removed, making H2S <10mg / Nm 3 ;

[0014] The 780-850℃ high-temperature synthesis gas from the synthesis gas outlet at the top of the differential fluidized bed steam gasifier first enters the high-efficiency cyclone separator II, and the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier for recycling; the synthesis gas from the top of the high-efficiency cyclone separator II enters the circulating fluidized bed catalytic bed, and the tar and CH4 in the synthesis gas are converted into H2, CO and CO2 by steam reforming reaction under the catalysis of Ni-based catalyst. The reaction is as follows: Tar + H2O → C m H n +H2+CO+CO2,C m H n+H2O→H2+CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed 8 is ≤20mg / Nm 3 ;

[0015] Step 4: The synthesis gas coming out of the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed is cooled to 350°C through the superheater and air preheater 3, and then enters the dust collector for dust removal. The synthesis gas cooled to 350°C enters the high-temperature steam shift reactor to convert CO and water vapor into CO2 and H2, and the temperature is raised to 380-450°C; then it is cooled to 190-200°C through the air preheater 2 and then enters the low-temperature steam shift reactor to convert CO and water vapor into CO2 and H2. After the synthesis gas temperature rises to 250-260°C, it enters the air preheater 1 and then enters the condenser to condense the water vapor in the synthesis gas into water, releasing the latent heat of vaporization to heat the feed water of the waste heat boiler; then the synthesis gas enters the organic amine scrubber to absorb the CO2 in the synthesis gas, and the synthesis gas enters the pressure swing adsorption system through the compressor to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system is sent to the circulating fluidized bed through a pipeline to burn and release heat.

[0016] Furthermore, the method also includes step five: discharging 50% of the partially failed catalyst from the return valve three at the bottom of the circulating fluidized bed catalyst bed, together with the catalyst discharged from the lower part of the dust collector, and sending it to the Ni-based catalyst regeneration bed for regeneration. The Ni-based catalyst regeneration bed heats the catalyst to 950°C, and at the same time introduces steam and air to remove carbon deposits on the catalyst surface. The regenerated catalyst is returned to the circulating fluidized bed catalyst bed for use, forming a closed cycle.

[0017] Option 2: A biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device, comprising a first screw feeder, a second screw feeder, a third screw feeder, a circulating fluidized bed, a high-efficiency cyclone separator, a differential fluidized bed steam gasifier, a superheater, a circulating fluidized bed catalytic bed, a high-efficiency cyclone separator, a third air preheater, a second air preheater, a first air preheater, a dust collector, a high-temperature steam shift reactor, a low-temperature steam shift reactor, a condenser, an organic amine scrubber, a pressure swing adsorption system, a compressor, and a synthesis gas heater;

[0018] The first screw feeder is a biomass feeder, the second screw feeder is a material feeder, and the material consists of limestone, dolomite and Ni-based catalyst. The third screw feeder is a Ni-based catalyst feeder. The discharge ports of the first and second screw feeders are both connected to the circulating fluidized bed, and the discharge port of the third screw feeder is connected to the circulating fluidized bed catalytic bed. The flue gas outlet at the top of the circulating fluidized bed is connected to the flue gas inlet of the first high-efficiency cyclone separator, and the discharge port at the lower end of the high-efficiency cyclone separator is connected to the flue gas inlet of the first high-efficiency cyclone separator. The return valve 1 is connected to the return port 1 of the differential fluidized bed steam gasifier and the circulating fluidized bed respectively, and the discharge port of the differential fluidized bed steam gasifier is connected to the return port 2 of the circulating fluidized bed through the return valve 2; the flue gas outlet at the top of the high-efficiency cyclone separator 1 is connected to the flue gas inlet of the synthesis gas heater, the flue gas outlet of the synthesis gas heater is connected to the flue gas inlet of the waste heat boiler, the steam outlet of the waste heat boiler is connected to the steam inlet of the back-pressure steam turbine generator set, and the exhaust outlet of the back-pressure steam turbine generator set is connected to the exhaust outlet of the back-pressure steam turbine generator set. The syngas outlet of the superheater is connected to the superheated steam inlet of the superheater, and the superheated steam outlet of the superheater is connected to the superheated steam inlet at the bottom of the differential fluidized bed steam gasifier; the synthesis gas outlet at the top of the differential fluidized bed steam gasifier is connected to the synthesis gas inlet of the high-efficiency cyclone separator II, the discharge port at the bottom of the high-efficiency cyclone separator II is connected to the lower part of the differential fluidized bed steam gasifier, the synthesis gas outlet at the top of the high-efficiency cyclone separator II is connected to the synthesis gas inlet of the synthesis gas heater, the synthesis gas outlet of the synthesis gas heater is connected to the synthesis gas inlet at the bottom of the circulating fluidized bed catalytic bed, the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed is connected to the synthesis gas inlet of the superheater, the synthesis gas outlet of the superheater is connected to the air preheater III, the dust collector, the high-temperature steam shift reactor, the air preheater II, the low-temperature steam shift reactor, the air preheater I, the condenser, the organic amine scrubber, the compressor and the pressure swing adsorption system in sequence, and the exhaust port of the pressure swing adsorption system is connected to the air inlet at the lower part of the circulating fluidized bed through a pipeline.

[0019] Furthermore, the feed water outlet of the condenser is connected to the feed water inlet of the waste heat boiler, and the feed water of the waste heat boiler enters the waste heat boiler after heat exchange in the condenser.

[0020] Furthermore, the outlet of the return valve 3 at the bottom of the circulating fluidized bed catalyst bed and the outlet at the lower end of the dust collector are connected to the inlet of the Ni-based catalyst regeneration bed through pipelines respectively.

[0021] A method for producing hydrogen by gasifying biomass tar with steam and coupling it with a waste heat boiler for power generation, the method comprising the following steps:

[0022] Step 1: biomass is fed into a circulating fluidized bed for combustion through a screw feeder 1, and the material is fed into a circulating fluidized bed for calcination through a screw feeder 2, wherein the material consists of dolomite, limestone and a Ni-based catalyst;

[0023] High-temperature air at 400-450°C enters the circulating fluidized bed from the wind chamber at the bottom of the circulating fluidized bed to assist combustion. The high-temperature flue gas from the flue gas outlet at the top of the circulating fluidized bed carries the circulating material into the high-efficiency cyclone separator 1, where the circulating material is separated and enters the return valve 1. A portion of the circulating material passes through the return valve 1 and directly enters the circulating fluidized bed, while the remaining circulating material passes through the return valve 1 and enters the differential fluidized bed steam gasifier.

[0024] Step 2: The high-temperature flue gas from the flue gas outlet at the top of the high-efficiency cyclone separator 1 enters the waste heat boiler through the syngas heater. The steam generated by the waste heat boiler is sent to the back-pressure steam turbine generator set for power generation. The steam discharged from the back-pressure steam turbine generator set enters the superheater and is heated to 500-550°C. The superheated steam then enters the differential fluidized bed steam gasifier from the bottom of the differential fluidized bed steam gasifier.

[0025] Step 3: In the differential fluidized bed steam gasifier, the high-temperature circulating material and high-temperature superheated steam heat the differential fluidized bed steam gasifier to 600-700°C. The biomass tar is sprayed into the differential fluidized bed steam gasifier and reacts with the high-temperature steam at this temperature to produce synthesis gas H2, CO, CO2 and CH4 as well as trace amounts of H2S. At the same time, CaO generated by the decomposition of limestone and dolomite reacts with CO2 to produce CaCO3, and CaO reacts with H2S to produce CaS. CaCO3 and CaS enter the circulating fluidized bed through return valve 2 and decompose into CO2, SO2 and CaO. CaO is separated by high-efficiency cyclone separator 1 and then re-enters the differential fluidized bed steam gasifier for recycling.

[0026] Step 4: The 600-700℃ synthesis gas from the top of the differential fluidized bed steam gasifier first enters the high-efficiency cyclone separator 2, and the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier for recycling; the synthesis gas from the top of the high-efficiency cyclone separator 2 enters the synthesis gas heater, and the 900-950℃ high-temperature flue gas at the outlet of the high-efficiency cyclone separator 1 is used to heat the synthesis gas to 780-830℃; then the synthesis gas passes through the circulating fluidized bed catalyst bed to catalytically reform the tar, CH4 and water vapor in the synthesis gas into H2, CO and CO2, tar + H2O → C m H n +H2+CO+CO2,C m H n +H2O→H2+CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet of the circulating fluidized bed catalyst bed is ≤20mg / Nm 3The synthesis gas then passes through the superheater and air preheater 3, then cools down to 350°C and enters the dust collector. After dust removal, the synthesis gas enters the high-temperature steam shift reactor, where the temperature rises to 380-450°C and enters the air preheater 2, where the air is preheated to 250-300°C. The synthesis gas temperature drops to 190-200°C before entering the low-temperature steam shift reactor. When the steam / CO molar ratio is ≥2, the total CO conversion rate of CO+H2O=H2+CO2 is above 95%. The synthesis gas is heated to 250-260°C and then enters the air preheater 1, where the air is preheated from room temperature to 130-150°C. The synthesis gas temperature drops to 120-150℃, and then the synthesis gas enters the condenser, and the waste heat boiler feed water is used to condense the water vapor in the synthesis gas and recover the latent heat of vaporization in the steam; the synthesis gas then enters the organic amine scrubber to remove the remaining dust, trace H2S and more than 90% of CO2 in the synthesis gas. The temperature of the clean synthesis gas drops to 50-60℃, and the organic amine aqueous solution absorbs CO2 and regenerates; the synthesis gas then enters the pressure swing adsorption system through the compressor to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system contains H2, CO, and CO2, which are sent to the circulating fluidized bed for combustion to release heat.

[0027] Furthermore, the method also includes step five: discharging 50% of the partially failed catalyst from the return valve three at the bottom of the circulating fluidized bed catalyst bed, together with the catalyst discharged from the lower part of the dust collector, and sending it to the Ni-based catalyst regeneration bed for regeneration. The Ni-based catalyst regeneration bed heats the catalyst to 950°C, and at the same time introduces steam and air to remove carbon deposits on the catalyst surface. The regenerated catalyst is returned to the circulating fluidized bed catalyst bed for use, forming a closed cycle.

[0028] The beneficial effects of the present invention compared to the prior art are: the present invention solves the problem of the outlet of biomass tar, and converts biomass tar into H2, realizing the high-value utilization of tar. The present invention adopts the heat of 900-950℃ high-temperature circulating ash, plus 500-550℃ superheated steam as the fluidizing medium and reactant, to ensure that the temperature of the differential fluidized bed gasifier is within a reasonable temperature range, greatly reducing the equipment investment cost. The present invention uses a waste heat boiler equipped with a back-pressure steam turbine generator set to couple power generation with tar gasification and hydrogen production, which has significant economy and innovation. The present invention uses a circulating fluidized bed catalytic bed to catalytically reform the tar, CH4 and water vapor in the synthesis gas into H2 and CO, so that the tar concentration in the synthesis gas is lower than 20mg / m 3 , avoiding the problem of tar contamination of subsequent heat exchange equipment. In addition, after using the high-temperature steam shift reactor (WSG-1) and the low-temperature steam shift reactor (WSG-2), the volume proportion of hydrogen exceeds 80%, and after the organic amine absorbs CO2, the volume proportion of hydrogen reaches over 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1This is a schematic diagram of the structure of a biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device of the present invention. Figure 1 , Differential fluidized bed steam gasifier operating temperature: 780-850℃;

[0030] Figure 2 This is a schematic diagram of the structure of a biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device of the present invention. Figure 2 , Differential fluidized bed steam gasifier operating temperature: 600-700℃;

[0031] Figure 3 yes Figure 1 A local enlarged view of point A;

[0032] Figure 4 yes Figure 1 A partial enlarged view of point B;

[0033] Figure 5 yes Figure 2 A partial enlarged view of point C;

[0034] Figure 6 yes Figure 2 A partial enlarged view of point D.

[0035] The names of the components and their corresponding reference numerals in the above drawings are as follows:

[0036] Screw feeder one 1-1, screw feeder two 1-2, screw feeder three 1-3, circulating fluidized bed 2, high-efficiency cyclone separator one 3, return valve one 4, differential fluidized bed steam gasifier 5, return valve two 6, superheater 7, circulating fluidized bed catalytic bed 8, high-efficiency cyclone separator two 9, air preheater three 10, air preheater two 11, air preheater one 12, dust collector 13, high-temperature steam shift reactor 14, low-temperature steam shift reactor 15, condenser 16, organic amine scrubber 17, pressure swing adsorption system 18, waste heat boiler 19, steam turbine generator set 20, compressor 21, synthesis gas heater 22, spray gun 23, return valve three 24, Ni-based catalyst regeneration bed 25. DETAILED DESCRIPTION

[0037] Specific implementation method 1: Figure 1 、 Figure 3 and Figure 4As shown, this embodiment discloses a biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device, including a screw feeder 1-1, a screw feeder 2 1-2, a screw feeder 3 1-3, a circulating fluidized bed 2, a high-efficiency cyclone separator 3, a differential fluidized bed steam gasifier 5, a superheater 7, a circulating fluidized bed catalytic bed 8, a high-efficiency cyclone separator 2 9, an air preheater 3 10, an air preheater 2 11, an air preheater 1 12, a dust collector 13, a high-temperature steam shift reactor 14 (WSG-1), a low-temperature steam shift reactor 15 (WSG-2), a condenser 16, an organic amine scrubber 17, a pressure swing adsorption system 18 (PSA) and a compressor 21;

[0038] Screw feeder 1-1 is a biomass feeder, and a biomass inlet is provided at the upper end of screw feeder 1-1, and the biomass outlet of screw feeder 1-1 is connected to the circulating fluidized bed 2 (the biomass is fed into the circulating fluidized bed 2 for combustion, and the circulating fluidized bed 2 is an adiabatic combustion chamber); screw feeder 2 1-2 is a material feeder, and a material inlet is provided at the upper end of screw feeder 2 1-2, and the material outlet of screw feeder 2 1-2 is connected to the circulating fluidized bed 2, and the material is composed of limestone and dolomite. The mass ratio of the material to the dolomite is 1:1; the screw feeder 2 1-2 feeds the material into the circulating fluidized bed 2 for calcination, and the calcined product serves as the bed material and the catalyst of the differential fluidized bed steam gasifier 5; the screw feeder 3 1-3 is a Ni-based catalyst feeder, and the upper end of the screw feeder 3 1-3 is provided with a Ni-based catalyst inlet, and the discharge port of the screw feeder 3 1-3 is connected to the circulating fluidized bed catalyst bed 8 (the screw feeder 3 1-3 feeds the Ni-based catalyst into the circulating fluidized bed catalyst bed 8);

[0039] The flue gas outlet at the top of the circulating fluidized bed 2 is connected to the flue gas inlet of the high-efficiency cyclone separator 3. The discharge port at the lower end of the high-efficiency cyclone separator 3 is connected to the feed port 1 of the differential fluidized bed steam gasification furnace 5 through a return valve 4. The discharge port of the differential fluidized bed steam gasification furnace 5 is connected to the return port of the circulating fluidized bed 2 through a return valve 26.

[0040] The flue gas outlet at the top of the high-efficiency cyclone separator 3 is connected to the flue gas inlet of the waste heat boiler 19, the steam outlet of the waste heat boiler 19 is connected to the steam inlet of the back-pressure steam turbine generator set 20, the exhaust steam outlet of the back-pressure steam turbine generator set 20 is connected to the superheated steam inlet of the superheater 7, and the superheated steam outlet of the superheater 7 is connected to the superheated steam inlet at the bottom of the differential fluidized bed steam gasifier 5;

[0041] The synthesis gas outlet at the top of the differential fluidized bed steam gasifier 5 is connected to the synthesis gas inlet of the high-efficiency cyclone separator 2 9, the discharge port at the bottom of the high-efficiency cyclone separator 2 9 is connected to the feed port 2 at the lower part of the differential fluidized bed steam gasifier 5, the synthesis gas outlet at the top of the high-efficiency cyclone separator 2 9 is connected to the synthesis gas inlet at the bottom of the circulating fluidized bed catalytic bed 8, the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed 8 is connected to the synthesis gas inlet of the superheater 7, the synthesis gas outlet of the superheater 7 is connected to the air preheater 3 10, the dust collector 13, the high-temperature steam shift reactor 14, the air preheater 2 11, the low-temperature steam shift reactor 15, the air preheater 12, the condenser 16, the organic amine scrubber 17, the compressor 21 and the pressure swing adsorption system 18 in sequence, and the exhaust port of the pressure swing adsorption system 18 is connected to the air inlet at the lower part of the circulating fluidized bed 2 through a pipeline.

[0042] The feed water outlet of the condenser 16 is connected to the feed water inlet of the waste heat boiler 19 , and the feed water of the waste heat boiler 19 enters the waste heat boiler 19 after entering the condenser 16 for heat exchange.

[0043] The outlet of the return valve 3 24 at the bottom of the circulating fluidized bed catalytic bed 8 discharges about 50% of the Ni-based catalyst, and the outlet at the lower end of the dust collector 13 is connected to the inlet of the Ni-based catalyst regeneration bed 25 through pipelines (the regenerated Ni-based catalyst is recycled).

[0044] Specific implementation method 2: Figure 1 、 Figure 3 and Figure 4 As shown (differential bed temperature: 780-850°C), this embodiment discloses a method for realizing biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation using the device described in the first embodiment, the method comprising the following steps:

[0045] Step 1: Biomass (biomass refers to agricultural and forestry wastes, and the amount added is related to the amount of biomass tar produced by gasification and hydrogen production. As the amount of tar increases, the required heat increases, and the amount of biomass increases) is fed into the circulating fluidized bed 2 for combustion through a screw feeder 1-1, and limestone and dolomite (the mass ratio of limestone to dolomite is 1:1) are fed into the circulating fluidized bed 2 for calcination through a screw feeder 2 1-2. The calcined products serve as bed material and catalyst (as circulating material of the circulating fluidized bed 2); at the same time, high-temperature air at 400-450°C enters the circulating fluidized bed 2 from the wind chamber at the bottom of the circulating fluidized bed 2 to assist combustion. The circulating fluidized bed 2 is an adiabatic combustion furnace with a fluidization velocity of 6-10m / s and a circulation ratio of 30-100; The 900-950°C high-temperature flue gas from the flue gas outlet at the top of the fluidized bed 2 carries the recycled material (limestone and dolomite calcined products) into the high-efficiency cyclone separator 3. The recycled material is separated by the high-efficiency cyclone separator 3 and fed into the differential fluidized bed steam gasifier 5 through the return valve 4. At the same time, biomass tar (via the spray gun 23) is sprayed into the differential fluidized bed steam gasifier 5 under steam atomization (the diameter of the tar droplets after atomization is <100 microns) (the biomass tar injection rate is 5-20 t / h). It reacts with the 500-550°C high-temperature steam fed into the gasifier to produce synthesis gas (main components: H2, H2O, CO, CO2, CH4) at a bed temperature of 780-850°C.

[0046] Step 2: The high-temperature flue gas (900-950°C) exiting the flue gas outlet at the top of the high-efficiency cyclone separator 3 enters the waste heat boiler 19. The steam generated by the waste heat boiler 19 is fed into the back-pressure steam turbine generator set 20 for power generation. The steam discharged from the back-pressure steam turbine generator set 20 (with a pressure of 0.2-0.3 MPa and a temperature of 200-250°C) enters the superheater 7 and is heated to 500-550°C. The superheated steam then enters the differential fluidized bed steam gasifier 5 from the bottom thereof.

[0047] Step 3: In the differential fluidized bed steam gasifier 5, the high-temperature circulating material and high-temperature superheated steam heat the differential fluidized bed steam gasifier 5 to 780-850°C, with a steam: tar mass ratio of 0.5-2.5:1, and react to produce synthesis gas H2, CO, CO2, CH4 and trace H2S. The volume of synthesis gas produced per kg of tar is 1.6-2.0 Nm 3 (dry gas), where H2=60-65%, CO=10-15%, CO2=18-20%, CH4≤5%, H2S<100mg / Nm 3 At the same time, the CaO formed after the calcination of limestone and dolomite reacts with H2S. The reaction time in the differential fluidized bed steam gasifier 5 is not less than 10s, and more than 90% of H2S is removed, making H2S <10mg / Nm 3(Meet the H2S concentration requirements of the subsequent water gas shift reaction catalyst);

[0048] The 780-850℃ high temperature syngas from the syngas outlet at the top of the differential fluidized bed steam gasifier 5 has a tar content of ≤1g / Nm 3 The (dry gas) first enters the high-efficiency cyclone separator 29, where the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier 5 for recycling; the synthesis gas coming out of the top of the high-efficiency cyclone separator 29 enters the circulating fluidized bed catalytic bed 8 (fluidization speed: 3-5m / s, residence time greater than 10s), where the tar and CH4 in the synthesis gas are converted into H2, CO and CO2 by steam reforming reaction under the catalysis of Ni-based catalyst (Ni-based catalyst particle size is 0.05-0.2mm, fed by screw feeder 3 1-3), and the reaction is as follows: Tar + H2O → C m H n (Hydrocarbon) + H2 + CO + CO2, C m H n +H2O→H2+CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed 8 is ≤20mg / Nm 3 , such low tar content will not deactivate the downstream steam shift catalyst;

[0049] Step 4: The synthesis gas from the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed 8 passes through the superheater 7 and the air preheater 10, and is cooled to 350°C. It then enters the dust collector 13 (the dust collector 13 can be an existing mature ceramic filter or metal mesh filter or other dust collectors that can withstand temperatures above 350°C. The dust removal efficiency of the dust collector 13 reaches more than 99.9%, and the dust content in the synthesis gas is ≤5mg / m 3 After dust removal, the synthesis gas at a temperature of 350°C enters the high-temperature steam shift reaction tower 14 (WGS-1, reaction conditions: commercial catalyst SCST-221, 350°C, SV = 1300-2700h -1 ), CO and water vapor are converted into CO2 and H2, and the temperature is raised to 380-450°C; then it enters the air preheater 11, where the air is preheated to 250-300°C. After the synthesis temperature drops to 190-200°C, it enters the low-temperature steam shift reaction tower 15 (WGS-2, reaction conditions: commercial catalyst SCST-231, 190-200°C, SV = 4600-5100h -1), CO and water vapor are converted into CO2 and H2, the steam / CO molar ratio is ≥2, the total CO conversion rate of CO+H2O=H2+CO2 is above 95%; the synthesis gas is heated to 250-260℃ and then enters the air preheater 12, the air is preheated from room temperature to 130-150℃, and the synthesis temperature is reduced to 120-150℃, after which the synthesis gas enters the condenser 16 (existing mature technology), and the waste heat boiler 19 is used to feed water to condense the water vapor in the synthesis gas into water, releasing the latent heat of vaporization to heat the feed water of the waste heat boiler 19 (recovering the latent heat of vaporization in the steam to improve the thermal efficiency of the system); after that, ... The synthesis gas enters the organic amine scrubber 17 (mature technology) to remove the remaining dust, trace H2S and more than 90% of CO2 in the synthesis gas. The clean synthesis temperature drops to 50-60°C, and the organic amine aqueous solution absorbs CO2 and then regenerates (heated to 120-150°C, and then CO2 and water vapor are separated and condensed to obtain high-purity CO2, thereby achieving CO2 capture); the synthesis gas then enters the pressure swing adsorption system 18 (PSA) through the compressor 21 to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system 18 contains H2, CO, CO2, etc., which are sent to the circulating fluidized bed 2 through a pipeline for combustion to release heat.

[0050] The high-temperature steam shift reactor 14 (WGS-1) and the low-temperature steam shift reactor 15 (WGS-2) convert more than 95% of CO into CO2 and H2.

[0051] Furthermore, the method also includes step five; discharging 50% of the partially failed catalyst from the return valve three 24 at the bottom of the circulating fluidized bed catalytic bed 8, together with the catalyst discharged from the lower part of the dust collector 13, and sending it to the Ni-based catalyst regeneration bed 25 for regeneration. The Ni-based catalyst regeneration bed 25 heats the catalyst to 950°C, and at the same time introduces steam and air to remove carbon deposits on the surface of the catalyst. The regenerated catalyst is returned to the circulating fluidized bed catalytic bed 8 for use, forming a closed cycle.

[0052] Specific implementation method three: Figure 2 、 Figure 5 and Figure 6 As shown, this embodiment discloses a biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device, including a screw feeder 1-1, a screw feeder 2 1-2, a screw feeder 3 1-3, a circulating fluidized bed 2 (a biomass circulating fluidized bed), a high-efficiency cyclone separator 3, a differential fluidized bed steam gasifier 5, a superheater 7, a circulating fluidized bed catalytic bed 8, a high-efficiency cyclone separator 2 9, an air preheater 3 10, an air preheater 2 11, an air preheater 1 12, a dust collector 13, and a high-temperature steam shift reactor 14 (WSG-1, reaction conditions: 350°C, SV = 1300-2700h -1), low temperature steam shift reactor 15 (WSG-2, reaction conditions: 190-200 ° C, SV = 4600-5100h -1 ), condenser 16, organic amine scrubber 17, pressure swing adsorption system 18 (PSA), compressor 21 and synthesis gas heater 22;

[0053] Screw feeder 1-1 is a biomass feeder, screw feeder 2 1-2 is a material feeder, the material consists of limestone, dolomite and Ni-based catalyst (the mass ratio of limestone, dolomite and Ni-based catalyst is 1:1:1), and screw feeder 3 1-3 is a Ni-based catalyst feeder; the discharge ports of screw feeder 1-1 and screw feeder 2 1-2 are both connected to the circulating fluidized bed 2 (biomass is fed into the circulating fluidized bed 2 for combustion through screw feeder 1-1; limestone, dolomite and Ni-based catalyst are fed into the circulating fluidized bed 2 for calcination through screw feeder 2 1-2, and the calcined product is used as bed material and catalyst), and the discharge port of screw feeder 3 1-3 is connected to the circulating fluidized bed catalytic bed 8;

[0054] The flue gas outlet at the top of the circulating fluidized bed 2 is connected to the flue gas inlet of the high-efficiency cyclone separator 3. The discharge port at the lower end of the high-efficiency cyclone separator 3 is connected to the differential fluidized bed steam gasifier 5 and the return port 1 of the circulating fluidized bed 2 through a return valve 4. The discharge port of the differential fluidized bed steam gasifier 5 is connected to the return port 2 of the circulating fluidized bed 2 through a return valve 2.

[0055] The flue gas outlet at the top of the high-efficiency cyclone separator 3 is connected to the flue gas inlet of the synthesis gas heater 22, the flue gas outlet of the synthesis gas heater 22 is connected to the flue gas inlet of the waste heat boiler 19, the steam outlet of the waste heat boiler 19 is connected to the steam inlet of the back-pressure steam turbine generator set 20, the exhaust steam outlet of the back-pressure steam turbine generator set 20 is connected to the superheated steam inlet of the superheater 7, and the superheated steam outlet of the superheater 7 is connected to the superheated steam inlet at the bottom of the differential fluidized bed steam gasifier 5;

[0056] The synthesis gas outlet at the top of the differential fluidized bed steam gasifier 5 is connected to the synthesis gas inlet of the high-efficiency cyclone separator 2 9, the discharge port at the bottom of the high-efficiency cyclone separator 2 9 is connected to the lower part of the differential fluidized bed steam gasifier 5, the synthesis gas outlet at the top of the high-efficiency cyclone separator 2 9 is connected to the synthesis gas inlet of the synthesis gas heater 22, the synthesis gas outlet of the synthesis gas heater 22 is connected to the synthesis gas inlet at the bottom of the circulating fluidized bed catalytic bed 8, the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed 8 is connected to the synthesis gas inlet of the superheater 7, the synthesis gas outlet of the superheater 7 is connected to the air preheater 3 10, the dust collector 13, the high-temperature steam shift reactor 14, the air preheater 2 11, the low-temperature steam shift reactor 15, the air preheater 12, the condenser 16, the organic amine scrubber 17, the compressor 21 and the pressure swing adsorption system 18 in sequence, and the exhaust port of the pressure swing adsorption system 18 is connected to the air inlet at the lower part of the circulating fluidized bed 2 through a pipeline.

[0057] The feed water outlet of the condenser 16 is connected to the feed water inlet of the waste heat boiler 19 , and the feed water of the waste heat boiler 19 enters the waste heat boiler 19 after heat exchange in the condenser 16 .

[0058] The outlet of the return valve 3 24 at the bottom of the circulating fluidized bed catalytic bed 8 (discharging about 50% of the Ni-based catalyst, not the entire circulating amount) and the outlet at the lower end of the dust collector 13 are connected to the inlet of the Ni-based catalyst regeneration bed 25 through pipelines (the regenerated Ni-based catalyst is recycled).

[0059] Specific implementation method four: Figure 2 、 Figure 5 and Figure 6 As shown (differential bed temperature: 600-700°C, in-situ absorption of CO2), this embodiment discloses a method for realizing biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation using the device described in specific embodiment 3, the method comprising the following steps:

[0060] Step 1: biomass is fed into the circulating fluidized bed 2 for combustion through a screw feeder 1-1, and the material is fed into the circulating fluidized bed 2 through a screw feeder 2 1-2. The material consists of dolomite, limestone and Ni-based catalyst (the mass ratio of limestone, dolomite and Ni-based catalyst is 1:1:1, and the calcined products of dolomite and limestone and the Ni-based catalyst serve as bed material and catalyst, and also as circulating material); 400-450°C high-temperature air enters the circulating fluidized bed 2 from the wind chamber at the bottom of the circulating fluidized bed 2 to assist combustion. The circulating fluidized bed 2 is adiabatic. The combustion furnace has a fluidization velocity of 6-10 m / s and a circulation ratio of 30-100. The high-temperature flue gas (900-950°C) coming out of the flue gas outlet at the top of the circulating fluidized bed 2 carries the circulating materials (limestone, dolomite calcined products and Ni-based catalyst) into the high-efficiency cyclone separator 3. The circulating materials are separated by the high-efficiency cyclone separator 3 and enter the return valve 4. A portion of the circulating materials directly enters the circulating fluidized bed 2 through the return valve 4, and the remaining circulating materials enter the differential fluidized bed steam gasifier 5 through the return valve 4.

[0061] Step 2: The high-temperature flue gas (900-950°C) exiting the flue gas outlet at the top of the high-efficiency cyclone separator 3 enters the waste heat boiler 19 through the synthesis gas heater 22. The steam generated by the waste heat boiler 19 is fed into the back-pressure steam turbine generator set 20 for power generation. The steam discharged from the back-pressure steam turbine generator set 20 (with a pressure of 0.2-0.3 MPa and a temperature of 200-250°C) enters the superheater 7 and is heated to 500-550°C. The superheated steam then enters the differential fluidized bed steam gasifier 5 from the bottom thereof.

[0062] Step 3: In the differential fluidized bed steam gasifier 5, the high-temperature circulating material and the high-temperature superheated steam heat the differential fluidized bed steam gasifier 5 to 600-700°C. The biomass tar is sprayed into the differential fluidized bed steam gasifier 5 through the spray gun 23 under steam atomization (the diameter of the tar droplets after atomization is <100 microns) (the biomass tar injection rate is 5-20 t / h), the steam: tar mass ratio = 0.5-2.5:1, and reacts with the high-temperature steam at this temperature to produce synthesis gas H2, CO, CO2 and CH4 and trace H2S. The volume of synthesis gas produced per kg of tar is 1.5-1.8 Nm 3 (dry gas), where H2 = 70-75%, CO = 6-8%, CO2 = 8-10%, CH4 = 7-8% (dry basis), H2S < 100 mg / Nm 3At the same time, the CaO generated by the decomposition of limestone and dolomite reacts with CO2 to form CaCO3, realizing in-situ removal of CO2; CaO reacts with H2S to form CaS, and CaCO3 and CaS enter the circulating fluidized bed 2 through the return valve 2 6 and decompose into CO2, SO2 and CaO. The CaO is separated by the high-efficiency cyclone separator 3 and then enters the differential fluidized bed steam gasification furnace 5 for recycling;

[0063] In the differential fluidized bed steam gasifier 5, at 600-700°C, CaO reacts with CO2 to form CaCO3, which promotes the reaction CO+H2O=H2+CO2 in the positive direction, resulting in a 10% increase in H2 concentration and a significant decrease in CO and CO2. However, due to the decrease in bed temperature, CH4 increases by 2-3%, and the tar content in the synthesis gas increases to 1.5-2g / Nm 3 (dry gas); In addition, the CaO formed after the calcination of limestone and dolomite reacts with H2S, and the reaction time in the differential fluidized bed steam gasifier 5 is not less than 10s, removing more than 90% of H2S, so that the H2S in the synthesis gas is less than 10mg / Nm 3 , meeting the H2S concentration requirements of the subsequent water gas shift reaction catalyst;

[0064] Step 4: The 600-700°C synthesis gas from the top of the differential fluidized bed steam gasifier 5 first enters the high-efficiency cyclone separator 29, and the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier 5 for recycling; the synthesis gas from the top of the high-efficiency cyclone separator 29 enters the synthesis gas heater 22, and the 900-950°C high-temperature flue gas from the outlet of the high-efficiency cyclone separator 3 is used to heat the synthesis gas to 780-830°C to meet the temperature requirements of the subsequent catalyst reaction; then the synthesis gas passes through the circulating fluidized bed catalyst bed 8 (780-830°C, fluidization velocity: 3-5m / s, residence time 10s, Ni-based catalyst particle size 0.05-0.2mm, fed by the screw feeder 1-3) to catalytically reform the tar and CH4 in the synthesis gas with water vapor into H2, CO and CO2, and the reaction is as follows: tar + H2O → C m H n (Hydrocarbon) + H2 + CO + CO2, C m H n +H2O→H2+CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet of the circulating fluidized bed catalytic bed 8 is ≤20mg / Nm 3Such a low tar content will not deactivate the downstream steam shift catalyst; the synthesis gas then passes through the superheater 7 and the air preheater 10, and is cooled to 350°C before entering the dust collector 13 (the dust collector 13 can be an existing mature ceramic filter or metal mesh filter or other dust collectors that can withstand temperatures above 350°C. The dust removal efficiency of the dust collector 13 reaches more than 99.9%, and the dust content in the synthesis gas is ≤5mg / m 3 ), the dedusted synthesis gas (temperature is 350 ° C) enters the high-temperature steam shift reactor 14 (WGS-1, reaction conditions: commercial catalyst SCST-221, 350 ° C, SV = 1300-2700h -1 ), the temperature rises to 380-450°C before entering the air preheater 11, where the air is preheated to 250-300°C. The synthesis gas temperature drops to 190-200°C before entering the low-temperature steam shift reactor 15 (WGS-2, reaction conditions: commercial catalyst SCST-231, 190-200°C, SV = 4600-5100h -1 ), when the steam / CO molar ratio is ≥2, the high and low temperature water gas shift reaction: CO+H2O=H2+CO2, the total CO conversion rate is above 95%; the synthesis gas is heated to 250-260℃ and then enters the air preheater 12, which preheats the air from room temperature to 130-150℃, and the synthesis gas temperature drops to 120-150℃. After that, the synthesis gas enters the condenser 16 (existing mature technology), and the waste heat boiler 19 is used to feed water to condense the water vapor in the synthesis gas, recovering the vaporization latent heat in the steam (improving the thermal efficiency of the system); the synthesis gas then enters the organic amine scrubber 17 (mature technology), remove the remaining dust, trace H2S and more than 90% of CO2 in the synthesis gas, the temperature of the clean synthesis gas is reduced to 50-60℃, and the organic amine aqueous solution absorbs CO2 and then regenerates (heated to 120-150℃, and then CO2 and water vapor are separated and condensed to obtain high-purity CO2, realizing CO2 capture); then the synthesis gas enters the pressure swing adsorption system 18 (PSA) through the compressor 21 to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system 18 contains H2, CO, and CO2, which are sent to the circulating fluidized bed 2 for combustion to release heat.

[0065] Furthermore, the method also includes step five; discharging 50% of the partially failed catalyst from the return valve three 24 at the bottom of the circulating fluidized bed catalytic bed 8, together with the catalyst discharged from the lower part of the dust collector 13, and sending it to the Ni-based catalyst regeneration bed 25 for regeneration. The Ni-based catalyst regeneration bed 25 heats the catalyst to 950°C, and at the same time introduces steam and air to remove carbon deposits on the surface of the catalyst. The regenerated catalyst is returned to the circulating fluidized bed catalytic bed 8 for use, forming a closed cycle.

[0066] Effect of the fourth specific embodiment: CaO produced by calcining limestone and dolomite in the circulating fluidized bed 2 enters the differential fluidized bed steam gasifier 5, and absorbs CO2 in situ at 600-700°C, so that CO+H2O=CO2+H2 proceeds in the positive direction, the CO2 concentration is greatly reduced to 8-10%, and the H2 concentration is greatly increased to 70-75%, thereby reducing the pressure of the subsequent high and low steam shift reactors and the organic amine scrubber 17.

[0067] This tar gasification hydrogen production process is also suitable for gasification hydrogen production from agricultural and forestry biomass, residual waste from recycled paper mills (moisture ≤ 15%), sorted organic domestic waste (moisture ≤ 15%) and rural abandoned agricultural mulch films.

[0068] The differential fluidized bed structure of the present invention has been disclosed in the invention patent with publication number CN102876339B, publication date December 25, 2013, and titled “A Gasification and Cracking Reaction Device”.

[0069] The above are only preferred specific implementation methods of the patent of the present invention, but the scope of protection of the patent of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the patent of the present invention, who makes equivalent replacements or changes based on the technical solution of the patent of the present invention and the invention patent concept of the patent, should be covered by the scope of protection of the patent of the present invention.

Claims

1. A biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device, characterized by: It includes a screw feeder 1 (1-1), a screw feeder 2 (1-2), a screw feeder 3 (1-3), a circulating fluidized bed (2), a high-efficiency cyclone separator 1 (3), a differential fluidized bed steam gasifier (5), a superheater (7), a circulating fluidized bed catalytic bed (8), a high-efficiency cyclone separator 2 (9), an air preheater 3 (10), an air preheater 2 (11), an air preheater 1 (12), a dust collector (13), a high-temperature steam shift reactor (14), a low-temperature steam shift reactor (15), a condenser (16), an organic amine scrubber (17), a pressure swing adsorption system (18) and a compressor (21); The first screw feeder (1-1) is a biomass feeder, the second screw feeder (1-2) is a material feeder, and the material is composed of limestone and dolomite. The third screw feeder (1-3) is a Ni-based catalyst feeder. The discharge ports of the first screw feeder (1-1) and the second screw feeder (1-2) are both connected to the circulating fluidized bed (2). The upper end of the third screw feeder (1-3) is provided with a Ni-based catalyst inlet, and the discharge port of the third screw feeder (1-3) is connected to the circulating fluidized bed catalyst bed (8). The flue gas outlet at the top of the circulating fluidized bed (2) is connected to the flue gas inlet of the high-efficiency cyclone separator (3). The discharge port at the lower end of the air separator (3) is connected to the feed port (1) of the differential fluidized bed steam gasification furnace (5) through the return valve (4), and the discharge port of the differential fluidized bed steam gasification furnace (5) is connected to the return port of the circulating fluidized bed (2) through the return valve (6); the flue gas outlet at the top of the high-efficiency cyclone separator (3) is connected to the flue gas inlet of the waste heat boiler (19), the steam outlet of the waste heat boiler (19) is connected to the steam inlet of the back pressure steam turbine generator set (20), the exhaust steam outlet of the back pressure steam turbine generator set (20) is connected to the superheated steam inlet of the superheater (7), and the superheated steam outlet of the superheater (7) is connected to the exhaust steam inlet of the superheater (7). The superheated steam inlet at the bottom of the differential fluidized bed steam gasification furnace (5) is connected; the synthesis gas outlet at the top of the differential fluidized bed steam gasification furnace (5) is connected to the synthesis gas inlet of the high-efficiency cyclone separator (9); the discharge port at the bottom of the high-efficiency cyclone separator (9) is connected to the feed port 2 at the lower part of the differential fluidized bed steam gasification furnace (5); the synthesis gas outlet at the top of the high-efficiency cyclone separator (9) is connected to the synthesis gas inlet at the bottom of the circulating fluidized bed catalytic bed (8); the synthesis gas outlet at the top of the circulating fluidized bed catalytic bed (8) is connected to the synthesis gas inlet of the superheater (7); the synthesis gas outlet of the superheater (7) is connected to the air preheater (7) in turn. The air preheater 3 (10), the dust collector (13), the high-temperature steam shift reactor (14), the air preheater 2 (11), the low-temperature steam shift reactor (15), the air preheater 1 (12), the condenser (16), the organic amine scrubber (17), the compressor (21) and the pressure swing adsorption system (18) are connected, and the exhaust port of the pressure swing adsorption system (18) is connected to the air inlet at the lower part of the circulating fluidized bed (2) through a pipeline; the screw feeder 2 (1-2) feeds the material into the circulating fluidized bed (2) for calcination, and the calcined product serves as bed material on the one hand and as a catalyst for the differential fluidized bed steam gasification furnace (5) on the other hand; The synthesis gas coming out from the top of the high-efficiency cyclone separator 2 (9) enters the circulating fluidized bed catalytic bed (8), where the tar and CH4 in the synthesis gas are converted into H2, CO and CO2 through steam reforming reaction under the catalysis of Ni-based catalyst.

2. The biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device according to claim 1 is characterized in that: The feed water outlet of the condenser (16) is connected to the feed water inlet of the waste heat boiler (19), and the feed water of the waste heat boiler (19) enters the condenser (16) for heat exchange and then enters the waste heat boiler (19).

3. The biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device according to claim 2, characterized in that: The outlet of the return valve 3 (24) at the bottom of the circulating fluidized bed catalyst bed (8) and the outlet at the lower end of the dust collector (13) are connected to the inlet of the Ni-based catalyst regeneration bed (25) through pipelines.

4. A method for realizing biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation using the device according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: Step 1: biomass is fed into a circulating fluidized bed (2) through a screw feeder (1-1) for combustion, limestone and dolomite are fed into a circulating fluidized bed (2) through a screw feeder (1-2) for calcination, and the calcined product serves as the circulating material of the circulating fluidized bed (2). The high-temperature flue gas from the top of the circulating fluidized bed (2) carries the circulating material into a high-efficiency cyclone separator (3), and the circulating material is separated by the high-efficiency cyclone separator (3) and fed into a differential fluidized bed steam gasifier (5) through a return valve (4). At the same time, biomass tar is sprayed into the differential fluidized bed steam gasifier (5) under steam atomization, and reacts with the fed high-temperature steam of 500-550°C to generate synthesis gas at a bed temperature of 780-850°C. Step 2: The high-temperature flue gas from the flue gas outlet at the top of the high-efficiency cyclone separator (3) enters the waste heat boiler (19), and the steam generated by the waste heat boiler (19) is sent to the back-pressure steam turbine generator set (20) to generate electricity; the steam discharged from the back-pressure steam turbine generator set (20) enters the superheater (7) and is heated to 500-550°C, and the superheated steam enters the differential fluidized bed steam gasification furnace (5) from the bottom of the differential fluidized bed steam gasification furnace (5); Step 3: In the differential fluidized bed steam gasifier (5), the high temperature circulating material and high temperature superheated steam heat the differential fluidized bed steam gasifier (5) to 780-850°C, with a steam: tar mass ratio of 0.5-2.5:1, and the reaction generates synthesis gas H2, CO, CO2, CH4 and trace H2S. The volume of synthesis gas produced per kg of tar is 1.6-2.0 Nm 3 , among which, H2=60-65%, CO=10-15%, CO2=18-20%, CH4≤5%, H2S<100mg / Nm 3 At the same time, the CaO formed after the calcination of limestone and dolomite reacts with H2S, and the reaction time in the differential fluidized bed steam gasifier (5) is not less than 10s, removing more than 90% of H2S, making H2S <10mg / Nm 3 ; The 780-850℃ high-temperature synthesis gas from the synthesis gas outlet at the top of the differential fluidized bed steam gasifier (5) first enters the high-efficiency cyclone separator II (9), and the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier (5) for recycling; the synthesis gas from the top of the high-efficiency cyclone separator II (9) enters the circulating fluidized bed catalytic bed (8), and the tar and CH4 in the synthesis gas are converted into H2, CO and CO2 by steam reforming reaction under the catalysis of Ni-based catalyst. The reaction is as follows: Tar + H2O → C m H n +H2 +CO+CO2,C m H n +H2O → H2 +CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet at the top of the circulating fluidized bed catalyst bed (8) is ≤20mg / Nm 3 ; Step 4: The synthesis gas from the synthesis gas outlet at the top of the circulating fluidized bed catalyst bed (8) is cooled to 350°C through the preheater (7) and the air preheater (10), and then enters the dust collector (13) for dust removal. The synthesis gas cooled to 350°C enters the high-temperature steam shift reactor (14), where CO and water vapor are converted into CO2 and H2, and the temperature is raised to 380-450°C; then it passes through the air preheater (11) and is cooled to 190-200°C before entering the low-temperature steam shift reactor (15), where CO and water vapor are converted into After being converted into CO2 and H2, the synthesis gas temperature rises to 250-260℃ and then enters the air preheater (12) and the condenser (16), condensing the water vapor in the synthesis gas into water, releasing the latent heat of vaporization to heat the feed water of the waste heat boiler (19); then the synthesis gas enters the organic amine scrubber (17) to absorb the CO2 in the synthesis gas, and the synthesis gas enters the pressure swing adsorption system (18) through the compressor (21) to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system (18) is sent to the circulating fluidized bed (2) through the pipeline to burn and release heat.

5. The method of biomass tar steam gasification to produce hydrogen coupled with waste heat boiler power generation according to claim 4, characterized in that: The method further includes step five: discharging 50% of the partially failed catalyst from the return valve three (24) at the bottom of the circulating fluidized bed catalyst bed (8), and sending it together with the catalyst discharged from the lower part of the dust collector (13) to the Ni-based catalyst regeneration bed (25) for regeneration. The Ni-based catalyst regeneration bed (25) heats the catalyst to 950° C., and simultaneously introduces steam and air to remove carbon deposits on the catalyst surface. The regenerated catalyst is returned to the circulating fluidized bed catalyst bed (8) for use, forming a closed cycle.

6. A biomass tar steam gasification hydrogen production coupled with a waste heat boiler power generation device, characterized by: It includes a screw feeder 1 (1-1), a screw feeder 2 (1-2), a screw feeder 3 (1-3), a circulating fluidized bed (2), a high-efficiency cyclone separator 1 (3), a differential fluidized bed steam gasifier (5), a superheater (7), a circulating fluidized bed catalytic bed (8), a high-efficiency cyclone separator 2 (9), an air preheater 3 (10), an air preheater 2 (11), an air preheater 1 (12), a dust collector (13), a high-temperature steam shift reactor (14), a low-temperature steam shift reactor (15), a condenser (16), an organic amine scrubber (17), a pressure swing adsorption system (18), a compressor (21) and a synthesis gas heater (22); The screw feeder 1 (1-1) is a biomass feeder, the screw feeder 2 (1-2) is a material feeder, the material consists of limestone, dolomite and Ni-based catalyst, and the screw feeder 3 (1-3) is a Ni-based catalyst feeder; the discharge ports of the screw feeder 1 (1-1) and the screw feeder 2 (1-2) are both connected to the circulating fluidized bed (2), and the discharge port of the screw feeder 3 (1-3) is connected to the circulating fluidized bed catalytic bed (8); the flue gas outlet at the top of the circulating fluidized bed (2) is connected to the flue gas inlet of the high-efficiency cyclone separator 1 (3), and the discharge port at the lower end of the high-efficiency cyclone separator 1 (3) is connected to the differential fluidized bed steam gasification furnace (5) and the flue gas inlet of the high-efficiency cyclone separator 1 (3) through the return valve 1 (4). The return port 1 of the circulating fluidized bed (2) is connected, and the discharge port of the differential fluidized bed steam gasification furnace (5) is connected to the return port 2 of the circulating fluidized bed (2) through the return valve 2 (6); the flue gas outlet at the top of the high-efficiency cyclone separator 1 (3) is connected to the flue gas inlet of the synthesis gas heater (22), the flue gas outlet of the synthesis gas heater (22) is connected to the flue gas inlet of the waste heat boiler (19), the steam outlet of the waste heat boiler (19) is connected to the steam inlet of the back pressure steam turbine generator set (20), the exhaust steam outlet of the back pressure steam turbine generator set (20) is connected to the superheated steam inlet of the superheater (7), and the superheated steam outlet of the superheater (7) is connected to the superheated steam outlet at the bottom of the differential fluidized bed steam gasification furnace (5). The syngas outlet at the top of the differential fluidized bed steam gasifier (5) is connected to the syngas inlet of the high-efficiency cyclone separator (9), the discharge port at the bottom of the high-efficiency cyclone separator (9) is connected to the lower part of the differential fluidized bed steam gasifier (5), the syngas outlet at the top of the high-efficiency cyclone separator (9) is connected to the syngas inlet of the syngas heater (22), the syngas outlet of the syngas heater (22) is connected to the syngas inlet at the bottom of the circulating fluidized bed catalytic bed (8), the syngas outlet at the top of the circulating fluidized bed catalytic bed (8) is connected to the syngas inlet of the superheater (7), the syngas outlet of the superheater (7) is connected to the air preheater (10), the dust collector (13) in sequence. ), a high-temperature steam shift reactor (14), an air preheater 2 (11), a low-temperature steam shift reactor (15), an air preheater 1 (12), a condenser (16), an organic amine scrubber (17), a compressor (21) and a pressure swing adsorption system (18), the exhaust port of the pressure swing adsorption system (18) is connected to the air inlet at the bottom of the circulating fluidized bed (2) through a pipeline, limestone, dolomite and Ni-based catalyst are fed into the circulating fluidized bed (2) through the screw feeder 2 (1-2) for calcination, and the calcination product is used as bed material and catalyst; the synthesis gas passes through the circulating fluidized bed catalyst bed (8) to catalytically reform the tar, CH4 and water vapor in the synthesis gas into H2, CO and CO2.

7. The biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device according to claim 6, characterized in that: The feed water outlet of the condenser (16) is connected to the feed water inlet of the waste heat boiler (19), and the feed water of the waste heat boiler (19) enters the waste heat boiler (19) after heat exchange in the condenser (16).

8. The biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation device according to claim 6, characterized in that: The outlet of the return valve 3 (24) at the bottom of the circulating fluidized bed catalyst bed (8) and the outlet at the lower end of the dust collector (13) are connected to the inlet of the Ni-based catalyst regeneration bed (25) through pipelines.

9. A method for realizing biomass tar steam gasification hydrogen production coupled with waste heat boiler power generation using the device according to any one of claims 6 to 8, characterized in that: The method comprises the following steps: Step 1: biomass is fed into a circulating fluidized bed (2) through a screw feeder (1-1) for combustion, and materials are fed into a circulating fluidized bed (2) for calcination through a screw feeder (1-2), wherein the materials are composed of dolomite, limestone and a Ni-based catalyst; 400-450°C high-temperature air enters the circulating fluidized bed (2) from the wind chamber at the bottom of the circulating fluidized bed (2) to assist combustion; the high-temperature flue gas from the flue gas outlet at the top of the circulating fluidized bed (2) carries the circulating materials into a high-efficiency cyclone separator (3), the circulating materials are separated by the high-efficiency cyclone separator (3) and enter a return valve (4), a portion of the circulating materials directly enters the circulating fluidized bed (2) through the return valve (4), and the remaining circulating materials enter the differential fluidized bed steam gasifier (5) through the return valve (4); Step 2: The high-temperature flue gas from the flue gas outlet at the top of the high-efficiency cyclone separator (3) enters the waste heat boiler (19) through the synthesis gas heater (22), and the steam generated by the waste heat boiler (19) is sent to the back-pressure steam turbine generator set (20) to generate electricity; the steam discharged from the back-pressure steam turbine generator set (20) enters the superheater (7) and is heated to 500-550°C, and the superheated steam enters the differential fluidized bed steam gasification furnace (5) from the bottom of the differential fluidized bed steam gasification furnace (5); Step 3: In the differential fluidized bed steam gasifier (5), the high-temperature circulating material and the high-temperature superheated steam heat the differential fluidized bed steam gasifier (5) to 600-700°C. The biomass tar is sprayed into the differential fluidized bed steam gasifier (5) and reacts with the high-temperature steam at this temperature to generate synthesis gas H2, CO, CO2 and CH4 and a trace amount of H2S. At the same time, the CaO generated by the decomposition of limestone and dolomite reacts with CO2 to generate CaCO3, and CaO reacts with H2S to generate CaS. CaCO3 and CaS enter the circulating fluidized bed (2) through the return valve 2 (6) and are decomposed into CO2, SO2 and CaO. CaO is separated by the high-efficiency cyclone separator 1 (3) and enters the differential fluidized bed steam gasifier (5) again for recycling. Step 4: The 600-700℃ synthesis gas coming out from the top of the differential fluidized bed steam gasifier (5) first enters the high-efficiency cyclone separator II (9), and the circulating materials carried in the synthesis gas are separated and returned to the differential fluidized bed steam gasifier (5) for recycling; the synthesis gas coming out from the top of the high-efficiency cyclone separator II (9) enters the synthesis gas heater (22), and the 900-950℃ high-temperature flue gas at the outlet of the high-efficiency cyclone separator I (3) is used to heat the synthesis gas to 780-830℃; then the synthesis gas passes through the circulating fluidized bed catalyst bed (8) to catalytically reform the tar, CH4 and water vapor in the synthesis gas into H2, CO and CO2, tar + H2O → C m H n +H2 +CO+CO2,C m H n +H2O → H2 +CO, CH4+H2O=3H2+CO; the tar removal rate reaches 99%, and the H2 volume ratio increases by more than 10%; the tar content in the synthesis gas from the synthesis gas outlet of the circulating fluidized bed catalyst bed (8) is ≤20mg / Nm 3 Then the synthesis gas passes through the superheater (7) and the air preheater 3 (10) and is cooled to 350°C, and enters the dust collector (13). After dust removal, the synthesis gas enters the high-temperature steam shift reactor (14), and the temperature rises to 380-450°C before entering the air preheater 2 (11), where the air is preheated to 250-300°C. After the synthesis gas temperature drops to 190-200°C, it enters the low-temperature steam shift reactor (15); when the steam / CO molar ratio is ≥2, the total CO conversion rate of CO+H2O=H2+CO2 is above 95%; after the synthesis gas is heated to 250-260°C, it enters the air preheater 1 (12), where the air is preheated from room temperature to 130-150°C. The temperature of the synthesis gas is reduced to 120-150°C, and then the synthesis gas enters the condenser (16), and the water vapor in the synthesis gas is condensed by using the waste heat boiler (19) to feed water, and the latent heat of vaporization in the steam is recovered; the synthesis gas then enters the organic amine scrubber (17), and the remaining dust, trace H2S and more than 90% of CO2 in the synthesis gas are removed. The temperature of the clean synthesis gas is reduced to 50-60°C, and the organic amine aqueous solution absorbs CO2 and regenerates; the synthesis gas then enters the pressure swing adsorption system (18) through the compressor (21) to obtain 99.9% H2. The exhaust gas of the pressure swing adsorption system (18) contains H2, CO, and CO2, which are sent to the circulating fluidized bed (2) for combustion and release heat.

10. The method of biomass tar steam gasification to produce hydrogen coupled with waste heat boiler power generation according to claim 9, characterized in that: The method further includes step five: discharging 50% of the partially failed catalyst from the return valve three (24) at the bottom of the circulating fluidized bed catalyst bed (8), and sending it together with the catalyst discharged from the lower part of the dust collector (13) to the Ni-based catalyst regeneration bed (25) for regeneration. The Ni-based catalyst regeneration bed (25) heats the catalyst to 950° C., and simultaneously introduces steam and air to remove carbon deposits on the catalyst surface. The regenerated catalyst is returned to the circulating fluidized bed catalyst bed (8) for use, forming a closed cycle.

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