Biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas

Abstract

The invention relates to the technical field of synthesis gas preparation, in particular to a biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas, and the biomass circulating fluidized bed gasification device and method for preparing the CO-rich synthesis gas comprise a calcium oxide feeding assembly, a gas supply assembly, a heat exchange assembly, a separation assembly, a furnace body and a folded plate. The gas supply assembly comprises a gasified gas supply part, an oxygen supply part and a mixing part, the mixing part is connected with the oxygen supply part and the first gasified gas conveying end, and the output end of the material supply assembly faces the low-temperature area; the discharging pipe section is provided with a calcium oxide nozzle, and the calcium oxide feeding assembly is connected with the calcium oxide nozzle. According to the biomass circulating fluidized bed gasification device and method for preparing the CO-rich synthesis gas, generation of carbon monoxide and cracking of tar are enhanced, and the quality of the synthesis gas is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthesis gas preparation, in particular to a biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas. BACKGROUND

[0002] In recent years, with the depletion of fossil energy and the increasing environmental problems, biomass energy has become an important direction to replace fossil fuels due to its renewability and carbon neutrality. Biomass gasification, as a core technology for converting solid biomass into combustible gas (H2, CO, CH4, etc.), has the advantages of cleanliness, high efficiency and strong adaptability, and can be widely used in power generation, synthetic fuel and chemical raw material production. Especially, the biomass circulating fluidized bed gasification technology has been widely applied due to its wide fuel applicability, high carbon conversion rate, low pollution emission and easy scaling.

[0003] However, the existing biomass circulating fluidized bed gasification technology still has the following key technical bottlenecks: first, the adaptability of biomass raw materials is poor. Different types of biomass raw materials exhibit different gasification characteristics in the fluidized bed gasification furnace. The traditional single-temperature zone gasification furnace is prone to generate a large amount of tar when processing high-volatile biomass, and for high-fixed carbon or high-ash raw materials, the gasification reaction is incomplete or easy to slag, which limits the universality of the device. Second, the conversion rate of carbon to CO is low. The dry synthesis gas produced in the conventional biomass gasification process also contains about 10-40% of carbon dioxide. The directional conversion rate of carbon in biomass to CO in the gasification process needs to be improved. In addition, the tar content in the traditional biomass gasification process is high. In the existing gasification process, the tar concentration at the synthesis gas outlet is often higher than 100 mg / m 3 , and a complex tar cracking and purification system needs to be additionally configured, increasing the operating cost. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, an embodiment of the present application provides a biomass circulating fluidized bed gasification device for preparing CO-rich synthesis gas, which enhances the generation of carbon monoxide and the cracking of tar, and improves the quality of synthesis gas.

[0006] The biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to an embodiment of the present application comprises: a furnace body and a folded plate, the folded plate is arranged in the hearth to divide the hearth into a high-temperature zone and a low-temperature zone, the upper part of the low-temperature zone is in communication with the lower part of the high-temperature zone, and the bottom of the low-temperature zone is provided with a fluidizing air chamber and a slag discharge pipe; A separation assembly, the furnace body has a discharge pipe section, the discharge pipe section inlet is connected with one end of the high temperature zone away from the low temperature zone, the separation assembly inlet is connected with the outlet of the discharge pipe section, the separation assembly first outlet is connected with the furnace body and the first outlet of the separation assembly faces the bending part of the baffle plate; A gas supply assembly and a heat exchange assembly, the heat exchange assembly is arranged in the discharge pipe section, the gas supply assembly includes a gasification gas supply part, an oxygen gas supply part and a mixing piece; The mixing piece is connected with the oxygen gas supply part and the first gas supply end of the gasification gas respectively, the mixing piece is arranged on the furnace body and the output end faces the baffle plate; The second gas supply end of the gasification gas supply part is connected with the separation assembly; The third gas supply end of the gasification gas is connected with the gas supply port of the heat exchange assembly, the heat exchange gas port is arranged on the furnace body, one end of the heat exchange gas port is connected with the gas outlet of the heat exchange assembly, and the heat exchange gas port faces the high temperature zone; The fourth gas supply end of the gasification gas is connected with the fluidized wind chamber; A material supply assembly, the second outlet of the separation assembly is connected with the material supply assembly, and the material supply assembly is connected with the furnace body, and the output end of the material supply assembly faces the low temperature zone; A calcium oxide material supply assembly, the discharge pipe section is provided with a calcium oxide spray port, and the calcium oxide material supply assembly is connected with the calcium oxide spray port.

[0007] The biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to the embodiment of the application can enhance the generation of carbon monoxide and the cracking of tar and improve the quality of synthesis gas.

[0008] In some embodiments, the heat exchange assembly is arranged at one end of the discharge pipe section adjacent to the high temperature zone, and the calcium oxide spray port is arranged at one end of the discharge pipe section adjacent to the separation assembly.

[0009] In some embodiments, the gas supply assembly further includes a first regulating valve, a second regulating valve, a third regulating valve and a fourth regulating valve, the first gas supply end of the gasification gas supply part is connected with the first regulating valve, and the first regulating valve is connected with the mixing piece; The second gas supply end of the gasification gas supply part is connected with the second regulating valve, and the second regulating valve is connected with the separation assembly; The third gas supply end of the gasification gas is connected with one end of the third regulating valve, and the other end of the third regulating valve is connected with the gas supply port of the heat exchange assembly; The fourth gas supply component is connected with one end of the fourth adjusting valve, and the other end of the fourth adjusting valve is connected with the fluidizing air chamber, so as to control the temperature of the low-temperature zone by controlling the amount of gas supplied to the fluidizing air chamber, and the temperature of the low-temperature zone is 600-700 DEG C.

[0010] In some embodiments, the gas supply assembly comprises: the oxygen gas supply component comprises an oxygen gas storage and an oxygen gas adjusting valve, the oxygen gas storage is connected with the oxygen gas adjusting valve, the other end of the oxygen gas adjusting valve is connected with the mixing component, and the oxygen gas adjusting valve adjusts the output amount of oxygen gas to control the temperature of the high-temperature zone, and the temperature of the high-temperature zone is 900-1000 DEG C.

[0011] In some embodiments, the biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas further comprises a first temperature monitoring component and a second temperature monitoring component, the first temperature monitoring component and the second temperature monitoring component are arranged on the furnace body, the first temperature monitoring component is directed to the low-temperature zone, and the second temperature monitoring component is directed to the high-temperature zone.

[0012] In some embodiments, the separation assembly comprises a separator, an overflow pipe and a return feeder, the separator is connected with the discharge pipe section, the bottom of the separator is connected with the return feeder, the return feeder is connected with the inlet of the overflow pipe, and the outlet of the overflow pipe is connected with the furnace body and is directed to the bending part of the baffle.

[0013] In some embodiments, the separation assembly further comprises a gas outlet pipe, the gas outlet pipe is arranged on the top of the return feeder, and the gas outlet pipe is connected with the feeding assembly.

[0014] In some embodiments, the connection between the overflow pipe and the return feeder has a preset spacing in the vertical direction from the bottom of the return feeder.

[0015] In some embodiments, the feeding assembly comprises a bunker, a feeding component and a material pipe, the bunker is connected with the input end of the feeding component, the output end of the feeding component is connected with the inlet of the material pipe, the gas outlet pipe is connected with the inlet of the material pipe, and the outlet of the material pipe is connected with the furnace body and is directed to the low-temperature zone.

[0016] The biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to the embodiments of the present application utilize the above biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas, which comprises: The material output from the high-temperature zone is cooled by the heat exchange assembly and then sprayed with calcium oxide powder, so that the calcium oxide absorbs the carbon dioxide in the material to generate calcium carbonate. The calcium carbonate enters the separator with the material, solid particles are captured and transported to the upper part of the baffle of the furnace body through the return feeder and overflow pipe, where the unreacted coke is burned under the oxygen-rich atmosphere to release heat, the high temperature produced by the burning causes the calcination of calcium carbonate, and the carbon dioxide produced by the two continues to enter the high-temperature gasification zone to react with the coke through the Boudouard reaction and react with hydrogen through the reverse water gas shift reaction to promote the generation of carbon monoxide together, and the high temperature promotes the cracking of tar; according to the density difference between calcium oxide and calcium carbonate, the higher density calcium oxide produced by calcination and regeneration falls into the low-temperature zone to inhibit the generation of tar, and the lower density calcium carbonate is suspended in the high-temperature zone under the action of the oxygen-rich mixed gas stream to continue calcination until complete calcination.

[0017] The biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to the embodiment of the present application can enhance the generation of carbon monoxide and the cracking of tar, and improve the quality of synthesis gas. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a schematic diagram of a biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to an embodiment of the present application.

[0019] Figure 2 FIG. 2 is a schematic diagram of a biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to an embodiment of the present application.

[0020] REFERENCE SIGNS: furnace body 1, hearth 11, low-temperature zone 111, high-temperature zone 112, discharge pipe section 12, fluidizing air chamber 13, slag discharge pipe 14, baffle 2, separation assembly 3, separator 31, overflow pipe 32, return feeder 33, gas outlet pipe 34, material supply assembly 4, material bin 41, material feeding member 42, material pipe 43, gas supply assembly 5, gasification gas supply component 51, oxygen gas supply component 52, oxygen gas storage member 521, oxygen gas regulating valve 522, mixing member 53, heat exchange assembly 6, calcium oxide supply assembly 7, first regulating valve 8, second regulating valve 9, third regulating valve 10, fourth regulating valve 20. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0022] The biomass circulating fluidized bed gasification device and method for preparing CO-rich synthesis gas according to the embodiment of the present application comprise: The furnace body 1 and the baffle plate 2 are arranged inside the furnace chamber 11, which divides the furnace chamber 11 into a high-temperature zone 112 and a low-temperature zone 111. The upper part of the low-temperature zone 111 is connected to the lower part of the high-temperature zone 112. A fluidizing air chamber 13 is provided at the bottom of the low-temperature zone 111. An air distribution plate is provided at the output end of the fluidizing air chamber 13 facing the low-temperature zone. The air distribution plate plays a role in uniformly distributing the gas, so that the bed material is in a low-flow-rate fluidized state. The inlet of the slag discharge pipe 14 is connected to the low-temperature zone 111 and is equipped with a valve to facilitate slag discharge.

[0023] Separation component 3, furnace body 1 has discharge pipe section 12, the inlet of discharge pipe section 12 is connected to the end of high temperature zone 112 away from low temperature zone 111, the inlet of separation component 3 is connected to the outlet of discharge pipe section 12, the first outlet of separation component 3 is connected to furnace body 1 and the first outlet of separation component 3 faces the bend of baffle 2. The gas supply component 5 and the heat exchange component 6 are arranged in the discharge pipe section 12. The gas supply component 5 includes a gasification gas supply component 51, an oxygen supply component 52 and a mixing component 53. The mixing component 53 is connected to the oxygen supply component 52 and the first gas delivery end of the gasification gas, respectively. The mixing component 53 is arranged on the furnace body 1 and its output end faces the baffle plate 2. The second gas delivery end of the gasification gas supply component 51 is connected to the separation component 3. The third gas delivery end of the gasification gas is connected to the gas delivery port of the heat exchange component 6. A heat exchange gas port is provided on the furnace body 1. One end of the heat exchange gas port is connected to the gas outlet of the heat exchange component 6 and the heat exchange gas port faces the high temperature zone 112. The fourth gas delivery end of the gasification gas is connected to the fluidizing air chamber 13. The second outlet of the separation component 3 is connected to the feeding component 4, and the feeding component 4 is connected to the furnace body 1. The output end of the feeding component 4 faces the low temperature zone 111. The calcium oxide feeding assembly 7 has a calcium oxide nozzle on the discharge pipe section 12, and the calcium oxide feeding assembly 7 is connected to the calcium oxide nozzle.

[0024] This invention discloses a biomass circulating fluidized bed gasification device and method for preparing CO-rich syngas, which enhances carbon monoxide generation and tar cracking, thereby improving syngas quality.

[0025] Specifically, the fourth gas supply end of the gasification gas supply component 51 is connected to the fluidizing air chamber 13 to supply gas to the fluidizing air chamber 13. An air distribution plate is provided between the fluidizing air chamber 13 and the furnace 11. The slag discharge pipe 14 passes through the air distribution plate and the fluidizing air chamber 13 from the bottom of the furnace 11 to discharge waste slag. The fluidizing air chamber 13 and the air distribution plate are used to provide gasification medium to the low-temperature zone 111 of the furnace body 1 to achieve low-velocity fluidization of the bed material, for example, in a bubbling or turbulent state, which is conducive to the pyrolysis of biomass particles transported to the low-temperature zone 111, the catalytic decomposition of tar by CaO, and the fixation of alkali metals and chlorine. Alternatively, in the low-temperature zone 111, after the biomass is input into the low-temperature zone 111 by the feeding component 4, it is mixed with the bed material and CaO and then pyrolyzed and gasified to generate gases mainly containing hydrogen, carbon monoxide and carbon dioxide, as well as coke, and then enters the high-temperature zone 112.

[0026] The high-temperature zone 112, at the bend of the folding plate, is also suitable for receiving calcium carbonate particles, unreacted coke, and calcium oxide input from the separation component 3, as well as oxygen-enriched mixed gas output from the oxygen supply component 52 and the gasification gas supply component 51 through the mixing component 53. This allows the unreacted coke to undergo combustion near the folding plate at the bottom of the high-temperature zone 112. The released heat causes the calcium carbonate to calcine and decompose into carbon dioxide and calcium oxide. Calcium oxide, due to its higher density, falls into the low-temperature zone 111 by gravity, catalyzing tar cracking to reduce tar production. It reacts with alkali metals to generate corresponding alkali metal salts, thus fixing the alkali metals. The alkali metals are then discharged from the low-temperature zone 111 through the slag discharge pipe to prevent them from entering the high-temperature zone 112. CaO can also absorb gases such as carbon dioxide, HCl, and SO2. Waste residue is also discharged from the low-temperature zone 111 through the slag discharge pipe, promoting the generation of CO and H2, reducing corrosion of the equipment, and lowering pollutant emissions. The separation component separates the solid particles of the material output from the furnace body and returns them to the area where the baffle plate is located. The carbon dioxide produced from the combustion of unreacted coke and the calcination of calcium carbonate from the separation component 3 can also enter the upper part of the high-temperature zone 112 to undergo a Boudouard reaction with the coke from the low-temperature zone, and a reverse water-gas shift reaction with H2, thus fully converting the carbon in the biomass to CO. The lower-density calcium carbonate continues to be calcined in this area under the influence of the gradually expanding channel structure formed between the baffle plate 2 and the furnace body 1 and the oxygen-rich mixed gas flow, until complete calcination. Alternatively, near the baffle plate area at the bottom of the high-temperature zone 112, the calcium carbonate particles input from the separation component 3 continue to undergo the calcination reaction, and the resulting calcium oxide, due to its increased density, cannot be entrained by the airflow and falls into the low-temperature zone 111.

[0027] The third gas supply end of the gasification gas supply component 51 is connected to the gas supply port of the heat exchange component 6 to supply gasification gas to the heat exchange component 6. The heat exchange component 6 exchanges heat between the gasification gas and the higher temperature exhaust gas of the high temperature zone 112. The heated gasification gas enters the high temperature zone 112 after passing through the heat exchange component 6 to regulate the temperature of the high temperature zone 112 and prevent the temperature of the high temperature zone 112 from falling below the preset range. Alternatively, the gasification gas input to the high temperature zone 112 can be preheated before being input to the high temperature zone 112 to prevent the gasification gas temperature input to the high temperature zone 112 from being too low, which would cause excessive temperature fluctuations in the high temperature zone 112.

[0028] The gas (mainly containing hydrogen, carbon monoxide, and carbon dioxide) and coke particles in the low-temperature zone 111 are discharged to the high-temperature zone 112 under the action of the gas output from the fluidizing chamber 13. In the high-temperature zone 112, the Boudouard reaction, the reverse water-gas shift reaction, and the tar thermal cracking reaction occur to generate clean synthesis gas rich in carbon monoxide. The product from the high-temperature zone 112 flows into the separation component 3 through the discharge pipe section 12.

[0029] The syngas in high-temperature zone 112 continues to rise to the discharge pipe section 12 for heat exchange with the heat exchange component 6. The gasified gas supplied by the third gas delivery end of the gasification gas supply component 51 to the gas delivery port of the heat exchange component 6 is heated, and the heated gasified gas enters high-temperature zone 112. A calcium oxide nozzle is arranged at the outlet after the discharge pipe section 12 to inject calcium oxide. The calcium oxide reacts with carbon dioxide, further reducing the carbon dioxide content in the syngas and improving the quality of the syngas.

[0030] Solid particles in the material flowing out of the discharge pipe section 12 are captured by the separation component 3. The finer particles are sent back to the low-temperature zone 111 for further reaction, while the coarser particles pass through the upper part of the baffle plate 2 and undergo coke combustion and calcium carbonate calcination under the action of oxygen-enriched mixed gas. The carbon dioxide produced by both processes continues to enter the high-temperature zone 112 to react with coke and H2, promoting the generation of carbon monoxide. Based on the density difference between calcium oxide and calcium carbonate, the higher-density calcium oxide regenerated by calcination falls into the low-temperature zone 111. The discharge pipe section 12 is equipped with a calcium oxide nozzle, and the calcium oxide feeding component 7 is connected to the calcium oxide nozzle to spray calcium oxide, which absorbs carbon dioxide and increases the ratio of carbon monoxide to hydrogen in the synthesis gas of the material.

[0031] This invention discloses a biomass circulating fluidized bed gasification device and method for preparing CO-rich syngas. By setting up a baffle plate 2 and calcium oxide nozzles, the baffle plate 2 divides the furnace 11 into a high-temperature zone 112 and a low-temperature zone 111, facilitating gasification reactions at different temperatures in the high-temperature zone 112 and the low-temperature zone 111, thus separating the gasification reactions at different temperatures. In the low-temperature zone 111, calcium oxide catalyzes tar cracking, reducing tar generation and lowering subsequent purification costs. It also reacts with alkali metals and chlorine, fixing these elements that may cause equipment corrosion, and discharging them through the slag discharge pipe. The high-temperature zone 112 further utilizes the high-temperature environment to promote tar thermal cracking, while simultaneously enhancing the Boudouard reaction and the reverse water-gas shift reaction, promoting the conversion of carbon in biomass to carbon monoxide. This enhances the adaptability to biomass feedstock, improves gasification efficiency, and reduces production costs by eliminating the need for separate tar treatment equipment through reduced pollutant emissions. It also improves the quality of the product gas and enhances the system's stability and operational flexibility.

[0032] In some embodiments, the heat exchange assembly 6 is disposed at one end of the discharge pipe section 12 adjacent to the high-temperature zone 112, and the calcium oxide nozzle is disposed at one end of the discharge pipe section 12 adjacent to the separation assembly 3. The materials output from the high-temperature zone include solid particles and syngas. The heat exchange component 6 is used to cool the material in the high-temperature zone 112 to the optimal reaction temperature range for CaO to absorb carbon dioxide, which is about 700°C, thereby improving the quality of the syngas in the material; at the same time, it heats the gasified gas input into the high-temperature zone 112 to improve the stability of the temperature in the high-temperature zone 112.

[0033] In some embodiments, the gas supply assembly 5 further includes a first regulating valve 8, a second regulating valve 9 and a third regulating valve 10, the first gas delivery end of the gasified gas supply component 51 is connected to the first regulating valve 8, and the first regulating valve 8 is connected to the mixing component 53; The second gas supply end of the gasification gas supply component 51 is connected to the second regulating valve 9, and the second regulating valve 9 is connected to the separation component 3. The third gas supply end of the gasification gas supply component 51 is connected to one end of the third regulating valve 10, and the other end of the third regulating valve 10 is connected to the gas supply port of the heat exchange component 6.

[0034] Specifically, the first regulating valve 8 is adapted to adjust the flow rate of the gasified gas input to the mixing unit 53, and then cooperate with the oxygen supply unit 52 to output mixed gas with different oxygen contents to the furnace body 1.

[0035] The third gas supply end of the vaporized gas supply component 51 is connected to one end of the third regulating valve 10, and the other end of the third regulating valve 10 is connected to the gas inlet of the heat exchange component 6. The third regulating valve 10 then adjusts the amount of vaporized gas output to the heat exchange component 6, or the amount of vaporized gas output from the heat exchange component 6 to the high-temperature zone 112, thereby regulating the temperature of the high-temperature zone 112. The second regulating valve 9 is adapted to regulate the amount of vaporized gas output to the separation component 3.

[0036] In this embodiment, a first regulating valve 8, a second regulating valve 9, and a third regulating valve 10 are used. The first regulating valve 8 adjusts the flow rate of the vaporized gas input to the mixing component 53, working in conjunction with the oxygen supply component 52 to output a mixture with different oxygen contents, thus optimizing the combustion and vaporization reaction and improving vaporization efficiency. The third regulating valve 10 adjusts the amount of vaporized gas output to the heat exchange component 6, or in other words, adjusts the amount of vaporized gas output from the heat exchange component 6 to the high-temperature zone 112, thereby controlling the temperature of the high-temperature zone 112 to a certain extent and ensuring the stability of the vaporization process.

[0037] In some embodiments, the gas supply assembly 5 includes: an oxygen supply component 52 including an oxygen storage unit 521 and an oxygen regulating valve 522, the oxygen storage unit 521 being connected to the oxygen regulating valve 522, the other end of the oxygen regulating valve 522 being connected to a mixing unit 53, and the oxygen regulating valve 522 regulating the oxygen output to control the temperature of the high-temperature zone 112.

[0038] Oxygen regulating valve 522 regulates the amount of oxygen output from oxygen storage unit to regulate the amount of oxygen output to mixing unit 53, thereby adjusting the oxygen content of the mixed gas output to furnace 11. The mixed gas is injected into the gasifier furnace 11, and the oxygen enrichment ratio can be selectively adjusted. Coarse particles enter the upper part of the baffle plate through separation component 3, and coke combustion and calcium carbonate calcination occur under the action of oxygen-enriched mixed gas. The carbon dioxide produced by both continues to enter the high-temperature gasification zone to react with coke and H2. According to the density difference between calcium oxide and calcium carbonate, the high-density calcium oxide regenerated by calcination falls into the low-temperature zone 111. The mixer is used to guide CaO to the low-temperature pyrolysis zone while helping to maintain the atmosphere and temperature of the high-temperature zone 112.

[0039] Excess oxygen input from the mixing unit 53 can also enter the upper part of the high-temperature zone 112, accelerating the chemical reaction in the high-temperature zone 112. Since the chemical reaction in the high-temperature zone 112 absorbs heat energy, the temperature of the high-temperature zone 112 can be controlled.

[0040] Furthermore, the operator can adjust the gas output from the third gas supply end of the gasification gas supply component 51 and the output of the oxygen regulating valve 522, thereby comprehensively adjusting the temperature and atmosphere of the high-temperature zone 112. Atmosphere refers to the type and proportion of gases.

[0041] Furthermore, a biomass circulating fluidized bed gasification device and method for preparing CO-rich syngas also includes a first temperature monitoring element and a second temperature monitoring element. The first and second temperature monitoring elements are mounted on the furnace body 1, with the monitoring end of the first temperature monitoring element facing the low-temperature zone 111 and the second temperature monitoring element facing the high-temperature zone 112. This allows for the detection of the temperatures in the low-temperature zone 111 and the high-temperature zone 112, facilitating the adjustment of the amount of gasified gas and oxygen output from the heat exchange component 6 to the high-temperature zone 112 based on the temperature of the high-temperature zone 112, thereby controlling the temperature of the high-temperature zone 112. Alternatively, the temperature of the low-temperature zone 111 can be adjusted by regulating the amount of gasified gas in the fluidized air chamber.

[0042] In some embodiments, the separation assembly 3 includes a separator 31, an overflow pipe 32, and a return feeder 33. The separator 31 is connected to the discharge pipe section 12, the bottom of the separator 31 is connected to the return feeder 33, the return feeder 33 is connected to the inlet of the overflow pipe 32, and the outlet of the overflow pipe 32 is connected to the furnace body 1 and faces the bend of the baffle plate.

[0043] Specifically, the inlet of separator 31 is connected to the outlet of discharge pipe section 12. Cyclone separator 31 is connected to gasifier furnace 11 and return feeder 33 for gas-solid separation and carbon dioxide capture and circulation.

[0044] The return feeder 33 is used to separate the solid particles captured by the cyclone separator 31 and send the fine particles (mainly unreacted coke, calcium oxide and bed material) back to the low temperature zone 111 through the return air, so as to make full use of the unreacted carbon in the raw materials.

[0045] The overflow pipe 32 connects the return feeder 33 and the gasifier furnace 11, and is located in the middle of the gasifier furnace 11. It is used to transport the CaCO3 particles, unreacted coke and calcium oxide separated from the separator 31 received by the return feeder 33 to the upper part of the baffle plate and carry out coke combustion and CaCO3 particle calcination in an oxygen-rich atmosphere to realize the internal circulation of carbon dioxide in the furnace.

[0046] In some embodiments, the separation component 3 further includes an exhaust pipe 34, which is disposed at the top of the return feeder 33 and connected to the feeding component 4. The exhaust pipe 34 connects the upper part of the return feeder 33 and the feed pipe 43, using the return air as the carrying air to transport fine particles and biomass particles into the low-temperature zone 111 of the furnace 11. The return air is the gas output from the furnace body 1 to the separation component 3 and is output to the feeding component 4 to balance the pressure difference between the feeding component 4 and the furnace 11, so that the biomass feedstock output by the feeding component 4 can be output into the low-temperature zone 111 within the furnace 11. This serves as the main input feedstock for the gasification reaction, improving the stability of the gasifier's operation.

[0047] In some embodiments, the connection between the overflow pipe 32 and the return feeder 33 and the bottom of the return feeder 33 have a preset distance in the vertical direction.

[0048] The bottom of the return feeder is typically an area where particulate material accumulates and flows. If the overflow pipe 32 is directly connected to the bottom, particles will accumulate at the connection point, causing blockage. Setting a preset spacing can prevent material from accumulating directly at the inlet of the overflow pipe 32, allowing particles more time to mix and homogenize within the return feeder 33, thereby improving the uniformity of the returned material, reducing the risk of blockage, and enhancing the stability of system operation.

[0049] In some embodiments, the feeding assembly 4 includes a hopper 41, a feeder 42, and a feed pipe 43. The hopper 41 is connected to the input end of the feeder 42, the output end of the feeder 42 is connected to the inlet of the feed pipe 43, and the air outlet pipe 34 is connected to the inlet of the feed pipe 43.

[0050] The hopper 41 is suitable for carrying biomass raw materials, and the feeder 42 can be an existing screw conveyor.

[0051] This implementation, by setting up the feeder 42, can quantitatively and evenly deliver raw materials to the feed pipe 43, ensuring the stability of the supply. Secondly, the setting of the air outlet pipe 34 can balance the air pressure in the feed pipe 43, preventing the raw material from being obstructed or the equipment from being damaged due to excessive air pressure. At the same time, it can also recover some unreacted materials (such as coke and fine calcium oxide particles), improving energy utilization efficiency.

[0052] In some embodiments, a biomass circulating fluidized bed gasification device and method for preparing CO-rich syngas further includes a fourth regulating valve 20, wherein the fourth gas supply end of the gasification gas supply component 51 is connected to one end of the fourth regulating valve 20, and the other end of the fourth regulating valve 20 is connected to the fluidizing air chamber 13.

[0053] In this embodiment, the amount of gasified gas in the fluidized air chamber 13 is controlled by the fourth regulating valve 20, thereby controlling the amount of gasified gas output from the fluidized air chamber 13 at the bottom of the low-temperature zone 111. This ensures that the bed material and biomass in the low-temperature zone 111 are in a low-flow-rate fluidization (bubbling or turbulent) state, allowing them to mix and react fully, thus improving the stability of the system operation.

[0054] This invention discloses a gasification method for a biomass circulating fluidized bed gasification device for preparing CO-rich syngas, comprising: After the material output from the high-temperature zone 112 is cooled by the heat exchange component 6, it is sprayed with calcium oxide powder so that the calcium oxide absorbs carbon dioxide to generate calcium carbonate. After the calcium carbonate enters the separator 31 with the material, the solid particles are captured and transported to the upper part of the baffle plate 2 of the furnace body 1 through the return feeder 33 and the overflow pipe 32. The unreacted coke is burned and released heat in the oxygen-rich atmosphere. The high temperature generated causes the calcium carbonate to calcine. The carbon dioxide generated by both continues to enter the high-temperature gasification zone 112 to react with the coke in the Boudouard reaction and with hydrogen in the reverse water-gas conversion reaction, which together promotes the generation of carbon monoxide. The high temperature also promotes the cracking of tar. According to the density difference between calcium oxide and calcium carbonate, the higher density calcium oxide regenerated by calcination falls into the low-temperature zone 111, which can play a role in inhibiting the generation of tar. The lower density calcium carbonate is suspended in the high-temperature zone 112 under the action of the gradually expanding channel structure formed between the baffle plate 2 and the furnace body 1 and the oxygen-rich mixed gas flow, and continues to be calcined until calcination is complete.

[0055] Specifically, the mixture of material or solid particles and syngas output from the high-temperature zone 112 is too hot. After the heat exchange component 6 cools it down, for example, to 700°C, calcium oxide powder is sprayed on it so that the sprayed calcium oxide absorbs carbon dioxide to generate calcium carbonate, thus avoiding the calcination and decomposition of calcium carbonate due to excessively high temperature and improving the quality of syngas.

[0056] After the material enters the separator 31, the separation component 3 outputs the solid particles (including unreacted coke and calcium carbonate) to the upper part of the baffle plate 2 of the furnace body 1. The oxygen supply component 52 adjusts the oxygen output to provide sufficient oxygen, and the unreacted coke is burned in an oxygen-rich atmosphere. The combustion releases heat and generates high temperature to calcine the calcium carbonate. The carbon dioxide produced by the coke combustion and calcium carbonate calcination in the high-temperature zone 112 continues to enter the high-temperature gasification zone to react with the coke and H2. Based on the density difference between calcium oxide and calcium carbonate, the higher-density calcium oxide regenerated by calcination falls into the low-temperature zone, while the lower-density calcium carbonate is suspended in the high-temperature zone 112 under the action of the oxygen-rich mixed gas flow to continue calcination. Then, the material output from the high-temperature zone 112 is cooled by the heat exchange component 6, thereby completing the circulation of part of the carbon dioxide in the gasification device.

[0057] This invention discloses a biomass circulating fluidized bed gasification device and method for preparing CO-rich syngas, which enhances carbon monoxide generation and tar cracking, thereby improving syngas quality. In the description of this invention, it should be understood that terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0059] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" of the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A biomass circulating fluidized bed gasification apparatus for producing a CO-rich synthesis gas, characterized by, The utility model relates to a kind of calcium looping process system, including: Furnace body and folding plate, furnace body has hearth, folding plate is arranged in hearth and hearth is divided into high-temperature zone and low-temperature zone, the upper portion of the low-temperature zone is communicated with the lower portion of high-temperature zone, the bottom of the low-temperature zone is equipped with fluidization air chamber and slag discharge pipe; Separation assembly, the furnace body has discharge pipe section, the inlet of the discharge pipe section is connected with the end of high-temperature zone away from low-temperature zone, the inlet of the separation assembly is connected with the outlet of the discharge pipe section, the first outlet of the separation assembly is connected with the furnace body and the first outlet of separation assembly is towards the bending of folding plate; Gas supply assembly and heat exchange assembly, the heat exchange assembly is arranged in the discharge pipe section, the gas supply assembly includes gasification gas supply component, oxygen supply component and mixing piece, The mixing piece is connected with the oxygen supply component and the first gas supply end of gasification gas respectively, the mixing piece is arranged on furnace body and output end is towards folding plate, The second gas supply end of the gasification gas supply component is connected with the separation assembly, The third gas supply end of the gasification gas supply component is connected with the gas supply port of the heat exchange assembly, the heat exchange gas port is arranged on the furnace body, one end of the heat exchange gas port is connected with the gas outlet of the heat exchange assembly, and the heat exchange gas port is towards high-temperature zone, The fourth gas supply end of the gasification gas supply component is connected with the fluidization air chamber, Feeding assembly, the second outlet of the separation assembly is connected with the feeding assembly, and the feeding assembly is connected with the furnace body, and the output end of the feeding assembly is towards low-temperature zone; Calcium oxide feeding assembly, the discharge pipe section is provided with calcium oxide nozzle, and the calcium oxide feeding assembly is connected with the calcium oxide nozzle.

2. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas from biomass according to claim 1, characterized in that, The heat exchange assembly is arranged at the end of the discharge pipe section adjacent to the high-temperature zone, and the calcium oxide nozzle is arranged at the end of the discharge pipe section adjacent to the separation assembly.

3. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas from biomass according to claim 1, characterized in that, The gas supply assembly further includes first regulating valve, second regulating valve, third regulating valve and fourth regulating valve, the first gas supply end of the gasification gas supply component is connected with the first regulating valve, and the first regulating valve is connected with the mixing piece; The second gas supply end of the gasification gas supply component is connected with the second regulating valve, and the second regulating valve is connected with the separation assembly; The third gas supply end of the gasification gas supply component is connected with one end of the third regulating valve, and the other end of the third regulating valve is connected with the gas supply port of the heat exchange assembly; The fourth gas supply end of the gasification gas supply component is connected with one end of the fourth regulating valve, and the other end of the fourth regulating valve is connected with the fluidization air chamber, and the temperature of the low-temperature zone is controlled by controlling the amount of gasification gas input into the fluidization air chamber, and the temperature of the low-temperature zone is 600-700 ℃.

4. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas from biomass according to claim 3, characterized in that, The oxygen supply component includes oxygen storage and oxygen regulating valve, the oxygen storage is connected with the oxygen regulating valve, the other end of the oxygen regulating valve is connected with the mixing piece, the output amount of oxygen is controlled by the oxygen regulating valve to control the temperature of the high-temperature zone, and the temperature of the high-temperature zone is 900-1000 ℃.

5. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas from biomass according to claim 4, characterized in that, Further comprising a first temperature monitoring member and a second temperature monitoring member, the first temperature monitoring member and the second temperature monitoring member are arranged on the furnace body, the first temperature monitoring member monitors the end towards the low-temperature zone, and the second temperature monitoring member monitors the end towards the high-temperature zone.

6. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas according to claim 5, wherein, Further comprising: The separation assembly comprises a separator, an overflow pipe and a return feeder, the separator is connected with the discharge pipe section, the bottom of the separator is connected with the return feeder, the return feeder is connected with the inlet of the overflow pipe, and the outlet of the overflow pipe is connected with the furnace body and faces the bending part of the baffle.

7. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas according to claim 6, wherein, The separation assembly further comprises an air outlet pipe, the air outlet pipe is arranged at the top of the return feeder, and the air outlet pipe is connected with the feeding assembly.

8. A circulating fluid bed gasification apparatus for the production of a CO rich synthesis gas according to claim 6, wherein, Further comprising: The connection part between the overflow pipe and the return feeder has a preset interval with the bottom of the return feeder in the vertical direction.

9. A circulating fluid bed gasification apparatus for gasifying biomass to produce a CO-rich synthesis gas according to claim 7, wherein, The feeding assembly comprises a bin, a feeding member and a material pipe, the bin is connected with the input end of the feeding member, the output end of the feeding member is connected with the inlet of the material pipe, the air outlet pipe is connected with the inlet of the material pipe, and the outlet of the material pipe is connected with the furnace body and faces the low-temperature zone.

10. A method for producing a CO-rich syngas using the biomass circulating fluidized bed gasification apparatus and method for producing a CO-rich syngas according to claim 1, wherein Further comprising: The high-temperature zone output material is sprayed with calcium oxide powder after being cooled by the heat exchange assembly, so that the calcium oxide absorbs the carbon dioxide in the material to generate calcium carbonate; After the calcium carbonate enters the separator with the material, the solid is captured and transported to the upper part of the baffle of the furnace body through the return feeder and the overflow pipe, wherein the unreacted coke is burned under the oxygen-rich atmosphere to release heat, the high temperature generated by the burning causes the calcination of the calcium carbonate, and the carbon dioxide generated by the two continues to enter the high-temperature gasification zone to react with the coke through the Boudouard reaction and react with hydrogen through the reverse water gas shift reaction, thereby promoting the generation of carbon monoxide together, and the high temperature promotes the cracking of tar; according to the density difference between the calcium oxide and the calcium carbonate, the higher-density calcium oxide generated by the calcination and regeneration falls into the low-temperature zone, which can inhibit the generation of tar, and the lower-density calcium carbonate is suspended in the high-temperature zone under the action of the oxygen-rich mixed gas stream to continue the calcination until the calcination is complete.

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