A circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal

Abstract

The present invention provides a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal, comprising a compound agent storage bin 1, a coal storage bin 2, a spiral coal feeder 3, a gasifier feed port 4, a gasifier 5, a gasifying agent inlet 6, a slag cooler 7, a gasifier slag outlet 8, a booster air pump 9, an ignition burner 10, a cyclone dust collector bin pump 11, a bag dust collector bin pump 12, an ash bin bin pump 13, an ash bin 14, a cyclone dust collector 15, a bag dust collector 16, an air preheater 17, a fan 18, a carbon dioxide booster pump 19, an air preheater 20, a return device 21, a cyclone separator 22, and a gas delivery pipe 23. The present invention has the following advantages: by changing the particle size of raw coal, adding compounding agents to the raw coal, adjusting the composition of the gasifying agent, filling refractory bricks at the bottom of the furnace, etc., the problem of poor fluidization effect and slagging of high-alkali and low-ash melting point coal in a fluidized bed gasifier is effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of coal gasification, and in particular to a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal. Background Art

[0002] Since the circulating fluidized bed gasifier has the characteristics of uniform temperature distribution in the bed, small bed pressure difference, and sufficient material reaction, most types of coal can operate efficiently in the fluidized bed gasifier, and the gasification product has a high content of effective gas components, and almost no VOCs and tar substances are produced, which has significant advantages. However, when using high-alkali and low-ash melting point raw coal for gasification reaction in a fluidized bed gasifier, problems such as poor fluidization effect and slagging at the bottom of the furnace are prone to occur, resulting in poor stability of the gasification process of the fluidized bed gasifier. Therefore, for high-alkali and low-ash melting point raw coal, it is necessary to improve the circulating fluidized bed gasification device and process to improve the operating stability of the gasifier. Summary of the invention

[0003] In order to solve the above technical problems, the object of the present invention is to provide a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal, including a compound agent storage bin 1, a coal storage bin 2, a spiral coal feeder 3, a gasifier feed port 4, a gasifier 5, a gasifying agent inlet 6, a slag cooler 7, a gasifier slag outlet 8, a booster air pump 9, an ignition burner 10, a cyclone dust collector bin pump 11, a bag dust collector bin pump 12, an ash bin pump 13, an ash bin 14, a cyclone dust collector 15, a bag dust collector 16, an air preheater 17, a fan 18, a carbon dioxide booster pump 19, an air preheater 20, a return device 21, a cyclone separator 22, and a gas delivery pipe 23.

[0005] As a further illustration of the present invention, the compound agent storage bin 1 is placed on the upper part of the coal storage bin 2, the coal storage bin 2 is connected to the screw coal feeder 3, and the screw coal feeder 3 is placed on the top of the feed port 4 of the circulating fluidized bed gasifier.

[0006] As a further illustration of the present invention, the gasifying agent inlet 6 and the circulating fluidized bed gasifier slag outlet 8 are provided at the bottom of the circulating fluidized bed gasifier 5, and a pressurized purge gas interface is provided around the coke slag easy deposition area at the bottom of the circulating fluidized bed gasifier 5, and is connected to the booster air pump 9.

[0007] As a further illustration of the present invention, the circulating fluidized bed gasifier 5 is connected to the cyclone separator 22 through the coal gas delivery pipe 23, the cyclone separator 22 is connected to the returner 21 at the bottom, and the lower end of the returner 21 is connected to the circulating fluidized bed gasifier 5.

[0008] As a further illustration of the present invention, the air preheater 20 is connected to the cyclone separator 22 and the air preheater 17 through pipelines, respectively, and the air preheater 17 is connected to the cyclone dust collector 15 through a pipeline.

[0009] As a further illustration of the present invention, the cyclone dust collector 15 is connected to the cyclone dust collector bin pump 11 and the bag dust collector 16 through pipelines, respectively, and the bag dust collector 16 is connected to the bag dust collector bin pump 12 through a pipeline.

[0010] As a further illustration of the present invention, the cyclone dust collector silo pump 11 and the bag dust collector silo pump 12 are connected to the ash silo 14 through pipelines, and the ash silo 14 is connected to the ash silo pump 13 through pipelines.

[0011] As a further illustration of the present invention, the bottom of the gasifier 5 is filled with refractory bricks, or refractory bricks + pouring filling.

[0012] As a further illustration of the present invention, the particle size of the raw coal can be adjusted according to the density of the raw coal. In terms of true density, if the density of the raw coal is in the range of 1.0-1.5 g / cm 3 , the particle size is 15-50 mm; if the density of raw coal is 1.5-2.0 g / cm 3 , the particle size can be reduced to 0-15 mm.

[0013] As a further illustration of the present invention, the compounding agent is composed of kaolin, coal gangue, clay, and carbide slag, which, by mass fraction, include 30-100% kaolin, 20-40% clay, 5-10% coal gangue, and 5-10% carbide slag.

[0014] Compared with the prior art, the present invention has the following positive effects:

[0015] 1. A circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal, which increases the particle size of the raw coal, increases the circulating return amount of the cyclone separator 22, and reduces the load of the subsequent gas-solid separation equipment process.

[0016] 2. A circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal. The carbon dioxide booster pump 19 can provide carbon dioxide blowing gas to the gasifier inlet 4 and the return feeder 21, thereby realizing pneumatic conveying and efficient entry of solid materials into the furnace, and at the same time realizing efficient utilization of greenhouse gas carbon dioxide.

[0017] 3. A circulating fluidized bed gasification device and process suitable for high-alkali, low-ash melting point coal, by adding a proper amount of compounding agent to the raw coal through the compounding agent storage bin 1, the ash melting point of the high-alkali, low-ash melting point coal can be increased to prevent the coal ash from slagging at the bottom of the circulating fluidized bed gasifier 5.

[0018] 4. A circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal, which uses the booster air pump 9 to blow the non-fluidized and slag-prone areas at the bottom of the gasifier to change the distribution of the slag and balance the height of the slag layer at the bottom of the gasifier, thereby improving the slag removal efficiency and avoiding large amounts of slag deposition.

[0019] 5. A circulating fluidized bed gasification device, process and equipment suitable for high-alkali, low-ash melting point coal. For high-alkali, low-ash melting point coal, the bottom of the gasifier 5 can be filled with refractory bricks, or refractory bricks and cast filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The invention relates to a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, any product identical or similar to the present invention obtained by anyone under the enlightenment of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0022] like Figure 1 As shown, the present invention provides a circulating fluidized bed gasification device and process suitable for high-alkali and low-ash melting point coal, including a compound agent storage bin 1, a coal storage bin 2, a spiral coal feeder 3, a gasifier feed port 4, a gasifier 5, a gasifying agent inlet 6, a slag cooler 7, a gasifier slag outlet 8, a booster air pump 9, an ignition burner 10, a cyclone dust collector bin pump 11, a bag dust collector bin pump 12, an ash bin pump 13, an ash bin 14, a cyclone dust collector 15, a bag dust collector 16, an air preheater 17, a fan 18, a carbon dioxide booster pump 19, an air preheater 20, a return device 21, a cyclone separator 22, and a gas delivery pipe 23.

[0023] The compounding agent storage bin 1 stores granular compounding agents, which are added to the coal storage bin 2 together with raw coal of a certain particle size from the outside. The compounding agent and the raw coal are fully mixed through the spiral coal feeder 3 and enter the feeding port 4 of the circulating fluidized bed gasifier. The air preheater 17 preheats the air sent by the fan 18 and sends it to the ignition burner 10 for igniting the initial raw coal in the gasifier 5. The air preheated by the air preheater 17, the steam and oxygen from the outside are sent to the gasifier 5 through the gasification agent inlet 6 to provide gas raw materials for the gasification reaction. The raw coal gas generated by the gasifier 5 is sent to the cyclone separator 22 through the coal gas delivery pipe 23, and the coke slag at the bottom of the gasifier 5 is discharged through the gasifier slag outlet 8, and is discharged to the outside after being cooled by the slag cooler 7. After the cyclone separator 22 separates the larger particles of fly ash carried in the raw gas, the raw gas is sent to the cyclone dust collector 15, and the larger particles of fly ash are sent to the return material 21. The carbon dioxide booster pump 19 continuously transports carbon dioxide from the outside to the return material 21, purges the larger particles of fly ash in the return material 21, and sends it to the gasifier 5 to participate in the reaction again. The carbon dioxide booster pump 19 transports carbon dioxide from the outside to the air preheater 20 for preheating, and the preheated carbon dioxide is sent to the spiral coal feeder 3 to purge the raw coal into the gasifier feed port 4. After the cyclone dust collector 15 separates the smaller particles of fly ash in the raw gas, the raw gas is sent to the bag dust collector 16 to further separate the fine particles of fly ash. The fly ash separated by the cyclone dust collector 15 and the bag dust collector 16 are sent to the cyclone separator silo pump 11 and the bag dust collector silo pump 12 respectively. The nitrogen from the outside world is sent to the ash bin 14 for collection through the cyclone separator bin pump 11 and the bag filter bin pump 12, and the fly ash is sent to the outside world by the ash bin pump 13.

[0024] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0025] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A circulating fluidized bed gasification device suitable for high-alkali and low-ash melting point coal, characterized in that: It consists of a compound agent storage bin 1, a coal storage bin 2, a spiral coal feeder 3, a gasifier feed port 4, a gasifier 5, a gasifier inlet 6, a slag cooler 7, a gasifier slag outlet 8, a booster air pump 9, an ignition burner 10, a cyclone dust collector bin pump 11, a bag dust collector bin pump 12, an ash bin bin pump 13, an ash bin 14, a cyclone dust collector 15, a bag dust collector 16, an air preheater 17, a fan 18, a carbon dioxide booster pump 19, an air preheater 20, a return device 21, The invention is composed of a cyclone separator 22 and a crude synthesis gas conveying pipe 23; the compound agent storage bin 1 is placed on the upper part of the coal storage bin 2, the coal storage bin 2 is connected to the screw coal feeder 3, and the screw coal feeder 3 is placed on the top of the gasifier feed port 4; the gasifier 5 is provided with the gasifying agent inlet 6 and the gasifier slag outlet 8 at the bottom, and a booster purge gas interface is provided around the coke slag deposition area at the bottom of the gasifier 5, and is connected to the booster air pump 9; the gasifier The furnace 5 is connected to the cyclone separator 22 through the crude synthesis gas conveying pipe 23, and the cyclone separator 22 is connected to the return material 21 at the bottom, and the lower end of the return material 21 is connected to the gasification furnace 5; the carbon dioxide booster pump 19 conveys carbon dioxide from the outside to the spiral coal feeder 3 and the return material 21 to provide blowing gas, so that feeding and returning can be carried out; the air preheater 20 is connected to the cyclone separator 22 and the air preheater 17 through pipelines, respectively, and the air preheater 17 is connected to the cyclone dust collector 15 through pipelines; the cyclone dust collector 15 is connected to the cyclone dust collector bin pump 11 and the bag dust collector 16 through pipelines, respectively, and the bag dust collector 16 is connected to the bag dust collector bin pump 12 through a pipeline; the cyclone dust collector bin pump 11 and the bag dust collector bin pump 12 are connected to the ash bin 14 through a pipeline, and the ash bin 14 is connected to the ash bin bin pump 13 through a pipeline.

2. The circulating fluidized bed gasification device according to claim 1, characterized in that: The pressure of the blowing gas carbon dioxide is 30-100 kPa.

3. The circulating fluidized bed gasification device according to claim 1, characterized in that: The compounding agent storage bin 1 is used to add a compounding agent capable of increasing the melting point of coal ash into the coal storage bin 2; the compounding agent accounts for 1-10% of the raw coal by mass.

4. The circulating fluidized bed gasification device according to claim 1, characterized in that: The boost air pump 9 is provided to use the boost air flow to purge the non-fluidized area and the slagging area at the bottom of the gasifier 5 to prevent the deposition of coke slag, avoid the formation of large coke slag, and improve the slag removal efficiency. The boost air flow purge pressure is 50-1000 kPa.

5. The circulating fluidized bed gasification device according to claim 1, characterized in that: The bottom of the gasifier 5 is filled with refractory bricks, or refractory bricks and castables; the refractory temperature of the refractory bricks and castables is greater than 1100°C.

6. A process for gasifying high-alkali and low-ash melting point coal using the circulating fluidized bed gasification device according to claim 1, characterized in that: The compounding agent is added to the raw coal, and pressurized purge gas is provided to the slagging-prone area at the bottom of the gasification furnace, thereby increasing the particle size of the raw coal.

7. The process according to claim 6, characterized in that: The compounding agent is composed of kaolin, coal gangue, clay and carbide slag, and in terms of mass fraction, includes 30-100% kaolin, 20-40% clay, 5-10% coal gangue and 5-10% carbide slag.

8. The process according to claim 6, characterized in that: A pressurized purge gas is provided to the slagging-prone area at the bottom of the gasifier. The purge gas is one or more of carbon dioxide, oxygen, water vapor, and air from the outside or prepared during production. The pressure of the pressurized gas is 30-100 kPa.

9. The process according to claim 6, characterized in that: The raw coal particle size is adjusted according to the raw coal density. The specific adjustment method is: if the raw coal density ranges from 1.0 to 1.5 g / cm 3 , the particle size is 15-50mm; if the raw coal density is 1.5-2.0 g / cm 3 , the particle size is 0-15 mm.

Images