Ammonia distillation waste gas and waste liquid treatment system for coal chemical industry

Abstract

The utility model discloses a coal chemical industry ammonia distillation waste gas and waste liquid treatment system which is characterized in that a gasification furnace is provided with a pulverized coal inlet, a gasification agent inlet, a flue gas outlet, a waste gas inlet and a waste water inlet, the flue gas outlet of the gasification furnace is connected with a cyclone separator, and a high-temperature coal gas outlet of the cyclone separator is connected with a coal gas cooling tower; a condensate outlet of the gas cooling tower is connected with the ammonia still, and a waste gas outlet and a waste liquid outlet of the ammonia still are respectively connected with a waste gas inlet and a waste water inlet of the gasifier. Waste gas and waste liquid generated by the ammonia still are circularly sent back to the gasification furnace to be used as a gasification agent and participate in the reaction of the gasification furnace, hydrogen sulfide (H2S) in the waste gas and the waste liquid reacts to produce salt compounds which are discharged along with slag, the problem of treatment of ammonia still waste water and waste gas is solved, recycling of industrial waste water and waste gas is realized, and the production cost is reduced. And the pollution to the environment is reduced.

Description

Technical Field

[0001] The utility model relates to the field of coal chemical industry, in particular to a treatment system for ammonia evaporation waste gas and waste liquid in coal chemical industry. Background Technique

[0002] In the coal gasification process, waste gas and waste liquid containing hydrogen sulfide (H2S) are generated. To reduce the harm to the environment, the waste gas and waste liquid generated in coal gasification need to be further treated. The coal gas condensate generated in the coal gasification process will enter the subsequent ammonia evaporation system. The waste gas and waste liquid generated in the ammonia evaporation system contain components such as water (H2O), ammonia (NH3), and hydrogen sulfide (H2S). If the waste gas is directly sent to the flare combustion system, due to the short residence time of the waste gas in the combustion system, it is difficult to achieve harmless emission, and at the same time, fuel gas is consumed, resulting in low economic benefits; the existing treatment methods for the bottom wastewater of the ammonia evaporation system also have great limitations, and the hydrogen sulfide (H2S) in the wastewater cannot be effectively treated, causing great harm to the environment after discharge. Content of the Utility Model

[0003] In view of the above problems existing in the treatment of waste gas and wastewater in the existing coal chemical ammonia evaporation system, the applicant provides a coal chemical ammonia evaporation waste gas and waste liquid treatment system with a reasonable structure, which circulates the waste gas and waste liquid of the ammonia evaporation tower into the gasifier for resource utilization, minimizing the generation of waste and the negative impact on the environment, and having certain economic benefits at the same time.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A coal chemical ammonia evaporation waste gas and waste liquid treatment system, the gasifier is provided with a pulverized coal inlet, a gasifying agent inlet, a flue gas outlet, a waste gas inlet, and a wastewater inlet. The flue gas outlet of the gasifier is connected to a cyclone separator, the high-temperature coal gas outlet of the cyclone separator is connected to a coal gas cooling tower, the condensate outlet of the coal gas cooling tower is connected to an ammonia evaporation tower, and the waste gas outlet and the waste liquid outlet of the ammonia evaporation tower are respectively connected to the waste gas inlet and the wastewater inlet of the gasifier.

[0006] As a further improvement of the above technical solution:

[0007] A bottom heat exchanger is arranged between the waste liquid outlet and the wastewater inlet.

[0008] A waste heat recovery system and a dust removal system are arranged between the cyclone separator and the coal gas cooling tower.

[0009] The dust removal system includes a cyclone dust collector and a bag filter, and the cyclone dust collector and the bag filter are connected to a ash bin.

[0010] The gasifier is provided with a return feeder outlet, and the return feeder outlet is connected to the return feeder inlet of the cyclone separator.

[0011] The gasifier inlet for the gasifying agent is connected to the gasifying agent supply device, and the gasifying agent supplied by the gasifying agent supply device includes at least two of air, steam, and oxygen.

[0012] The gasifier is provided with a slag discharge port, which is connected to a slag bin; the purified gas outlet of the gas cooling tower is connected to the product gas going to the battery limit; the gaseous ammonia outlet of the ammonia distillation tower is connected to the gaseous ammonia extraction device.

[0013] The pulverized coal inlet, the return feeder outlet, and the waste water inlet of the gasifier are arranged at the lower part of the gasifier, the flue gas outlet is arranged at the upper part of the gasifier, and the gasifying agent inlet, the waste gas inlet, and the slag discharge port are arranged at the bottom of the gasifier.

[0014] The condensate inlet of the ammonia distillation tower is arranged at the upper part of the ammonia distillation tower, the gaseous ammonia outlet is arranged in the middle and lower part of the ammonia distillation tower, the waste gas outlet is arranged at the top of the ammonia distillation tower, and the waste liquid outlet is arranged at the bottom of the ammonia distillation tower.

[0015] The beneficial effects of the present utility model are as follows:

[0016] The present utility model recycles the waste gas and waste liquid generated by the ammonia distillation tower and sends them back to the gasifier for use as the gasifying agent to participate in the reaction of the gasifier. The hydrogen sulfide (H2S) in the waste gas and waste liquid reacts to produce salt compounds and is discharged with the furnace slag, solving the problems of ammonia distillation wastewater and waste gas treatment, realizing the reuse of industrial wastewater and waste gas, and reducing environmental pollution. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the present utility model.

[0018] In the figure: 1. Gasifier; 101. Pulverized coal inlet; 102. Gasifying agent inlet; 103. Flue gas outlet; 104. Return feeder outlet; 105. Waste gas inlet; 106. Waste water inlet; 107. Slag discharge port;

[0019] 2. Cyclone separator; 201. Flue gas inlet; 202. High-temperature gas outlet; 203. Return feeder inlet;

[0020] 3. Waste heat recovery system; 4. Cyclone dust collector; 5. Bag filter;

[0021] 6. Gas cooling tower; 601. Gas inlet; 602. Purified gas outlet; 603. Condensate outlet;

[0022] 7. Product gas going to the battery limit; 8. Ash bin;

[0023] 9. Ammonia distillation tower; 901. Condensate inlet; 902. Gaseous ammonia outlet; 903. Waste gas outlet; 904. Waste liquid outlet;

[0024] 10. Bottom heat exchanger; 11. Ammonia gas extraction device; 12. Raw coal conveying device; 13. Gasifying agent supply device; 14. Slag bin. Detailed implementation manners

[0025] The following combines with the attached drawings to illustrate the detailed implementation manners of the present utility model.

[0026] As Figure 1 shown, the coal chemical ammonia evaporation waste gas and waste liquid treatment system of the present utility model includes a gasifier 1, a cyclone separator 2, a waste heat recovery system 3, a dust removal system, a gas cooling tower 6 and an ammonia evaporation tower 9. The dust removal system includes a cyclone dust collector 4 and a bag filter 5, and the cyclone dust collector 4 is connected to the bag filter 5 and the ash bin 8.

[0027] The gasifier 1 is provided with a pulverized coal inlet 101, a gasifying agent inlet 102, a flue gas outlet 103, a return feeder outlet 104, a waste gas inlet 105, a waste water inlet 106 and a slag discharge port 107. The pulverized coal inlet 101, the return feeder outlet 104 and the waste water inlet 106 are arranged at the lower part of the gasifier 1, the flue gas outlet 103 is arranged at the upper part of the gasifier 1, and the gasifying agent inlet 102, the waste gas inlet 105 and the slag discharge port 107 are arranged at the bottom of the gasifier 1. The pulverized coal inlet 101 is connected to the raw coal conveying device 12, the gasifying agent inlet 102 is connected to the gasifying agent supply device 13, and the slag discharge port 107 is connected to the slag bin 14. The gasifying agent supplied by the gasifying agent supply device 13 includes at least two of air, steam and oxygen, and can be applicable to air gasification with air and steam as the gasifying agent, or oxygen-enriched gasification with oxygen, air and steam as the gasifying agent, or pure oxygen gasification with oxygen and steam as the gasifying agent.

[0028] The cyclone separator 2 is provided with a flue gas inlet 201, a high-temperature gas outlet 202 and a return feeder inlet 203. The flue gas inlet 201 and the high-temperature gas outlet 202 are arranged at the top of the cyclone separator 2, and the return feeder inlet 203 is arranged at the bottom of the cyclone separator 2. The flue gas inlet 201 is connected to the flue gas outlet 103 of the gasifier 1, and the return feeder inlet 203 is connected to the return feeder outlet 104 of the gasifier 1.

[0029] The gas cooling tower 6 is provided with a gas inlet 601, a purified gas outlet 602 and a condensate outlet 603, and the purified gas outlet 602 is connected to the product gas to the boundary area 7. The high-temperature gas outlet 202 of the cyclone separator 2 is sequentially connected to the waste heat recovery system 3, the cyclone dust collector 4, the bag filter 5, and then connected to the gas inlet 601 of the gas cooling tower 6.

[0030] The ammonia distillation column 9 is provided with a condensate inlet 901, a gaseous ammonia outlet 902, an exhaust gas outlet 903 and a waste liquid outlet 904. The condensate inlet 901 is arranged at the upper part of the ammonia distillation column 9, the gaseous ammonia outlet 902 is arranged at the middle and lower part of the ammonia distillation column 9, the exhaust gas outlet 903 is arranged at the top of the ammonia distillation column 9, and the waste liquid outlet 904 is arranged at the bottom of the ammonia distillation column 9. The condensate inlet 901 is connected to the condensate outlet 603 of the gas cooling tower 6, the gaseous ammonia outlet 902 is connected to the gaseous ammonia extraction device 11, the exhaust gas outlet 903 is connected to the exhaust gas inlet 105 of the gasifier 1, and the waste liquid outlet 904 is connected to the waste water inlet 106 of the gasifier 1. A bottom heat exchanger 10 is arranged between the waste liquid outlet 904 and the waste water inlet 106. The bottom heat exchanger 10 exchanges heat with the waste liquid of the ammonia distillation column 9 and then inputs it into the gasifier 1.

[0031] During the actual use of the present utility model, pulverized coal is fed into the gasifier 1 from the raw coal conveying device 12, and the gasifying agent is fed into the gasifier 1 from the gasifying agent supply device 13. The pulverized coal and the gasifying agent react to generate high-temperature flue gas. The high-temperature flue gas is input into the cyclone separator 2 from the flue gas outlet 103. The cyclone separator 2 separates the high-temperature flue gas into high-temperature coal gas and semi-coke particles. The semi-coke particles are cycled back to the gasifier 1 from the return feeder outlet 104. The high-temperature coal gas is successively subjected to waste heat recovery by the waste heat recovery system 3, dust removal by the cyclone dust collector 4 and the bag filter 5, and then enters the gas cooling tower 6. The fly ash removed by the cyclone dust collector 4 and the bag filter 5 is sent to the ash bin 8. The gas cooling tower 6 cools the high-temperature coal gas to generate purified coal gas and condensate. The purified coal gas is sent to the product gas to the boundary area 7, and the condensate is sent to the ammonia distillation column 9 for ammonia distillation treatment. The ammonia distillation column 9 performs ammonia distillation treatment on the condensate. The obtained gaseous ammonia is sent to the gaseous ammonia extraction device 11, and the obtained exhaust gas and waste liquid are cycled back to the gasifier 1 for recycling and used as the gasifying agent to participate in the reaction of the gasifier 1. Harmful components such as hydrogen sulfide (H2S) in the exhaust gas and waste liquid react with oxygen (O2) or water vapor (H2O) to generate sulfur dioxide (SO2). The sulfur dioxide will react with the alkali metal compounds in the gasifier 1 to generate salt compounds, and the salt compounds will be discharged to the slag bin 14 together with the slag later.

[0032] The present utility model circulates the exhaust gas and waste liquid generated by the ammonia distillation column 9 back to the gasifier 1 for use as the gasifying agent to participate in the reaction of the gasifier 1. The hydrogen sulfide (H2S) in the exhaust gas and waste liquid reacts to produce salt compounds and is discharged with the slag, reducing the generation of ammonia distillation exhaust gas and waste liquid, solving the problems of ammonia distillation waste water and exhaust gas treatment, realizing the reuse of industrial waste water and exhaust gas, reducing environmental pollution, and also improving economic benefits by using the exhaust gas and waste liquid as the gasifying agent.

[0033] The above description is an explanation of the present utility model, not a limitation of the present utility model. Without departing from the spirit of the present utility model, the present utility model can be modified in any form.

Claims

1. A coal chemical ammonia distillation waste gas and liquid treatment system, characterized in that: The gasifier (1) is provided with a pulverized coal inlet (101), a gasifying agent inlet (102), a flue gas outlet (103), a waste gas inlet (105), and a waste water inlet (106). The flue gas outlet (103) of the gasifier (1) is connected to a cyclone separator (2). The high-temperature coal gas outlet (202) of the cyclone separator (2) is connected to a coal gas cooling tower (6). The condensate outlet (603) of the coal gas cooling tower (6) is connected to an ammonia distillation tower (9). The waste gas outlet (903) and the waste liquid outlet (904) of the ammonia distillation tower (9) are respectively connected to the waste gas inlet (105) and the waste water inlet (106) of the gasifier (1).

2. The coal chemical ammonia distillation waste gas and liquid treatment system according to claim 1, characterized in that: A bottom heat exchanger (10) is provided between the waste liquid outlet (904) and the waste water inlet (106).

3. The coal chemical ammonia distillation waste gas and waste liquid treatment system according to claim 1, characterized in that: A waste heat recovery system (3) and a dust removal system are provided between the cyclone separator (2) and the coal gas cooling tower (6).

4. The coal chemical ammonia distillation waste gas and waste liquid treatment system according to claim 3, characterized in that: The dust removal system includes a cyclone dust collector (4) and a bag filter (5). The cyclone dust collector (4) and the bag filter (5) are connected to an ash bin (8).

5. The coal chemical ammonia distillation waste gas and liquid treatment system according to claim 1, wherein: The gasifier (1) is provided with a return feeder outlet (104), and the return feeder outlet (104) is connected to the return feeder inlet (203) of the cyclone separator (2).

6. The coal chemical ammonia distillation waste gas and liquid treatment system according to claim 1, characterized in that: The gasifying agent inlet (102) of the gasifier (1) is connected to a gasifying agent supply device (13), and the gasifying agent supplied by the gasifying agent supply device (13) includes at least two of air, steam, and oxygen.

7. The coal chemical ammonia distillation waste gas and waste liquid treatment system according to claim 1, wherein: The gasifier (1) is provided with a slag discharge port (107), and the slag discharge port (107) is connected to a slag bin (14); the purified coal gas outlet (602) of the coal gas cooling tower (6) is connected to a product gas to the battery limit (7); the gaseous ammonia outlet (902) of the ammonia distillation tower (9) is connected to a gaseous ammonia extraction device (11).

8. The coal chemical ammonia distillation waste gas and waste liquid treatment system according to claim 1, wherein: The pulverized coal inlet (101), the return feeder outlet (104), and the waste water inlet (106) of the gasifier (1) are arranged at the lower part of the gasifier (1), the flue gas outlet (103) is arranged at the upper part of the gasifier (1), and the gasifying agent inlet (102), the waste gas inlet (105), and the slag discharge port (107) are arranged at the bottom of the gasifier (1).

9. The coal chemical ammonia distillation waste gas and liquid treatment system according to claim 1, characterized in that: The condensate inlet (901) of the ammonia distillation tower (9) is arranged at the upper part of the ammonia distillation tower (9), the gaseous ammonia outlet (902) is arranged at the middle and lower part of the ammonia distillation tower (9), the waste gas outlet (903) is arranged at the top of the ammonia distillation tower (9), and the waste liquid outlet (904) is arranged at the bottom of the ammonia distillation tower (9).

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