Coal gasification sewage comprehensive treatment method

Abstract

The invention relates to the field of sewage treatment, and specifically relates to a coal gasification sewage comprehensive treatment method. The method comprises the following steps: flocculation sedimentation, cartridge filtration, electro-adsorption desalination, alkali-addition softening precipitation and pH regulation, precision filtration, gasification membrane ammonia removing, shortcut nitrification and denitrification, and deep carbonization and nitrification. According to the method, sewage is subjected to desalination treatment and recycling from the source, such that desalinated water is saved, production cost is reduced, treatment scale and investment of subsequent treatment equipment are reduced, and treatment effect is improved.

Description

technical field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a comprehensive treatment method for coal gasification sewage. Background technique

[0002] Coal gasification is the first unit process of coal chemical industry, using coal water slurry gasification technology to produce H 2 and CO. The principle is that the coal-water slurry and pure oxygen are sprayed out at high speed through the nozzle, mixed and atomized in parallel flow, and under the conditions of pressure 6.5MPa and temperature about 1400°C, flame-type non-catalytic partial oxidation reaction is carried out in the gasifier. Coal slurry temperature rise and water evaporation, coal pyrolysis volatilization, residual carbon combustion gasification and chemical reaction between gases, etc., finally generate CO, H 2 Raw gas as the main component. The ash and slag are discharged in a liquid state, and the crude gas is sent to the downstream conversion process. ...

Examples

Embodiment 1

[0090] With a gas production capacity of 100,000 m3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the amount of desalted water in the washing tower is 100m 3 / h, the sewage discharge is 100m 3 / h. In the discharged sewage, the conductivity is 4000μS / cm, the total hardness is 1000mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 300mg / L.

[0091] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes and reacts with suspended matter such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 4 hours. Suspended matter settles to the bottom of the pond, and the slag is discharged every 4 hours, and sent to the ash yard.

[0092] The second step is security filtering. Sewage to remove suspended solids is filtere...

Embodiment 2

[0100] With gas production of 2 million m 3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the amount of desalinated water in the washing tower is 2000m 3 / h, the sewage discharge is 2000m 3 / h. In the discharged sewage, the conductivity is 4500μS / cm, the total hardness is 1100mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 400mg / L.

[0101] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes and reacts with suspended solids such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 3 hours. Suspended matter settles to the bottom of the pool, and the slag is discharged every 4 hours, and sent to the gasification slag field.

[0102] The second step is security filtering. Sewage to remove suspended soli...

Embodiment 3

[0111] With a gas production capacity of 500,000 m 3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the desalinated water volume of the washing tower is 500m 3 / h, the sewage discharge is 500m 3 / h. In the discharged sewage, the conductivity is 3500μS / cm, the total hardness is 900mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 250mg / L.

[0112] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes with the suspended matter such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 5 hours. Suspended matter settles to the bottom of the pool, and the slag is discharged every 4 hours, and sent to the gasification slag field.

[0113] The second step is security filtering. Sewage to remove suspended solids i...

technical field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a comprehensive treatment method for coal gasification sewage. Background technique

[0002] Coal gasification is the first unit process of coal chemical industry, using coal water slurry gasification technology to produce H 2 and CO. The principle is that the coal-water slurry and pure oxygen are sprayed out at high speed through the nozzle, mixed and atomized in parallel flow, and under the conditions of pressure 6.5MPa and temperature about 1400°C, flame-type non-catalytic partial oxidation reaction is carried out in the gasifier. Coal slurry temperature rise and water evaporation, coal pyrolysis volatilization, residual carbon combustion gasification and chemical reaction between gases, etc., finally generate CO, H 2 Raw gas as the main component. The ash and slag are discharged in a liquid state, and the crude gas is sent to the downstream conversion process. ...

Examples

Embodiment 1

[0090] With a gas production capacity of 100,000 m3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the amount of desalted water in the washing tower is 100m 3 / h, the sewage discharge is 100m 3 / h. In the discharged sewage, the conductivity is 4000μS / cm, the total hardness is 1000mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 300mg / L.

[0091] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes and reacts with suspended matter such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 4 hours. Suspended matter settles to the bottom of the pond, and the slag is discharged every 4 hours, and sent to the ash yard.

[0092] The second step is security filtering. Sewage to remove suspended solids is filtere...

Embodiment 2

[0100] With gas production of 2 million m 3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the amount of desalinated water in the washing tower is 2000m 3 / h, the sewage discharge is 2000m 3 / h. In the discharged sewage, the conductivity is 4500μS / cm, the total hardness is 1100mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 400mg / L.

[0101] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes and reacts with suspended solids such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 3 hours. Suspended matter settles to the bottom of the pool, and the slag is discharged every 4 hours, and sent to the gasification slag field.

[0102] The second step is security filtering. Sewage to remove suspended soli...

Embodiment 3

[0111] With a gas production capacity of 500,000 m 3 / h coal gasification unit as an example, assuming that there is no water loss during the washing process, the desalinated water volume of the washing tower is 500m 3 / h, the sewage discharge is 500m 3 / h. In the discharged sewage, the conductivity is 3500μS / cm, the total hardness is 900mg / L, the COD is 500mg / L, the ammonia nitrogen is 300mg / L, and the chloride ion is 250mg / L.

[0112] The first step is flocculation and sedimentation. Add 1-2ppm polyacrylamide to the sewage, and after the pipeline mixer fully mixes with the suspended matter such as fly ash in the sewage, it enters the sedimentation tank through the diversion pipe of the radial flow sedimentation tank, and the sedimentation time is 5 hours. Suspended matter settles to the bottom of the pool, and the slag is discharged every 4 hours, and sent to the gasification slag field.

[0113] The second step is security filtering. Sewage to remove suspended solids i...

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