Recycling process of coal gas waste heat

Abstract

The invention provides a recycling process of coal gas waste gas, belonging to the field of heat exchange, and particularly relates to a recycling process of the coal gas waste heat gasified by a pressure moving bed. For an existing pressure moving bed, when being used for recycling the coal gas waste heat, the coal gas waste heat is recovered as low-pressure steam by a waste heat boiler and cannot be taken as raw material water steam, so that the gasification costs are increased. According tho the invention, the recycling process of coal gas waste heat consists of a high-pressure mass transfer and heat transfer device (34), a low-pressure mass transfer and heat transfer device (14), a heat exchanger (49), a power recycling device (31), a recycling hot water pressure pump (23), a pressure machine (16), pipelines and the like, the existing coal gas waste heat recycling process is optimized, the coal gas recycling process is adopted in a recycling process of the coal gas waste heat gasified by the pressure moving bed, so that external supply steam consumption steam can be reduced dramatically, the coal gas sewage amount and the coal gas waste water processing expenses can be decreased greatly, the output of high value-added byproducts such as tar and the like can be increased, and the gasification cost of the moving pressure bed are better lowered.

Description

technical field [0001] The invention belongs to the field of heat exchange, and in particular relates to a process technology device and process for gas waste heat recovery of a pressurized moving bed gasification process. Background technique [0002] It is well known that coal-to-chemical synthesis products such as H 2 , NH 3 、CH 4 、CH 3 OH, oil, etc., adopting a pressurized moving bed for coal gasification not only has the advantage of the lowest oxygen consumption per unit crude gas, but also has the advantage of being able to use relatively cheap raw coals with high moisture content and high ash content. [0003] However, because the maximum temperature of coal gasification in the pressurized moving bed furnace must be lower than or equal to the ash melting point temperature of the raw coal entering the furnace. The melting point of some raw coal ash is 1200°C, while the melting point of some raw coal ash can reach 1500°C. Since the main reaction of coal gasificati...

AI Technical Summary

Problems solved by technology

Because the output of this low-pressure steam is very large, almost reaching the same amount as the total amount of steam entering the furnace, because the pressure is too low, it is impossible to be used as raw material steam for coal gasification, and the utilization value is low, thus greatly increasing the consumption of coal gas and its products. cost

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