Lurgi crushed coal fixed bed pressurized gasification environment-friendly yield-increasing system and process

Abstract

The invention discloses a lurgi crushed coal fixed bed pressurized gasification environment-friendly yield-increasing system and process. The system comprises a gasification furnace, a heat exchanger, a cooling scrubber, a waste heat boiler, a CO transformation cooling system, a CO2 absorption tower and a flash tank, which are connected in sequence, wherein the lower part of the side wall of the gasification furnace is provided with a gasifying agent spray inlet; the flash tank is connected with the heat exchanger; and the heat exchanger is connected with the gasifying agent spray inlet. Feed coals are gasified in the gasification furnace to produce a crude gas; the crude gas is cooled through the cooling scrubber and the waste heat boiler and then enters the CO transformation cooling system to obtain a synthesis gas; the synthesis gas is introduced into the CO2 absorption tower, and CO2 is absorbed by using a low-temperature methanol barren solution; an absorbent is regenerated in the flash tank; and the separated CO2 is introduced into the heat exchanger to exchange heat with the crude gas and then is introduced into the gasification furnace for secondary reaction. The environment-friendly yield-increasing system hardly discharges CO2 and is beneficial for productivity promotion, energy conservation and emission reduction; and CO2 in the crude gas is recycled for reaction, so that the yield of CO is obviously increased and the whole yield is improved.

Description

technical field [0001] The invention belongs to the technical field of coal treatment, and relates to a Lurgi crushed coal fixed-bed pressurized gasification environmental protection production increase system; the invention also relates to a process for producing purified synthesis gas by using the system. Background technique [0002] During the rapid development of the coal chemical industry in the early stage, Lurgi's pulverized coal gasification technology has gained huge market recognition due to its mature technology and mild gasification conditions, and has a large market share in the field of coal gasification. With the improvement of environmental protection standards in various countries, and the gradual maturity and popularization of advanced gasification such as entrained gasification, Lurgi’s crushed coal gasification technology has low purity of effective gas due to low gasification temperature (effective syngas accounts for 10% of crude gas) about 65%, while ...

AI Technical Summary

Problems solved by technology

With the improvement of environmental protection standards in various countries, and the gradual maturity and popularization of advanced gasification such as entrained gasification, Lurgi’s crushed coal gasification technology has low purity of effective gas due to low gasification temperature (effective syngas accounts for 10% of crude gas) about 65%, while the effective synthesis gas of advanced entrained entrained gasification technology generally accounts for more than 90% of the crude gas), CO 2 The shortcomings of high content (accounting for more than 30% of the crude gas volume), large sewage treatment volume, etc. have become increasingly prominent, and are at a disadvantage in market competition

The currently operating Lurgi crushed coal pressurized gasification system, the CO separated from the crude gas 2 Most of them are directly emptied (this will worsen the greenhouse effect); or used for other purposes after a series of purification treatments (higher cost)

The invention patent application "coal gas pulverized coal energy saving and environmental protection secondary gasification process" (application number 201210122359.7, publication number CN102660328A, publication date 2012.09.12) discloses a process for secondary gasification of coal gas produced by low-temperature coal gasification. A gasification system was added after the gasifier to process pulverized coal, tar and CO 2 etc., but these transformation costs are relatively high, and will have a certain impact on subsequent processing procedures

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