Coal-to-clean gas technology and device

Abstract

The invention relates to a process for production of clean fuel gas from coal. The process includes: gasifying crushed coal, extracting crude coal gas with a volume ratio of 5-60% when leading gas out of a crude coal gas apparatus (3) through the middle part of a gasification chamber, performing dedusting by a cyclone separator (20), leading out the rest crude coal gas through a crude coal gas channel (III) on a dual channel static coal distributor (2) and removing part of dust and tar by a cyclone separator (21), then carrying out re-dedusting and cooling by a washing cooler (5), then letting the crude coal gas enter a waste heat boiler (24) to recover waste heat, finally separating condensate liquid from the cooled crude coal gas by a gas-liquid separator (11), sending the condensate liquid isolated crude coal gas (18) to a downstream procedure, and sending the washed condensate liquid to a coal gas water separation apparatus (15) for recovery. The process and device provided by the invention have the advantages of energy saving, low operation cost, small coal dust carried amount, and little tar containing coal gas water.

Description

technical field [0001] The invention belongs to the field of coal-based clean gas, and in particular relates to a novel process and device for coal-based clean gas. Background technique [0002] Crushed coal pressurized gasifier is a fixed bed coal gasifier, due to the low requirements for raw coal, that is, except for strong caking coal, other coal types can be gasified, especially low-rank coal and high ash melting point low quality coal. The gasifier is widely used in the field of coal-to-synthetic ammonia, methanol, dimethyl ether, synthetic oil and coal gas. As the current coal gasification technology develops in the direction of large diameter and high pressure, the amount of coal processed per unit time is gradually increasing. As a coal inlet for pressurized gasification of crushed coal, the coal lock needs to be continuously pressurized and released. To meet the development needs of large-scale coal gasification, in addition, the high pressure increases the coal g...

AI Technical Summary

Problems solved by technology

As the current coal gasification technology develops in the direction of large diameter and high pressure, the amount of coal processed per unit time is gradually increasing. As a coal inlet for pressurized gasification of crushed coal, the coal lock needs to be continuously pressurized and released. To meet the development needs of large-scale coal gasification, in addition, the high pressure increases the coal gasification capacity and the amount of gas produced, coupled with the poor thermal stability of low-rank coal, etc., a single gas outlet will inevitably bring out a large amount of coal dust, resulting in subsequent gas Washing cooling, waste heat recovery and other sections cause blockage or separation difficulties. At the same time, excessive water is used for washing in the washing process, resulting in an increase in the production of gas and water and a decrease in high-grade heat.

[0003] Chinese Patent No. 200580041975.8 discloses a fixed-bed coal gasifier with a single coal lock and a single gas outlet on the static distributor. This gasifier is a commonly used pressurized gasifier for crushed coal at present, and there are outstanding problems The problem of dust in the crude gas is serious, the by-product is more low-pressure steam, and the gas contains dust, tar and water.

[0004] Chinese patent: 201320037548.4 discloses the use of a single coal lock, no static distributor, and a single gas channel, which also has the above problems

The purpose of this patent is to reduce the gas enrichment area, reduce the gas flow rate, and reduce the amount of coal dust carried out. It has a certain effect, but the effect is limited

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