Low-pressure gasification system and gas making method

Abstract

The invention discloses a low-pressure gasification system, which comprises a coal slurry supply unit, a low-pressure water-cooled wall gasifier and a synthesis gas washing unit, wherein the low-pressure water-cooled wall gasifier comprises a gasification chamber used for gasifying water coal slurry and a quenching chamber adjacently arranged below the gasification chamber to quench combustion products produced in the gasification chamber and obtain crude synthesis gas; the synthesis gas washing unit is connected to the quenching chamber and is used for washing the crude synthesis gas to generate synthesis gas; the gasification chamber is communicated with the quenching chamber through a downcomer; an ascending pipe sleeve is arranged on an outer wall of the downcomer; and quenching wateris introduced into the ascending pipe sleeve and sprays from the upper end of the ascending pipe sleeve so as to cool the combustion products. Due to the low-pressure gasification system, the carbon dioxide content in the generated synthesis gas is greatly reduced, so that decarbonizing equipment in a synthesis ammonia device can be reduced when the synthesis gas enters a downstream process. Therefore, the energy consumption in the whole downstream process is greatly reduced, the cost is reduced, and the coal types are little limited. The invention also provides a gas making method.

Description

technical field [0001] The invention relates to the field of industrial gas production, in particular to a low-pressure coal gasification system and a gas production method. Background technique [0002] At present, domestic industrial gas is mainly suitable for small and medium-sized energy users in the fields of ceramics, glass, metallurgy, textile printing and dyeing, papermaking and urban gas supply. [0003] The main source of traditional gas is fixed bed two-stage coal gasification technology, which is an improved furnace type based on fixed bed intermittent gasification. This technology has the advantages of low construction cost and simple structure. However, this technology has high requirements for coal use, and only lump white coal or coking coal can be used, and the coal types are limited; moreover, the amount of carbon dioxide in the synthesis gas generated by this technology is relatively high, which requires that the synthesis gas must be decarbonized in the f...

AI Technical Summary

Problems solved by technology

However, this technology has high requirements for coal use, and only lump white coal or coking coal can be used, and the coal types are limited; moreover, the amount of carbon dioxide in the synthesis gas generated by this technology is relatively high, which requires that the synthesis gas must be decarbonized in the first gas cabinet, and then After being pressurized by the Roots blower, it can enter the downstream process such as the desulfurization system, etc.

In addition, the fixed-bed two-stage coal gasification technology also has problems such as low carbon conversion rate and high pollution.

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