CO conversion technique matched to coal gasification

Abstract

This invention discloses a process for converting CO in pulverized coal gasification. The process comprises: introducing crude synthesis gas from pulverized coal gasification into a gas-liquid separator, mixing the gas from separator top with outside middle-pressure overheated steam, middle-pressure steam and a small amount of condensate from steam stripping, introducing into a pre-conversion furnace, controlling the temperature increase, introducing the converted gas into 1# conversion furnace, performing in-depth CO conversion, introducing high-temperature shift gas into a middle-pressure waste boiler to generate4.0 MPa steam with the condensate produced in the process, introducing all middle-pressure steam into fresh converted gas for recycling, quenching with the condensate for humidification, converting in 2# conversion furnace, cooling he converted gas by a water preheater, introducing into 3# conversion furnace, recovering waste heat until the output gas is less than or equal to 40 deg.C, and introducing into the following procedures. The CO concentration is decreased from 60-65 mol. % to less than or equal to 0.4 mol. %. The pre-conversion furnace can prevent catalyst poisoning. The pressure decrease of the conversion system is reduced, thus can ensure the pressure at the inlet of the synthesis gas compressor.

Description

technical field [0001] The invention relates to a CO conversion process, in particular to a CO conversion process matched with pulverized coal gasification. Background technique [0002] The CO shift process is widely used in ammonia synthesis units and hydrogen production units. It is a major part of the purification process. Its process location is set after the gasification or conversion process. According to whether the selected catalyst is sulfur-resistant, it is divided into sulfur-resistant shift and non-resistant There are two processes of sulfur shift; according to the use temperature of the catalyst, it is divided into medium temperature shift and low temperature shift. Different transformation processes are mainly reflected in the changes in the number of transformation reaction stages, reaction temperature, and heat recovery methods, which mainly depend on the performance of the transformation catalyst, the raw materials for gas production used in industrial prod...

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Problems solved by technology

[0010] 2. The content of CO and H2S is high, the CO concentration in the crude gas is as high as 61.71% (V dry basis), and the H2S content reaches 1.20% (V dry basis);

[0012] Therefore, the current CO shift process can no longer be matched with it, and it is urgent to develop a CO shift process that is compatible with the pulverized coal gasification developed by Shell.

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