Fine coal gasification product crude synthetic gas CO sulfur-tolerant shift technology

Abstract

The invention relates to a fine coal gasification product crude synthetic gas CO sulfur-tolerant shift technology. According to the invention, a low and high water / gas mixed process is adopted. A low water / gas technology and a low water / gas catalyst are adopted in a first stage. Through the controlling over the water / gas of crude synthetic gas, the reaction depth and bed layer hot spot temperature of a pre-shifting furnace are controlled. Therefore, on a basis that no methanation side reaction occurs, the crude synthetic gas containing high-density CO is subjected to the sifting reaction under low water / gas technical conditions. A high water / gas technology is adopted in subsequent stages. The second stage adopts one-time middle-pressure superheated vapor and a proper amount of technical condensate, such that the water / gas ratio of the synthetic gas reaches 1.30-1.35. Sufficient shifting reaction driving force is provided, such that a purpose of controlling shifting outlet CO content is achieved. The technology provided by the invention is advantaged in mild low water / gas process operation conditions, smooth operation, no methanation side reaction, and substantially reduced vapor usage amount. With the high water / gas processes, relatively low shifting outlet CO content can be well controlled.

Description

technical field [0001] The invention belongs to the field of CO-containing industrial gases, and in particular relates to a process for sulfur-resistant conversion of pulverized coal gasification product crude synthesis gas. Background technique [0002] According to the inlet water / gas control, the sulfur-tolerant conversion process can be divided into two categories: high water / gas process and full low water / gas process. At present, the domestic pulverized coal gasification crude synthesis gas sulfur-resistant conversion mostly adopts high water / gas process, that is, the crude synthesis gas is added with medium-pressure superheated steam and an appropriate amount of process condensate at one time before the conversion, so that the water / gas of the synthesis gas reaches 1.30- 1.35, then carry out adiabatic transformation reaction in stages, remove heat and control the inlet temperature of the next stage by means of heat exchange, waste boiler by-product, low-pressure steam,...

AI Technical Summary

Problems solved by technology

This process makes full use of the characteristics of low water content in the raw syngas produced by pulverized coal gasification (waste boiler process), and controls the reaction depth of each shift furnace by controlling the water / gas in the raw syngas, thereby controlling the hot spot temperature of the bed , so that under the condition of low hot spot temperature, that is, under the condition that methanation side reaction does not occur, the high-concentration CO is partially shifted, and a large amount of quenching water is distributed at the inlet of each shift furnace, thereby reducing the consumption of medium-pressure steam. However, the process has problems such as insufficient reaction driving force, unfavorable reaction balance, high CO content at the conversion outlet, and serious loss of raw materials. The problem is more prominent for the process flow of the subsequent section equipped with a methanation furnace to remove carbon oxides.

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