Process for preparing fuel gas from gasified synthesis gas through high-temperature hydrodesulfurization

Abstract

The invention relates to a process for preparing fuel gas from gasified synthesis gas through high-temperature hydrodesulfurization. The process is free of a synthesis gas washing process, a COS hydrolysis unit and a synthesis gas cooling unit, the process flow is shortened, and the investment is reduced. The high-temperature synthesis gas does not need to be washed and cooled, the sensible heat loss of the synthesis gas is small, the heat efficiency is relatively high, and energy conservation and consumption reduction are facilitated. The COS hydrogenation reduction removal process is considered in desulfurization, the removal rate of sulfides is increased, and the purification effect is guaranteed. Compared with the process that gasified high-temperature synthesis gas directly enters a waste boiler cooler, the process adopts a post-dust-removal gas circulating chilling process, so that the risk of slagging and ash deposition of a waste boiler is reduced. Compared with a gas circulation chilling process after water washing, the gas circulation chilling process after dust removal has the advantages that water carried by the synthesis gas can be reduced to the maximum extent, the influence of water components on the performance of a desulfurization adsorbent is reduced, and the heat value of the fuel gas can be increased.

Description

technical field [0001] The invention relates to a process for preparing fuel gas from gasified synthesis gas through high-temperature hydrodesulfurization. Background technique [0002] Producing fuel gas from raw materials such as coal, petroleum coke or residual oil, and using it in gas-fired boilers or IGCC units in urban refineries is an effective way to solve the high cost of natural gas resources and the limitations of coal-fired boilers. Conventional fuel gas production process using coal, petroleum coke or residual oil as raw materials is configured as gasification, syngas cooling to ~40°C, wet desulfurization and purification, and the purified and desulfurized syngas is sent to boilers or gas turbines for combustion and power generation. Wet desulfurization of MDEA at room temperature and low temperature (~-50°C) methanol washing process, no matter which liquid phase desulfurization process is used, the overall process will go through the process of high temperature...

AI Technical Summary

Problems solved by technology

The desulfurization process only considers the removal of H2S, and does not see the removal of organic sulfur such as COS. The effect of metal oxide catalysts on the removal of H2S is relatively obvious, but the effect on the removal of organic sulfur is not obvious, so it is difficult to guarantee The sulfur content of the purified syngas reaches the standard

In addition, the gasified high-temperature syngas directly enters the waste boiler cooler, and the molten ash is easy to solidify and deposit on the surface of the waste boiler during cooling, which affects the heat transfer efficiency

[0007] For fixed-bed gasification and fluidized-bed gasification with low gasification temperature, the tars and volatile phenols entrained in the synthesis gas will enter the water system during the process of water washing and cooling, resulting in organic compounds such as volatile phenols in the wastewater rather intractable

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