Technological method for preparing methanol by combining coke oven gas with water gas

Abstract

The invention discloses a technological method for preparing methanol by combining coke oven gas with water gas. The method comprises the following steps: purifying coke oven gas; performing direct fine desulfurization and purification to water gas at a low temperature; mixing the cleaned and qualified coke oven gas and water gas to ensure the mixed gas to reach a hydrogen carbon ratio that (H2 - CO) / (CO2 + CO) = 2.05-2.10, pressurizing the mixed gas, and sending the mixed gas into a methanol synthesis tower for synthesizing methanol at low pressure. The method of the invention avoids the problem of serious imbalance of hydrogen carbon ratio in the process of preparing methanol by only using coke oven gas, the methanol one-step conversion is increased, the utilization rate of effective ingredients is increased, the production cost is reduced; the problem of low sulfur capacity of the existing catalyst to the organic sulfur such as CS2 and COS is solved, the technological process has no cold-hot fatigue, finally the total sulfur content of water gas can reach 0.1ppm or more; and the technological method of the invention designs a difunctional ventilation gas-recycling device so that one device can be used to realize two purposes.

Description

technical field [0001] The present invention relates to a method for synthesizing methanol with coke oven gas, in particular to a method for synthesizing methanol at low pressure with coke oven gas and water gas. . Background technique [0002] At present, the scale of my country's methanol plants is generally small, and the coal-head route using coal as raw material accounts for 78%. The disadvantage is that the unit capacity investment is high, and the production cost is 1,700-2,100 yuan / ton, which is about the investment of foreign large-scale methanol plants. 2 times. The scale of foreign methanol plants represented by the Middle East and Central and South America is generally large. Currently, the production capacity of the largest methanol plant in the world has reached 1.7 million tons per year. At the end of April 2008, the Saudi Methanol Company's 1.7 million tons / year giant methanol plant was put into operation in Al Jubail, bringing the total production capacity ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to make up for the serious unbalanced hydrogen-to-carbon ratio in the existing technology of coke oven gas conversion to methanol, and to provide a process for coke oven gas with water gas and low-pressure synthesis of methanol