脱除输煤CO_2气中甲醇的工艺方案探讨

Discussion on the Process Scheme of Removing Methanol in CO_2 Gas as Pulverized Coal Carrier Gas

介绍了低温甲醇洗装置CO_2产品气脱除甲醇的三种方法:水洗法、膜分离法和变温吸附法;针对某项目输煤CO_2气体中甲醇含量超标的问题,脱除甲醇装置可设置在甲醇洗装置出口、CO_2压缩机出口、气化装置出口放空气处,分析了三种方法在不同设置位置的优劣,并从占地、投资、公用工程、压力、节能等方面详细对比了中压变温吸附法和高压变温吸附法。结果表明,吸附法适用于气化装置前脱除甲醇,水洗法适于气化装置后脱除甲醇,水洗法投资高于吸附法,吸附法操作费用约为水洗法的28.4%,推荐采用中压变温吸附法工艺技术。

3 methods of removing methanol in CO2 product gas were introduced：membrane separation,temperature swing adsorption and water scrubbing. With reference to excessive methanol content in CO2 gas as pulverized coal carrier gas of one project,methanol removal unit could put at the rectisol unit outlet,CO2 compressor outlet and vent gas at the outlet of gasification unit. And the advantages and disadvantages of the above 3 methods at different positions were analyzed. Detailed comparisons were made between MP temperature swing adsorption and HP temperature swing adsorption from the aspects of plot space,investment, utilities, pressure,energy conservation, etc. The result showed that swing adsorption method was suitable for removing methanol before the gasification unit, and water scrubbing method was suitable for removing methanol after the gasification unit, and the investment of water scrubbing method was higher than that of the swing adsorption method,the operation cost of swing adsorption method was about 28.4% that of water scrubbing method. The MP temperature swing adsorption process technology was recommended in removing methanol in CO2 gas.