煤制天然气甲烷化合成原料气深度脱硫工艺分析

煤制天然气甲烷化原料气经低温甲醇洗净化后仍含有体积分数约1×10^-7的硫分,容易导致镍基催化剂中毒,需要进行深度脱硫。结合国内煤制天然气装置的运行情况,对国内煤制天然气企业主要采用的戴维甲烷化工艺和托普索甲烷化工艺配套的深度脱硫工艺进行了介绍,并从脱硫级数、脱硫剂有效成分、原始开车前预处理过程及脱硫槽床层温度控制等方面进行了对比,结果表明:两种工艺均能将总硫体积分数脱除至10×10^-9,满足甲烷化镍基催化剂稳定运行的要求。最后从脱硫槽床层温度控制和脱硫剂床层防凝两方面提出了煤制天然气脱硫剂的运行保护措施。

Analysis of Methanation Feed Gas Ultra Desulfurization for Coal-to-SNG

In view of the problem that coal gas methanation feed gas still contained high concentration of sulfur after low temperature methanol washing,which led to nickel-based catalyst poisoning,the ultra desulfurization processes of Davy methanation process and Topsoe methanation process applied in the main domestic coal-to-SNG enterprises were introduced combined with the operation situation of domestic coal-to-SNG plants.The comparison was made from the aspects of the number of desulfurization stages,active components of desulfurizer,pretreatment process before initial start-up and the temperature control of desulfurization tank bed.The results showed that both processes could remove the total sulfur content to 10×10^-9,which met the requirements of stable operation of nickel-based methanation catalyst.Finally,the operation protection measures of desulfurizer for coal-to-SNG were put forward from temperature control of desulfurization tank bed and anticoagulation of desulfurizer bed.