低温甲醇洗以冷甲醇为溶剂，在低温高压下通过溶解作用脱除酸性气体CO2、H2S、COS等，气体净化程度高，选择性好，被广泛应用于煤或重油为原料的大型合成氨和煤制气装置中。煤炭间接液化是将煤炭经气化、净化再经费托合成，产生气态烃、液态烃及合成蜡等产品，并产生大量费托尾气。如将其中低碳烃分离，并将尾气中可再次利用的CO和H2作为合成气进行循环利用，则可以大大提高合成油工厂的综合能量利用效率，提高经济效益。 本论文主要针对费托合成过程的尾气处理工艺，采用流程模拟软件Aspen Plus考查低温甲醇洗工艺吸收费托合成过程产生的费托尾气，提出低温甲醇洗吸收费托尾气的最佳工艺设计。本论文主要从以下几个方面进行低温甲醇洗工艺的相关研究：调研国内外低温甲醇洗工艺的研究现状，包括低温甲醇洗工艺流程，相关气体溶解度数据测量方法以及热力学模型方面的研究工作； 参考文献中气体溶解度的实验方案，以Setaram BT 2.15微量热仪的温度控制系统，提高温度控制精度，建立气体溶解度测量装置，并采用恒定容积法计算50、-15和-30℃时不同压力下CO2在甲醇中的溶解度，标定气体溶解度实验装置的可靠性； 采用恒定容积法测量低温下CH4、C2H6和C2H4在-30~-20℃时的溶解度，并对比亨利系数和PC-SAFT模型对溶解度计算结果的准确性，结果表明PC-SAFT方程能够很好关联气体在甲醇中的溶解度，可准确描述气体溶解度随温度、压力变化趋势，可用于含碳气体吸收的工艺计算； 以上述研究结果为依据，对PC-SAFT热力学模型进行回归，并在Aspen Plus平台对F-T尾气吸收进行流程模拟计算，提出石脑油预洗和甲醇预洗方案，对比流程步骤和能耗、回收率等指标，确定采用低温甲醇预洗方案中的最佳方案。;The low temperature methanol washing process was widely used in the large-scale ammonia synthesis and coal gas plants, due to the acid gas such as: CO2, H2S, COS could be selectively dissolved in methanol under low temperature and high pressure.In the process of indirect coal liquefaction, the products such as gaseous hydrocarbon, liquid hydrocarbon and synthetic wax can be obtained by gasification, purification and Fischer-Tropsch (F-T) synthesis processes. However, the tail gas of F-T synthesis process contains a lot of lower hydrocarbons. Therefore, the lower hydrocarbons effective separation and syngas (CO and H2) reutilization can greatly improve the energy utilization efficiency and economic benefit of the synthetic oil plant.In aim of this paper was to optimize the tail gas treatment process of F-T synthesis. Aspen Plus was used to simulate the absorption process for the F-T synthesis tail gas by low temperature methanol washing process, and the optimum process of low temperature methanol washing was put forward. The results of the work are detailed as follows:1. Investigating the research progress of low-temperature methanol washing process, including the process improvement, related gas solubility data measurement method and thermodynamic model improvement；2. An apparatus for measuring the solubility of gas is established with the Setaram BT2.15 temperature control system. The reliability of the determined device was verified by measuring the solubility of CO2 in methanol at 50℃, -15℃ and -30℃;3. The solubility of CH4, C2H6 and C2H4 at -30~-20 ℃ was measured by constant volume method, and the accuracy of Henry's coefficient and PC-SAFT model was compared. The results show that the PC-SAFT equation can well correlate the solubility of gas in methanol, and can accurately describe the variation trend of gas solubility with temperature and pressure. Thus，the PC-SAFT equation can be used to calculate the process of carbon gas absorption; 4. Based on the above results, the PC-SAFT thermodynamic model was regressed, and the process simulation of F-T tail gas absorption was carried out on the Aspen Plus. The naphtha pre-washing and methanol pre-washing schemes were put forward, and the best scheme of low temperature methanol pre-washing was determined by comparing the process steps, energy consumption, recovery rate and other indexes.