炼厂干气湿法脱硫流程模拟分析

Analysis of Process Simulation for Refinery Dry Gas Wet Desulfurization

对炼厂干气进行脱硫处理非常必要,可减轻设备和管道腐蚀,减少催化剂中毒,同时还可以回收利用其中的硫来制造硫磺和硫酸。本文以一套加氢装置为例,介绍了采用ASPEN PLUS软件进行的干气湿法脱硫[以甲基二乙醇胺(MDEA)溶液为吸收剂]模拟分析结果。由于吸收反应在电解质溶液中进行,吸收塔模拟计算选用ASPEN PLUS流程模拟软件的电解质NRTL模型,解析塔物性方法选用UNIFAC物性。原料气指标:流量为617.74kg/h,温度为40℃,H2S含量为1.2%(摩尔分数)。分析结果表明:吸收剂温度以不高过38℃为宜,再生温度以不超过114℃为宜;取吸收塔理论板数为12块,吸收剂的质量流量为2300～2500kg/h,吸收剂中MDEA浓度为25%,再生塔顶温度为100℃,则脱硫处理后干气中的H2S含量可满足国家燃烧排放标准的要求(<20μL/L)。

Desulfurizing the dry gas from refinery is very necessary as this process can mitigate equipmen t and pipeline corrosion ,reduce catalyst poisoning and recycle sulfur in the dry gas to make brimstone and sulfuric acid.This article presents the results of an analysis of simulation conducted using ASPEN PLUS soft- ware of dry gas wet desulfurization （using MDEA solution as the absorbent）.As absorption reaction takes place in electrolyte solution, the electrolyte model NRTL of ASPEN PLUS process simulation software is adopted for the simulation of the absorption column and UNIFAC is used as the properties of the stripper.The indices of the feed gas are：flow rate：617.74kg/h;temperature： 40℃;H2S content： 1.2% （mol fraction）.The analytic results show that the ideal temperature of the absorbent is not higher than 38℃ and that the ideal regeneration temperature is not higher than l l4℃.Assuming the theoretical plate number of the absorption column is 12, the mass flow rate of absorbent is 2300-2500kg/h,the MDEA concentration in the absorbent is 25% and that the temperature at the top of the regeneration tower is 100℃ ,the content of H2S in the desulfurized dry gas will meet the national combustion and emission standards on H2S content （〈20μL/L）.