H_2S、CO_2、COS、CH_3SH在MDEA-TMS-H_2O中的气液平衡研究

A study of gas-liquid equilibrium of H_2S、CO_2、COS、CH_3SH in the mixed MDEA-TMS-H_2O solution

酸性气体在溶液中的气液平衡数据是天然气净化技术领域的重要基础资料。为此,在实验室利用容积为2L的气液平衡测定装置,测定了不同温度和溶液配比条件下硫化氢、二氧化碳、甲硫醇、硫氧碳在甲基二乙醇胺(Meth-yldiethanolamine,MDEA)、环丁砜(Tetramethylene sulfone,TMS)水溶液中的平衡溶解度,并根据气液两相平衡状态方程,结合国外研究成果,利用测定的平衡溶解度数据关联出相关参数,建立了相应的热力学计算模型,用于预测该复杂体系中酸气分压与溶液负荷的气液平衡关系。所建模型准确可靠,误差不大于5%。该研究成果可用于天然气处理新装置的设计和对现有天然气处理装置操作参数的优化,对我国自主开发处理高含有机硫酸性天然气净化技术具有重要意义。

The gas-liquid equilibrium data of acid gas in solution are fundamental information for the research of natural gas purification technology. Therefore, in the laboratory, a 2L gas-liquid equilibrium measurement device was used to measure the equilibrium solubility of H2S, CO2, CH3SH and COS in the mixed solutions of Methyldiethanolamine (MDEA), Tetramethylene sulfone (TMS) respectively under different temperatures and different proportions. With the relevant parameters being correlated from the measured data, a corresponding thermodynamic calculation model was set up, based on the gas-liquid two phase state equilibrium equation, and in combination with the overseas research results. This model is adopted to forecast the gas-liquid equilibrium relationship between the partial pressure of solution load of an acid gas system with reliable results whose error rate is less than 5%. This study can be used not only for the design of natural gas treatment plants under construction but for the optimization of operating parameters in natural gas treatment plants under service, being of significance for Chinese operators to develop their own expertise on dealing with high-sulfur natural gas treatment.