高硫醇含量天然气净化用MDEA复配溶剂的研究

MDEA complex solvents for purification of natural gas with high mercaptan content

为了提高MDEA脱硫溶剂对天然气中硫醇的脱除率,尝试了以二甲基亚砜、环丁砜、N-甲基吡咯烷酮这三种强极性非质子物理溶剂为复配成分的MDEA溶剂。在研究中选取了甲硫醇及乙硫醇两种典型的有机硫为研究对象,使用静态气-液两相平衡釜为工具,以带有火焰光度检测器(FPD)的气相色谱为检测仪器,考察和选取了吸收温度、气液比这两个重要的吸收参数,评价了三种复配溶剂及单纯MDEA溶剂对目标有机硫及硫化氢的脱除能力。结果表明,二甲基亚砜、环丁砜、N-甲基吡咯烷酮这三种强极性非质子溶剂均能显著提高溶剂对甲硫醇、乙硫醇的脱除率,但随着物理溶剂使用量的增加溶剂对硫化氢的脱除率呈下降趋势。

In order to improve the removal of mercaptan from natural gas by MDEA desulfurization solvent, MDEA is compounded with three strong polar aprotic physical solvents-dimethyl sulfoxide, sulfolane and N-methylpyrrolidone, respectively.Two typical organic sulphides, methyl-mercaptan(MeSH) and ethyl-mercaptan(EtSH), were selected as the research objects. The static vapor-liquid equilibrium still was used as a tool, and the gas chromatography with a flame photometric detector(FPD) was used as the detection instrument. Two important absorption parameters, absorption temperature and gas-liquid ratio, were investigated and selected, and the removal ability of the three compound solvents and the pure MDEA solvent for the target organic sulfur compounds and hydrogen sulfide was evaluated. The results show that the removal of MeSH and EtSH can be significantly improved by the three polar aprotic physical solvents, but the removal of hydrogen sulfide show a decreasing trend with the increase of the amount of the physical solvents.