胺液中N-甲基二乙醇胺含量的测定

Determination of methyldiethanolamine content in amine solution

由于天然气净化厂脱硫胺液中含有甘醇类降解产物,二甘醇（DEG）和三甘醇（TEG）难于准确称量,以DEG或TEG为内标物的毛细管气相色谱法测定胺液中MDEA的含量时,会产生较大的误差。为避免这种影响,建立了以甲苯为内标物的毛细管气相色谱测定法：选用美国Agilent HP-50＋毛细管柱来分析胺液中甲基二乙醇胺（MDE）的含量;定量方法为内标法;对三甘醇（TEG）和甲苯进行分析对比,最终选用甲苯作为内标物;使用MINITAB 15.1处理实验数据。实验结果表明：MDEA和甲苯出峰稳定,重复性好;方法回收率为99%-101%,相对标准偏差〈2%。该法精密度和准确度较高,不仅可用于天然气净化厂胺液中MDEA含量的测定,而且对同类胺液的MDEA含量测定研究也有一定的借鉴作用。

Due to have some glycol degradation products in the amine solution from natural gas desulfurization and it was difficult to weigh the diethylene glycol（DEG） or triethylene glycol（TEG） exactly, DEG or TEG was used as the internal standard reference substance of capillary gas chromatography to determine the contents of methyldiethanolamine（MDEA） in the natural gas desulfurization solution would lead to large errors. In order to avoid it, a method of capillary gas chromatography was developed in which the HP-50＋ capillary column was adopted to determine the contents of MDEA, the internal standard method was used with the toluene as the internal standard reference substance and the MINITAB 15.1 was applied to perform data processing. The results showed that the peaks of MDEA and toluene were stable, the recovery was 98% to 101% and the relative standard deviation was less than 2%. This method had the advantages of accuracy and precision, not only could use for determining the content of MDEA in amine solutions from natural gas treating plants, but also could provide a reference for research on determining the content of MDEA in similar kinds of amine solution.