川东北高含硫天然气中有机硫化合物的分析方法研究

基于脉冲火焰光度检测器(PFPD)对硫化合物具有高的灵敏度和选择性以及价格低廉等优点,采用硫化氢选择性吸收法和气相色谱-脉冲火焰光度法(GC-PFPD)相结合技术,对川东北高含硫天然气中有机硫化合物的形态分布进行了分析。优化了天然气预处理工艺条件,采用惰性的预处理系统除去高含硫天然气中的硫化氢,收集剩余的有机硫气体,用GC-PFPD法进行分析检测,根据标准物质保留时间定性方法和外标定量方法进行了定性和定量研究。结果表明:在最佳的实验条件下,该方法能充分除去高含硫天然气中硫化氢,且操作简单,对同一样品重复测定5次,各组分的相对标准偏差(RSD)都在10%以内,方法的加标回收率在91%~104%之间。

Study on the analytical method of organic sulfides in high sulfur natural gas from northeastern sichuan

Pulsed-flame photometric detector(PFPD) provides improved detection sensitivity and high selectivity for sulfides, and it is more economical compared to some other detectors. The method for separation and determination of organic sulfides in high-sulfur natural gas in northeastern Sichuan was established by applying technique that combines hydrogen sulfide (H_2S) selective absorption with gas chromatography with pulsed-flame photometric detector (GC-PFPD). The preproeessing conditions of natural gas were optimized. H_2S in high sulfur natural gas was removed by inert pretreatment system, and the remaining organic sulfides collected were detected by GC-PFPD. Qualitative and quantitative research of organic sulfur compounds in natural gas was established with the retention time of the ref-erence material and the external standard method. The experimental results indicated that H_2S in high sulfur natural gas can be removed completely by this method under the optimum conditions, and the method can simplify operation procedures and shorten operation time. Five repeatable determinations of the same sample showed that the relative standard deviations (RSD) of the organic sulfur com-pounds were all smaller than 10 % and standard recovery of the method was between 91% and 104 %.