二维中心切割气相色谱法测定加氢过程气中微量硫化物

Determination of trace sulfide in gas during hydrogenation by two-dimensional central cutting gas chromatography

关键词:  二维中心切割  气相色谱  加氢过程气  有机硫  尾气达标排放

Key words:  two-dimensional central cutting  gas chromatography  gas for hydrogenation reduction process  organic sulfur compound  emission control

摘要:

建立了利用二维气相色谱中心切割技术与双检测器相结合,测定硫磺回收加氢过程气微量硫化物的分析方法。目标化合物经预柱分离进入热导检测器,同时通过辅助电子气路控制系统压力变化设定阀切换时间,将目标化合物切入脉冲火焰光度检测器进行检测。确定了加氢过程气中H₂S、SO₂、COS、CH₃SH、C₂H₅SH、CS₂在柱切换与不切换时的保留时间,建立了双柱、双检测器定性和定量分析方法。该方法进行加氢过程气的分析,目标化合物相对标准偏差RSD＜1.0%,最低检出限＜1×10-6(体积分数),线性相关系数R≥0.999 9。该方法将常量硫化氢与微量硫化物完全分离,节省了H₂S预处理步骤,解决了H₂S与微量SO₂、微量有机硫共存下硫形态的准确定量分析问题。 

Abstract:

An analytical method was established for the determination of trace sulfides in sulfur recovery hydrogenation process using a two-dimensional gas chromatographic center-cutting technique in combination with a dual detector. The target compound was separated into TCD through a precolumn and the target compound was cut into the PFPD for detection by setting a valve switching time which is controlled by an assisting electronic circuit through the system pressure change. The retention time of hydrogen sulfide, sulfur dioxide, carbonyl sulfide, methanethiol, ethanethiol and disulfide in the process of hydrogenation and reduction was determined. The double column and dual detector were established for qualitative and quantitative analysis method. The method was applied to the analysis of gas during hydrogenation and reduction. The relative standard deviation (RSD)of the target compound was below 1.0%, the lowest detection limit was less than 1×10-6 and the linear correlation coefficient R was greater than or equal to 0.9999. The method completely separates the hydrogen sulfide from the trace sulfide, saves the pretreatment step of the hydrogen sulfide, and solves the accurate and quantitative analysis of the sulfur form under the coexistence of hydrogen sulfide, trace sulfur dioxide and trace organic sulfur compound.