天然气中微痕量氢同位素的在线连续分析  

On-line Continuous-Flow Microananlysis of Hydrogen in Natural Gases

作　　者：陶成[1] 刘文汇[1] 孟庆强[1] 杨华敏[1] 周宇[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院无锡石油地质研究所,无锡214151

出　　处：《分析化学》2012年第3期482-486,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(No.40739902)资助

摘　　要：为实现天然气中丰度很低的氢同位素分析,自制氢气富集分离装置,利用在159和77 K温度条件下5A分子筛对不同气体组分的物理吸附性能差异,使天然气样品中微痕量氢与烃类组分分离,并进一步富集后,由载气送入色谱-同位素质谱计系统,分析其同位素组成。分析过程为在线连续流模式,与色谱同位素质谱工作站联动控制,从根本上解决了微痕量氢同位素分析的技术瓶颈。采用本方法分析了已知氢同位素组成的不同浓度人工混合样品,结果表明,本分析方法具有较高的精确度和良好线性,能够满足天然气中氢浓度低至1×10-5(V/V)样品准确分析的要求,标准偏差小于3.3‰。用此方法对不同含油气盆地6个天然气样品进行了分析检测,并对样品中氢同位素组成特征及成因进行了探讨。A hydrogen preconcentration equipment was developed to separate and enrich the micro-hydrogen in natural gases with molecular sieve trap at 77 K and 159 K.The enriched hydrogen was carried into GC-isoto ratio mass spectrometric（IRMS） system by carrier gas to analyze the isotope composition.This on-line continuous-flow process can overcome the difficulty for the determination of micro-hydrogen in natural gases.A set of manual standard samples were analyzed by the method.The results show the method is applicable for the 1×10-5（V/V） hydrogen in the sample and has a good reproductivity and linearity,the relative standard deviation is less than 3.3‰.Using this method,the six gas samples from different oil-gas-bearing basins were analyzed.Further more,the isotope composition origin of hydrogen in natural gas was discussed.

关 键 词：天然气 氢同位素 色谱-质谱分析 

分 类 号：TE642[石油与天然气工程—油气加工工程]