激光拉曼天然气分析应用研究

Study on the application of laser Raman spectroscopy in natural gas analysis

目前,天然气组分分析通常采用气相色谱分析方法,但气相色谱仪运行时需要有多个色谱柱和分离分析步骤,较为复杂费时。激光拉曼光谱分析技术为一项通过测定物质的光散射信号来实现目标分析物的分析方法,具有实时、简便、快捷的技术优势,目前已广泛应用于固体及液体样品的分析。通过分析比对现有的天然气分析方法的技术特点,结合激光拉曼技术在气体分析方面的技术发展,提出了将激光拉曼光谱发展成为天然气组成快速分析的方案,并探讨了激光拉曼天然气分析应用情况,为激光拉曼天然气分析技术发展探路。在定性分析方面,不同于传统的通过拉曼位移识别谱峰,而是通过特定的天然气标准气体物质系列的激光拉曼光谱分析,可快速准确获取天然气中烃类组分的特征谱峰,从而进行天然气中各个组分的定性分析,然后用外标法定量,即采用天然气气体标准物质进行单点校准,可进行定量分析。采用激光拉曼光谱法测定了2个典型的天然气样品,分析结果表明激光拉曼光谱法和气相色谱法水平相当。

Gas chromatography(GC)is currently employed for natural gas composition analysis.It is more complicated and time-consuming for it requires multiple columns and separation analysis steps.Laser Raman spectroscopy is an analysis method by measuring the light scattering signal of the substance,and it has advantages of real-time,simple and fast.Now it had been widely applied in analysis of solid and liquid samples.In this paper,the technical characteristics of existed natural gas composition analysis method was studied and then laser Raman spectroscopy was proposed as a scheme for the rapid analysis of natural gas composition due to its development in gas analysis.This paper also discussed the application of laser Raman natural gas analysis,which would benefit to the development of application laser Raman technology to natural gas analysis.In the aspect of qualitative analysis,the characteristic peaks of hydrocarbon components in natural gas could be quickly and accurately obtained through measuring a specific series of laser standard gas substance.Quantitative analysis was carried out by the external standard method,using natural gas reference material for single point calibration.Two typical natural gas samples were tested by laser Raman spectroscopy,the results showed that Raman spectroscopy and gas chromatography were in the comparable level.