激光拉曼光谱及其在天然气分析中的应用展望

Application prospect of natural gas component analysis using Laser Raman spectroscopy

激光拉曼光谱法既不需要高纯载气,又无需分离样品气,可同时分析多个气体组分,能实时进行快速测定,提高测定分析效率,节省分析成本,已大量应用于材料、石油、化工、环保生物、医学、地质等研究领域。但由于气体分子的散射截面小,散射强度很微弱,应用激光拉曼光谱法分析的准确度及重现性均有待提高。因此,目前激光拉曼光谱法应用于天然气分析仅处于实验室研究阶段。为此,分析了该技术在天然气分析中的应用前景,结论认为:综合利用激光光源技术、拉曼光谱技术、表面增强拉曼散射光纤探针技术等,可大大提高气体组分的拉曼散射光强度,从而有效提高激光拉曼光谱法在天然气分析中的检测灵敏度、重现性及准确度,有望研制出满足天然气分析要求的激光拉曼天然气分析仪,实现天然气多组分快速同步分析。同时,还可进行天然气组成、有毒害物及其他杂质分析;从而使激光拉曼光谱法在天然气分析中的推广应用成为可能。

Laser Raman spectroscopy needs neither high-purity carrier gas nor the separation of sample gas, and can simultaneously analyze multiple gas components with a fast speed of measurement, a high efficiency of gas analytic test and even a low analytic cost. That is why it is widely used in material science, petroleum industry, chemical industry, environmentally-friendly biotechnology, medical field, geological studies, etc. However, due to the small scattering area and the weak scattering strength of gas molecules, the application of Laser Raman spectroscopy to natural gas component analysis is still at the laboratory research stage, and its accu- racy and reproducibility are to be highly improved. In view of this, through the analysis of such application prospect, it is presented that the integration of laser light source, spectroscopy surface-enhanced Raman scattering and fiber probe technologies will significantly improve the intensity of Raman scattering light, as a result, to effectively improve the test sensitivity, reproducibility and accuracy of natural gas component analysis. On this basis, it is also predicted that a satisfactory Laser Raman analyzer will be possibly developed to achieve instant and simultaneous analysis of natural gas components. Apart from that, with this analyzer, we can also achieve the simultaneous analysis of gas composition, harmful substances and other impurities. And that will make it possible for Laser Raman Spectroscopy to be widely applied to natural gas component analysis.