Broadening of the ν2 Raman Band of CH4 by C3H8 and C4H10

Raman spectroscopy is a promising method for the analysis of natural gas. It is necessary to account for the broadening effects on spectral lines to improve measurement accuracy. In this study, the broadening coefficients for methane lines in the region of the nu(2) band perturbed by propane, n-butane, and isobutane at room temperature were measured. We estimated the measurement errors of the concentration of oxygen and carbon dioxide in the case of neglecting the broadening effects on the methane spectrum by the pressure of C-2-C-6 alkanes. The obtained data are suited for the correct simulation of the methane spectrum in the hydrocarbon-bearing gases and can be used to improve the accuracy of the analysis of natural gas by Raman spectroscopy.

Automated summary

Raman spectroscopy shows promise for natural gas analysis. This study measured the broadening coefficients for methane lines perturbed by propane, n-butane, and isobutane at room temperature. Neglecting the broadening effects on the methane spectrum by the pressure of C-2-C-6 alkanes leads to estimation errors in measuring the concentration of oxygen and carbon dioxide. The obtained data can improve the accuracy of natural gas analysis by Raman spectroscopy.