Investigation of pressure-dependent absorption cross-section measurement of methane in subcritical to supercritical CO2

Absorption cross-section measurements of CH4 at the experimental condition of pressure ranges from 1 to 75 bar and at a uniform temperature of 323 K using 3.39 μm He-Ne laser is reported in this study. The experiments were performed in a spherical chamber using the mixture of CH4 and CO2 at mentioned pressure. The present study also focuses on the effect of the subcritical to supercritical CO2 (sCO2) environment on the absorption cross-section of CH4 quantitative measurement. Absorption cross-section is a significant term that provides the probability of molecules that can be absorbed with specific wavelengths. This quantitative data of absorption cross-section plays a vital role in measuring the CH4 concentration in the sCO2 environment and interpreting the PLIF measurement. The results obtained for the absorption cross-section of CH4 in the experimental rig at different pressure was compared with simulated data.