Quantitative Raman Spectroscopic Determination of the Composition, Pressure, and Density of CO2-CH4 Gas Mixtures

The Raman spectra for pure CO2 and CH4 gases their ten gas mixtures were collected at pressures temperatures ranging from 2 MPa to 40 room temperature (?24°C) 300°C, respectively. A systematic analysis was carried out establish a methodology the quantitative determination of composition, pressure, density CO2-CH4 mixtures. shift in peak position ?1 band sufficiently large enable accurate pressure CH4-dominated fluids (>50 mol% CH4). An equation representing observed relationship CH4, density, composition developed calculate quantification factor F (CH4)/F (CO2) demonstrated be near constant value 5.048 ± 0.4 used determine molar ratio an unknown CO2-CH4?bearing fluid with high internal (>10 MPa) based on area ratio. effect variation spectral parameters also investigated up 300°C. results showed that must considered when are spectroscopic obtained six samples prepared fused silica capillary capsules validated by comparison microthermometry measurements.