Diffusion in CO2–CH4 Mixtures to 225 Atmospheres Pressure

Abstract

Diffusion coefficients have been measured in two mixtures of CO₂ and CH₄. (1) 50 mole percent CO₂—50 percent CH₄; (2) 75 mole percent CO₂—25 mole percent CH₄. C¹⁴ tagged CO₂ was used, so that no gradient in chemical composition was necessary. For the first mixture the results agreed with Enskog's dense gas theory at all temperatures and pressures. For the 75 percent CO₂ mixture at 25°C there was a positive deviation from theory, corresponding to the increased importance of glancing collisions for CO₂ near saturation. The results are consistent with our previous data for self‐diffusion in the two pure gases.