Absorbance enhancement in the infrared spectra of CH₄/CO₂ gas mixtures: quantitative analysis of binary gas diffusion.

at ~1 bar and 298.45 or 308.15 K is successfully investigated with the same IR signals within a closed system: for methane, the absorbance is appropriately corrected accounting for equimolar counter diffusion as a constraint; for carbon dioxide, the absorbance varies linearly with the concentration so that no correction is needed. Homonuclear foreign species transparent to IR radiation can also be indirectly analyzed if the broadening effect is appropriately described, as reported in this article.