Methane solubility in liquid hydrocarbons at high pressure

Methane solubility in organic mixtures containing n-dodecane and C5—C10 hydrocarbons in different ratios was studied in the 0–40 MPa pressure range. Absorption measurements were carried out at temperatures of 303–343 K. The solubility of methane in liquid hydrocarbon mixtures increases upon pressure increase over the whole pressure range of 0–40 MPa and upon increase in the content of volatile components in the mixtures. Methane dissolves in the mixtures in two stages: the first one with heat evolution and the second one, after a certain pressure has been attained, with heat absorption, which is especially noticeable for a mixture consisting of volatile hydrocarbons. Methane solubility in organic liquids is five times higher than methane sorption on asphaltenes, nine times higher than the sorption on kerogen, and close to methane sorption on microporous carbons.