A chromatographic technique was used to measure experimental capacity factors for the n-alkanes from C9H20 to C36H74 in CO2 from 308.2 to 348.2 K and from 100 to 240 bar. Infinite dilution activity coefficients, gamma(i)(infinity), were calculated for the solid n-alkanes (C24H50 to C36H74) utilizing regular solution theory to characterize the stationary phase. This allowed the estimation of solubilities from capacity factors for the solid n-alkanes in CO2.