A semi-theoretical approach for predicting k(L)a values (referred to liquid volume) in 18 organic liquids [acetone, aniline, 1-butanol, benzene, cyclohexane, decalin, 1,2-dichloroethane, 1,4-dioxane, ethanol (96%), ethylacetate, ethylbenzene, ligroin, methanol, nitrobenzene, 2-propanol, tetralin, toluene, and xylene] at various operating conditions (including elevated temperatures and pressures) was developed. It was found that the approach is applicable regardless of the hydrodynamic regime (at u(G) <= 0.1 m/s). Temperatures up to 353 K and pressures up to 0.5 MPa were tested. Two different distributors (multiple-hole and single-hole type) were employed. The liquid-phase mass transfer coefficient k(L) was calculated theoretically from the penetration theory on the basis of original definition of gas-liquid contact time. The interfacial area a was defined with respect to the liquid volume. It was found that their product k(L)a must be multiplied by some correction factor in order to take account of the non-spherical (ellipsoidal) shape of the bubbles. When the correction term is correlated to both the Eotvos number (Eo) and the dimensionless temperature ratio, 198 experimental k(L)a values can be fitted reasonably well (average relative error 9.3%).