The gas-liquid equilibrium in systems containing CO2, monoethanolamine (MEA), water and many organic solvents, for example alcohols, glycols, esters of glycols and so on, has been investigated. Some regularities of solubility as the function of dielectric constant of solvent and other properties have been found. Thermodynamic analysis has shown some peculiarities of stripping process which allows a reduction of energy consumption. Pilot plant tests of some absorbents, for example mixtures of MEA with N-methylpyrrolidone, tetrahydrofurfuril alcohol, benzyl alcohol, ethylene glycol and other mixtures, have confirmed the calculation results. The experience of industrial usage of energy saving technology of CO2 removing from synthesis gas at several commercial plants by substitution of part of water by organic solvent has been accumulated.