This study investigates the liquid-liquid equilibrium measured between coal tar absorption oil and aqueous solution of methanol, ethylene glycol, diethylene glycol, triethylene glycol or 1,3-butandiol, which was expected to increase the distribution coefficients of the nitrogen heterocyclic compounds in the coal tar absorption oil. The distribution coefficients of the nitrogen heterocyclic and homocyclic compounds are found to be larger with the aqueous solution of each selected compound than those with water. The distribution coefficients of the nitrogen heterocyclic compounds are found to be higher than those of the homocyclic compounds. For the emulsion liquid membrane permeation, the aqueous solutions of the organic compounds are used as the membrane solutions. The nitrogen heterocyclic compounds selectively permeated with any membrane solution, and the permeation rates of the components in the absorption oil are found to be enhanced relative to those without additive in the membrane solution. The overall volumetric permeation coefficients increased as the distribution coefficients and the effects of the organic compounds in the membrane solution used in the present study.