The development of an approximate model to study pressurized gasification of black liquor in an integrated combined cycle configuration is analyzed. Black liquor, an useful fuel in the paper industry, is obtained as a by-product of the papermaking processes. In the entrained flow gasification process, black liquor is atomized in a burner nozzle and partially combusted in a cylindrical reactor to form a combustible fuel gas and a molten smelt of alkali salts. The gasification process causes increased control of the fate of sulfur and sodium in the process, used to improve the pulp yield and mill quality. The limitation of the model is that the distribution of mass transfer from droplets to the gas phase must be prescribed.