FEEDING OF A COAL-STEAM MIXTURE TO A COAL GASIFIER BY THERMAL PRECONDITIONING OF A COAL-WATER MIXTURE

Innovation in the feeding process was considered for the improvement of efficiency in a coal gasification process. Thermal preconditioning of a coal-water mixture was taken into account to compensate latent heat loss, which was a serious problem in the case of a coal-water mixture fed to the pressurized coal gasifier. A thermal preconditioning experimental apparatus which included a vaporizer and a heat exchanger with auxiliary steam injection equipment was chosen, and its safe operation as an experimental apparatus was confirmed. Estimation of the operating characteristics for a coal gasifier based on the experimental conditions of thermal preconditioning has revealed that the application of the thermal preconditioning process has merits such as higher cold gas efficiency and lower oxygen demand per unit production of CO and H2. This suggests that the use of a thermal preconditioning process is effective in improving the efficiency of a coal gasification process. © 1990, The Society of Chemical Engineers, Japan. All rights reserved.