A MATHEMATICAL-MODEL FOR TUBULAR REACTORS IN DIRECT COAL-LIQUEFACTION

In direct coal liquefaction, research and development on gas-liquid-so lid three-phase reactors is an important project. A model for tubular reactors in direct coal liquefaction is proposed. Since the ratio leng th-to-diameter is very large, both the gas and slurry phases are assum ed to move as plug flows. Based on this model, the profiles of tempera ture and hydrogen consumption, along with the lengths of tubular adiab atic reactors, tubular isothermal reactors and tubular industrial reac tors, can be calculated, considering the variations of gas flux, slurr y flux, gas density, hold-up, and rate of the hydrogenation reaction. The variable parameters are the diameters D, initial reacting temperat ure T(o), and heat-transfer coefficient K. The method for controlling reaction temperatures along tubular industrial reactors can then be fo und and the optimum parameters for designs of tubular reactors obtaine d. A tubular reactor to process 1000 tons of coal per day has been ana lyzed.