A mathematical model for tubular reactors in direct coal liquefaction

In direct coal liquefaction, research and development on gas-liquid-solid three-phase reactors is an important project. A model for tubular reactors in direct coal liquefaction is proposed. Since the ratio length-to-diameter is very large, both the gas and slurry phases are assumed to move as plug flows. Based on this model, the profiles of temperature and hydrogen consumption, along with the lengths of tubular adiabatic reactors, tubular isothermal reactors and tubular industrial reactors, can be calculated, considering the variations of gas flux, slurry flux, gas density, hold-up, and rate of the hydrogenation reaction. The variable parameters are the diameters D, initial reacting temperature To, and heat-transfer coefficient K. The method for controlling reaction temperatures along tubular industrial reactors can then be found and the optimum parameters for designs of tubular reactors obtained. A tubular reactor to process 1000 tons of coal per day has been analyzed.