Kinetic modeling of direct liquefaction of wyodak coal catalyzed by sulfated iron oxides

This paper describes the kinetics of the direct liquefaction of Wyodak coal using tetralin and 1000 psig (cold) H[sub 2] were experimentally measured and mathematically modeled. Experiments were carried out in a 27-cm[sup 3] horizontally shaken autoclave microreactor at 648-698 K for reaction times of 5--120 min. Some experiments were carried out at lower temperatures to determine if the model would be accurate at such conditions. Three catalyst combinations were used, Mo/Fe[sub 2]O[sub 3]/SO[sub 4], Fe[sub 2]O[sub 3]/SO[sub 4], and Fe[sub 2]O[sub 3], each with elemental sulfur. Four reaction pathways were considered: coal to asphaltenes, coal to gas, coal to oils, and asphaltenes to oils. In each pathway (except for the conversion of coal to gas), parallel thermal and catalytic reactions were included. The conversion of coal to asphaltenes was found to be primarily thermal and conversion of asphaltenes to oils was primarily catalytic, while conversion of coal to oils had significant thermal and catalytic contributions. The frequency factor and activation energy of each significant rate constant were estimated by correlating data for all temperatures (16 parameters).