KINETICS OF ASPHALTENE HYDROCONVERSION .2. CATALYTIC HYDROCRACKING OFA COAL RESIDUE

Catalytic hydrocracking of an asphaltene-rich residue obtained by dire ct liquefaction of a Spanish subbituminous coal was carried out at dif ferent temperatures and reaction times. A kinetic study of asphaltene conversion was performed, and the chemical changes produced in the oil fraction during the process were studied by elemental analysis and H- 1 n.m.r. There was a high asphaltene conversion (max. 47 wt%) to oil gas, and the data fitted first-order kinetics for asphaltene conversi on and for oil and gas formation. The presence of catalyst and hydroge n considerably inhibited coke formation. Hydrogen was predominantly in corporated in the oil fraction, giving less aromatic structures, and c racking reactions mainly occurred in the asphaltenic fraction. (C) 199 7 Elsevier Science Ltd.