Catalytic hydropyrolysis by impregnated sulphided Mo catalyst

Abstract

Catalytic hydropyrolysis (HyPy) using impregnated sulphided Mo catalyst is studied in a thermobalance and in a 100 g fixed-bed reactor. Mo loading (0.5%) in impregnated coal is effective. Higher yields of oil and phenols (PCX) and lower concentration of sulphur in oil are obtained in catalytic HyPy than in non-catalytic HyPy, showing that the quality and quantity of oil are markedly improved in catalytic HyPy. The presence of catalyst remarkably increases the rate of oil formation, indicating that the rate of saturation of free radicals is greatly enhanced by hydrogenation. Catalytic HyPy can be performed at a lower temperature compared with non-catalytic HyPy, thus increasing the efficiency of hydrogen utilization. An increase in coal particle size (< 90 μm, 90–250 μm and 250–500 μm) leads to an enhance in conversion and oil yield in both catalytic and non-catalytic HyPy, which indicates that hydrogen diffusion is extensively depressed when coal agglomeration is extended. The catalytic ability increases with enhancing hydrogen pressure. The promotion of hydrogenation by impregnated MoS 2 catalyst is related to the ability of adsorption and dissociation of gaseous hydrogen.