Flash hydropyrolysis of coal impregnated with catalyst through solvent swelling

Abstract A new catalyst-supporting method which enhances the primary reaction of the flash hydropyrolysis of coal is presented. The method consists of two steps: (1) impregnation of ZnCl 2 or SnCl 2 from a methanol solution into the micropores of the coal, utilizing the swelling induced by the methanol; (2) sulfidation (activation) of the catalyst by exposing the coal to a gas stream containing 5 vol% of H 2 S at room temperature. Pyrolysis of the coal thus prepared produces an increase in both conversion and liquid yield by accelerating hydrogen transfer from gaseous hydrogen to the coal fragments. After further treatment of the catalyst-impregnated coal with tetralin at 100 °C, further increases in conversion and liquid yield are obtained on pyrolysis. The relative importance of the hydrogen radical transfer paths during the flash pyrolysis is examined.