To observe the effect of the heating rate on the desulphurization, Bolu- Mengen lignite was desulphurized in the temperature range of 450-750-degrees-C using flash and slow pyrolysis methods. A reduction of 57.6 % and 34.2 % in the total sulphur was obtained for the slow and flash pyrolysis at a pyrolysis temperature of 750-degrees-C, respectively. It was observed that the flash pyrolysis is shifted toward higher temperatures with respect to the slow pyrolysis. The flash pyrolysis having high thermal efficiency has a potential as a desulphurization process.