Roles of inherent mineral matters for lignite water slurry electrolysis in H2SO4 system

Highlights: • Cell voltage of demineralized lignite electrolysis was higher than that of lignite. • Current of lignite electrolysis was higher than that of demineralized lignite. • Some metal ions entered into electrolyte improved conductivity. • Pyrolysis reactivity of demineralized lignite was improved by electrolysis. - Abstract: To understand roles of inherent mineral matters in lignite water slurry (LWS) electrolysis, lignite and demineralized lignite electrolyses were carried out in H2SO4 system. The results showed that cell voltage for LWS electrolysis was lower than that for demineralized lignite water slurry (DLWS) under constant current condition. Some inherent mineral matters changed into the corresponding metal ions which entered into electrolyte, and thus improved the electrolysis oxidation reactions for coal organic structure. Meanwhile, the relative amount of O-containing functional groups in demineralized lignite increased with electrolysis time, improving its pyrolysis reactivity. However, the pyrolysis reactivity of raw lignite decreased due to the removal of the inherent mineral matters from electrolysis