Electrolysis of coal slurries to produce hydrogen gas: Effects of different factors on hydrogen yield

The study was aimed to investigate the effects of different factors (such as acid concentration, cell potential, temperature, coal types, and geometric area of the membrane) on the coal slurry electrolysis and hydrogen evolution. It was observed that all of the above factors affected hydrogen production upon completion of the electrolysis. The results revealed that an increase in the initial acid concentration up to 5.0 M brought about an increase in the current density and hydrogen evolution. However, the higher the acid concentration was taken (>7.0 M) then the lower the current density and hydrogen evolution were, which resulted in significant change due to the agglomeration of coal samples and stuck on the electrode surface.Furthermore, the CO₂ evolution (14 ml) was observed only at high temperature (100 °C) and high (2.0 V) cell potential when the H₂ amount was 776 ml. The coal type was observed to have influenced the electrolysis.