On the Electrolysis of Coal Slurries

Slurries of anthracite and lignite were used in suspension in . Gas chromatography was used to measure and ; absorption spectroscopy was used to measure dissolved Fe. Voltammograms were taken of the system solution slurry. Hydrogen was evolved at cell potentials more negative than 0.6V. The limiting current density of this evolution was initially around 5–10 mA/cm 2 at 80°C. However, when the coal was filtered off from the solution, the current density was around the same. Atomic absorption spectra showed iron dissolved in solution. If coal was sufficiently washed in solution, the limiting current for hydrogen evolution at low potential dropped to around 0.1 mA/cm 2 . The evolution of hydrogen was near 100% in faradaic efficiency. Anode gases were only ∼ 10% in current efficiency. Results with pure carbon were radically different. Limiting current was low, but anode gases approached 80% . The essential facts of Coughlin and Farooque's work are confirmed; details are counter‐indicated. Coal slurry electrolysis as a method for cheap hydrogen evolution is not in good prospect, because of the low current density available after the removal of Fe. It may be possible to obtain commercially interesting products from the anodic reactions.