On a possible role for electrochemical oxidation in coal liquefaction

The feasibility of coal conversion via electrochemical liquefaction has been investigated. Because of the complicating presence of inorganic materials in coals, humic acids extracted from lignites have been used as model substrates. Considerable reductions in molecular mass, as revealed by size exclusion chromatography, were achieved by anodic oxidation at 1.7 V for slurries in acid, and more especially for solutions in alkali. NMR spectroscopy of methylated humic acids before and after oxidation suggests cleavage of ether linkages between aromatic clusters, with generation of carboxyl groups.