Hydrogenation of brown coal. 3. Roles of hydrogen and hydrogen-donor solvents in systems catalysed by iron and tin compounds

The role of hydrogen and hydrogen-donor solvents in the liquefaction of a Victorian brown coal without added catalyst and in the presence of iron-and tin-based catalysts has been studied. Results of an investigation of the effect of temperature and pressure on the conversion parameters, of independent studies of asphaltene hydrogenation, and of work with model ethers are described. A mechanism is tentatively proposed to describe the role of iron, tin and iron-tin catalyst systems based upon these results.