High conversions in Ni-Mo-and NaAlO2-Ni-Mo-catalysed no-solvent hydrogenation of a low-rank coal were obtained in a 35 mL reactor (1 g coal charge) heated in a horizontal position with vertical agitation. Much lower conversions were obtained in a 55 mL reactor (3 g coal charge) heated in a vertical position with a stirrer; however, the favourable effect of NaAlO2 addition in giving high oil/asphaltene ratios was preserved. The effects of addition of solvent (tetralin and decalin) and varying the coal loading in the 55 mL autoclave showed the importance of good accessibility of the reactant gas to the coal particles.
- Coal liquefaction: Mass transfer
- Reactor type