The use of polystyrene networks and phenolic resites to model the effectiveness of Fe and Mo catalysts in coal hydropyrolysis

This chapter discusses the effects of iron (Fe) and molybdenum (Mo) catalysts in hydropyrolysis and temperature programmed reduction, a cured phenolic co-resin prepared from phenol and 4-hydroxy diphenylmethane and a polystyrene–divinylbenzene network. The conversion characteristics of these models are compared with those of a bituminous and a low-rank coal. Iron and molybdenum compounds are the subject of precursors for sulphided catalysts for both coal liquefaction and hydropyrolysis. Iron at relatively low concentrations is less effective than sulphided Mo. For low-rank coals at high pressure, catalysts only increased tar yields typically by less than 10% daf coal, but without a catalyst, the tar yields of 40–50% are appreciably higher than for bituminous coals. Although rapid heating is used in process situations, slow heating is being applied in temperature programmed reduction (TPR) to specify organic sulfursulfursulfur forms in coals. The use of model compounds is widely used to probe reaction pathways in coal liquefaction. The effects of Fe and Mo catalysts on bond scission and product distribution during hydropyrolysis is investigated using two solid phase models––namely, a cross-linked polystyrene–divinylbenzene and a 4- hydroxydiphenylmethane-containing phenolic resin.