Selective steam reforming of alkylated hydrocarbons and coal liquids over NiOFe2O3 catalysts

The major objective of the present work is to develop a new process for upgrading coal liquids by achieving the selective dealkylation of alkylated aromatics in coal liquids without hydrogen. A selective steam reforming process was investigated using NiOFe2O3 catalysts at 480°C in a stream of nitrogen at atmospheric pressure. The catalysts used were of three kinds. Catalyst A was prepared by a conventional coprecipitation method of nitrates with ammonium solution, and had a molar ratio of Fe2O3 to NiO of 0.3:0.7. Catalyst B was prepared by impregnation of K2CO3 on catalyst A. The preferred amount of K2CO3 was found to be 0.3 wt.-% of catalyst A. Catalyst C was the catalyst supported on active carbon. The effective amount of the NiOFe2O3 (0.7:0.3) phase was about 8 wt.-% on the active carbon. Selective steam reforming of toluene using the above catalysts was effected to determine optimum reaction conditions. Reaction temperature of 480°C and W/F of 42.8 gcat./h/mole feeds for catalysts A and B were found to give optimum results. However, W/F in the case of catalyst C was 30.1 g h/mole feed. In all cases, the partial pressure of nitrogen was 0.17 atm and the molar ratio of water-to-toluene was 5.1. Coal liquids as well as tetralin, indane and acenaphthene generally found in the coal liquids were individually tested under the same reaction conditions. Catalyst C showed highest activities and long catalyst life. Typically, 45% of toluene fed was converted to benzene and gaseous products such as hydrogen, carbon monoxide, carbon dioxide and methane. The selectivity for benzene was about 70% maximum. Indane in the coal liquids was selectively converted to alkylbenzenes such as benzene, toluene, ethylbenzene and xylenes, but tetralin and acenaphthene were dehydrogenated to naphthalene and acenaphthylene, respectively.