REACTIONS OF COAL MODEL COMPOUNDS IN THE PRESENCE OF HYDROGEN DONOR SOLVENTS AND HIGHLY DISPERSED CATALYSTS

Reactions of 1,2-(1,1'-)dinaphthylethane (DNE) and 1,2-diphenylethane (DPE) in a hydrogen donor solvent in the absence or in the presence of highly dispersed catalysts such as Mo(CO)(6)-S and Ru(acac)(3) were c arried out at 658 or 698 K under a hydrogen atmosphere in order to inv estigate quantitative hydrogen transfer process in the cracking of C-C bond in coal. Dinaphthylethane mainly produced 1-methylnaphthalene, a nd diphenylethane afforded benzene, toluene, and ethylbenzene as the m ajor low molecular weight products. In addition, hydrogenation of DNE and DPE occurred. In the absence of a catalyst, more than 70 mol % of hydrogen was transferred from the hydrogen donor solvent. In the prese nce of Mo and Ru catalyst, the hydrogen required for stabilizing free radicals and hydrogenating aromatic rings was predominantly derived fr om gas phase without or with a small amount of the solvent. However, t he amount of hydrogen transferred from gas phase considerably decrease d and the amounts of hydrogenated products and decomposed products of DNE and DPE lowered with increasing concentration of the hydrogen dono r solvent even with the dispersed Mo or Ru catalyst. The hydrogen dono r solvent retarded the catalyzed cracking of DNE and DPE because of co mpetitive adsorption of the model compound and the hydrogen donor solv ent on the catalyst surface.