AN INVESTIGATION OF HYDROGEN-TRANSFER IN COPROCESSING USING MODEL DONORS AND REDUCED RESIDS

Hydrogen donor reactions in the coprocessing of coal and petroleum res ids have been investigated using different hydrogen-rich model compoun ds and reduced resids as donors and aromatics as accepters. Three hydr ogen-rich donor species were compared: cyclic olefins, hydroaromatics, and cycloalkanes; the aromatic accepters included pyrene and anthrace ne; and the resids were reduced by a modified Birch method. Hydrogen w as transferred at 380 degrees C most readily by cyclic olefins, follow ed by hydroaromatics, and the least by cycloalkanes. Catalysis by thio phenol promoted hydrogen transfer by the cycloalkanes at 380 degrees C but had little effect at 440 degrees C. Reduced resids transferred su bstantially more hydrogen to an aromatic acceptor than did the parent resids. In a ternary system of resid, cycloalkanes, and aromatic, the reduced resids yielded more hydrogen transfer and promoted hydrogen do nation from the cycloalkanes in a nitrogen atmosphere. Reduction of re sids by the Birch method appeared to be an effective means of increasi ng the hydrogen donor ability of resids,