MECHANISM AND KINETICS OF SELECTED HYDROGEN TRANSFER-REACTIONS TYPICAL OF COAL LIQUEFACTION

A series of hydrogen transfer reactions has been done using model compounds (donors and acceptors) at reaction conditions consistent with coal liquefaction. Emphasis was placed upon acceptors having C-C linkages and oxygen compounds with functionality likely to be present in coal. The cracking of dibenzyl was shown to be faster than that of diphenylbutane, diphenylmethane, and 1-phenylhexane at 400-450 °C. With oxygen-containing compounds, the relative order of reactivity was: furans < phenols < ketones < aldehydes < chain ethers. A study of hydrogen transfer using either a deuterium atmosphere or deuterium-tagged donors was undertaken with the oxygen-containing compounds. It was shown that much of the hydrogen necessary to stabilize free radicals comes from the donor solvent or intramolecular rearrangement and not from dissolved gas. © 1979, American Chemical Society. All rights reserved.