Hydrogenation-dehydrogenation of pyrenes catalysed by sulphided cobalt-molybdate at coal liquefaction conditions
✍ Scribed by Keith P. Johnston
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 727 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0016-2361
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✦ Synopsis
The hydrogenation and dehydrogenation kinetics of pyrene and hydropyrenes were studied in batch microreactors, both with and without catalyst, as a function of time, temperature, pressure and catalyst concentration.
Under catalytic conditions at 648 K and-dihydropyrene and pyrene reached equilibrium in 3 min with a molar ratio of 0.41. The heat of the hydrogenation reaction was -lo+1 kcal mol-' compared with -12 kcal mol-' for the hydrogenation of phenanthrene to 9,10dihydrophenanthrene. The hydrogenation and dehydrogenation rates were negligible without catalyst. At 648 K with catalyst, 70%of the hydropyrenes reverted to pyrene in 5 min under nitrogen. The rapid pyrene4.5-dihydropyrene equilibration implies that the equilibrium constant may be of more importance than the hydrogenation rate constant for predicting the amount of hydrogen available for donation by pyrene-like components in coal liquefaction solvents.