Reactions of tetralin with tritiated gaseous hydrogen were carried out at 5.00 MPa and at 200−400 °C on several noble metal catalysts prepared:  Pt/Al2O3, Pd/Al2O3, and Pt−Pd/Al2O3. Hydrogenation and dehydrogenation activities of the catalysts were compared. By tracing changes in the radioactivities of 3H in the products before and after reaction, amounts of the hydrogen exchange between tetralin and tritiated hydrogen were measured to determine the behavior of hydrogen in the reaction. Further, effects of sulfur present in the feedstocks on the catalytic performance were investigated and resultant differences in the sulfur tolerance among the catalysts were clarified.

Hydrogen transfer reactions of coal with tritiated gaseous hydrogen in the presence of tetralin were performed using a flow reactor under the following conditions: pressure 50 kg/cm 2 , temperature 200-400 °C, and reaction time 120-420 min. When Wandoan coal (WA) was used as a coal sample, functional groups participated in the hydrogen transfer reaction even at 200 °C and then decomposed at 250 °C. At 300 °C, ether bonds were cleaved to generate hydroxy groups which were decomposed at 350 °C. When the higher rank Pocahontas coal (POC) was used, functional groups participated in the hydrogen transfer reaction even at 250 °C and then decomposed at 300 °C. Further, ether bonds were cleaved at 350 °C to generate hydroxy groups which were decomposed at 400 °C. These results showed that in the case of POC coal, a 50 °C higher temperature was needed to obtain functional group behavior similar to the case of WA coal.

No abstract

No abstract

No abstract