Tetralin, supercritical

Stewart, J., Supercritical Pyrolysis of the Endothermic Fuels Methylcyclohexane, Decalin, and Tetralin, Ph.D. Thesis, Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 1999. 

One other example showed that the tetralin/xy lene mixture in the supercritical state was required. A test carried out in the liquid region at 3(X) °C and 250 psi gave a conversion of only 9%. A temperature of 300 °C is quite low relative to the 425 °C tests described above. It would have been more informative to carry out the test at about 10 °C below Tc and at least the mixture vapor pressure. At these subcritical conditions it would have been possible to determine if there is any difference between yields with strictly supercritical xylene-tetralin and a very hot liquid xylene-tetralin mixture. As with previously described patents, quite specific and irrelevant tests are compared for the purpose of showing that the invention is superior to other methods of operation. 

The reduction of l,4-androstadiene-3,17-dione (AAD) as an industrial route to estradione using supercritical tetralin as both the solvent and the hydrogen donor Was investigated at Schering AG in cooperation with the University of Gottingen [177,178]. The reaction kinetics were studied at between 350-600 °C and 50-300 bar. A pilot plant with a possible throughput of up to 30 L h was studied successfully over 1 year with continuous processes run up to 4 days at 575 °C and pressures up to 100 bar at contact times of less than 1 s. 

Adschiri et al. removed 70 wt.% of the nitrogen from coal-derived pitches by catalytically hydrotreating the pitch in a supercritical toluene-tetralin mixture at 450 °C [67]. These pitches could be used for the production of high-quality electrode carbon. The more conventional process for this reaction involves catalytic hydrotreating of the pitch in the liquid phase. The higher dif-fusivities in the SCF resulted in higher reaction rates. Moreover, catalyst coking could be reduced effectively due to the increased pressure and hence the solvent power of the SCF. 

Wai and collaborators have succeeded in the hydrogenation of arenes with Rh nanopartides in a water-in-supercritical CO2 emulsion [33]. The catalytic system was prepared by mixing an aqueous solution of RhCls and a mixture of surfactants containing sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and a co-surfactant perfluoropolyetherphosphate (PFPE-PO4). The introduction of dihydrogen in the reactor allowed the formation of Rh(0) colloids with a mean size in the range 3-5 nm which led to the reduction of naphthalene to tetraline and that of phenol to cyclohexanol as major products. 

Zhou, L., Erkey, C. and Akgerman, A. (1995) Catalytic oxidation of toluene and tetralin in supercritical carbon dioxide, AIChE Journal 41,2122-2130... 

Supercritical oxidations to pharmaceutically relevant compounds is an area of emerging interest. Dapurkar and co-workers have examined the oxidation of tetralin to 1-tetralone in SCCO2 over a mesoporous CrMCM-41 molecular sieve (119). They found that SCCO2 not only improves the selectivity of the reaction (>90% in scC02 vs 75% in liquid solvent), but it also reduces catalyst leaching from the mesoporous support. 

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