Hydrogenation of Some Condensed-Ring Aromatic Hydrocarbons.

Abstract

A S A RESULT of extensive research since 1930, the general principles governing aromatic hydrogenation are reasonably well understood today ( 4 ) . However, quantitative data on the catalytic hydrogenation of condensed polynuclear aromatics with commercial catalysts is still quite limited in spite of the importance of ring saturation in connection with certain hydrocarbon conversion processes ( I , 2, 3 ) . This article describes the effect of temperature on the hydrogenation of naphthalene, phenanthrene, and pyrene over four different catalysts a t 1000 p.s.i.g. The principal result of the work was to show the shift, with increasing temperature, from catalyst activity to thermodynamic equilibrium as the controlling factor in the extent of hydrogenation. EXPERIMENTALCatalysts. Properties of the fresh catalysts are given in Table I. Prior to use, the platinum, palladium, and cobalt molybdate catalysts were stabilized against major activity changes by several hydrogenation tests with interposed air regenerations; nickel tungsten sulfide was conditioned with feed, but was not regenerated. The extent to which this procedure affected the activities of the various catalysts was not determined.Feedstocks. The aromatics were dissolved in n-cetane to provide feedstocks containing about 5 weight ' % of aromatic. Sulfur contents were 0.011, 0.010, and 0.012 weight % and nitrogen contents were 0.004, 0.001, and 0.003 weight % in the naphthalene, phenanthrene, and pyrene feeds, respectively.Procedure. The experiments were conducted in a conventional, continuous-flow system. The feed and product were analyzed by ultraviolet absorption spectroscopy. In some experiments with naphthalene, partition chromatography was also used in order to obtain a direct measurement of Decalin as well as Tetralin and naphthalene in the product. I00100 r 2 / A

Thermal Transfer Fluid: 1-Phenyl-1-tetrahydronaphthylethane

“…Metal sulfide catalysts have been reported to hydrogenate high sulfur naphthalene with an accompanying dehydrosulfurizing reaction. Quantitative data are still limited (Hogan, 1962; Era, 1967; Sonoda, 1973).…”