The hydrogenation of the main components of an anthracene oil has been investigated in a cocurrent downÑow trickle bed reactor at 623 K and 9É8 MPa. The catalyst employed was sulÐded
The product of NiÈMo/c-Al 2 O 3 . the e †ectiveness factor and chemical rate constant was determined for the reactions involved in the hydrogenation of naphthalene, acenaphthene, phenanthrene, anthracene, Ñuoranthene and pyrene. Reaction rates were expressed as a weighted average of the rate on the liquid-covered surface and on the dry surface. The external surface of the catalyst was considered to consist of a dynamic and a low liquid renewal area. The latter, identiÐed as the area wetted by stagnant liquid, was assumed to be not reactive. The product of the e †ectiveness factor and the intrinsic rate constant were determined for dry and wetted catalyst surfaces by employing an estimation of the unit fraction of inactive surface. An estimation of the e †ectiveness factors was performed by employing the kinetic constants previously determined by Rosal et al. (Ind. Eng. Chem. Res., 31 (1992) 1007È12). The results showed that the e †ectiveness factor for the wetted surface followed a pattern in good agreement with theoretical predictions and was especially low for the hydrogenation of anthracene, a reaction whose rate was relatively high.
1988 SCI (