Tk. Rantakyla et al., INVESTIGATION OF THE HYDROGENATION OF SOME SUBSTITUTED ALKYLBENZENES IN A LABORATORY-SCALE TRICKLE-BED REACTOR, Journal of chemical technology and biotechnology, 67(3), 1996, pp. 265-275
The liquid-phase hydrogenation kinetics of toluene, cumene and mesityl
ene was studied over an alumina-supported nickel catalyst in a laborat
ory scale trickle-bed reactor operating isothermally at temperature of
75-115 degrees C and at hydrogen pressures of 20-40 bar. The experime
nts performed in the absence of intraparticular diffusion resistance s
howed that the catalyst deactivated rapidly at the initial stage of th
e experiment, after which a virtually stable level of the catalyst act
ivity was attained. The systematic kinetic experiments carried out wit
h a stable aged catalyst revealed that cumene and mesitylene at high c
oncentrations retarded the hydrogenation rate, whereas such an effect
was not observable for toluene. The results of the kinetic experiments
were interpreted quantitatively with a reaction mechanism involving s
equential addition of hydrogen to absorbed aromatic molecules.