Forced periodic operation of a trickle-bed reactor

The study concerns experimental and theoretical investigations of forced un steady-state operations in comparison to the steady-state operation. Change s in the control variables influence the regime and the performance of a tr ickle-bed reactor. As an example for a periodically operated reactor, a det ermined forced unsteady-state technique was used in which the catalyst is c ontacted periodically with different liquid flow rates. Therefore the aims of the study were to look for such periodic operation conditions in which a periodical variation of the liquid stream leads to an improvement in react or performance and to a mathematical model for the simulation and explanati on of the observed effects. The hydrogenation of alpha-methylstyrene to cum ene with surface-deposited palladium catalyst, C6H5C(CH3) = CH2 + H-2 --> C 6H5CH(CH3)(2), was taken as, a model reaction. It will be shown that under liquid Bow interruption the time-average conversion is higher than under st eady state operating conditions. The reason for such a result will be offer ed with a dynamic heterogeneous mathematical model. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.