Monolithic catalysts as more efficient three-phase reactors

Monolithic reactors are an attractive alternative to conventional multi-pha se reactors. Advantages are the low pressure drop, the absence of a need fo r a catalyst separation, and the large geometrical surface area. The main d isadvantage is, however, the lack of practical experience with monolithic r eactors. A pilot-scale study has been carried out to evaluate the performan ce of a monolithic reactor on a larger scale. The results of this study hav e demonstrated that a higher productivity can be obtained for a monolithic reactor compared to a trickle-bed reactor for a solid catalysed gas-liquid reaction that is mass transfer limited in the gas-phase reactant. A higher selectivity has been demonstrated for the selective hydrogenation of benzal dehyde towards benzylalcohol when a monolithic reactor is used instead of a trickle-bed reactor as a result of the narrower residence-time distributio n. (C) 2001 Elsevier Science B.V. All rights reserved.