A novel structured catalyst packing for catalytic distillation of ETBE

Catalytic distillation can offer significant reduction of capital costs in G/L/S processes that are equilibrium limited. As an alternative to existing catalytic distillation packings, containing bales or pockets of catalyst s tacked in (a section of) the distillation column, a novel structured cataly st packing is proposed. The novel packing consists of a common structured d istillation packing, on which a binderless film of zeolite crystals is grow n via in-situ hydrothermal synthesis. The combination of standard distillat ion packing structures and thin, binderless zeolitic catalyst films, is exp ected to yield an active and selective system with good distillation charac teristics. As a first step towards demonstrating this principle, structured packings coated with zeolites beta and mordenite were used to synthesize t he 'green' octane booster ethyl tert-butyl ether (ETBE) in a liquid phase b atch system The prepared structured catalyst packings showed activities and selectivities that are comparable to or higher than the activity of the co nventional Amberlyst-15 ion-exchange resin catalyst. Even though the novel catalyst packing has a three times lower catalyst density compared to the c urrently used packings containing catalyst pockets, it is anticipated that this difference can be compensated for by the potential activity increase o f the zeolitic coating, and the higher efficiency and selectivity of the co ating. Furthermore, this concept can be applied to many other processes, es pecially since zeolitic catalysts can offer distinct advantages over more t raditional heterogeneous catalysts. (C) 1999 Elsevier Science Ltd. All righ ts reserved.