Use of zeolite membrane reactors for selectivity enhancement: application to the liquid-phase oligomerization of i-butene

This work investigates the use of a zeolite membrane reactor (ZMR) in the l iquid-phase oligomerization of i-butene. The membrane was used for the sele ctive removal of i-octene from the reaction environment, thus reducing the formation of unwanted C-12 and C-16 hydrocarbons. MFI (silicalite) membrane s prepared by secondary growth on stainless steel porous tubes were used fo r this purpose, given the non-polar nature of the compounds to be separated . Preliminary non-reactive tests demonstrated the capability of the membran e to separate i-octene from i-butene and from C-12 and C-16 hydrocarbons. R eaction experiments were then carried out over an acid resin catalyst bed l ocated on the membrane tube side. The ZMR produced a very significant incre ase in the selectivity, and as a consequence also in the yield of i-octenes (intermediate product in the oligomerization of i-butene), compared to a c onventional fixed bed reactor (FBR). (C) 2001 Elsevier Science B.V. All rig hts reserved.