Alkylation of 1-butene with isobutane using EMT and Y zeolites

Abstract

Alkylate is the preferred blending stock of reformulated gasoline as it is clean burning, producing less emissions, and possesses high energy and octane. Commercial liquid catalysts employed for the alkylation of butene with isobutane pose significant environmental hazards. Many solid acids have been investigated towards this reaction, but none have reached commercial success. Although high initial activity is demonstrated, rapid deactivation ensues, primarily due to a loss in hybride transfer functioning.

The preferential adsorption of the olefin relative to the isoparaffin makes deactivation an inevitable outcome. The catalyst surface selectively adsorbs butene from the feed, regardless of the feed composition. Eventually the surface acid sites become saturated with oliogomers of butene. Pulse feed delivery, with interim isobutane flush periods, can restore deactivated catalysts to fresh state levels. It is possible that catalytic distillation may hold some promise for this challenging reaction, if a suitable solid acid catalyst can be found.