Cold flow studies and computer simulation of a slurry transport reactor for the alkylation of isobutane using zeolite-based catalysts

Abstract

The mixing characteristics of a slurry transport column have been investigated by residence time distribution measurements in a pilot plant scale cold flow unit. The column (3 m high, 0.15 m ID) simulates a slurry reactor design proposed for the paraffin–olefin alkylation process with zeolite catalysts. The experimental results show that high levels of mixing are achieved in the bottom zone of the column through an especially designed slurry distributor, while the overall column response can approach the desired well-mixed behavior at sufficiently high recycle ratios. The effect of various process parameters, such as the paraffin-to-olefin ratio, the catalyst holdup, and the product recycle ratio, on the slurry reactor performance were investigated by computer simulation using a literature kinetic scheme for alkylation with zeolite catalysts. The simulation results suggest that mixing inside the reactor must be further enhanced by additional means, e.g., stagewise addition of olefin, if the catalyst holdup is not to exceed the upper limit for Newtonian behavior.