Cumene → 1-Ethenyl-4-methylbenzene

Participants

Reaction Steps

This example illustrates the dehydrogenation of cumene and p-ethyltoluene using a diluent comprising steam and nitrogen. Three and three-tenths grams of the catalyst prepared in Example II, ground to 18 to 40 mesh, was employed in the reactor described in Example II. Initially p-ethyltoluene was flowed into the reactor at 0.38 liquid hour space velocity, 11:1 diluent to p-ethyltoluene ratio (8:1 steam and 3:1 nitrogen) at 588° C., yielding a relatively poor conversion and selectivity. The catalyst was decoked with 5% oxygen and nitrogen for about 1 hr. Cumene was then run at 0.38 liquid hour space velocity, 11:1 diluent ratio (8:1 steam and 3:1 nitrogen) at 588° C. providing 40% conversion to alphamethylstyrene and 88% selectivity. The feed was then switched from cumene to p-ethyltoluene using the same diluent dilution and conditions providing 22% conversion to p-methylstyrene and 93% selectivity. Conditions were then changed to 0.72 liquid hour space velocity, 10:1 diluent ratio for the p-ethyltoluene (8:1 steam and 2:1 nitrogen) at 598° C., yielding 40% conversion and 92% selectivity to p-methylstyrene.

Provenance & Evidence