Styrene from Butadiene

Butadiene can be dimerized to 4-vinylcyclohexene (VCH) either thermally (which requires a pure butadiene feed) or catalytically (which can use dilute butadiene in a steam-cracked C4 cut). VCH can be converted to styrene in a 1-step oxidative dehydrogenation process or a 2-step catalytic dehydrogenation process via ethylbenzene.

This review gives approximate designs and cost estimates on these routes for producing 250 million lb/yr (113,000 metric tons/yr) of styrene from the butadiene available from two 1,000 million lb/yr ethylene plants based on gas oil cracking.

It is concluded that catalytic dimerization of dilute butadiene is the more attractive VCH process, while the two routes for its dehydrogenation to styrene are substantially equivalent.