PEP Review 79-3-3
Published: January 1980
This review presents process designs for vapor phase ethylation of toluene to p-ethyltoluene and its subsequent dehydrogenation to p-methylstyrene, and compares them with those for the conventional vapor phase alkylation of benzene and its dehydrogenation to styrene.
Mobil Oil have patented a process for selective production of the para isomer of ethyltoluene and on p-methylstyrene polymers. Interest in p-methylstyrene monomer as an alternative to styrene is motivated by the cheaper toluene starting raw material and by the reportedly superior properties of the methylstyrene polymers.
In large U.S. plants, the p-ethyltoluene intermediate has a calculated value less than that of ethylbenzene, while the p-methylstyrene value is less than that of styrene. Potential process improvements mentioned in the review might result in additional savings. Neither of the products can be produced in existing ethylbenzene or styrene units without equipment modifications.