Abstract:
Fresh and recycle ethylbenzene is preheated and fed with superheated steam
to the reactor at a temperature of 600-620'C. Steam to ethylbenzene molar
ratio is 12-15 to one. The reaction occurs adiabatically over a fixed
catalyst bed, with 60 percent conversion, and 87-89 percent styrene into
aqueous and organic phases. The organic phase, containing styrene,
ethyl benzene, benzene, toluene and some higher boiling tar is first charged
to the splitting column in which benzene, toluene and some ethylbenzene is
taken overhead. The bottom is distilled under high vacuum to separate the
unreacted ethyl benzene from the product styrene and tar. The final
fractionation involves the recovery of polymer grade styrene. Renzene from
the splitting column is further purified and recycled to the alkylation
section of the plant.