Patent ID: 9714203
Date: 2017-07-25
CPC Classifications: C07C

Claim:
1. A method for reducing the amount of steam used in a dehydrogenation section of an alkenyl aromatic hydrocarbon production facility, said dehydrogenation section for dehydrogenating ethylbenzene to styrene monomer, said method comprising: i) heating a feed stream comprising ethylbenzene and water as an azeotrope to provide an ethylbenzene/feed steam stream containing vaporized ethylbenzene and feed steam having a feed steam to ethylbenzene ratio of about 0.4 wt/wt to about 0.6 wt/wt; ii) mixing the ethylbenzene/feed steam stream with heating steam from a steam superheater; iii) supplying the ethylbenzene/feed steam stream and heating steam to a first reactor in the dehydrogenation section; iv) dehydrogenating the ethylbenzene in the first reactor, a second reactor, and at least a third reactor of the dehydrogenation section to produce styrene monomer; and v) reheating an effluent from the first reactor in at least a first reheat exchanger and an effluent from the second reactor in at least a second reheat exchanger, wherein each reheat exchanger is provided with heating steam from at least one steam superheater, said heating steam having a temperature of less than about 899° C. and said method utilizing a total heating steam to ethylbenzene ratio of less than about 0.65 wt/wt.