METHOD FOR REDUCING ENERGY CONSUMPTION IN THE PRODUCTION OF STYRENE MONOMER UTILIZING AZEOTROPIC WATER/ETHYLBENZENE FEED VAPORIZATION

摘要

The present invention is directed to reduced-energy improvements in methods and systems to produce styrene monomer via ethylbenzene dehydrogenation. The methods and systems reduce utility cost and provide savings in comparison with the current technology practiced in the industry.

主权项

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 to about 0.6; 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.