SMARTSM Styrene Monomer Advanced Reheat Technology - CB&I

SMART SM Styrene Monomer Advanced Reheat TechnologyProcess FlowDiagramEthylbenzeneRecycle EthylbenzeneDistillation SectionBenzeneOffgasInhibitorSteamSuperheaterO 2 /AirDehydrogenationReactorCondensateSteamWasteHeatBoilerGasCompressionSeparatorCondensateDM *TolueneStyreneMonomerProduct* Dehydrogenated MixtureTarProcessDescriptionThe major reactions in the process are the dehydrogenationof ethylbenzene to styrene and thesubsequent oxidation of the hydrogen producedin the first reaction. This hydrogen is reacted withoxygen over a highly selective catalyst. Theremoval of hydrogen from the process substantiallyincreases single-pass EB conversions whilemaintaining high SM selectivity. The heat generatedis used to reheat the reaction mixture,avoiding expensive interstage heat exchangerequipment.Dehydrogenation side reactions also producebenzene and toluene, as well as some light compounds.A small steam superheater supplies partof the endothermic reaction heat for the dehydrogenationreaction. The reaction system containstwo catalysts: a conventional EB dehydrogenationcatalyst and an oxidation catalyst. The reactoreffluent is cooled by generating steam. The dehydrogenatedmixture is distilled to recover thestyrene product, benzene and toluene by-products,and recycle ethylbenzene.ProcessChemistryDehydrogenationC 6 H 5 CH 2 CH 3C 6 H 5 CH=CH 2+H 2–HeatEthylbenzeneStyreneHydrogenOxidationH 2Hydrogen+ 1/2 O 2 H 2 O +OxygenWaterHeatwww.CBI.com/lummus-technologyOnly employees, agents, or representatives authorized under and pursuant to written agreementwith CB&I are authorized to distribute this brochure to an actual or potential client of CB&I.©Copyright 2012 by Chicago Bridge & Iron Company. All rights reserved.