Patent ID: 9067846
Filing Date: 2015-06-30
Classification: C07C

Abstract:
1. A process for selectively producing various substantially styrene-, methylstyrene- and ethylbenzene-free C6-C9 aromatic hydrocarbon product blends from a hydrocarbon feed stream containing C5-C9 hydrocarbons including styrene, methylstyrene and sulphur compounds, comprising (a) distilling a feed stream containing C5-C9 hydrocarbons including styrene, methylstyrene and sulphur compounds to produce a distillate containing C5-C7 hydrocarbons, and a bottoms fraction containing C8-C9 hydrocarbons, including styrene and methylstyrene, (b) reacting the bottoms fraction with a C1 to C3 lower alcohol in the presence of an acidic catalyst selective for etherification of styrene and methylstyrene to produce an effluent containing styrene and methylstryene ethers, (c) optionally distilling the effluent containing styrene and methylstyrene ethers to remove the ethers and provide a distillate containing either C8 or C8 and C9 aromatic hydrocarbons, (d) hydrogenating the distillate containing C5-C7 hydrocarbons optionally combined with either the distillate containing C8 aromatic hydrocarbons or the distillate containing C8 and C9 aromatic hydrocarbons, in the presence of a suitable catalyst to convert dienes to mono-olefins, and produce an effluent containing the mono-olefins, (e) distilling the effluent containing the mono-olefins to remove C5 hydrocarbons and produce an effluent containing C6-C9 hydrocarbons, (f) hydrogenating the effluent containing the C6-C9 hydrocarbons in the presence of a suitable catalyst, to convert mono-olefins to saturated alkanes, to convert sulphur compounds to hydrogen sulphide, removing the hydrogen sulphide, and producing an effluent containing saturated alkanes, (g) subjecting the effluent containing saturated alkanes to liquid-liquid extraction to separate the selected substantially styrene-, methylstyrene- and ethylbenzene-free C6-C9 aromatic hydrocarbon product blend.