SEPARATING STYRENE FROM C6 - C8 AROMATIC HYDROCARBONS

摘要

The invention disclosed relates to a process for refining a hydrocarbon feed to make substantially styrene-free C6-C8 aromatic hydrocarbons (BTX). The hydrocarbon feed, for example, unhydrotreated pyrolysis gasoline, is distilled to make a BTX rich stream containing styrene which is fractionated to separate C6 and C7 hydrocarbons from C8 hydrocarbons including styrene. Styrene in the C8 hydrocarbons reacts in the presence of a selective etherification catalyst with a C1-C3 lower alkyl alcohol to form the corresponding styrene ether, which is then separated by distillation into a styrene ether stream and a C8 hydrocarbons rich stream. The C8 hydrocarbons rich stream is then re-mixed with the C6 and C7 hydrocarbons, and sent to hydrogenation reactors to remove sulphur and olefinic hydrocarbons to form substantially styrene-free BTX.