Process for benzene reduction and sulfur removal from fcc naphthas

Abstract

A process for the removal of sulfur compounds and benzene of a catalytically cracked petroleum naphtha comprising benzene, organic sulfur compounds and olefins, by fractionating the cracked naphtha into a relatively low boiling range, olefinic, light catalytic naphtha (LCN) and an olefinic heavy catalytic naphtha (HCN) which boils above the range of the LCN the boiling ranges of the LCN and the HCN being defined by a cut point selected to maintain most of the benzene in the cracked naphtha in the LCN together with olefins in the boiling range of the LCN. The LCN is subjected to an optional non-hydrogenative desulfurization step followed by a fixed bed alkylation step in which the benzene in the LCN is alkylated with the olefins contained in this fraction. The HCN is treated by a similar an alkylation step using the olefins contained in this fraction to alkylate the sulfur compounds, forming alkylated products which boil above the gasoline boiling range. The LCN and HCN are then fractionated to remove light ends and higher boiling sulfur reaction products (disulfides, alkylated thiophenes) boiling above the gasoline boiling range.