Patent ID: 8722952

Claim:
A process for production of gasoline having a benzene content of less than about 0.4 weight % comprising: a) combining in an extractive distillation (ED) column equipped with a re-boiler (a) a pre-heated feed material consisting of benzene concentrated unprocessed catalytically cracked gasoline fraction obtained from a fluidized catalytic cracking unit of a petroleum refinery without any pre-treatment, wherein the gasoline fraction contains impurities, 10-30 weight % benzene, and 70-90 weight % close-boiling non-aromatic hydrocarbons, and the impurities comprise one or more of metals at a level not exceeding 1 ppb, 1-400 ppm oxygenates, 0.1-3 ppm chlorides, 100-700 ppm sulphur, 0.6-14 ppm nitrogen, and organic peroxides at a peroxide level of 20-50 millimoles/liter; and (b) a pre-heated solvent mixture comprising an aromatic selective solvent selected from the group consisting of N-Methyl-2-Pyrrolidone (NMP), N-Formyl-Morpholine (NFM) and Di-Methyl-Formamide (DMF) and a co-solvent at a solvent mixture to feed material weight ratio of from about 1 to about 10, and wherein the feed material is introduced into the ED column at its middle section and the solvent mixture is introduced into the column at its top section; b) maintaining the ED re-boiler temperature in the range of about 140° C. to about 185° C.; c) recovering a raffinate phase containing gasoline having a benzene content of less than 0.4 weight % from the top of the ED column and an extract phase containing benzene and solvent mixture from the bottom of the ED column; and d) separating the solvent mixture from the extract phase in a Solvent Recovery Column (SRC) to obtain benzene free solvent from the bottom and benzene having a purity of greater than 97 weight % from the SRC top.