Patent ID: 9005405
Filing Date: 2015-04-14
Classification: B01D,C07C

Abstract:
1. A process for recovering high purity benzene from a feedstock containing aromatic hydrocarbons and non-aromatic hydrocarbons that comprises the steps of: (a) removing sulfur and nitrogen contaminants from the feedstock through a hydrodesulfurization (HDS) unit to yield a hydrotreated feedstock; (b) introducing the hydrotreated feedstock into in a distillation column to remove a heavy portion of the hydrotreated feedstock and to recover a C (c) introducing a lean solvent stream that is recycled from the bottom of a solvent recovery column (SRC) into an upper portion of the EDC as a selective solvent feed; (d) recovering a first non-aromatic hydrocarbon-rich stream from the top of the EDC and withdrawing a first solvent-rich stream containing the solvent and substantially all the benzene that was present in the C (e) introducing the first solvent-rich stream into a middle portion of the SRC and recovering an aromatic hydrocarbon stream consisting essentially of benzene and that is substantially free of the solvent and non-aromatic hydrocarbons from the top of the SRC and removing the lean solvent stream from the bottom of the SRC; (f) introducing the first non-aromatic hydrocarbon-rich stream from step (d) into a lower portion of a liquid-liquid extraction (LLE) column and introducing a slip stream from the lean solvent stream from step (c) into an upper portion of the LLE column as the solvent feed stream; and (g) recovering a second non-aromatic hydrocarbon-rich stream from the top of the LLE column as a raffinate product and removing a second solvent-rich stream from the bottom of the LLE column, which is recycled into the middle portion of the EDC wherein the LLE column is operated under conditions to achieve 0 to 2 wt % benzene in the second non-aromatic hydrocarbon-rich stream through extraction of benzene from the first non-aromatic hydrocarbon-rich stream which contains higher than 50 wt % benzene.