Aromatic extraction process using mixed polyalkylene glycols/glycol ether solvents
Patent 4781820 Issued on November 1, 1988. Estimated Expiration Date: July 9, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
This invention relates to an improved more energy efficient process for the separation of aromatic and non-aromatic hydrocarbons from a mixed carbon feed which comprises the following steps:(a) contacting said feed in an extraction zone with an extraction solvent to provide an aromatic-rich solvent phase and a raffinate phase;(b) cooling said aromatic-rich solvent and raffinate phases;(c) introducing said cooled aromatic-rich solvent phase to a separation zone containing aromatic hydrocarbons and a solvent-rich phase containing mixed extraction solvent and water;(d) introducing said cooled raffinate phase to a separation zone in the presence of water as based on the total weight of water and the raffinate phase to provide a raffinate phase containing non-aromatic hydrocarbons and a solvent/water phase;(e) adjusting the water present in the solvent-rich phase of step (c) and the solvent/water phase of step (d);(f) recycling at least or portion the phases in step (e) to step (a);(g) separately contacting the raffinate of step (d) and the extract of step (c) with water to form two water phases and a raffinate product and an extract product;(h) combining the water phases of step (g);(i) recycling at least a portion of the combined water phase of step (h) to step (d).