Solvent extraction of hydrocarbon oils producing an increased yield of improved quality raffinate

摘要

The present invention is directed to an improved selective solvent extraction process wherein a hydrocarbon feed stream containing a mixture of aromatics and non-aromatics is contacted with an aromatics selective solvent in an extraction zone to produce an aromatics rich extract phase and an aromatics lean raffinate phase, water in a carefully controlled amount is added to the recovered extract phase resulting in the separation of the extract phase into a hydrocarbon rich pseudo- raffinate which is recycled to the extraction zone for processing with fresh feed and an increased yield of raffinate of higher quality than is obtained without pseudo-raffinate recycle.