Patent ID: 7326823

Claim:
In a method for recovering at least one target aromatic compound from a mixture of aromatic and non-aromatic compounds using a solvent extraction system process under operating parameters such that a solvent is employed to absorb said aromatics and produce an aromatic extract that contains primarily aromatics with minor amounts of non-aromatic impurities, said target aromatic compound being subsequently separated by distillation from said aromatic extract to form a first aromatic product that contains primarily said target aromatic compound and minor amounts of said non-aromatic impurities, said non-aromatic impurities being required to be present in said first aromatic product in amounts less than a predetermined maximum specification, the improvement comprising compositionally analyzing said aromatic extract to determine at least two separate groups of lighter and heavier boiling non-aromatics, the first group of said at least two separate groups having lighter boiling points that start with the lowest boiling point non-aromatic present in said extract, the second group of said at least two separate groups having non-aromatic boiling points higher than said first group, determining the distribution of lighter and heavier non-aromatics between said at least two groups, and adjusting said operating parameters so that said first aromatic product has a non-aromatic impurity content that is nearer to its predetermined maximum specification.