Methods for enhanced aromatic extraction employing sulfone-sulfoxide compositions

A process for separating hydrocarbon compounds of similar volatility by extractive distillation, comprising the steps of:

• a. contacting a feed mixture with an extractive distillation composition, wherein the feed mixture comprises at least
• i. at least one first hydrocarbon compound, and
• ii. at least one second hydrocarbon compound;
• and
• b. distilling the feed mixture within an extractive distillation zone to at least partially separate the feed mixture into a first stream enriched in the first hydrocarbon compound, and a second stream enriched in the second hydrocarbon compound;
• wherein the extractive distillation composition comprises
• i. dimethyl sulfone, and
• ii. greater than about 21 percent by volume of dimethyl sulfoxide.

A process for separating hydrocarbon compounds of similar boiling points by extractive distillation, comprising the steps of:

• a. introducing a feed mixture into an extractive distillation zone having an upper portion and a lower portion, wherein the feed mixture comprises at least
• i. a first hydrocarbon compound comprising a C7-C10 aliphatic compound, and
• ii. a second hydrocarbon compound comprising benzene, toluene, ortho-xylene, meta-xylene, para-xylene, or a mixture thereof;
• and
• b. introducing an extractive distillation composition into the upper portion of the extractive distillation zone;
• and
• c. distilling the feed mixture to at least partially separate the feed mixture into a first stream rich in the first hydrocarbon compound, and a second stream rich in the second hydrocarbon compound;
• wherein the extractive distillation composition comprises:
• i. from about 25 to about 75 parts by weight of dimethylsulfoxide,
• ii. from about 25 to about 75 parts by weight of dimethylsulfone.