Patent ID: 6617483
Filing Date: 2003-09-09
Classification: C07C,C10G

Abstract:
A process for separating hydrocarbon compounds of similar boiling points by extractive distillation, comprising the steps of:a. contacting a feed mixture with an extractive distillation composition within an extractive distillation zone, wherein the feed mixture comprises at least i. a first hydrocarbon compound, and ii. a second hydrocarbon compound; and b. distilling the feed mixture 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; and wherein the extractive distillation composition comprises, i. at least one akylene glycol compound, and ii. at least one compatibility agent, wherein the at least one compatibility agent is selected from materials (1) having a Hansen's Solubility Polar Parameter from about 2.7 to about 6.4 (calories/cm3)Â½, and a Hansen's Solubility Hydrogen Bonding Parameter from about 1.0 to about 4.4 (calories/cm3)Â½; (2) having a boiling point higher than the boiling point of the mixture of hydrocarbon compounds; and (3) does not comprise (a) an N-hydrocarbyl-substituted pyrrolidone compound or residue, or an N-hydrocarbyl-substituted-2-thiopyrrolidone compound or residue, or (b) a polyalkyleneglycol ether compound of the formula: R4Oâ€”[CHR5â€”(CHR6)xâ€”O]yâ€”R7 wherein R4, R5, R6 and R7 may be hydrogen alkyl, aryl, aralkyl, alkylaryl and mixtures thereof, and wherein R4 or R7 are not both hydrogen.