CYCLOHEXANE ISOLATION PROCESS Russian patent published in 2004 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: invention relates to isolation of cyclohexane from reaction mixture of cyclohexanone and cyclohexanol synthesis and may find use in caprolactam production. According to invention, cyclohexane isolation is accomplished by rectification in two in-series arranged columns. From the top of the first column, gases, water, and a part of unreacted cyclohexane are withdrawn, while partially concentrated fraction of reaction products is tapped from still at 75-120 C. In the process proposed, boiling temperature in the still of the second column is lowered and thereby amount of vapors produced in vaporization of concentrated product is also reduced. Because of maintaining low concentration of reaction products in still, losses of cyclohexane in the first-column still are reduced so making milder conditions for isolation of reaction product fraction with minimum loss of cyclohexanone and minimum contamination of mixture with impurities, which are hard-to-separate from cyclohexanone and cyclohexanol. EFFECT: enhanced cyclohexane isolation efficiency. 3 dwg, 2 tbl, 4 ex