Study Of Separation For The Binary Systems Of Cyclohexanol And Cyclohexanone By Extraction Rectification

Cyclohexanone is an important intermediate product of caprolactam and adipic acid in industry. Catalytic dehydrogenation of cyclohexanol to cyclohexanone, which is an important industrial reaction for the manufacture of caprolactam, which is used as a material for synthesis of nylon. Catalytic dehydrogenation of cyclohexanol to cyclohexanone was pilot studied by Cu-Zr catalyzer. The yield of cyclohexanone can be reached to 80% and the selectivity is nearly 100%. The production is admixture of cyclohexanol and cyclohexanone whether catalytic dehydrogenation of cyclohexanol to cyclohexanone or oxidation of cyclohexane, which should be separated.The admixture was studied by extraction rectification. First, The solvent was selected by extraction solvent qualitative rule; Second, The relative volatility (Ternary Systems) was calculated by mend UNIFAC model; Finally, the diglycol was selected by extraction rectification.The atmospheric vapor-liquid equilibrium data of the binary systems cyclohexanol- cyclohexanone, cyclohexanone-diglycol and cyclohexanol-diglycol were measured with a ROSE cell. Integral test was adopted to test the thermodynamics consistency. The fugacity coefficient of vapor phases was calculated by the modified Peng-Robinson equation. The activity coefficient of the liquid phases was calculated by Wilson equation and NRTL equation and satisfactory correlation results of these experimental data were obtained. The relative deviation between the experimental data and the results of model computation for binary system was under 3%, the relative deviation between the experimental data and the results of model computation for ternary system was under 4%.Solvent was selected using a decompression rectification and extraction rectification experiments indicate that the mixture can be separated, the quality of products can meet the requirements. In the same conditions, the theoretical numbers of plates were calculated by using the Wilson equation and NRTL equation. When using decompression rectify, its number of plates were 15 under the operating pressure 4 kPa, with the value of literature at the same; the number of plates were 36 under the operating pressure 15 kPa. When using extraction rectify, the number of plates were 39, the follow-up numbers were 11. When using decompression extraction rectify, the number of plates were 18 under operating pressure 15 kPa, the follow-up numbers were 11.