Measurement of activity coefficients at infinite dilution using gas-liquid chromatography. 7. Results for various solutes with N-methyl-2-piperidone as stationary phase

Activity coefficients at infinite dilution provide a useful tool for the selection of solvents for extractive distillation or extraction. In this work activity coefficients at infinite dilution are reported for 36 solutes (alkanes, alkenes, alcohols, ketones, aromatic hydrocarbons, cyclic hydrocarbons, aldehydes, ethers, esters, halocarbons, and acetonitrile) in N-methyl-2-piperidone at three temperatures (303.41, 313.43, and 323.45) K, measured with the help of gas-liquid chromatography. The experimental data are compared with data from literature and with the results of the modified UNIFAC (Dortmund) method. Furthermore the selectivity of N-methyl-2-piperidone for the separation of hexane from benzene was compared with the selectivity of N-methyl-2-pyrrolidone and N-methyl-6-caprolactam. The observed temperature dependence of the activity coefficients at infinite dilution is confirmed using excess enthalpy data predicted with modified UNIFAC (Dortmund).