A review on the separation of benzene/cyclohexane mixtures by pervaporation processes

Separation of benzene (Bz) and cyclohexane (Chx) is one of the most challenging processes in the chemical industry. On account of the only 0.6°C difference in volatilities of the two components, conventional distillation processes are not practical. Azeotropic distillation and extractive distillation, on the other hand, although feasible and in use in many industries, are accompanied by high capital and operating costs and also are complex processes in nature. Membrane pervaporation (PV) is a viable alternative to the conventional techniques both from economical and technical points of view. While extractive distillation/PV hybrid has attracted industrial attention, progresses in PV separation of Bz/Chx suggest that this technique can handle a greater share in the process. In this paper, an extensive review is presented on the properties, production, conventional and alternative separation processes of benzene and cyclohexane. Special emphasis is given to the performance of membrane PV processes.