Development of a Novel Catalytic Distillation Process for Cyclohexanol Production: Mini Plant Experiments and Complementary Process Simulations

Abstract

A new, two-step process concept for the production of cyclohexanol by indirect hydration of cyclohexene using formic acid as a reactive entrainer is suggested, and its principle technical feasibility is demonstrated. The first step of this process is based on an ester formation reaction of cyclohexene with formic acid. This reaction was carried out in a mini plant stainless steel catalytic distillation column of 2.35 m height. The column was packed with noncatalytic structured packings (SULZER-DX) and catalytic structured packings (KATAPAK-S). The experiments were conducted under low-pressure conditions (<0.6 bar) to avoid formic acid decomposition. Concentration and temperature profiles were obtained under steady-state conditions. Up to 98.3% conversion of cyclohexene and 75.5 mol % ester concentration in the bottom product of the column was obtained. In a similar manner, the second step of the process, i.e. the hydrolysis of the cyclohexyl formate formed in the first step, was investigated experimentall...