Design and Control of Heterogeneous Reactive Distillation Process for Cyclohexanol Synthesis

In the industrial market, Nylon 6, 6 is an important product and its production rate has reached 1.1 million tons per year by 1999. On the other hand, cyclohexanol has been used as a precursor in the synthesis of intermediates of Nylon 6, 6, i.e. the adipic acid and ε-caprolactam. An “Asahi process” to produce cyclohexanol from benzene by consecutive hydrogenation and one-step hydration steps has been commercialized since 1986. However, the one-step hydration step suffering from very low reaction rate and conversion is the bottleneck in the process. As a result, it is desirable to enhance this hydration step for better production. In this thesis, it is aimed to study the design and control of such a hydration step by employing reactive distillation. Moreover, the possibility of using reactive distillation in alternative two-step reactions is also studied in this thesis and a novel configuration, a two reaction zone in one reactive distillation column, is proposed.