Control of an azeotropic distillation process for anhydrous ethanol production

The capabilities and suitability of the Aspen Plus® modular simulator to treat the problem of complex chemical processes control is investigated. A case study is illustrated for the simulation and control of an azeotropic heterogeneous distillation process to produce anhydrous ethanol. The study is structured in three stages. Firstly, a flow diagram of the major equipment items of the process is constructed in Aspen Plus™ to support the steady state simulation and to generate a sensitivity analysis. In a second stage, a literature based control scheme is reproduced using the Aspen Dynamics™ software, as a basis for dynamic simulation. Finally, an intelligent control is designed to replace two PI controllers form the literature scheme. A normalized Mamdani-type fuzzy control system was developed within the Custom Modeler™ environment to build up a modified control arrangement, attaining from 99.55 to 99.62% purity of ethanol.