ETBE synthesis via reactive distillation .2. Dynamic simulation and control aspects

Ethyl tert-butyl ether (ETBE) is growing in importance as a gasoline oxygenate and octane enhancer. Its gasoline blending properties are superior to methyl tert-butyl ether (MTBE), and its semirenewability is attracting subsidies from many governments. Synthesis of ETBE via reactive distillation offers advantages of higher conversion, improved energy efficiency, and lower capital costs. A dynamic simulation, based on the MESH equations with supplementary equations to model the main chemical reaction, was developed using SpeedUp. The simulations were then utilized for the study of transient open-loop responses and for control system design. The control of a reactive distillation column presents several difficulties not normally associated with distillation, and dynamic simulation proved to be the ideal tool for the study and resolution of these problems. Some general recommendations for the control of reactive ETBE columns are made, including the need to address control issues early in the design process to recognize implications on process equipment design.