Multi-Objective Optimization of ETBE Intensified Processes Considering Economic, Environmental, and Inherent Safety Aspects

Process intensification has gained significant importance during the last few years because of its potential to develop innovative structures with improved energy efficiency and better economics. One approach that has been developed in this field is the transformation of a process flowsheet with a series of conventional units into another one with minimal pieces of equipment. In this work we consider a base process to produce ethyl tert-butyl ether, which consists of a reactor and an isobaric distillation sequence. Given a set of design options provided by the gradual intensification of any processes that contain a dividing wall, reactive distillation, or reactive dividing wall columns, we take those intensified structures and make them subject to a multi-objective optimization task. The formulation consists of the minimization of the combination of economic, environmental, and inherent safety components. Different policies are simulated through weights assigned to each of those components. It is shown that the optimal structure depends on the priorities given to each term of the multi-objective formulation, and that the application of the optimization procedure further improves the economic and environmental potential provided by the base, fully intensified process, with reductions of up to 27.9 and 6.2 percent in those metrics.