Otimização energética e econômica de configurações convencionais e termicamente acopladas da destilação extrativa.

Abstract

Extractive distillation is one of the most important procedures for the separation of azeotropic mixtures in the chemical industry, but it is a relatively expensive method, given its high energy demand. The limitations of this operation has been stimulating for decades, studies on alternatives to minimize them. The intensification process through thermal coupling between distillation columns is an option that has been receiving increasing attention, considering the good results that papers published in this area have shown. But recently some researchers presented findings that go against all efficiency credited to the thermal coupling, which makes it even more necessary studies about this technology. Due to such differences, questions arise regarding the most appropriate method for implementing a distillation system thermally coupled, as observed employing various methods in the attempt at achieving a design for those configurations that impact is not always the best alternative. This paper described a procedure for obtaining the optimal design of conventional distillation sequences (CS) and thermally coupled (TCS), in addition to obtaining the optimum operating based on the optimization method developed by Figueiredo et al. (2015). The methodology was applied to the simulation of two systems, acetone-methanol-water (M1) and acetone-methanol-DMSO (M2), and their results were compared in terms of TAC and SEC with literature. The application of the optimization procedure resulted in reductions of 30% and 15% of the TAC of the CS and TCS configurations, respectively, when compared with the literature, proving its efficiency. Futhermore, the use of different solvents has allowed us to reach the conclusion that not always the thermal coupling is the best option.