Análise da viabilidade econômica do sistema de recompressão mecânica do vapor para produção do etanol hidratado.

Abstract

Distillation is a great user of energy and this represents a good part of the capital and operacional costs in the chemicals and petrochemicals industries. The use of a heat-pump in distillation process is a way to reduce the operacional cost due to the economy of energy from the process despite the adicional apport be greater. The objective of is this study is to verify the economic viability of the system of distillation with mechanic recompression of vapor for separation of the mixture ethanol-water with tax and time of return on additional investment as objective function. The study, divided in three parts, used for simulation of the systems with commercial simulator (HYSIM version C2.54). In the first stage, a conventional distillation unit is simulated and an evaluation of the costs done, aiming at to establish excellent conditions of operation. An adapted distillation system with a direct recompression vapor heatpump is simulate in the second stage, with an economic evaluation, comparing the results with those of a convencional distillation system operating at 1,5 atm. Fially, the effect of the pressure drop through the distillation column is investigated. In that condition, the results shows the use of a vapor recompression scheme is not economically attractive , the return on investment beeing 7.0% per year. Changing the pressure for 1,2 atm, the return on investment increases to 14% per year. This results shows the sensibility of the project regarding the pressure and how much its reduction turns available the heat-pump scheme.