Economic and energy evaluation of in situ recovery of butanol by applying a cyclic vacuum in a multi-fed batch reactor

Abstract

In this work, butanol production by fermentation using a cyclic vacuum and multi fed-batch operations was evaluated through a process simulation strategy. The saccharification of the substrate, corn stover, was simulated in an integrated reactor with fermentation and in situ product recovery. Optimizations were carried out to achieve as objectives the maximum economic potential and the minimum electricity requirements of the heat-pump system needed for energy integration. Multi-objective optimizations were performed in MATLAB®. It was found that a cyclic vacuum was not required to achieve the maximum economic potential and that a multi-fed batch operating strategy is enough to obtain the maximum economic potential. Using these strategies, the electricity requirements were decreased by 5% and the economic potential was increased by 9% (~4 MM USD/year) when compared to a fed-batch reactor with in situ recovery using only one feed.