Energy efficient design of bio-butanol purification process from acetone butanol ethanol fermentation

Butanol has the potential as a transportation fuel since its energy density is similar to gasoline and higher than ethanol. The Acetone-Butanol-Ethanol (ABE) fermentation is the current main method to produce biobutanol where the fermentation should be operated in diluted surroundings to avoid toxicity to microorganisms. This article aims to develop efficient separation sequences to purify individual components from the ABE fermentation. The base design comes from the reference proposed by Patrascu et al. [3]. With an updated thermodynamic model, several novel design alternatives are proposed and investigated to reduce energy consumption in the separation sequences. Therein, the proposal of removing acetone at first, and purifying ethanol via integration of distillation and membrace not only reduces total energy consumption and total annual cost by 57% and 52%, but also reaches targeting purity of 99.5% for butanol, acetone and ethanol. Heat integration and column stacking can reduce the overall energy consumption furthermore. This study also carries on plantwide control for the processes with heat integration and column stacking. The superior control performance with +/- 10% changes in throughput and feed compositions is validated for the proposed plantwide process control scheme. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This article focuses on developing efficient separation sequences for purifying individual components from ABE fermentation, aiming to reduce energy consumption and achieve target purities. The proposed design alternatives, including the removal of acetone, integration of distillation and membrane for ethanol purification, heat integration, and column stacking, significantly reduce energy consumption and costs while maintaining target purities. Furthermore, a plantwide control scheme is validated for the integrated processes.