Sustainable design and optimization of the recovery process of acetic acid from vinasse: Operational, economic, and environmental analysis

Acetic acid production through biological routes has gain attention as an alternative to catalytic processes and, currently, 10% of the world production come from biological processes. It is a by-product of ethanol production through fermentation, but its recovery faces challenges such as high-water content and the presence of other organic acids. Therefore, the aim of the present work is to develop the optimal design of the recovery process of acetic acid from vinasse through liquid-liquid extraction followed by heterogeneous azeotropic distillation. Three configurations were evaluated: Conventional (CONV); Full-Heat Integrated (FHINT); and Mechanical Vapor Recompression (MVR). The total annual cost (TAC) was optimized using the genetic algorithms method. The MVR configuration presents the lowest TAC, but the capital cost of this process is high when compared to the other configurations. The CONV configuration, even with the lowest CAPEX, does not present good economic and environmental indicators. The FHINT configuration had intermediate OPEX, and slightly higher CAPEX compared to the CONV configuration. If payback is not a decisive factor, the MVR configuration is the most suitable due to its excellent operational and environmental indicators; but if so, the FHINT configuration is more suitable due to its lower CAPEX.

Automated summary

This study aimed to optimize the recovery process of acetic acid from vinasse through liquid-liquid extraction and heterogeneous azeotropic distillation. Results showed that the MVR configuration had the lowest total annual cost (TAC), but high capital cost; the CONV configuration had the lowest CAPEX but poor economic and environmental indicators; the FHINT configuration had intermediate OPEX and slightly higher CAPEX compared to the CONV configuration.