Synergistic fermenter-electrolytic cell integration and phenomena-based process intensification for competitive bio-succinic acid production

The production of bio-succinic acid through fermentation presents a promising strategy for obtaining building-block chemicals from renewable sources. However, the limited yield of bio-succinic acid from fermentation and the complex purification procedures have hindered its competitiveness against petroleum-based succinic acid. One way to tackle this challenge is to develop a more efficient and sustainable production route, that is to integrate process synthesis with process intensification. In the present study, an existing flowsheet from our previous work based on process synthesis on bio-succinic acid batch fermentation was selected and subjected to heuristic and phenomena-based process intensification approaches. The heuristic approach involved integrating an electrolytic cell with the fermenter, employing an anionic exchange membrane for continuous extraction of organic acids. The resulting modified process flowsheet served as a base case for a systematic phenomena-based process intensification approach. Through this approach, intensified unit operations, such as an electro-membrane reactor and a membrane crystallizer, were generated. A total of 114 intensified process flowsheet alternatives were developed and ranked according to an enthalpy index. The top-ranked alternatives were evaluated in terms of economic performance and environmental impact. Notably, all analyzed process flowsheets exhibited improved indicators, with a minimum selling price below that of petroleum-based succinic acid (approximately $2kg^-1).