Coupled succinic acid fermentation and biogas upgrading enabled by in situ product recovery

Biological CO₂-capture technologies, such as biogas upgrading, constitute essential tools toward decarbonization of the chemical and energy industries. Biological succinic acid production is one such process that naturally fixes CO₂ while producing an important platform chemical for the chemical and food industries. However, the high costs associated with biosuccinic acid production render it economically uncompetitive compared to petrochemically produced succinic acid. Here, we propose an integrated platform combining fermentation for succinic acid production from industrial waste streams with the successful upgrade of raw biogas from anaerobic digestion, which repurposes the process into a multi-product platform for increasing its economic viability. To reduce downstream separation costs, the fermentation process is also coupled with an in situ separation module that increases the performance of both the succinic acid fermentation and the biogas upgrade, reaching a CH₄ percentage of 93% in the final biogas and triggering a 32.5% increase in succinic acid production. Moreover, the use of the electrochemical module aids in the separation of succinic acid from the fermentation broth, resulting in 94.80% recovery of the succinic acid produced. All experiments were performed at semi-pilot scale.