ABSTRACT
Biomethanation is an established method for food waste treatment and concomitant energy recovery as biogas. During the biochemical process of biomethanation, products such as alcohols, solvents, lactate, and fatty acids are formed, which are collectively called total soluble products (TSPs). Maintaining optimal TSP concentration enhances process control and biomethane production. The most promising and cost-effective method for recovery of TSPs, including volatile fatty acid (VFA), is adsorption using polymeric ion exchange resins, such as amberlite, lewatit, purolite, amberlyst, and conductive materials like activated carbon. When unprotonated, the carboxyl group has a negative charge that allows ionic bonding with a positively charged functional group on the resin. Purified VFAs are obtained from resins using extractants and downstream processed to produce value-added products. Timely recovery of targeted TSPs prevents acidification and provides optimal pH for methanogens, leading to enhanced biomethane production. Subsequently, a biorefinery can be developed from the TSPs extracted, generating a circular economy for sustainable development.
