A review of carboxylate production and recovery from organic wastes

Petrochemically-derived platform chemical dependence is incompatible with decarbonisation targets, and the production rate of waste is increasing. Carboxylic acids are produced by fermenting organic waste; a process that also remediates the waste's environmental impacts. Biogas is the dominant product of industrial-scale waste fermentations however carboxylates are more economically valuable than biogas and are more sustainable. This has propagated interest in producing and recovering carboxylates over biogas. This review catalogues and normalises recent carboxylate production and recovery data, making the studies more readily comparable whilst identifying the gaps in the literature. It was found there is little consensus around the optimum production and recovery methodologies for carboxylates, with limited consideration of the economic and environmental implications of these processes. More work is needed, at pilot scale and larger, focussing on the carboxylate production and recovery methodologies most applicable to industry, and to establish a consensus around the optimisation of these processes.