Potentialities of biotechnological recovery of methane, hydrogen and carboxylic acids from agro-industrial wastewaters

Abstract

This paper aimed to explore the anaerobic resource conversion from some agro-industrial wastewaters (AWWs) employing three biorefinery platforms (methane, hydrogen, and carboxylic acids). Additionally, it presents the reported quantitative and qualitative characterization of AWWs, bioproduct conversion yields, by which it was possible to estimate the gross value added of the by-products. The studied AWWs showed to have excellent economic potentials for resource recovery, in which the CA platform seems to be more economically advantageous, especially when a chain elongation process is considered. However, the traditional anaerobic digestion is simpler in terms of process control, and methane purification is usually easier and cheaper. Because of the low yields achieved, it seems that hydrogen production is the least attractive technological route. Therefore, it is necessary to analyze other factors such as the gross value-added, consolidation of the production and recovery techniques, among others, to adopt the best choice of resource recovery platform.