Integral valorization of residual biomass: Hydrogen, polyhydroxyalkanoates, and compost production

Abstract The growing demand for effective waste management strategies targeting a sustainable transition from a fossil fuel-based economy to a resource-efficient economy heightens the need for new biotechnological processes and innovations. Organic fraction of municipal solid waste (OFMSW) and sludge produced in wastewater treatment plants (WWTPs) are two organic streams offering a great opportunity for the production of bioenergy and value-added products. A biorefinery concept, in which biohydrogen is obtained through the dark fermentation (DF) process together with an acidogenic effluent rich in volatile fatty acids, which are valuable chemicals and a carbon source for the production of polyhydroxyalkanoate (PHA), could be a promising strategy. This chapter is intended to provide a general overview of the DF process of OFMSW and sludge for the production of bioenergy (bio-H2), PHA (bioplastic precursors), and compost in an integrated valorization process. The main operational parameters, the latest findings, and the challenges facing bio-H2 and PHA generation are addressed.