Chapter 8 - Energy and valuable organic products recovery from anaerobic processes

Abstract

Anaerobic processes which can recover energy and valuable organic products are crucial technologies of the “waste-to-resource” transition. Due to numerous advantages and versatility, these technologies have attracted considerable attention within the scientific community and practitioners. In this study, processes focusing on gaseous and liquid products recovery from different stages of anaerobic digestion are characterized. Processes aimed at the recovery of biogas containing methane are well known and successfully applied in wastewater treatment plants. In order to improve the energy balance, up to achieving energy neutrality or even excess energy production, anaerobic digestion can be enhanced by substrate pre-treatment, co-digestion of sewage sludge with organic waste or biogas upgrading into bio-methane. Organic waste has the potential to recover valuable liquid products, such as volatile fatty acids or medium chain carboxylic acids. Recovery of both energy in gaseous products and valuable organic liquid products is an appropriate approach for sustainable wastewater treatment and organic waste management.