Envisioning the sustainability of bioenergy production from anaerobic digestion

Abstract

One of the main challenges of modern society is related to the provision of energy systems that cover its needs while preserving the environment. In this context, biogas is being promoted as a sustainable form of energy since it shares the principles of circular economy by converting wastes into several valuable products such as energy, water and nutrients. Life Cycle Assessment is considered an appropriate method for the quantification of the environmental consequences of biogas production. The objective of this doctoral thesis was to examine the environmental sustainability of different biogas systems (agricultural and sewage biogas) and to evaluate their suitability in accordance with the European energy objectives. The work developed in the thesis provided remarkable evidence of environmental benefits and impacts in different biogas systems to improve conventional biogas production through the application of measures that reduce derived impacts of biogas plants, to promote the implementation of innovative systems that integrates biogas production with digestate treatment and to identify methodological barriers in the application of LCA to biogas systems and discuss progress opportunities.