Life cycle assessment of waste management from the Brazilian pig chain residues in two perspectives: Electricity and biomethane production

Abstract

The decarbonization of production chains has focused on a more sustainable future with minor damage to the environment and protection of natural resources through existing waste while promoting economic development. Adopting public policies has encouraged circular approaches such as the waste to energy (WtE). Anaerobic digestion (AD) has been the most studied WtE strategy to help to reach the objectives in the agriculture sector. The swine waste represents an essential source of energy that can be converted into biogas by this treatment. The multiplicity of uses of the AD product (biogas) is strongly related to the environmental viability of the adopted technology. Hence, this study evaluates the environmental viability of five treatment biogas plants using residues from Brazilian swine production through a life cycle assessment (LCA), comparing the generation of electricity and biomethane as critical paths to promote change in the national energy matrix and increase decarbonization in the agricultural sector. Based on the results, both strategies prove to be environmentally favourable for mitigating environmental impacts caused during waste handling. Electricity generation can mitigate 100% of greenhouse gas (GHG) emissions, while biomethane production mitigates up to 114% of GHG emissions. Furthermore, the configuration of biogas production plants proves to be an exciting strategy to assist the treatment of waste generated in the context of small productive properties, making the adoption of this treatment economically feasible.