Life cycle assessment-based optimization approaches for sustainable disposal of municipal solid waste

Abstract

Increasing municipal solid waste (MSW) has caused severe environmental pollution and social problems, which require effective treatment and resource utilization. Therefore, combined with advanced sustainable gasification technology, a classified MSW collection, transportation, and treatment process was established in this study. To optimize MSW management, a mathematical multi-objective model was established to optimize the revenue from the value-added energy electricity products and control greenhouse gas (GHG) emission. Life cycle assessment (LCA) was introduced into the objective evaluation to quantitatively evaluate the environmental greenhouse effect caused by gasification technology. Then, to further explore regional variations in gasification implementation, four practical case studies were presented to demonstrate the applicability and efficiency of the proposed model in selecting the disposal processes, determining volumes, generating income, and controlling GHG emissions. The sensitivity analysis of the gasification ratio (GR) in different cases shows that an increase in GR will improve economic benefits and reduce GHG emissions. In addition, the optimal GR varies in countries; for example, it was 0.6–0.7 in China, 0.9 in the USA, 0.6–0.8 in the UK and Japan. Therefore, a practical and effective management method for MSW gasification based on LCA is proposed, which can assist in the development of targeted, valid emission reduction measures for MSW gasification to reduce the environmental impact and provide practical guidance for the MSW gasification implementation. • A multi-objective model was built to optimize sustainable MSW gasification system. • Life cycle assessment is validly applied to the normalized evaluation of environmental objective. • The balance between economic and environmental benefits was achieved. • Different technical configurations can be set up to adapt to more real and universal situations. • Practical guidance is provided in sustainable MSW management from real life case.