Energy-environment-economy assessment of waste management systems from a life cycle perspective: Model development and case study

How to choose an energy-efficient, environmentally friendly and economically affordable municipal solid waste (MSW) management system has been a major challenge to be taken up by decision makers. Although life cycle assessment (LCA) has been widely used for the evaluation of energy consumption and environmental burden, the economic factor is not considered yet in LCA procedures. Thus, in the present study life cycle 2E (energy and environment) assessment is extended to a 3E (energy, environment, and economy) model. To evaluate economic performance, life cycle cost (LCC) is adjusted in accordance with LCA. Afterwards, multi-criteria decision making (MCDM) method is improved to integrate 3E factors. Besides, a two-step weight factor analysis is added, not only to test the robustness of the model, but also to adopt different preferences proposed by different stakeholder groups. This novel 3E model is then applied for the comparison of different MSW treatment technologies: (1) landfill; (2) landfill with biogas conversion to electricity; (3) incineration with energy recovery. Results show that incineration scores 0.944/1 and performs best among all scenarios; landfill with biogas to electricity, with final score 0.722/1, ranks second; and landfill without energy recovery (score: 0/1) is the worst choice. Furthermore, the weight factor analysis also shows a highly credibility of the results: when changing each factor's weight from 0 to 1, less than 30% of the cases exhibit the variation in ranking order; almost no change in ranking order occurs when considering the different perspectives from government, enterprise and residents.