Assessment of the energy recovery potential of municipal solid waste under future scenarios

Rules on separate collection and recycling of municipal solid waste (MSW) can have a significant impact on the waste-to-energy (WTE) industry. Understanding the future energy recovery potential of MSW is therefore paramount to establish the role of WTE technologies in waste management plans. In this study we applied material flow analysis (MFA) to systematically quantify the energy recovery potential of MSW under plausible scenarios for 2030. These scenarios describe structural changes that are expected to affect the energy recovery potential, such as the increase in the separate collection rates and the implementation of more efficient material recovery facilities (MRFs). The assessment was performed for Madrid, Spain, as a case study. The results reveal that the gross energy recovery potential of MSW, i.e. the maximum amount of energy that could be obtained, is likely to decrease in the future mainly due to a higher diversion of plastic, paper, and cardboard to recycling. The gross energy recovery potential of the MSW generated in Madrid by 2030 ranges from 4,963 to 6,984 TJ year⁻¹ according to the scenarios defined in this study. This means a decrease of 34 – 7% compared with 2017. However, the waste streams susceptible to energy recovery –organic waste streams and MRFs’ rejects– account for 48 – 60% of the MSW generated under the 2030 scenarios. Furthermore, the electricity generation potential could increase between 8 and 55% by 2030 with respect to 2017 if more efficient incineration and/or gasification facilities are implemented. All in all, our findings clearly suggest that recycling targets do not necessarily compromise energy recovery.