Unlocking the potential of municipal solid waste: Emergy accounting applied in a novel biorefinery

The rampant municipal solid waste (MSW) generation caused mainly by people's lifestyle has required technological solutions to deal with this global issue. This paper assess an innovative and integrated biorefinery (2IB) to manage MSW. The 2IB is rooted in the circular economy concept, and it differs from any other currently existing technological route in managing MSW due to its integrated processes that receives both inorganic and organic fractions at the same time, besides unveiling an innovative aspect related to thermoplastic production. Due to its scientific-based advantages, the emergy accounting (withy 'm') is considered as method to quantify the 2IB environmental performance, comparing the results with alternatives MSW management facilities. Results show that 2IB has similar performance for the three traditional emergy indicators (m-EYR of 1.17, m-ELR of 5.73 and m-ESI of 0.20) compared to incineration and landfilling, indicating low yield, moderate load on the environment, and unsustainable. On the other hand, the emergy return indicator (ERI of 20.33) indicates higher performance for the 2IB, in which for each solar emjoule (sej) - the measure unit of emergy - invested it generates a return of about 20 sej that becomes available as benefits for societal development. From an emergy perspective, results support that 2IB should be considered as a powerful technological alternative to manage MSW. This study contributes from a theoretical perspective with discussions on the emergy accounting procedures applied on systems located at far right side of energy hierarchy, while contributing from a practical perspective by providing technical information about the 2IB that supports decision makers towards more sustainable MSW management systems.