PERFORMANCE OF ORGANIC RANKINE CYCLE SYSTEM IN COMBINATION WITH RESIDUAL MUNICIPAL SOLID WASTE GASIFICATION: A SIMULATION ANALYSIS

Abstract

Despite recycling is largely adopted in Europe, the amount of disposed municipal solid waste (MSW) from mechanical-biological treatment is increasing. At the same time, more environmentally friendly waste-to-energy (WtE) solutions are needed to promote sustainable management of residual MSW (RMSW) compared to incineration, which is the most common process to valorise MSW. Among the waste-to-energy solutions, gasification is considered a promising option and nowadays attention is paid to the use of residual MSW as feedstock. In addition, organic Rankine cycle (ORC) systems are one of the most suitable technologies to produce electricity from low-grade energy sources such as that obtained from the gasification of residual MSW. Therefore, in this work, a RMSW air gasifier in combination with an ORC unit are investigated using Aspen Plus for combined heat and power (CHP) applications. The simulation analysis is performed considering the potential syngas production from RMSW of a real composting facility in Italy. Three different working fluids are investigated to assess the energy performance of the integrated system for CHP production in district heating networks. The analysis reports an overall conversion efficiency of the integrated system in the range 38.4% - 48.5% and a maximum power production of the ORC unit of 2.14 MWe with the use of toluene. Therefore, the present study shows that the gasification of RMSW and the exploitation of its energy content in an ORC system is a viable option to reduce the environmental burden in compositing facilities by extending the lifetime of the landfills.