Optimized torrefaction of municipal solid waste for enhanced energy recovery
Rahul Raj, Siddharth Jain, Amit Kumar Sharma
Abstract
Municipal solid waste (MSW) management continues to pose significant challenges, driven by rising generation rates and their environmental consequences. This study presents an innovative approach to improve the energy potential of MSW by blending it with rice husk and applying torrefaction, a thermal pre-treatment that produces high-quality solid biofuels. This study diverges from earlier research by examining heterogeneous MSW-RH blends torrefied at temperatures ranging from 200 °C to 300 °C for durations of 30–60 min, incorporating process optimization through response surface methodology (RSM). The optimized conditions (290 °C, 30 min, 90% MSW) led to a significant enhancement in the higher heating value, reaching 16.53 MJ/kg. Additionally, the fixed carbon content increased from 18.5% to 42.8%, while volatile matter was reduced. Thermogravimetric analysis demonstrated enhanced thermal stability, and the energy return on investment (EROI) was recorded at 7.96, underscoring significant energy efficiency. A global warming potential (GWP) assessment showed a 73.2% reduction in CO2 emissions when compared to untreated MSW. The present study represents one of the initial efforts to show the practicality of torrefying MSW-RH blends for decentralized waste-to-energy systems. It advances circular economy objectives by minimizing reliance on landfills, facilitating resource recovery, and generating scalable, renewable fuel alternatives. .