Performance Optimization and Environmental Benefits of Biomass-Fueled Organic Rankine Cycles Using Nano-Enhanced Working Fluids.

Biomass-fueled Organic Rankine Cycles (ORCs) provide a sustainable pathway for power generation from renewable heat sources. This study examines three conventional working fluids—R245fa, Pentane, and Toluene—alongside two nano-enhanced blends—TiO₂/Toluene and Al₂O₃/R245fa. The objective was to evaluate thermodynamic performance, operational flexibility, and environmental impact under biomass combustion conditions. Results demonstrate that Toluene achieves the highest thermal (~23%) and exergy (~21%) efficiencies, with net power exceeding 1000 kW at optimal turbine inlet temperatures. Nano-enhanced fluids improved efficiencies by 10–12% at optimal nanoparticle loadings (0.03–0.05% vol). Environmental analysis revealed CO₂ reductions of ~2.1–2.3 t/year for conventional fluids and up to 3.0 t/year for TiO₂/Toluene. These findings align with recent research emphasizing fluid selection, nanoparticle enhancement, and biomass integration in ORC systems.