Thermal modelling and analysis of a novel solar integrated waste-to-energy plant for sustainable society

Abstract

Waste-to-energy incineration is an effective and sustainable solution to reduce produced waste and simultaneously generates electricity utilizing thermal energy. The waste-to-electrical efficiency of conventional incineration plants is limited to 20–25% due to the higher amount of moisture content in the feedstock and flue gas heat losses. In addition, tubes of the incineration boiler are subjected to corrosion problems at elevated temperatures. In the present research, a parabolic trough solar-integrated municipal solid waste power plant is proposed and thermodynamically evaluated for different useful outputs. The solar energy is harvested through parabolic trough collectors to reheat the working fluid of the incineration plant to increase the steam temperature before it is fed to the low-pressure turbine. Meanwhile, a single-effect absorption chiller is integrated to utilize the thermal energy of the trough collectors for cooling purposes. In addition, the thermal energy of flue gas is used to power an organic Rankine cycle that further drives a proton exchange membrane and reverse osmosis desalination unit for hydrogen and freshwater production, respectively. In this way, the steam temperature for reheating the low-pressure turbine is increased to further improve the performance of the proposed solar-integrated waste-to-energy plant without causing any corrosion problems to the incineration boiler. The integrated facility is thermodynamically analyzed based on a 560-tons/day incineration plant using the engineering equation solver (EES) software. The results indicate that the overall energy and exergy efficiencies of the proposed plant are 32.51% and 23.7%, respectively, while the coefficient of performance of the absorption chiller is 0.849. Moreover, it is concluded that the produced desalinated water and hydrogen rates are 23.96 kg/s and 0.000857 kg/s, respectively.