LAUSR

Abstract In this research, a conventional waste-to-energy plant is redesigned to enhance power generation while mitigating CO2 emissions. Accordingly, 65% of CO2 emitted is injected into the gasifier after being separated in the membrane separator to trigger the gasification via a mixture of air/CO2. The redesigned system is evaluated and compared to the traditional waste-to-energy plant with respect to thermodynamics and exergoeconomic standpoints. Afterward, the waste-to-energy plant is optimised by tri-objective grey wolf optimisation to optimise conflicting objective functions; subsequently, four Pareto frontiers are presented to provide a trade-off between the objective functions. The outcomes reveal higher first and second law efficiencies for the proposed waste-to-energy plant compared to the conventional waste-to-energy system up to 6% and 3%, respectively. The optimisation results indicate that levelised CO2 emissions of the proposed waste-to-energy plant are 35% lower than the conventional waste-to-energy system while net power output can be 22% higher if the proposed system operates on the conditions achieved by the TOPSIS scheme. The second law efficiency, levelised emissions, total specific cost/cost rate at the final optimum solution are 17%, 1.7 t/MWh, 31.2 US$/GJ, and 445.6 US$/h. Meanwhile, the payback period of the proposed system is lower than the conventional waste-to-energy system in almost all economic scenarios.