Thermodynamic analysis and multi-criteria optimization of a waste-to-energy plant integrated with thermoelectric generator

A new integrated energy plant is suggested and studied in the current research, aiming at enhancing the exergetic efficiency and minimizing the total product cost of a waste-to-energy (WTE) plant. For the integration, the condenser of the WTE plant is substituted with a thermoelectric generator. Accordingly, the conventional and integrated energy systems are studied comprehensively from energy, exergy, exergoeconomic, and environmental viewpoints and compared together. The parametric study indicated that the proposed system has important advantages over the conventional WTE plant, demonstrating higher exergy efficiency, higher power output, lower total product cost, and lower CO2 emission. In addition, the suggested integrated model is optimized using a multi-criteria optimization (MCO) approach with a specific MATLAB program. The MCO analysis for the best operating point reveals an exergetic efficiency of 17.22% and total cost rate of 184.2 $/h. Furthermore, investigating the scatter distribution of the effective parameters demonstrates that the TEG inlet pressure and figure of merit are the most sensitive parameters and should be kept at their lowest value. It can be concluded that the proposed integration would improve the performance of WTE plants while reducing the total product cost and levelized CO2 emissions.