Performance analyses of a waste-to-energy multigeneration system incorporated with thermoelectric generators

Sustainable development and efficient utilization of resources are considered to be indispensable necessities of future energy systems. Waste-to-energy technology, due to the potential of energy production as well as waste disposal, can pave the way for a more sustainable future. In this study, a new multigeneration system with steam gasification is proposed for power, heating-cooling, and hydrogen production. The integrated energy system comprises a steam gasifier, organic Rankine, Brayton waste heat recovery, absorption refrigeration systems, hydrogen production, and domestic heating systems. Thermoelectric generators are employed for recovering the rejected heat from the condenser and absorber of the absorption chiller. By this modification, the power generation improves by an average of 12%. Consequently, the proposed scheme is investigated and assessed from energy-exergy viewpoints. A comprehensive parametric study is also done to investigate the effect of key design characteristics. According to the parametric study, the gasification temperature has the highest impact on the performance of the system. The energetic and exergetic efficiencies of the proposed system are calculated as 52.3% and 41.3%. In addition, the findings demonstrate that the steam gasification subsystem has the highest exergy destruction rate and, thus, the highest potential for improvement in exergy efficiency.