Energy, exergy and exergo-economic analysis of a novel HT-PEMFC based cogeneration system integrated with plasma gasification of food waste

Landfill and incineration of food waste would result in a significant waste of resources. Plasma gasification, as a novel solid waste treatment technology with cleaner product, is suitable for this perishable kitchen waste with high water and oil content. In present research, a food waste plasma gasification driven HT-PEMFC cogeneration system is proposed. Based on the established models, a comprehensive study is conducted from the perspective of energy, exergy and exergo-economy. Effects of key operational parameters on critical performance indicators are investigated. Results show that current density imposes an obvious effect on the cogeneration efficiency, this efficiency is obtained as 0.523–0.457 at low current density varying from 0.1 to 0.4 A/cm2. Exergy analysis results indicate that the plasma gasifier and the stack have the largest exergy destructions, accounting for 62.1 % and 32.2 % of the total, respectively. Gasification temperature has a great effect on the system exergy efficiency which is 0.603–0.384 when this temperature increases from 1000 K to 1300 K. Current density also has an obvious effect on the exergo-economic performance, the exergy cost per unit is obtained as 46.1–51.8 $/GJ when current density varies from 0.2 to 0.4 A/cm2. The optimization results are obtained as cogeneration efficiency of 0.4636, exergy efficiency of 0.6125 and exergy cost per unit of 24.58 $/GJ. This research provides a novel solution for substantial treatment of food waste, and guidelines for sustainable development of efficient and clean utilization technology of municipal solid waste.