Exergy, techno-economic and environment analysis of food waste plasma gasification and syngas chemical looping processes

Abstract

To mitigate the problem of food waste, this study investigated two food waste treatment processes: plasma gasification hydrogen production and plasma gasification coupled with chemical looping, for converting food waste into high-quality hydrogen energy. Based on Aspen Plus software simulation results, the exergy, economic, and environmental benefits of the hydrogen production system were analyzed. Food waste hydrogen production using plasma gasification technology exhibits a high production capacity and economic input. Its hydrogen production capacity is 6.47 t/t H2 with a corresponding product cost of 2449.82 USD/t H2. The high economic input is mainly owing to the high power consumption of the plasma torches. Plasma gasification coupled with chemical looping can employ high-temperature gas to generate power, which can partially alleviate electricity consumption. In addition, in terms of thermodynamic benefits, the exergy efficiencies of plasma gasification hydrogen production and plasma gasification coupled with chemical looping are 31.44% and 54.31%, respectively. Plasma gasification coupled with chemical looping is more environmentally friendly based on the acidification and global warming potentials. The proposed novel process promotes food waste resource treatment and energy reuse.