Economically feasible production of green methane from vegetable and fruit-rich food waste

Abstract Increasing food waste (FW) generation is a major obstacle to achieving sustainable development by emitting greenhouse gas and wasting resources. The conventional FW treatment technologies cause environmental pollution and waste the potential energy of FW. Notably, the production of green methane (CH4) from FW has been proposed as a promising approach to overcome the environmental challenges associated with typical FW treatment and transportation technologies. The generated CH4 could be utilized as a fuel for natural gas vehicles (NGVs). The present study involved the development of a large scale process for the production of green CH4 from FW based on anaerobic digestion using pressure swing adsorption. Additionally, the economic feasibility of the process was evaluated by considering appropriate economic parameters and assumptions. Treatment of 50 t/d of FW in China resulted in the generation of 0.3 t of green CH4, and its minimum selling price was calculated at US$ 0.991/kWh. The benefits of scale-up as well as the developed FW treatment method were demonstrated by successful energy recovery and conversion of FW to green CH4. Importantly, the minimum selling price could be decreased to US$ 0.069/kWh, which is comparable to the current NGV fuel prices.