Low-carbon emitting university campus achieved via anaerobic digestion of canteen food wastes

University campuses of China accommodate over 30 million students and consume a large amount of fossil fuel energy, leading to high carbon emission. Implementation of bioenergy (e.g. biomethane) is one of promising ways to mitigate emission and foster low-carbon emitting campus. Biomethane potential from anaerobic digestion (AD) of food waste (FW) in 2344 universities of 353 cities of mainland China have been estimated herein. Results have shown that 1.74 million tons of FW are discharged from campus canteens annually, that can generate 195.8 million m3 biomethane and reduce 0.77 million ton CO2-eq. Wuhan, Zhengzhou, and Guangzhou are the top three cities having the most biomethane potential from campus FW, accounting up to 8.92, 7.89, and 7.28 million m3 year−1, respectively. Technical challenges and solutions have been summarized and discussed such as FW purity, accumulation of ammonia and fatty acid, foaming, and plant site selection. Low-carbon campuses are supposed to be achieved by using bioenergy, like biomethane, in appropriate ways after resolving technical and management challenges. •Biomethane potential of FW of 2344 university campuses in China were estimated.•195.8 million m3 biomethane are produced from university canteens of China.•Wuhan, Zhengzhou, and Guangzhou cities have the most biomethane potential.•Technical challenges and solutions have been summarized and discussed.•Five universities representing diversified regions/culture have been analyzed.