Estimate of restaurant food waste and its biogas production potential in China

Much attention has been paid to restaurant food waste (RFW) in recent years, due to its environmental impact and concerns about pollution, and its illegal use as animal feed. An evaluation of the quantity of RFW and its potentially availability for biogas production will not only improve the environment, but also contribute to energy security and human health. Based on a structured face-to-face survey in a representative sample of 12 provinces in six regions, the present study evaluated the quantity and utilization of RFW and its availability for biogas production in mainland China. The results showed that the total quantity of fresh RFW was 44.1 million metric ton annually based on the survey from 2014 to 2016. This comprised 27.4 million ton (62%) from commercial restaurants and 16.7 million ton (38%) from internal canteens. The RFW was distributed among the six regions as follows, in ascending order: Northwest China (3.0 million ton, 6.9%) < Northeast China (3.7 million ton, 8.5%) < North China (5.4 million ton, 12.2%) < Southwest China (6.7 million ton, 15.2%) < Central-South China (11.8 million ton, 26.9%) < East China (13.3 million ton, 30.3%). The annual biogas production potential from available RFW was estimated at 4209 million m(3) in total and varied from 20.8 million m(3) to 377.0 million m(3) across all the provinces. A strengths, weaknesses, opportunities, and threats (SWOT) analysis shows that the availability of food waste has great potential for biogas production, even though there are limiting factors that present risks for food waste commercial utilization. The findings of this study will help policy makers and enterprise managers to understand the current state of RFW, and to optimize the utilization of RFW. (C) 2018 Elsevier Ltd. All rights reserved.