Technical and economic feasibility analysis of an anaerobic digestion plant fed with canteen food waste

Abstract

China has implemented a number of laws and policies to promote the reuse of food wastes generated in restaurants and catering services. Resources in terms of energy and fertilizer are recovered from food wastes. In this study, in order to treat canteen food waste generated inside the campus of Huazhong University of Science and Technology (Wuhan, China), a medium scale biogas plant is designed and then simulated using BioWin software. According to obtained simulation results, the total daily biogas production rate is 2013 m3/d and the volatile solids destruction efficiency is about 74%. The campus has about 29 canteens and more than 61,700 students, so it is the ideal place for such a project, because the food waste in this case is concentrated and easy to collect. About 3300 tons of food waste are available per year in HUST, which can be transformed into 1136 MWh of electricity by using a biogas plant with an internal combustion engine. Due to reduced cost of transport and current reduction of taxes for renewable energy plants, the simple payback period of such a project results to be 7.8 years, while the equity payback is 9 years. Sensitivity analysis and risk analysis have shown that project economic feasibility depends strongly on Electricity Export Rate and Initial Investment. A change of these two parameters in the order of 10% can shift equity payback from 9 years to a maximum value of 12.4 years. The development of a Carbon Credit Market can be an important way to increase the economic convenience of this type of projects.