(613e) An Integrated and Distributed Anaerobic Digestion Waste-to-Energy System for Energy Recovery from Food Waste

Authors: 
Yen Wah, T., National University of Singapore
Zhang, J., National University of Singapore
Loh, K. C., National University of Singapore
High energy self-consumption and low energy production are two major reasons limiting the energy performance of waste-to-energy systems. As a major part of energy consumption, mixing in an anaerobic digester creates a homogeneous system enhancing mass transfer, and enables the solid wastes and microorganisms remain in suspension, but continuous mixing strategy is not cost-effective due to the demand of high electric energy. A high-energy efficient food waste-to-energy system was developed to combine anaerobic digestion and engine generator for energy recovery from food waste. Through investigating the effect of different mixing strategies on the performance of the anaerobic digestion process, mixing time was optimized to lower energy consumption and ensure that biogas production is economical and energy efficient. By testing an internal combustion engine generator, electricity generation potential and waste heat behavior were obtained when using different components of methane gas as fuel. Raising the methane content over 85% enhanced the performance of the engine generator, while the methane content at 60% was unable to drive the engine stably. In addition, the waste heat’s utilization and electricity generation efficiency, as well as energy distribution were studied through the analysis of the whole system.