Biogas-fuelled Stirling engine for electric power generation

Abstract

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder. It offers flexibility of fuel used for the power generation, hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power generation. In this study a Gamma V2-6 Stirling engine is used in a biogasfuelled power generation system. The engine has maximum capacity of 10kW. The required fuel input is 60,000BTU/hr or equivalent to 17 kW. The fuel is a biogas which comes from a biodigester. The system requires constant heat from the combustion chamber, hence a novel fuel distribution control is introduced. A specific burner is also designed to fulfil the purpose. In this study, a biogasfueled Stirling engine for electric power generation is designed and developed. The system has 5 kW capacity fuelled by 165 kg/day solid waste (biowaste) from local farm. The biodigester needed is 20 m3. Based on empirical model, the estimated energy efficiency of the system is 36%. In addition, the system offers potential utilization of hot water as by side product.