Biogas-fuelled internal combustion engines for micro-scale energy generation: a review of technologies and configurations for systems below 50 kW

The growing demand for sustainable and decentralised energy solutions drives the development of micro-scale biogas power generation systems using internal combustion engines (ICEs) as prime movers. This paper reviews the technological advances and structural configurations of ICEs designed to burn biogas in generator systems with power outputs of up to 50 kW. The study investigates the adaptation of spark-ignition and dual-fuel engines, optimisation of compression ratios, fuel delivery systems, and ignition strategies to increase efficiency and reliability. Furthermore, the impact of biogas composition on engine performance and emissions is investigated, addressing the challenges of changes in methane and pollutant content. The review provides information on recent innovations, including engine modifications to run lean and integration of advanced control systems to increase efficiency and durability. By synthesising current research and practical applications, this paper aims to guide the selection and development of optimised ICE solutions for distributed microgas power generation.