Performance evaluation of biogas fueled generator set

Biogas is one of the most promising renewable fuels for application in decentralized energy generation. In this context, gasoline-fueled spark ignition-based engines converted using commercial kits to run as flexible-fuel engines appear to be a low-cost alternative propulsion system. Therefore, this study aims to experimentally evaluate the performance parameters of a biogas-fueled generator set equipped with technology that has already diffused within society. The system comprises a 2.0-L petrol engine coupled to a synchronous generator, the power output, in-cylinder pressure and temperature, stability, and emission data of which were evaluated. The apparatus runs with biogas samples composed of CH4, C2H6, N2, CO2, and traces of other gases, of which the CO2 concentrations vary by up to 14%. The results show that adjusting the ignition timing for an intermediate configuration makes it possible to achieve a flexible fuel engine. In addition, the injection of CO2 into fuel allows an effective reduction of NOx emissions, although with slight decrease in performance. The efficiency decreases with an increase in the CO2 concentration. With 14% CO2, combustion ends at 75.66o on average, which contrasts with other average gaseous fuel combustion endings at 64.05o. Under such operation conditions, the in-cylinder temperature and NOx emission are approximately 1442.91 K and 271.47 ppm. Finally, with CNG, the in-cylinder temperature and NOx emissions are 1758.53 K and 1963.25 ppm on average.