Experimental Investigation of Performance and Emissions of a CI Engine Operating with HVO and Farnesane in Dual-Fuel Mode with Natural Gas and Biogas

New fuels, such as HVO and farnesane, present promising combustion properties and can be produced from renewable sources, while technological development, such as dual-fuel combustion, may offer potential improvements in efficiency and emissions. The present study presents an experimental investigation of combustion, emissions, and performance of a single-cylinder CI engine fueled by HVO and farnesane in dual-fuel mode with natural gas and biogas. For all scenarios, dual-fuel operation slightly increased ignition delay, but decreased combustion duration and in-cylinder pressure. Port injection of biogas reduced NOx (up to 21.7%) and PM emissions (up to 76.8%), but increased CO (up to 205.8%) and HC (up to 7.66 g/kWh) for every pilot fuel, whereas natural gas presented reductions of up to 18.3% in NOx (except for diesel), 83.1% in PM, and 13.0% in CO2, but produced more CO (up to 359.3%) and HC (up to 14.51 g/kWh). The use of HVO and farnesane under dual-fuel mode have proved to be interesting alternatives to reduce GHG emissions. Overall, farnesane presented the highest brake thermal efficiency, followed by HVO and diesel. The addition of CNG and biogas reduced BTE of up to 2.94% and 2.76%, respectively.