Reactivity controlled compression ignition performance with renewable fuels

Reactivity controlled compression ignition (RCCI) combustion makes use of in-cylinder blending of two fuels with differing reactivity to tailor the reactivity of the fuel charge for improved control of the combustion process. This approach has been shown in simulations and engine experiments to have the potential for high efficiency with very low NO_X and particulate matter (PM) emissions. Previous multi-cylinder RCCI experiments have been completed to understand the potential of this approach under more real-world conditions in a light-duty multi-cylinder engine (MCE) with production viable hardware. MCE experiments explored fuel injection strategy, dilution levels, piston geometry (including compression ratio), and fuel properties. Many renewable fuels have unique properties which enable expanded operation of advanced combustion methods for higher engine efficiency and lower energy requirements for emissions control devices. This study investigates the effect that renewable gasoline and diesel fuel replacements have on the load-expansion of RCCI, performance and emissions. The study focuses on ethanol blends for replacement of gasoline as the port-injected fuel (PFI) and biodiesel blends as the replacement for the direct injected (DI) fuel.