Meeting RFS2 Targets with an E10/E15-like Fuel - Experimental and Analytical Assessment of Higher Alcohols in Multi-component Blends with Gasoline

This paper evaluates the potential of adding higher alcohols to gasoline blendstock in an attempt to improve overall fuel performance. The alcohols considered include ethanol, normal- and iso-structures of propanol, butanol and pentanol as well as normal-hexanol (C2-C6). Fuel performance is quantified based on energy content, knock resistance as well as petroleum displacement and promising multi-component blends are systematically identified based on property prediction methods. These promising multi-component blends, as well as their respective reference fuels, are subsequently tested for efficiency and emissions performance utilizing a gasoline direct injection, spark ignition engine. The engine test results confirm that combustion and efficiency of tailored multi-component blends closely match those of the reference fuels. Regulated emissions stemming from combustion of these blends are equal or lower compared to the reference fuels across the tested engine speed and load regime. The presented analytical and experimental results confirm that higher alcohols can be utilized to create fuels with superior properties such as blends that closely mimic the properties of E10/E15 while exceeding the RFS2 fuel blend requirements of approximately 28% ethanol-equivalent alcohol content.