Ethyl 3-ethoxybutyrate, a new component of the transportation renewable fuel portfolio

• We characterize a novel fuel oxygenate, ethyl 3-ethoxybutyrate (EEB).
• EEB–diesel blends had cetane values that exceeded 40.
• Reduced criteria pollutant emissions was achieved with 5% and 10% EEB–diesel blends.
• Economically viable production of EEB at wastewater treatment plants is promising.
• EEB in the transportation fuel portfolio could lower global fossil carbon emissions.

The vast majority of energy that powers our global economy is from combustion of fossil fuels with the unintended consequence of increased deposition of carbon dioxide in the atmosphere and oceans. The scientific and technical challenges for the energy sector are to develop renewable energy sources that are sufficient to meet human energy consumption, are economically viable, and are ecologically sustainable. We investigated ethyl 3-ethoxybutyrate (EEB) as a fuel oxygenate in ultra low sulfur diesel (ULSD) with a bench-scale research engine and determined its economic potential as a renewable fuel with technoeconomic modeling using wastewater treatment plant biosolids as the feedstock for poly-3-hydroxyalkanoates (PHB), a bacterial storage polymer from which EEB can be synthesized. EEB blended well with ULSD, and cetane values of 10% and 20% v/v EEB–ULSD blends exceeded 40. A diesel internal combustion engine fueled with 5%, 10%, and 20% EEB–ULSD blends met or exceeded all tested transportation diesel fuel emissions criteria. Inedible organic feedstocks may be used to produce PHB; and thus, EEB might contribute to carbon reductions without compromising performance or air pollutant emissions. However, further research is needed to determine its role in the overall fuel portfolio.