Combustion and Emissions Performance of a Spark Ignition Engine Fueled with Water Containing Acetone-Butanol-Ethanol and Gasoline Blends

Butanol has proved to be a very promising alternative fuel in recent years. The production of bio-butanol, typically done using the acetone-butanol-ethanol (ABE) fermentation process is expensive and consumes a lot of energy. Hence it is of interest to study the intermediate fermentation product, i.e. water-containing ABE as a potential fuel. The combustion and emissions performance of ABE29.5W0.5 (29.5 vol.% ABE, 0.5 vol.% water and gasoline blend), ABE30 (30 vol.% ABE and gasoline blend) and ABE0 (pure gasoline) were investigated in this study. The results showed that ABE29.5W0.5 enhanced engine torque by 9.6%-12.7% and brake thermal efficiency (BTE) by 5.2%-11.6% compared to pure gasoline, respectively. ABE29.5W0.5 also showed similar brake specific fuel consumption (BSFC) relative to pure gasoline. According to the mass fraction burned (MFB) calculation, ABE29.5W0.5 presented a longer ignition delay and combustion duration, which meant that ABE29.5W0.5 had a lower combustion rate resulted by the reduced combustion temperature due to water addition. Additionally, ABE29.5W0.5 produced a lower nitrogen oxides (NO_x) and carbon monoxide (CO), but also increased unburned hydrocarbon (UHC), but showed decreased nitrogen oxides (NO_x) and carbon monoxide (CO) emissions compared to ABE30 and pure gasoline.