Influence of acetone-butanol-ethanol (ABE)-gasoline blends on regulated and unregulated emissions from a PFI SI engine

Bio-butanol has been widely investigated as a promising alternative fuel. However, the main issues preventing industrial-scale production of butanol are its relatively low production efficiency and high cost of component recovery from the acetone-butanol-ethanol (ABE) fermentation process. Therefore, ABE has attracted a lot of interest as an alternative fuel for the reason that it not only has positive characteristics of oxygenated fuels, but also reduces the production cost during fermentation. This investigation is focused on the regulated and unregulated emissions of a single cylinder port-fuel injection (PFI) spark-ignition (SI) engine fueled with ABE (volumetric concentration of A:B:E = 3:6:1) and gasoline blends. Blends of gasoline with various ABE content (0 vol.%, 10 vol.%, 20 vol.% ABE referred to as G100, ABE10, ABE20) were used as test fuels. Experiments were performed at an engine speed of 1200 rpm, and at engine loads of 3 and 5 bar brake mean effective pressures (BMEP) and under various equivalence ratios ( =0.83-1.25). Exhaust gases measured included nitrogen oxides (NOx), carbon monoxide (CO) and unburned hydrocarbons (UHC). Additionally, benzene, ethylbenzene, toluene and xylenes (BTEX) concentrations were also measured by a gas chromatograph coupled with a mass spectrometer (GC/MS) and a flame ionization detection (GC/FID). The results show that with an increase of ABE in the blended fuel, there are reductions of UHC, CO and NOx. For the unregulated emissions, ABE addition leads to decreases in benzene, toluene and xylene emissions but an increase in ethylbenzene.