Investigations on performance and pollutant emissions of spark-ignition engines fueled with n-butanol-, isobutanol-, ethanol-, methanol-, and acetone-gasoline blends: A comparative study

Several alternatives have been recently proposed in the literature for replacing gasoline fuel in spark-ignition engines. These alternatives were pertained based on different engine working conditions and they yield fairly different performance and emissions results. Consequently, there is a major need for comparing and evaluating the performance and environmental behavior of these alternatives at same conditions, especially the new proposed ones. Five different alternatives, as ethanol (E), methanol (M), n-butanol (nB), isobutanol (iB) and acetone (AC), were experimentally applied at same blend rates (3%, 7% and 10% by volume) in gasoline and same engine working conditions. This is the first time that such alternatives are compared with each others; in addition, the alternatives are compared with neat gasoline. The comparison basis was focused on the performance via brake power (BP), torque (Tq) and volumetric efficiency (VE) and the emissions via CO (carbon monoxide), CO2 (carbon dioxide) and UHC (unburnt hydrocarbons). Results demonstrated that the nB and iB alternatives provide a significant drop in BP, Tq and VE when compared to other alternatives as well as the neat gasoline. The maximum engine performance is obtained by both E and M. AC showed a moderate performance among all test fuels. Regarding the emissions, AC showed the lowest CO and UHC emissions, however, nB and iB showed the highest emissions.