Abstract
Ternary mixed biofuels are receiving increased scientific attention, and recently, researchers proposed different biofuel mixtures under dissimilar engine conditions; each researcher argued that his/her proposed one is the next generation alternative. Accordingly, such ternary biofuel mixtures are extremely needed to be compared against each other under the same engine conditions to provide the best/most promising one(s) as coming fuel alternative(s) for SI engines. In the current study, comparing of using ternary bio-methanol-iso-butanol-gasoline (MiB), bio-ethanol-n-butanol-gasoline (EnB), and bio-methanol-n-butanol-gasoline (MnB) fuel mixtures in pollutant releases and behavior/performance of SI engines is carried out for the first time. The ternary alcohol-gasoline combined fuels were also compared against dual alcohol-gasoline fuel mixtures. In particular, MiB is compared against iso-butanol-gasoline (iB) and bio-methanol-gasoline (M) fuel mixtures; EnB is compared against n-butanol-gasoline (nB) and bio-ethanol-gasoline (E) fuel mixtures; MnB is compared against nB and M fuel mixtures. The comparisons of all combined fuels (ternary and dual bases) are carried out experimentally at the same biofuel mixtures rates and engine working conditions and also compared against pure fossil-gasoline. The results showed that the behavior/performance of MiB, MnB, and EnB are all lower than the pure fossil-gasoline, except for pressure inside cylinder for MiB. The highest behavior/performance among all ternary biofuel mixtures is introduced by MiB. Comparisons of pollutant releases (CO, UHC, and CO2) showed that MiB has the lowest levels, while MnB showed the highest levels, among all ternary mixtures. Comparisons to pure fossil-gasoline, the MiB and EnB ternary mixtures introduced lower, but MnB showed higher pollutant releases than the pure fossil-gasoline fuel.