Effect of 2-Butanone addition on laminar burning velocity of gasoline XP95 at higher mixture temperatures

Abstract

2-Butanone, a product of pyrolysis of biomass, micro-biological fermentation of agricultural waste, possesses several advantages as a next generation biofuel for spark ignition engines. Very little is known about its combustion behavior due to non-availability of detailed combustion measurements. In this study, the laminar burning velocities (LBV) of 2-Butanone were measured and compared with benchmarked ethanol and gasoline using the externally heated diverging channel method. The measurements were conducted for 2-Butanone (B), premium gasoline (XP95) and their three different fuel blends (volume fraction: 10% B + 90% XP95, 30% B + 70% XP95, and 50% B + 50% XP95) for fuel-air equivalence ratios (ϕ) = 0.6–1.4, at elevated mixture temperatures of 300–620 K, and atmospheric pressure (1 bar). The present measurements of 2-Butanone show a good match with the values reported in literature and exhibit a good consistency with the predictions of Hemken 2017 reaction mechanism. The sensitivity analysis reveals that the inhibition effect of the key reaction R43: CH3 + H (+M) ⇔ CH4 (+M) is reduced by 34%, when the mixture temperature increased from 305 K to 620 K at ϕ = 1.1 and increased by 39% with an increase in mixture equivalence ratio from 0.7 to 1.3 at 620 K. The LBV of 2-Butanone shows a slight difference with ethanol and gasoline for leaner mixtures (ϕ = 0.6, 0.7). However, with increase in mixture strength (ϕ ≥ 0.8), the LBV becomes significantly higher than that of gasoline XP95 and slightly lower than ethanol regardless of the mixture temperature. With addition of 2-Butanone in gasoline XP95, the LBV improved by 14%, 24.6%, and 36.1% for 10% B + 90% XP95, 30% B + 70% XP95, and 50% B + 50% XP95 blends respectively, at ϕ = 1.0, 620 K. From the improved flame behavior of 2- Butanone under typical engine operating conditions against benchmarked ethanol, makes it a suitable biofuel substitute for gasoline in a sustainable transportation application.