Influences of C5 esters addition on anti-knock and auto-ignition tendency of a gasoline surrogate fuel

Abstract

The research octane numbers and auto-ignition characteristics of a toluene primary reference fuel (TPRF), when blended with three C5 esters, γ-valerolactone (GVL), methyl butanoate (MB), and methyl crotonate (MC), were investigated on a cooperative fuel research (CFR) engine and a constant volume combustion chamber (CVCC). In fuel preparation, ethanol was used to improve the miscibility, and the total additive comprised 1/3 ethanol and 2/3 GVL/MB/MC on a molar basis. The experimental results first reveal that the addition of the three series of additives boost fuel octane rating, and their boosting effects rank as MB > GVL ∼ MC when fuels are blended on a molar basis. In contrast, the auto-ignition tendency of the three series of fuel blends, when blended on the molar basis, ranks as the MC blends > the GVL blends> the MB blends. Different from the similar reactivities observed for the MC blends and the GVL blends in the RON tests, the MC blends exhibit higher auto-ignition propensity than the GVL blends, probably because the higher enthalpy of vaporization of GVL causes a more significant cooling effect. Finally, different from the literature studies that reported similar reactivities for pure MB and MC, in this study MB shows lower reactivity than MC when blending with the TPRF gasoline surrogate.

On knocking combustion development of oxygenated gasoline fuels in a cooperative fuel research engine

“…Details of the experimental apparatus can be obtained in the authors' previous studies. 17,18 Engine operational parameters in the RON and MON tests were controlled within the acceptable range defined by the standards ASTM D2699 19 and D2700, 20 respectively.…”

Bio-derived lactones – Combustion and exhaust emissions of a new class of renewable fuels

“…ε-caprolactone contains 6 carbon atoms in a cyclic ester structure. Based on the current production potential and higher carbon number of ε-caprolactone compared to GVL (an extensively researched lactone), 34,38,39 The possibility to utilise larger lactones, such as εCL, in diesel engines is therefore highly intriguing. This report is, to the best of our knowledge, the first example of the combustion of higher lactones in a compression ignition engine.…”

A Comprehensive Experimental and Kinetic Study of Laminar Flame Characteristics of H2 and CO Addition to Oxygenated Gasoline

“…Because of those practical complications, a surrogate for gasoline fuels is widely used to perform and validate both experiments and computational modeling. 13,14 A wide range of studies have been conducted, primarily focused on the addition of hydrogen to a surrogate, involving a single component, e.g., iso-octane. 15 Mandilas et al 16 determined the S L o of iso-octane/hydrogen mixtures and found that at stoichiometric conditions, the S L o of i-C 8 H 18 /H 2 mixtures increased positively with the increased mass fraction of hydrogen.…”

“…However, few studies have reported gasoline–hydrogen–air combustion characteristics because of commercial gasoline’s complex and variable composition. Because of those practical complications, a surrogate for gasoline fuels is widely used to perform and validate both experiments and computational modeling. , A wide range of studies have been conducted, primarily focused on the addition of hydrogen to a surrogate, involving a single component, e.g., iso -octane …”