2-Methylfuran: A bio-derived octane booster for spark-ignition engines

Abstract

The efficiency of spark-ignition engines is limited by the phenomenon of knock, which is caused by auto-ignition of the fuel-air mixture ahead of the spark-initiated flame front. The resistance of a fuel to knock is quantified by its octane index; therefore, increasing the octane index of a spark-ignition engine fuel increases the efficiency of the respective engine. However, raising the octane index of gasoline increases the refining costs, as well as the energy consumption during production. The use of alternative fuels with synergistic blending effects presents an attractive option for improving octane index. In this work, the octane enhancing potential of 2-methylfuran (2-MF), a next-generation biofuel, has been examined and compared to other high-octane components (i.e., ethanol and toluene). A primary reference fuel with an octane index of 60 (PRF60) was chosen as the base fuel since it closely represents refinery naphtha streams, which are used as gasoline blend stocks. Initial screening of the fuels was done in an ignition quality tester (IQT). The PRF60/2-MF (80/20 v/v%) blend exhibited longer ignition delay times compared to PRF60/ethanol (80/20 v/v%) blend and PRF60/toluene (80/20 v/v%) blend, even though pure 2-MF is more reactive than both ethanol and toluene. The mixtures were also tested *Revised Manuscript Click here to view linked References in a cooperative fuels research (CFR) engine under research octane number and motor octane number like conditions. The PRF60/2-MF blend again possesses a higher octane index than other blending components. A detailed chemical kinetic analysis was performed to understand the synergetic blending effect of 2-MF, using a well-validated PRF/2-MF kinetic model. Kinetic analysis revealed superior suppression of low-temperature chemistry with the addition of 2-MF. The results from simulations were further confirmed by homogeneous charge compression ignition engine experiments, which established its superior low-temperature heat release (LTHR) suppression compared to ethanol, resulting in better blending octane numbers. This work explores and provides a chemically sound explanation for the potential of 2-MF as an octane enhancer.

Influences of isomeric butanol addition on anti-knock tendency of primary reference fuel and toluene primary reference fuel gasoline surrogates

“…21,22 Therefore, it is reasonable to correlate the RONs measured by the CFR engine with the ignition delay times of the fuel/air mixtures. 23,24 In this study, the detailed chemical mechanism proposed by Alramadan et al, 14 including 1765 species and 7714 elementary reactions, was used for the auto-ignition simulation of the butanol/gasoline surrogate blends. All the simulations were carried out using the adiabatic constant-volume homogeneous batch reactor module in the Chemkin Pro Package.…”

Pyrolysis of Furan and Its Methylated Derivatives: A Shock-Tube/TOF-MS and Modeling Study

“…Several investigations of the pyrolysis and oxidation of 2,5-DMF, 2-MF, and F have been published. These range from studies in engines, ,− flames, − and various kinetic experiments − ,− to pure computational studies. , …”

H-Atom-Forming Reaction Pathways in the Pyrolysis of Furan, 2-Methylfuran, and 2,5-Dimethylfuran: A Shock-Tube and Modeling Study

“…Numerous investigations have been published that examine the pyrolysis and oxidation of 2,5-DMF, 2-MF, and the unsubstituted furan (F). These works range from engine tests, − flame studies, − and various kinetic experiments − to pure computational studies. − Several mechanisms ,,,,,,,,− were proposed to explain the different experimental findings.…”