Effects of dispersed multiwalled carbon nanotubes on the micro-explosion and combustion characteristics of 2-methylfuran – diesel mixture droplets. (15th May 2022)

• Record Type: Journal Article
• Authors: Ittoo, Bhavishkar; Ooi, Jong Boon; Tran, Manh-Vu; Jaliliantabar, Farzad; Hasan Najafi, Gholam; Swamy, Varghese
• Is Part Of: Fuel. Volume 316(2022)
• Publication Date: 2022-05-15
• Subjects: 2-Methylfuran -- Ignition delay -- Micro-explosions -- Multiwalled carbon nanotubes -- Combustion rate -- Droplet combustion; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.123308
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: High thermal conductivity of MWCNTs improves combustion characteristics of 2-methylfuran-diesel fuels. MWCNTs influence micro-explosion occurrence and micro-explosion intensity of MF-diesel fuels. MWCNT agglomeration (at high loadings) in the fuels leads to inferior combustion characteristics. MF-diesel blends with MWCNTs in suspension would perform better than neat diesel in diesel engines. Abstract: Isolated droplet combustion experiments have been carried out on neat diesel, a 15 vol% 2-methylfuran – 85 vol% diesel mixture (MF15), and nanofuels made from MF15 base fuel with addition of multiwalled carbon nanotubes (MWCNTs) at 25 ppm, 50 ppm, and 100 ppm concentrations (referred to as MF15C25, MF15C50, and MF15C100). Compared to MF15, the nanofuels displayed increased micro-explosion intensity and reduced micro-explosion occurrences, both effects being more pronounced at higher MWCNTs loadings. This behavior is attributed to the higher surface tension and viscosity of the nanofuels compared to that of MF15. The ignition delay decreased from 2.33 s to 1.71 s, the combustion rate constant increased from 0.82 mm 2 s −1 to 1.01 mm 2 s −1, and the combustion period reduced from 5.31 s to 4.54 s when going from pure MF15 to MF15C50. The improved combustion characteristics can be related to the superior thermal conductivity and large specific surface area of the dispersed MWCNTs in the nanofuels. The combustion characteristics of the nanofuel deteriorate at the highest MWCNTs dosing investigated here, possibly due to nanoparticle agglomeration. Overall, the present results suggest that dosing of MWCNTs at optimum levels improves the thermal efficiency and reduces the NOx emissions upon combustion of MF-diesel blends.