Combustion characteristics of gasoline fuel droplets containing boron-based particles

Abstract

Boron-based particles are dense energy carriers that are promising for a future carbon-neutral world, to store and transport abundant energy. Although it is prominent as a slurry fuel component in liquid aviation fuels, its effects on the combustion behavior of traditional hydrocarbon fuels used in public or industrial areas have not yet been clarified. In this study, combustion characteristics of gasoline-based fuel droplets containing 86–88%, and 95–97% < 1 µm amorphous boron, 10 µm AlB12, 28 – 35 µm MgB2 particles and 1% oleic acid surfactant. The experimental process was recorded via a high-speed camera and a thermal camera. The results showed that the ignition delay time was reduced in all gasoline-based fuels containing boron-based particles. The fuels with the lowest extinction time were gasoline-based fuel droplets containing AlB12 particles (∼1245 ms). Amorphous boron particles were transported to the flame region more than other particles and caused severe atomization phenomena. The highest maximum flame temperature for gasoline droplets at 2.5% particle load was recorded in high-purity amorphous boron particles with 537 K. At 7.5% particle load, the highest flame temperature and agglomerate temperature were observed at 513 K and 653 K, respectively, in gasoline droplets containing high-purity amorphous boron particles. In electric field tests, the shortest extinction time was detected for gasoline droplets with MgB12. Also, the addition of amorph boron particles into gasoline increase of 4.6% was seen in the flame speed. Droplet diameter regression plots show that particulate gasoline-based fuel droplets exhibit a decreasing trend, mostly following the D2-law. It has been revealed low-cost amorphous boron derivatives can be an important energy carrier for liquid hydrocarbon fuels.