A study of blending carbon nanoparticles made of coconut shell (fullerene C60) in vegetable oils on the droplet evaporation characteristics

Abstract

The droplet evaporation characteristics of crude vegetable oils, including crude coconut oil (CCO), crude palm oil (CPO), crude jathropa oil (CJO), and crude sunflower oil (CSFO) mixed with and without nanocarbon (fullerene C60) were investigated. The nanocarbon was produced from the waste biomass-based coconut shell. The droplet evaporation experiments were performed in an atmospheric chamber using a K type thermocouple and equipped with a Nikon D3300 camera at 60 frames per second. Droplet temperatures were measured in a real-time basis at a sampling frequency of 1 kHz. The crude vegetable oils were mixed with fullerene at 5 mg/L. In this study, the droplet evaporation behaviors of fullerene addition were studied and compared to pure vegetable oils. The results reported that the bubble formation and the flame propagation were formed faster in the cases of crude vegetable oils blended with fullerene by as much as 44% and 22%, respectively. The trend of early bubble formation was CCO5 > CPO5 > CJO5 > CSFO5. However, the initial flame propagation profile was CCO5 > CJO5 > CSFO5 > CPO5. A lot of local hot spots were identified for the blended vegetable oils with fullerene. The micro-explosion mechanism of blended vegetable oils with fullerene was obtained based on the droplet visualization. At a normal temperature, fullerene molecule was well attached to the carbonyl chain. The electronegativity between fullerene and triglyceride influenced the attachment form of fullerene to carbonyl chain with respect to droplet temperature. Finally, the addition of fullerene increased in the fuel reactivity, the droplet temperature, and shortened the ignition delay.