ABSTRACT
The present study is intended to investigate the effect of hybrid minor vegetable oil blends in twin cylinder compression ignition (CI) engines used in tractors on performance, emission and combustion characteristics. Rubber seed oil (RSO) and babassu oil (BSO) are blended in various proportions of 75:25, 50:50 and 25:75 and tested at a constant speed and variable load conditions. Brake thermal efficiency (BTE) for diesel is 32.2% and reduces for RSO, BSO and its blends. Minimum BTE is observed for R75B25, which is 27.7%. HC, CO, and smoke emissions are higher with RSO, BSO and their blends compared to diesel at all load conditions. NO emission for vegetable oil blends is lower compared to diesel due to poor combustion. Combustion of RSO, BSO and their blends started late with lower premixed combustion and slower combustion increased the diffusion combustion. Hence, the R50B50 blend is identified as the best blend for CI engines accessible in villages. Diglyme (DGE), an oxygenate, is blended 20% with R50B50 blend. At 100% load, BTE for R50B50 + DGE 20 is improved by 6% compared to R50B50 and on a par with diesel. The blend also reduced HC, CO and smoke emissions with slightly higher NO emission due to performance improvement.
Disclosure statement
No potential conflict of interest was reported by the authors.