Enhancement of combustion performance and emission control in Bauhinia malabarica biodiesel-diesel blends using aluminium oxide nanoparticles and electrostatic precipitators

This study investigates the enrichment of combustion performance and emission features of Bauhinia malabarica biodiesel (BMB)-diesel mixtures through the addition of aluminium oxide (Al₂O₃) nanoparticles and the use of electrostatic precipitators (ESPs) to mitigate nanoparticle emissions. Different volume concentrations of BMB were combined with conventional diesel fuel (CDF), and 100 ppm of Al₂O₃ was dispersed into 30 % BMB-CDF blends using ultrasonication with a surfactant. The combustion analysis exposed that the addition of BMB to CDF reduced in-cylinder pressure while increasing net heat release and advancing the crank angle for peak values. The 30 % BMB blend led to a drop in brake thermal efficiency (BTE), with a corresponding upsurge in brake-specific fuel consumption (BSFC) and nitrogen oxides (NOx) emissions of 10.4 %, 11.3 %, and 10.9 %, respectively. However, formations of hydrocarbons (HC), carbon monoxide (CO), smoke, and particulate matter (PM) decreased by 14.3 %, 6.3 %, 11.1 %, and 12.5 %, respectively. The incorporation of Al₂O₃ nanoparticles improved BTE by 5.2 % and reduced BSFC, HC, CO, NOx, and smoke by 4.2 %, 13.7 %, 14.9 %, 5.8 %, and 15.5 %, respectively. Although PM emissions increased by 47.2 % with the nanoparticle-enriched blend, integration of the ESP effectively captured exhaust nanoparticles, reducing PM emissions by 54.2 %. This study reveals the potential of Al₂O₃ nanoparticle-enriched BMB mixtures in enlightening combustion performance and dropping most emissions, with ESP serving as an effective tool for controlling nanoparticle emissions.