Influence of antioxidants and nanoparticles with Ceiba pentandra biodiesel/diesel blends on performance and emission characteristics of diesel engine

Abstract

The demand for renewable fuel sources has increased as a result of declining fossil fuel supplies and declining air quality. Plant-based biodiesel appears to be a desirable alternative to fossil diesel; however, the usage of biodiesel is restricted due to its low heating value, poor atomization, lower thermal efficiency, and higher nitrogen oxides (NOx) emissions. In particular, reducing NOx emissions from engines is crucial for environmental protection and public health. The addition of nanoparticles and antioxidant additives to biodiesel plays a crucial role in overcoming its limitations. Antioxidants help reduce NOx emissions by removing decomposing peroxides and free radicals, as well as by disrupting the chain reactions of free radicals. This study looks at the influence of incorporating butylated hydroxytoluene (BH) antioxidant and aluminium oxide (Al2O3) nanoparticles into a Ceiba pentandra biodiesel blend (CPB) on engine performance and emission characteristics. The experimental work has been carried out on a direct injection (DI) diesel engine by blending 250, 500, 750, and 1000 ppm of BH and 25, 50, and 75 ppm of Al2O3 with 20% CPB. A total of eight different test blends were prepared and utilized for engine operation, and the results were compared with baseline diesel fuel. The experimental results expose that adding BH and Al2O3 significantly reduced NOx emissions. Compared to diesel, the addition of 1000 ppm BH and 50 ppm Al2O3 reduced the emission of NOx by 16.1%, carbon monoxide (CO) by 52.38%, and unburned hydrocarbon (HC) by 25.93%. However, there was a slight increase of 2.27 % in brake thermal efficiency (BTE) and a decrease of 7.14% in brake specific fuel consumption (BSFC).