Influence of Cerium Oxide Nanoparticles Addition to Microalgae and Pongamia Biodiesel Blends in a Diesel Engine

The current experimental sutdy explores effect of mixing cerium oxide (CeO2) nanoparticles in a Scenedesmus sp. and Pongamia biodiesels. The Scenedesmus sp. microalgae biomass is cultivated in open raceway ponds then converted into biodiesel following conventional transesterification process. Thirty percent biodiesel blends of Scenedesmus sp. (A30) and Pongamia (P30), 100 ppm CeO2 nanoparticles in A30 (A30C100) and 100 ppm CeO2 nanoparticles in P30 (P30C100), and diesel are experimentally tested in an indirect injection CI engine. Nanoparticles addition improves engine average brake thermal efficiency (BTE) by 4.2% and 3.8% when added to Scenedesmus sp. and Pongamia biodiesel blends. However, only Scenedesmus biodiesel-nanoparticle blend (A30C100) could achieve BTE close to diesel at high loads. The peak pressures are found highest for nanoparticle added blends and their peak heat release rates are slightly shifted away from the top dead center. The A30 and P30 NOx emissions are found lower than diesel. Addition of nanoparticles increased NOx emissions of A30 and P30 blends by 4.6% and 6.1%. The average NOx emission of P30C100 blend is found even higher than diesel. Smoke emissions of all biodiesel variants tested in current study are found significantly lower than diesel. Scenedesmus sp. biodiesel scored better than Pongamia biodiesel.