The present study focuses on the investigation of environmental effects of adding aluminum oxide (Al2O3) nanoparticles as nano-additive in diesel-pyrolyzed biomass oil (PBO) blends. The PBO was extracted from jatropha seeds through the catalytic pyrolysis process at a temperature ranging from 450 degrees C to 550 degrees C. The esterification of PBO has been carried out using a catalyst in the presence of methyl alcohol to improve its physical properties and quality. The Al2O3 nano-additives were dispersed into PBO20 (20% of PBO and 80% of diesel) and PBO40 (40% of PBO and 60% of diesel) blends with a concentration of 50 ppm. The physical properties of test fuel blends were measured and compared with diesel. The engine emission tests were carried out using these blends at a constant speed of 1500 rpm by varying the load. The emission constituents such as CO, HC, and smoke were reduced. However, the emissions like CO2 and NO were increased by the addition of nano-additives compared to diesel.