Effects of Blending Biodiesel on the Emissions of Heavy-Duty Diesel Vehicles at Different Altitudes

Diesel engine blended with biodiesel is an important measure to solve the poor combustion conditions and performance degradation of heavy diesel vehicles in plateau areas, but it may also bring different emissions effects. To explore the impact of mixing biodiesel or pure diesel on emissions at different altitudes, this study takes an N3 truck as the research object, and conducts emissions tests at altitudes of 0 m, 2000 m and 2400 m, respectively, using diesel and blended diesel mixed 7% biodiesel. The emission characteristics of carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NO_X), and particulate emissions number (PN) were compared in the aforementioned environments. The results show that pollutants exhibit a clear pattern with VSP apart from NO_X; Altitude and the mixing of diesel and biodiesel has little impact on CO₂emissions; Blending biodiesel can effectively reduce emissions of CO caused by high altitude, but both blending biodiesel and increasing altitude will increase NO_X and PN emissions.