Study on the Emission Characteristics of Urban Buses at Different Emission Standards Fueled with Biodiesel Blends

Abstract Biodiesel is a promising clean and alternative fuel that can meet the demand of energy saving and environmental protection. In this study, the effects of biodiesel blends on the gaseous and particulate emission characteristics of China-III, IV, and V urban buses were investigated based on a heavy chassis dynamometer. The results showed that the biodiesel blend resulted in a reduction in CO, THC, PN, and PM emission but an increase in the NOx and CO2 emission, and the effects