Influence of Biodiesel on Vehicle Emissions and Ozone Formation 2020-36-0222

The fossil fuels burning is the main source of air pollutants in large cities. Anthropogenic emissions and their impact on air quality are of concern both regarding primary and secondary pollutants, such as tropospheric ozone. This molecule if formed from chemical reactions between fuel burning products, such as nitrogen monoxide and dioxide (NOx = NO + NO2) and volatile organic compounds (VOCs), in the presence of sunlight. With the perspective of increasing the biodiesel content in the mixture with diesel oil, actually in 12 % in Brazil, it became relevant to know the exhaust composition and it reactivity. This work presents a review of the literature and reveals that most scientific articles point out that biodiesel is a suitable alternative for such circumstances, however they point out harmful effects such as an increase in NOx emissions and carbonyls. For ozone, are presented the formation pathways, the influence of external factors and the implication regarding vehicle emissions. It was used a Diesel cycle vehicle fueled by different mixtures of 0, 10, 15, 20 and 30 % of biodiesel added to diesel. The emissions were collected using a 4 m³ FEP reaction chamber to simulate conditions of ozone formation, allowing the study without the influence of meteorological parameters. The results are presented highlighting each of the pollutants and show the differences in the composition of the exhaust gases when the fuel is changed. It was possible to conclude that biodiesel tends to form more NOx, and the ozone formed was consumed by the NO, not detecting a significant change in ozone levels.