How does the use of biodiesel affect urban air quality?

Abstract

This study aims to assess the influence of the use of a B20 fuel by road transports on urban air quality. For this purpose emission scenarios were designed and their impacts on air quality assessed using the WRF-EURAD modelling system applied over the Porto urban area. The scenarios consider emissions of CO, NOx, NMVOC, PM10, PM2.5, formaldehyde, acetaldehyde, acrolein and benzene from the use of pure diesel (reference scenario) and the use of a diesel blended with 20%(v/v) of biodiesel (B20 scenario). The results reveal that the use of B20 fuels improves the air quality over the Porto urban area, reducing the concentrations of most of the studied pollutants, with the exception of NO2. However, the concentrations vary in a small amount. Despite carbonyl compound emissions not being considered as individual input for the WRF-EURAD numerical modelling system, the equivalent ozone production estimated from the compound's emission variations indicate that the use of B20 can increase the O3 concentrations over the Porto urban area.