Petroleum contains a wide variety of volatile organic compounds (VOCs). Due to their low boiling points, VOCs can be emitted to the atmosphere and immediately contaminate the air. More critically, it is well documented that VOCs are key ozone (O3) precursors. The main anthropogenic VOC sources include fuel used for motor vehicles, consumer products, various industrial processes, fossil fuel combustion and solvent usage. Most of the sources use products generated from petroleum.
Photochemical smog, characterized by high concentrations of O3 and fine particles, is of great concern in many cities around the world. Although VOCs and NOx have been confirmed as the key precursors of O3, the development of an effective strategy for reducing O3 pollution in megacities is still problematic due to the non-linear dependency of O3 formation on NOx and VOCs. VOCs as a group include many hundreds of species, and each one reacts at different rate and with a different reaction mechanism. Furthermore, they are also emitted into the atmosphere at different mass emission rates, depending on the local and regional industries, land-use and biogenic sources. Hence, it is important to figure out which VOC species have the highest influence on the O3 formation. Without this knowledge we will not be able to formulate proper O3 reduction strategy, i.e. which target pollutants need to be controlled.
Last date updated on June, 2014