Keywords: atmospheric pollution, ozone concentrations, butane, photochemical smog, Mexico, air pollution, simulation, air quality
Reactivity of n-butane in the formation of photochemical smog in Mexico City
The formation of high concentrations of contaminants in Mexico City's atmosphere due to the vehicular transit constitutes an acute problem. Based on that, and before alternative fuels are proposed for clean use, it is widely justified to evaluate the environmental impact these may have as a source of pollution. As the liquefied petroleum gas mix used as a domestic fuel has been proposed alternatively for motor cars, we present here a simulation study of the photochemical smog formation driven by n-butane via two different reaction schemes. In the first one (Mechanism A), the reaction takes place through the hydroxyl radical, •OH, attack on an n-butane secondary-carbon-hydrogen in the absence or presence of carbonylic compounds. No significant n-butane consumption or ozone formation was found. The second scheme (Mechanism B) which we hypothesise will occur in the presence of carbonylic compounds goes via the •OH attack on an n-butane primary-carbon-hydrogen, led to some n-butane consumption and high ozone concentrations.