Monitoring and Modeling the Effect of Fuel Change on Air Quality in a Typical Heavy Traffic Residential Area in Kuwait

Abstract

A mobile laboratory was positioned adjacent to a heavy traffic intersection in a typical urban area in Kuwait to monitor the concentrations of vehicular atmospheric pollutants before and after switching to unleaded MTBE gasoline. Monitored NO_x and O₃ emissions increased by 26.5% and 27.7%, respectively, while those of CO and HC decreased by 45.7% and 42.6%, respectively. However, evaporative emissions of some hydrocarbons, especially aldehydes, increased due to the higher volatility of the oxygenated fuel. Meteorological and traffic variables were used in estimating pollutant concentrations in the area under study using MOBILE5 and CAL3QHC software. An average normalized mean square error (NMSE) between estimated and monitored concentrations was calculated to be 0.102 for the 2 months of the study period. The effects of vehicle speed, ambient temperatures, and fuel ASTM volatility class on CO, HC, and NO_x emissions were also investigated. It was found that CO and HC emissions increase as volatility increases, while NO_x emissions did not depend on volatility. Ambient temperature had a similar effect. On the other hand, vehicle speed had an optimum value that minimizes CO emissions.