BTEX in the exhaust emissions of motor vehicles

Abstract

Transportation involves the combustion of fossil fuels to produce energy translated into motion. Pollution is created from incomplete carbon reactions, unburned hydrocarbons, or other elements present in the fuel or the air during combustion. These processes produce pollutants of various species, including carbon monoxide, soot, various gaseous and liquid vapour hydrocarbons, oxides of sulphur and nitrogen, sulphate and nitrate particulates, and ash and lead. These primary pollutants can, in turn, react in the atmosphere to form ozone, secondary particulates, and other damaging secondary pollutants. Benzene, toluene ethylbenzene, and xylens, known collectively as the BTEX group, are an important fraction of non-methane hydrocarbons and have been found to be ubiquitous in the urban air. BTEX are known to be toxic and genotoxic and they also actively participate in the photochemical reactions. This chapter presents the results of research in the field of BTEX concentration in the exhaust gases of spark ignition engines under different operating conditions. The aim of this chapter is to obtain a clearer insight into the impact of different engine working parameters on the concentration of BTEX gases. Exhausts have been sampled directly at the tail pipe. Detection and quantification of BTEX concentration levels have been performed by using mobile GC Voyager Photovac equipped with capillary column Supelcowax 10 and photoionisation detector. The results indicate high concentration levels of target compounds, especially in conditions of incomplete combustion simulated by creating hydrocarbon–air-rich mixtures, low engine load, and low revolutions per minute of the experimental motor.