Polycyclic Aromatic Hydrocarbons in Emissions of the Internal Combustion Spark-Ignition Engine

A quantitative analysis of the concentrations of 16 compounds of the class of polycyclic aromatic hydrocarbons in the combustion products emitted into the atmosphere by an internal combustion piston engine was performed using the chromatograph mass spectroscopy method. The most common commercial gasolines AI-92, AI-95, and AI-98 were used as fuel. The effect of the octane number of gasoline on the release of polycyclic aromatic hydrocarbons was studied during engine operation in idle, high speed, load, and cold (warm-up) start, as well as in the transient mode of multiple sharp increase in speed from nmin = 750 min-1 to nmax = 5600 min-1 and back. To capture polycyclic aromatic hydrocarbons in the flow of engine exhaust gases, a setup was devised whose operation principle is based on aspiration of gases through sorbents with a well-developed surface. It is shown that the emission of most polycyclic aromatic hydrocarbons during engine running in the main modes of vehicle operation is many times greater (for individual compounds, for example, benzo(a)pyrene and benz(a)anthracene, tens or even hundreds of times) than the reference value established by the World Health Organization and the European Environment Agency for atmospheric air in populated areas. With an increase in the octane number of gasoline, the concentration of highly carcinogenic polycyclic aromatic hydrocarbons (benzo(a)pyrene and benz(a)anthracene) in exhaust gases decreases, but remains within the limits threatening the human life and health.