Analysis of Micro-Contaminants in Solid Particles from Direct Injection Gasoline Vehicles

Abstract

Exhaust emissions from vehicles are the subject of numerous studies and legal acts. In the European Union, exhaust emissions are regulated by “Euro” emission standards, which limit emissions of gaseous pollutants such as CO, CO2, HC, and NOx, as well as the particulate matter (PM) and particle number (PN). Solid particles consist of a number of micro-contaminants, inter alia polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives. Despite their highly mutagenic and carcinogenic character, these micro-contaminants are not regulated in Euro emissions standards. This paper presents both a general discussion of the phenomenon of particulate formation in and emission from direct injection gasoline engines, as well as a wide range of results on the subject. The subject of the micro-contaminants in solid particles from modern gasoline vehicles is explored. The samples of solid particles were collected from 11 groups of vehicles according to the WLTP test methodology. Solid particles from gasoline vehicles were analyzed via various analytical techniques, including ion chromatography (IC) to measure selected anion concentrations, gas chromatography with mass spectroscopy (GC-MS) to study 16 PAHs and selected PAH derivatives, scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) for images and elemental composition, and microwave plasma atomic emission spectroscopy (MP-AES) for qualitative screening analysis of 19 elements. The study of non-regulated compounds is crucial in efforts to establish the influence of solid particles on health and the environment. Furthermore, extended studies can provide a basis for further research on vehicle emissions or other fields, such as medicine or material engineering.

Emissions from Light-Duty Vehicles—From Statistics to Emission Regulations and Vehicle Testing in the European Union

“…In addition to the regulated pollutants, vehicle exhaust contains a number of elements and compounds that are not limited. In the exhaust stream, there are numerous particles and particulates formed by the incomplete combustion of fuel and co-combustion of engine oil [44][45][46][47]. Nonregulated gaseous emissions from internal combustion-powered engines encompass a range of pollutants beyond those subject to specific regulatory frameworks, such as methane, nitrous oxide, benzene, formaldehyde, acetaldehyde, acrolein, toluene, and xylene.…”

“…While solid particle mass and number are limited, currently there are no regulations regarding their chemical composition. The literature describes a possible way of solid particle formation starting from fuel pyrolysis through nucleation, coalescence, and agglomeration [45,[48][49][50]. In addition, the extreme conditions in the engine, e.g., high fuel-combustion temperature, locally reaching 2000 • C, and the high speed of the engine pistons [51], lead to abrasion of the elements and emission of metal particles.…”

“…As mentioned above, the particulate matter from vehicles with a gasoline engine contains a number of harmful elements and compounds. The literature focus is on the danger of compounds and elements that are part of PM [45,55,56]. For example, Pacura et al [45] studied the microcontaminants concentration in particulate matter from gasoline light-duty vehicles.…”

“…The literature focus is on the danger of compounds and elements that are part of PM [45,55,56]. For example, Pacura et al [45] studied the microcontaminants concentration in particulate matter from gasoline light-duty vehicles. Table 3 summarises the analysed groups of pollutants, i.e., organic polycyclic aromatic hydrocarbons and their derivatives, and inorganic impurities, i.e., selected metals and anions.…”

Research and Optimization on the Factors Influencing the Emission and Speed Jitter of GDI Engine Catalytic Converter Heating Conditions

“…Many countries have strict standards for vehicle emissions, while the European Union has been at the forefront for recent decades. European emissions regulations place limits on harmful pollutants like carbon oxide, hydrocarbons (HCs), particulate matter, and particle number (PN) for diesel and gasoline direct injection vehicles [2].…”