Investigation on VOC Emissions from Automobile Sources by Means of Online Mass Spectrometry

Abstract

This study reviews recent research on volatile organic compound (VOC) emissions from motorized vehicle sources by means of online mass spectrometry. Chemical ionization is a powerful tool that usually permits soft ionization of chemical species and it allows the time-resolved measurement of multiple VOCs, even in complex samples where many kinds of VOCs coexist. The vehicular exhaust gasses are investigated using H 3 O + , NO + , Hg + , and CH 3 C(O)O − as a reagent ion in online chemical ionization mass spectrometry. The proton transfer using H 3 O + as a reagent ion was used for the detection of nitro-organic compounds such as nitromethane and nitrophenol. The time-resolved measurement of the nitro-organic compounds in the laboratory experiments with a chassis dynamometer system revealed their emission properties, such as the dependence of the emissions as a function of vehicular velocity and acceleration/deceleration, as well as the effect of various types of exhaust gas treatment. The data regarding the nitromethane and nitrophenol emissions obtained in the field measurements were consistent with the results of the laboratory experiments done with a chassis dynamometer system. In the experiments involving evaporative emissions from gasoline-powered cars, NO + was used as a reagent ion. Online measurements showed that the adsorption of hydrocarbons in a sealed housing evaporative determination unit could result in emissions being underestimated, if the concentrations are monitored only before and after a diurnal breathing loss test. The composition analysis gave an estimated ozone formation potential (OFP) approximately 20 % higher for breakthrough emissions and refueling emissions than for the gasoline that was tested, but the OFP for the permeation emissions was almost the same as the OFP for the test fuel.

Ambient Nitro-Aromatic Compounds – Biomass Burning versus Secondary Formation in rural China

“…NACs (Inomata et al, 2016;Perrone et al, 2014;Le Breton et al, 2019). BB is considered a major driver of atmospheric NAC formation (Kahnt et al, 2013;Laskin et al, 2015) because the combustion of coal and wood, which leads to causes thermal degradation and pyrolysis of lignins, results to strong emission https://doi.org/10.5194/acp-2020-899 Preprint.…”

Secondary organic aerosol formation from gasoline and diesel vehicle exhaust under light and dark conditions

“…An array of instruments was used to characterize gas-and particulate-phase pollutants inside the 6-m 3 FBC. Gas-phase organic species were measured with two proton transfer reaction mass spectrometers (PTR-MS, Ionicon), as detailed in our previous studies 50,51 The data shown in this study were obtained in the 6-m 3 FBC. The ratio of the CO concentration in the 30-m 3 EDC and 6-m 3 FBC (i.e., chambers before and after passage through the pumps, respectively) was 0.183; the corresponding ratio of the THC concentrations was 0.194.…”

“…An array of instruments was used to characterize gas-and particulate-phase pollutants inside the 6 m 3 FBC. Gas-phase organic species were measured with two proton transfer reaction mass spectrometers (PTR-MS, Ionicon), as detailed in our previous studies 50,51 and Section S1 of the ESI. † The detection sensitivities are listed in Tables S1-S3 of the ESI.…”

Car Soundproof Improvement Through an SMA Adaptive System

“…Within this scenario, a critical role is played by the possibility of reducing weight [3], saving energy [4], abating chemical [5] and acoustic [6] emissions. A large number of subsystems are potentially involved: engines, aerodynamic shapes, gearboxes, cockpit, control unit settings, seals (for sound and water insulation), and so on.…”