Using an oxidation flow reactor to understand the effects of gasoline aromatics and ethanol levels on secondary aerosol formation

Niina Kuittinen; Cavan McCaffery; Stephen Zimmerman; Roya Bahreini; Pauli Simonen; Panu Karjalainen; Jorma Keskinen; Topi Rönkkö; Georgios Karavalakis

doi:10.1016/j.envres.2021.111453

Using an oxidation flow reactor to understand the effects of gasoline aromatics and ethanol levels on secondary aerosol formation

Environ Res. 2021 Sep:200:111453. doi: 10.1016/j.envres.2021.111453. Epub 2021 Jun 8.

Authors

Niina Kuittinen¹, Cavan McCaffery², Stephen Zimmerman³, Roya Bahreini⁴, Pauli Simonen⁵, Panu Karjalainen⁵, Jorma Keskinen⁵, Topi Rönkkö⁵, Georgios Karavalakis⁶

Affiliations

¹ Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, FI, 33720, Finland; University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA, 92507, USA.
² University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA, 92507, USA.
³ Department of Environmental Sciences, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA.
⁴ Department of Environmental Sciences, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA. Electronic address: bahreini@ucr.edu.
⁵ Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, FI, 33720, Finland.
⁶ University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA, 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA, 92521, USA. Electronic address: gkaraval@cert.ucr.edu.

PMID: 34097893
DOI: 10.1016/j.envres.2021.111453

Abstract

Fuel type and composition affect tailpipe emissions and secondary aerosol production from mobile sources. This study assessed the influence of gasoline fuels with varying levels of aromatics and ethanol on the primary emissions and secondary aerosol formation from a flexible fuel vehicle equipped with a port fuel injection engine. The vehicle was exercised over the LA92 and US06 driving cycles using a chassis dynamometer. Secondary aerosol formation potential was measured using a fast oxidation flow reactor. Results showed that the high aromatics fuels led to higher gaseous regulated emissions, as well as particulate matter (PM), black carbon, and total and solid particle number. The high ethanol content fuel (E78) resulted in reductions for the gaseous regulated pollutants and particulate emissions, with some exceptions where elevated emissions were seen for this fuel compared to both E10 fuels, depending on the driving cycle. Secondary aerosol formation potential was dominated by the cold-start phase and increased for the high aromatics fuel. Secondary aerosol formation was seen in lower levels for E78 due to the lower formation of precursor emissions using this fuel. In addition, operating driving conditions and aftertreatment efficiency played a major role on secondary organic and inorganic aerosol formation, indicating that fuel properties, driving conditions, and exhaust aftertreatment should be considered when evaluating the emissions of secondary aerosol precursors from mobile sources.

Keywords: Ethanol blends; Gasoline aromatics; Oxidation flow reactor; Secondary organic aerosol (SOA).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Aerosols
Air Pollutants* / analysis
Ethanol
Gasoline* / analysis
Vehicle Emissions / analysis

Substances

Aerosols
Air Pollutants
Gasoline
Vehicle Emissions
Ethanol