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

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)
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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.

Original languageEnglish
Article number111453
Number of pages11
JournalEnvironmental Research
Publication statusPublished - 2021
Publication typeA1 Journal article-refereed


  • Ethanol blends
  • Gasoline aromatics
  • Oxidation flow reactor
  • Secondary organic aerosol (SOA)

Publication forum classification

  • Publication forum level 2

ASJC Scopus subject areas

  • Biochemistry
  • General Environmental Science


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