Species profiles and normalized reactivity of volatile organic compounds from gasoline evaporation in China

Yanli Zhang, Xinming Wang, Zhou Zhang, Sujun Lü, Min Shao, Frank S.C. Lee, Jianzhen Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

76 Citations (Scopus)

Abstract

In China, fast increase in passenger cars and gasoline consumption with yet quite limited vapor recovery during gasoline distribution has procured growing concern about gasoline evaporation as an important emission source of volatile organic compounds (VOCs), particularly in megacities hard-hit by air quality problems. This study presents VOC species profiles related to major pathways of gasoline evaporative loss in China, including headspace displacement, refueling operations and spillage/leakage. Apart from liquid gasoline and headspace vapors, gasoline vapors emitted when refueling cars in service stations or tank trucks in oil marketing depots were also sampled in situ with vapor recovery units (VRUs) turning on/off. Alkanes, alkenes and aromatic hydrocarbons accounted for 55-66, 21-35 and 4-8% in refueling vapors, 59-72, 18-28 and 4-10% in headspace vapors and 33-51, 8-15 and 38-48% in liquid gasoline samples, respectively. During refueling with VRUs turning on, total VOCs in vapors were less than one fifth of that with VRUs turning off, and aromatic hydrocarbons had higher weight percentages of about 8% in contrast with that of about 4% during refueling with VRUs turning off. Refueling vapors, especially for that with VRUs turning off, showed a larger fraction of light hydrocarbons including C3-C5 light alkenes when compared to headspace vapors, probably due to splashing and disturbance during filling operation. In refueling or headspace vapors the ratios of i-pentane/benzene, i-pentane/toluene, and MTBE (methyl tert-butyl ether)/benzene ranged 8.7-57, 2.7-4.8, and 1.9-6.6, respectively; and they are distinctively much higher than those previously reported in vehicle exhausts. Calculated normalized reactivity or ozone formation potential of the gasoline vapors in China ranged 3.3-4.4g O3g-1 VOC, about twice that of gasoline headspace vapors reported in USA as a result of larger fractions of alkenes in China's gasoline vapors. The results suggested that reducing VOC emission from gasoline distribution sector would particularly benefit ground-level ozone control in China.

Original languageEnglish
Pages (from-to)110-118
Number of pages9
JournalAtmospheric Environment
Volume79
DOIs
Publication statusPublished - 1 Nov 2013

Keywords

  • Gasoline evaporation
  • Normalized reactivity
  • Ozone formation potential (OFP)
  • Source profiles
  • Vapor recovery units (VRU)
  • Volatile organic compounds (VOCs)

ASJC Scopus subject areas

  • Environmental Science(all)
  • Atmospheric Science

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