Assessing above-ground fuel storage tank emissions using lower-cost sensor packages and triggered canister samples

Area of Science:

• Environmental Chemistry
• Atmospheric Science
• Air Pollution Monitoring

Background:

• Fuel tank terminals are significant sources of volatile organic compounds (VOCs).
• These VOCs contribute to ground-level ozone formation and include hazardous air pollutants (HAPs).
• Current emission inventories lack routine measurements due to safety concerns.

Purpose of the Study:

• To characterize long-term emissions from fuel terminals using novel remote sensing.
• To identify specific VOCs and their contribution to ozone formation.
• To assess the effectiveness of hybrid measurement-modeling approaches for air quality assessment.

Main Methods:

• Conducted a 1.5-year study in Greensboro, NC, measuring and speciating VOCs.
• Utilized canister samples triggered by photoionization detector sensors during high concentration events.
• Employed lower-cost remote sensing for characterizing fuel terminal emissions.

Main Results:

• Gasoline headspace compounds constituted 95-97% of measured VOCs.
• Butane, iso-pentane, n-pentane, isobutane, ethanol, and 2-methylpentane were the most abundant compounds.
• Trans-2-pentene, trans-2-butene, and xylenes were major contributors to estimated ground-level ozone.

Conclusions:

• This study pioneers long-term characterization of fuel terminal emissions using hybrid remote sensing.
• Identified specific VOCs driving ozone formation, crucial for targeted pollution control.
• The hybrid approach is applicable to other airsheds for long-term VOC monitoring and concern identification.