Monitoring of BTEX from Urban and Oil and Natural Gas Activities in the San Joaquin Valley of California
Abstract
The volatile organic compound family of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) are air pollutants that can cause detrimental health effects and degrade air quality through oxidation reactions. BTEX is ubiquitous in the environment at trace levels ranging from sub-ppb to tens of ppb in urban and industrial areas where atmospheric mixing ratios are elevated. Although ambient atmospheric BTEX levels have dropped due to reformulation of gasoline, there is evidence of an increase of emissions from oil and natural gas operations. Progress has been made with screening methods to determine presence of BTEX however, very few sensors have the combination of sub-ppb sensitivity, selectivity, and relative low cost needed for ambient air monitoring. We present a new design of an inexpensive compact and field-deployable gas chromatograph with a photoionization detector (GC-PID) optimized to sample ambient (sub-ppb) levels of BTEX. In this study, we explore potential emissions of BTEX and their relationship to co-emitted greenhouse gases from oil and natural gas (ONG) activities in the southern San Joaquin Valley of California. Continuous measurements of BTEX and trace gases (CH4, CO2, and CO) are collected from a tower located in an urban center and downwind of major ONG activities in Bakersfield, CA as part of the CEC-funded SUMMATION project (SUper eMitters of Methane detection using Aircraft, Towers, and Intensive Observational Network). Early results will be presented of continuous measurements from Summer to Winter of 2021. Preliminary results of CH4 are up to 3 times higher than the background. We expect to see a correlation between elevated levels of CH4 and benzene from the ONG sector as well as a strong relationship between CO and toluene during peak traffic periods. The results will highlight the application of the compact and easily deployable GC-PID for community monitoring and screening of BTEX from ONG and urban emissions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.A55D1412F