Rearden_GCC_2015

1st Detect Proprietarywww.1stdetect.com
Preshious Rearden, Ph.D.
Senior Applications Chemist
prearden@1stdetect.com
GCC - October 20, 2015

Air Toxic Monitoring
US EPA Requires Oil Refineries To Monitor Benzene Levels
 Other Hazardous Air Pollutants (HAP) include 1,3-butadiene, toluene, ethylbenzene,
and xylenes
 Method 325 established by the EPA for fenceline monitoring of benzene at petroleum
refineries
• Method sets standards for sampler placement, sample collection, preparation, and
analysis
• Recommends a passive sampling approach
‒ 12 to 24 passive samplers placed at 15 to 30 degree intervals along the perimeter
of each refinery
‒ Sampling cycle: 14 days

Passive Sampling - Limitations and Challenges
Passive Sampling
 Samples analyzed off-line
 Inability to identify emission source
Miniature Mass Spectrometer As An Alternative
Approach To Passive Sampling

iONTRAC
Why iONTRAC?
 Program and monitor gas streams in real-time
 Data from unused channels stored for future analysis
 No carrier gases required
 Operator controlled or autonomous unattended operation
 Continuous monitoring
 Out-of-spec product alarms
 Cost Effective
 Miniature ion trap mass spectrometer
 Mass Range: 35 – 500 amu
 Dynamic Range: 2 orders of magnitude
 Gases Monitored: User programmable (up to 8 ions)

GOAL
To Demonstrate the Feasibility of the iONTRAC to Monitor HAPs
 Monitor benzene and ethylbenzene excursions
 Evaluate the iONTRAC’s performance under ambient conditions

Ambient Monitoring Technical Approach
 iONTRAC equipped with a preconcentrator utilizing a Carbopack X sorbent
• Sampling Time: 70 s
• Desorption Time: 60 s
 Instrument was placed in parking lot at 1st Detect’s facility in Webster TX
 System challenged with benzene and ethylbenzene at varying distances
 Mixtures of benzene and ethylbenzene analyzed
 Meteorological data recorded with each simulated emission
 Sampling Mode: Continuous
 Sample period: 5 days
• Hold Time: 200 s
• Desorption Temp: 300C

Experimental Set-up
iONTRAC
Weather Station
180 ft
Excursion

Baseline Recovery
Benzene
Ethylbenzene
Removed Sample
180 ft Excursion
m/z = 78
m/z = 91
m/z = 106
Intensity(a.u.)Intensity(a.u.)

Reproducibility
Added BenzeneBenzene
Intensity(a.u.)

Meteorological Effects
Wind Speed and Direction
3mphWNW
3mphN
3mphS
3mphENE
3mphE
iONTRAC
Sample
BenzeneToward iONTRAC
Away from iONTRAC
Intensity(a.u.)

VOC Detection
Benzene and Ethylbenzene
Benzene (m/z = 78)
Ethylbezene (m/z = 91)
Ethylbezene (m/z= 106)
100 ft
Intensity(a.u.)

Detection Levels
Benzene
Benzene and Ethylbenzene Detected at 200 ft
20 ft
Intensity as a Function of Distance
Intensity(a.u.)
Avg.Intensity(a.u.)
Intensity(a.u.)
200 ft

Summary
 iONTRAC offers continuous real-time monitoring of VOCs in
ambient air with:
• Rapid clear down rates (< 2 min)
• Stable and rapid response time
• Detection VOCs levels to a least 200 ft
• Simultaneous monitoring of multiple VOCs
• Faster detection times than passive sampling (<5 min)

Future Directions
 Optimize sampling and detection time
 Test additional compounds
 Increase the number of sampling ports on the iONTRAC
 Test units on-site at petroleum refineries
Where Do We Go From Here?

Acknowledgements
Corey Stedwell, Ph.D.
Daniel DeBord, Ph.D.
Madonna Mamerow, Ph.D.
Parminder Kaur, Ph.D.
James Wylde, Ph.D.
David Rafferty

Thank You!

Questions?

Rearden_GCC_2015

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