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How Texas Air Quality Study 2000 (TexAQS 2000) results identified

critical ozone precursors in Houston, Texas, and led to effective ozone

control strategies• High reactivity of Houston VOCs is attributed to light alkenes,

which have been underestimated by approximately a factor of ten in emissions inventories.

• Reduction/regulation of HRVOCs (and NOX) has led to a large decrease in ozone.

• Perfect knowledge of emissions is not always essential to developing an effective control strategy.

Mark Estes, Kasey Savanich, John Jolly, and the Air Modeling and Data Analysis Section,

Texas Commission on Environmental QualityPresented at the Global Emissions Initiative conference Tsinghua University, Beijing, China, 18 November 2015

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Fourth-Highest Eight-Hour Ozone Values in the HGB Area

2000

≤ 6666 - 7070 - 7474 - 7878 - 8282 - 8686 - 9090 - 9494 - 9898 - 102102 - 106106 - 110110 - 114> 114

Houston O3 in 2000 Peak 1-hr ozone: 225 ppbPeak 8-hr ozone: 144 ppb4th high 8-hr areawide: 117 ppb

Strong ozone gradients (>40 ppb increase in O3 in one hour) occurred 115 times at Houston monitors in 2000

Source: TCEQ ozone data

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Houston was found to have considerably higher reactivity than other cities (Kleinman et al., JGR 2005).

Higher OH reactivity was due to very high concentrations of light alkenes—ethene, propene, 1,3-butadiene, butenes. TexAQS scientists also found that highly-reactive VOC (HRVOC) emissions had been underestimated by a factor of about 10.

TCEQ historical analyses verified that light alkenes had often had high concentrations in the Houston industrial areas, but their significance had not been fully appreciated until TexAQS 2000.

From Kleinman et al. JGR 2005

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TexAQS 2000 data:High rates of ozone formation P(O3) occurred in and downwind of the industrial areas, and were linked to abundant HRVOCs (Daum et al. 2003, 2004; Kleinman et al. 2002, 2005; Ryerson et al. 2003; Wert et al. 2003). Ozone production efficiency was twice as high in industrial plumes (11-12 mol O3/mol NOZ) as in urban plumes (5.4 mol/mol) (Ryerson et al. 2003).

From Daum et al. 2003

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CAMx modeling: Photochemical grid modeling EI was roughly adjusted to reflect TexAQS observations of HRVOCs: point source VOC emissions increased from 6742 kg/hr to 12,386 kg/hr. Ozone performance improved, especially on high O3 days . 25 Aug 2000: modeled peak 1-hr ozone increased from 113 ppb to 198 ppb (observed: 194 ppb ).

https://www.tceq.texas.gov/assets/public/implementation/air/sip/sipdocs/2002-12-HGB/tsdpart1.pdf

TexAQS findings led to rules that required facilities to monitor HRVOC emissions, and set both short-term and long-term site-wide caps on HRVOC emissions from affected flares, fugitives, process vents, and cooling towers. TexAQS findings also allowed us to target additional studies that improved our knowledge of how flares, cooling towers, process vents, tank landing losses, barge loading, and coking towers could emit much more than previously known.

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Expected 2006-2014: ~-30%Observed 2000-2014: -55 to -64%Observed 2006-2014: -25 to -44%

Median monthly NOX decreased 37%

• HRVOC controls phased in from 2003-2006, but concentrations decreased between 2000 and 2003.

• Anticipated HRVOC emission decreases after 2006 were about ~30%, based upon bottom-up EI. From 2006-2014, ethene concentrations at TCEQ Houston sites decreased 25% to 44%; propene concentrations decreased 35% to 63%.

• Johansson et al. JGR 2014 measured top- down ethene fluxes decreasing 30% from 2006-2011, propene decreasing 63%.

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Geometric mean concentration data for ethene (top) and propene (bottom) has been combined with wind direction data at five auto-GC locations. The TCEQ triangulation analyses show that industrial point sources are the primary emission sources of these two alkenes. Narrow, strongly directional plumes measured at each site indicate that a subset of alkene sources are apparently associated with the highest concentrations.

The trend from 2003 to 2008 shows how some sources have greatly decreased emissions, and others have not.

Source: TCEQ data, analyzed by J. Jolly

Ethene, ppbC

Propene, ppbC

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Fourth-highest 8-hour ozone values in the HGB area (below) have decreased by -20% to -35% since 2000. Observed strong ozone

gradients (1-hr increase > 40 ppb/hr) decreased from 115 occurrences in 2000 to an average of 6 per year from 2011 to 2015 (95% decrease).

2000 2015

≤ 6666 - 7070 - 7474 - 7878 - 8282 - 8686 - 9090 - 9494 - 9898 - 102102 - 106106 - 110110 - 114> 114

Source : TCEQ ozone data

4th high O3 (ppbv)

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References and additional resourcesTexAQS 2000• Daum, P.H., L. I. Kleinman, S. R. Springston, L. J. Nunnermacker, Y.-N. Lee, J. Weinstein-Lloyd, J. Zheng, and C. M. Berkowitz (2003) A comparative study of O3 formation

in the Houston urban and industrial plumes during the 2000 Texas Air Quality Study. Journal of Geophysical Research, VOL. 108, NO. D23, 4715, doi:10.1029/2003JD003552, 2003.

• Daum, P.H., L. I. Kleinman, S. R. Springston, L. J. Nunnermacker, Y.-N. Lee, J. Weinstein-Lloyd, J. Zheng, and C. M. Berkowitz, (2004). Origin and properties of plumes of high ozone observed during the Texas 2000 Air Quality Study (TexAQS 2000). Journal of Geophysical Research, 109, D17306, doi:10.1029/2003JD004311, 2004.

• Jobson et al., (2004). Hydrocarbon source signatures in Houston, Texas: Influence of the petrochemical industry. J. Geophys. Res. 109, D24305, doi:10.1029/2004JD004887, 2004.

• Karl, Thomas, et al., (2003). Use of proton transfer-reaction mass spectrometry to characterize volatile organic compound sources at the La Porte super site during the Texas Air Quality Study 2000. Journal of Geophysical Research, 108(D16): 4508, doi:10.1029/2002JD003333, 2003.

• Kleinman et al., (2005). A comparative study of ozone production in five U.S. metropolitan areas. J. Geophys. Res., 110, D02301, doi:10.1029/2004JD005096, 2005. • Kleinman L. et al. (2002), Ozone production rate and hydrocarbon reactivity in 5 urban areas: A cause of high ozone concentration in Houston, Geophys. Res. Lett., 29

(10), doi:10.1029/2001GL014569, 2002. • Kuster, W. C.; Jobson, B. T.; Karl, T.; Riemer, D.; Apel, E.; Goldan, P. D.; Fehsenfeld, F. C. (2004). Intercomparison of Volatile Organic Carbon Measurement Techniques

and Data at La Porte during the TexAQS2000 Air Quality Study. Environ. Sci. Technol.; 2004; 38(1); 221-228. DOI: 10.1021/es034710r • McGaughey, Gary R., Nimish R. Desai, David T. Allen, Robert L. Seila, William A. Lonneman, Matthew P. Fraser, Robert A. Harley, Alison K. Pollack, Jason M. Ivy, James

H. Price, (2004), Analysis of motor vehicle emissions in a Houston tunnel during the Texas Air Quality Study 2000, Atmospheric Environment 38 (2004) 3363–3372. • Nam, Junsang, Mort Webster, Yosuke Kimura, Harvey Jeffries, William Vizuete, David T. Allen (2008), Reductions in ozone concentrations due to controls on variability

in industrial flare emissions in Houston, Texas, Atmospheric Environment, Volume 42, Issue 18, , June 2008, Pages 4198-4211, doi:10.1016/j.atmosenv.2008.01.035. • Nam, Junsang, Yosuke Kimura, William Vizuete, Cynthia Murphy, David T. Allen, (2006), Modeling the impacts of emission events on ozone formation in Houston,

Texas, Atmospheric Environment, Volume 40, Issue 28, September 2006, Pages 5329-5341. • Ryerson, T. B., et al. (2003). Effect of petrochemical industrial emissions of reactive alkenes and NOx on tropospheric ozone formation in Houston, Texas. Journal of

Geophysical Research, 108(D8), 4249, doi:10.1029/2002JD003070, 2003.• Webster et al. (2007), The effect of variability in industrial emissions on ozone formation in Houston, Texas, Atmospheric Environment 41 (2007) 9580–9593. • Wert, B. P., et al., (2003), Signatures of terminal alkene oxidation in airborne formaldehyde measurements during TexAQS 2000. Journal of Geophysical Research, VOL.

108, NO. D3, 4104, doi:10.1029/2002JD002502, 2003. • Xie, Yulong, and Carl M. Berkowitz, (2007), The use of conditional probability functions and potential source contribution functions to identify source regions and

advection pathways of hydrocarbon emissions in Houston, Texas, Atmospheric Environment, Volume 41, Issue 28, September 2007, Pages 5831-5847. • Xie, Yulong, and Carl M. Berkowitz, (2006), The use of positive matrix factorization with conditional probability functions in air quality studies: An application to

hydrocarbon emissions in Houston, Texas, Atmospheric Environment, Volume 40, Issue 17, June 2006, Pages 3070-3091. TexAQS 2006• De Gouw, J. A., et al. (2009), Airborne measurements of ethene from industrial sources using laser photo acoustic spectroscopy, ‐ Environ. Sci. Technol., 43, 2437–2442,

doi:10.1021/es802701a. • Gilman, J. B., et al. (2009), Measurements of volatile organic compounds during the 2006 TexAQS/GoMACCS campaign: Industrial influences, regional characteristics,

and diurnal dependencies of the OH reactivity, J. Geophys. Res., 114, D00F06, doi: 10.1029/2008JD011525. • Mellqvist, J., J. Samuelsson, J. Johanssson, C. Rivera, B. Lefer, S. Alvarez, and J. Jolly (2010), Measurements of industrial emissions of alkenes in Texas using the solar

occultation flux method, J. Geophys. Res., 115, D00F17, doi:10.1029/2008JD011682. • Parrish, D. D., et al. (2009), Overview of the Second Texas Air Quality Study (TexAQS II) and the Gulf of Mexico Atmospheric Composition and Climate Study

(GoMACCS), J. Geophys. Res., 114, D00F13, doi: 10.1029/2009JD011842. • Washenfelder, R. A., M. Trainer, G. J. Frost, T. B. Ryerson, E. L. Atlas, J. A. de Gouw, F. M. Flocke, A. Fried, J. S. Holloway, D. D. Parrish, J. Peischl, D. Richter, S. M.

Schauffler, J. G. Walega, C. Warneke, P. Weibring, and W. Zheng (2010), Characterization of NOx, SO2, ethene, and propene from industrial emission sources in Houston, Texas, J. Geophys. Res., doi:10.1029/2009JD013645.

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References and additional resources

TCEQ 2010 Flare Study final report: https://www.tceq.texas.gov/assets/public/implementation/air/rules/Flare/2010flarestudy/2010-flare-study-final-report.pdf TCEQ Flare Study 2010: peer-reviewed articles• Al-Fadhli, Fahad M., Yosuke Kimura, Elena C. McDonald-Buller, and David T. Allen (2012), Impact of Flare Destruction Efficiency and Products of Incomplete Combustion on Ozone Formation in Houston, Texas, Industrial and

Engineering Chemistry Research, DOI: 10.1021/ie201400z. • Herndon, Scott C., David D. Nelson, Jr., Ezra C. Wood, W. Berk Knighton, Charles E. Kolb, Zach Kodesh, Vincent M. Torres, and David T. Allen (2012), Application of the Carbon Balance Method to Flare Emissions

Characteristics, Industrial and Engineering Chemistry Research, Publication Date (Web): April 6, 2012 (Article), DOI: 10.1021/ie202676b.• Pavlovic, Radovan T., David T. Allen, and Elena C. McDonald-Buller (2011), Temporal Variability in Flaring Emissions in the Houston–Galveston Area, Industrial and Engineering Chemistry Research, Publication Date (Web):

September 20, 2011 (Article), DOI: 10.1021/ie2013357• Pavlovic, Radovan T., Fahad M. Al-Fadhli, Yosuke Kimura, David T. Allen, and Elena C. McDonald-Buller , Impacts of Emission Variability and Flare Combustion Efficiency on Ozone Formation in the Houston–Galveston–

Brazoria Area, Industrial and Engineering Chemistry Research, Publication Date (Web): April 5, 2012 (Article), DOI: 10.1021/ie203052w. • Torres, Vincent M., Scott Herndon, Ezra Wood, Fahad M. Al-Fadhli, and David T. Allen (2012), Emissions of Nitrogen Oxides from Flares Operating at Low Flow Conditions, Industrial and Engineering Chemistry Research,

Publication Date (Web): March 21, 2012 (Article), DOI: 10.1021/ie300179x. • Torres, Vincent M., Scott Herndon, Zach Kodesh, and David T. Allen (2012), Industrial Flare Performance at Low Flow Conditions. 1. Study Overview, Industrial and Engineering Chemistry Research, Publication Date (Web):

February 27, 2012 (Article), DOI: 10.1021/ie202674t. • Torres, Vincent M., Scott Herndon, and David T. Allen (2012), Industrial Flare Performance at Low Flow Conditions. 2. Steam- and Air-Assisted Flares, Industrial and Engineering Chemistry Research, Publication Date (Web):

February 27, 2012 (Article), DOI: 10.1021/ie202675f. • Wood, Ezra C., Scott C. Herndon, Ed C. Fortner, Timothy B. Onasch, Joda Wormhoudt, Charles E. Kolb, W. Berk Knighton, Ben H. Lee, Miguel Zavala, Luisa Molina, and Marvin Jones (2012), Combustion and

Destruction/Removal Efficiencies of In-Use Chemical Flares in the Greater Houston Area, Industrial and Engineering Chemistry Research, Publication Date (Web): April 18, 2012, DOI: 10.1021/ie202717m. Additional relevant Houston studies:• Johansson, J., J. Mellqvist, J. Samuelsson, B. Offerle, J. Moldanova, B. Rappenglück, B. Lefer, and J. Flynn (2014), Quantitative measurements and modeling of industrial formaldehyde emissions in the greater Houston area

during campaigns in 2009 and 2011, J. Geophys. Res. Atmos., doi: 10.1002/2013JD020159. • Johansson, J. K. E., J. Mellqvist, J. Samuelsson, B. Offerle, B. Lefer, B. Rappenglück, J. Flynn, and G. Yarwood (2014), Emission measurements of alkenes, alkanes, SO2, and NO2 from stationary sources in Southeast Texas over

a 5 year period using SOF and mobile DOAS, J. Geophys. Res. Atmos., 119, doi:10.1002/2013JD020485.• Robinson, R., T. Gardiner, and B. Lipscombe, 2008. Measurements of VOC emissions from petrochemical industry sites in the Houston area using Differential Absorption Lidar (DIAL) during summer 2007. Submitted to

Russell Nettles, TCEQ, by National Physical Laboratory, Teddington, Middlesex UK TW11 0LW, February 8, 86 pp. http://www.tceq.texas.gov/assets/public/implementation/air/am/contracts/reports/ei/DIAL.pdf• Ren, X., et al. (2013), Atmospheric oxidation chemistry and ozone production: Results from SHARP 2009 in Houston, Texas, J. Geophys. Res. Atmos., 118, 1-11, doi:10.1002/jgrd.50342. • Zhou, W., D.S. Cohan, and B. H. Henderson (2014), Slower ozone production in Houston, Texas following emission reductions: evidence from Texas Air Quality Studies in 2000 and 2006 , Atmos. Chem. Phys., 14, 2777–2788,

www.atmos-chem-phys.net/14/2777/2014/doi:10.5194/acp-14-2777-2014.TCEQ documents• Recommendations for improving bottom-up emissions inventories from problematic industrial point sources can be found at this website: http

://www.tceq.texas.gov/assets/public/comm_exec/pubs/rg/rg360/rg360-14/AppendixA.pdf• Training to operate a flare at high efficiency: https://sfot.ceer.utexas.edu/ • History of TCEQ HRVOC rulemaking: https://www.tceq.texas.gov/assets/public/implementation/air/rules/rule-history/115-history-hrvoc.pdf• Analyses of historical auto-GC and canister data 1996-2001: https://www.tceq.texas.gov/assets/public/implementation/air/am/docs/hgb/tsd1/attachment6-agc_voc.pdf ; analysis of auto-GC data, 2003-2008: http://

www.tceq.state.tx.us/assets/public/implementation/air/sip/hgb/hgb_sip_2009/09017SIP_completeNarr_ado.pdf (see pages 5-46 to 5-58).

Contact information : Mark.Estes@tceq.texas.gov512-239-6049