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Update on Results of FY11-12 Work Plan Activities

Presentation to the NETAC Policy and Technical Committees

Sue Kemball-Cook and Greg Yarwood

June 13, 2013

skemballcook@environcorp.com

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HRVOC Study in Sabine Industrial District

• Solar Occultation Flux (SOF) method used to– Measure emission fluxes of ethene and propene (kg/hr) – Show HRVOC plume locations and suggest source locations

• May 1-11, 2012• ENVIRON reported on study at June, 2012 NETAC meetings

Ethene Emissions Propene Emissions

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Study Follow-up

• Eastman, Westlake and Flint Hills reviewed operations for May 1-11– No upsets for Westlake and Flint Hills– May 7 at 11 pm until 2 am on May 8: Eastman flaring upset

released 588 lbs of ethene Event began after the completion of the SOF traverse that recorded the

high values of ethene – May 9 at 10:30 am to May 11 at 7 am: Eastman plant shutdown

flaring event released 2,624 lbs propene Successful measurement of this episode of high propene emissions

confirms that the SOF method is able to detect HRVOC emissions due to upset events

• Eastman provided NETAC with interim 2011 emission estimates to be superseded by 2011 data officially submitted to TCEQ

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Estimates of Ethene and Propene Emissions

• Typical day Eastman Complex emissions of ethene are underestimated in current emission inventories

• Propene emissions estimates in current inventories are greatly underestimated• There are episodes of emissions of ethene and propene that are higher by a factor of two than the

typical day emissions

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Haynesville Shale Emission Inventory Update• >3,000 Haynesville wells

currently producing– Exceeds the most

aggressive projection• Sharp decline in

development since 2010– Current drilling activity

below lowest projection• Expanded geographic

area• NETAC inventory,

developed in 2009, required an update

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Emission Inventory Development

• Sent survey to Haynesville producers– Chesapeake, Penn Virginia

and XTO responded• 2011 base year• Projected rig and well

counts to for 2012-2020 for three scenarios

• Estimated production using well decline curves derived from TRRC and LDNR data

• Estimated emissions accounting for on-the-books emission controls

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Moderate Scenario Emissions

• Estimates of 2012 NOx emissions ranged from 32-50 tpd • Estimates of 2020 NOx emissions ranged from 25-149 tpd • Even at a slow pace of development, the Haynesville Shale continues to be

a significant source of emissions that can affect ozone in Northeast Texas

NOx Emissions (tpd) VOC Emissions (tpd)

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Heavy-Duty Truck Idling Study

• During layovers, long-haul HDDV truck drivers park their truck with the engine on (idling)

• Extended idling releases ozone precursor emissions from diesel fuel combustion

• TCEQ requested that the Near Non-Attainment Areas provide data on extended truck idling activity in their areas– Extended idling restriction is one of the few remaining on-road emission

reduction strategies that can be enacted at the local level

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Method

• Identified major extended idling sites in 5-county area– Longitude and latitude, heavy-truck parking capacity

• Conducted on-site observations of idling trucks during late August 2012– Parking spot occupancy and idling rates at various times of

the day– Site samples at various times of day during midday and

overnight periods• Developed profiles of extended idling activity for

inclusion in the TCEQ’s on-road mobile source inventory

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Results• Visited 14 extended idling sites

multiple times from August 23-26, 2012

• Magnitude of idling hours for Gregg and Harrison is larger in the current TCEQ 2012 inventory than was observed during August 2012– Truck stop closures since 2004

study on which the TCEQ inventory is based

– Lower idling rates per parking space observed by ENVIRON than in 2004 study

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Ozone Modeling

• Developed 2006 ozone model from inputs provided by the TCEQ to the NNAs

• Model has an overall high bias in Northeast Texas during transport episodes and stagnant periods– Texas border monitors consistently overestimate ozone

Suggests transport in Texas is generally overestimated

• Test sensitivity to model updates aimed at improving model performance– The TCEQ provided two new WRF meteorological runs aimed at improving

performance over Northeast Texas– CAMx model version v5.40->v5.41– Updated chemical mechanism from CB6 to CB6r1– Revised emission inventory from TCEQ

More detailed emissions source categories for source apportionment modeling– Day-specific wildfire emissions

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Summary of June 2006 Model Performance Evaluation

• Tests with largest impact were Cb6r1 and new TCEQ emission inventory

• Both generally increased the model’s high bias. Further work is required to understand the causes of the high bias in both the revised 2005 and 2006 model.

Tyler

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2006 Ozone Source Apportionment Modeling• For all three monitors,

transport exceeds local contribution

• Contribution from sources outside the U.S. and from the stratosphere ~20 ppb

• The local contribution ranges from 8.5 ppb (Karnack) to 17 ppb (Longview)

• EGUs, on-road mobile and oil and gas are largest components of local contribution

Contribution of Local Emissions to Longview Ozone

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May-June 2005 Ozone Model

• Adapted NETAC’s existing 2005 ozone model to use the new TCEQ June 2006 modeling platform – Take advantage of updates to the ozone model and its inputs– Retain day-specific emissions and 2005 meteorology and make rest of inputs

consistent with 2006 model• Move to new modeling platform increased the high bias in the 2005

model.

1-hour Average Ozone at the Longview Monitor

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Gas Compressor Engine Study

• Update NETAC’s existing emission inventory for gas compressor engines within the 5-county area of Northeast Texas and Panola County

• Available engine data were reviewed in order to revise the engine horsepower distribution in the NETAC inventory that was based on 2005 and 2007 survey data gathered by Pollution Solutions

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Method

• Reviewed engine test reports collected by TCEQ’s Tyler office – Compressor engines in Northeast Texas subject to the East Texas

Combustion Rule and New Source Performance Standards (NSPS) Subpart JJJJ

• Researched other available data to characterize the population of Northeast Texas compressor engines

• Reviewed gas compressor engine data from TCEQ’s Special Inventory of oil and gas production sources in the Barnett Shale

• Sensitivity testing to evaluate the effect of assumptions on horsepower and well count distribution on the Northeast Texas gas compressor engine population

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Sensitivity Test Results

• Findings suggest that the number of engine tests of ≥240 HP reported to TCEQ in 2011 under the East Texas Combustion Rule is smaller than expected

• Possible shift in the engine population towards lower horsepower (< 240 HP) or to lean burn engines

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Current Status of Gas Compressor Engine Emission Inventory

• Pollutions Solution inventory for gas compressor engines in Northeast Texas was developed before recent emissions regulations (East Texas Combustion, NSPS JJJJ)

• The TCEQ is currently developing an emission inventory for the year 2011 – Accounts for the East Texas Combustion Rule– Applies engine population data for the Barnett Shale to all 33 East Texas

counties affected by the East Texas Combustion Rule– Not known if current Northeast Texas engine population is similar to that

of the Barnett Shale • The review of engine data showed that there is no publicly available

source of engine population data for Northeast Texas• Comprehensive, recent data on engine population is critical for the

development of an accurate emission inventory

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Other Reports

• Conceptual Model Update through 2011– SOF Study plume location and emission inventory

comparison– Emission trends– Ambient data analysis, high ozone day discussion– Modeling results

• Development of day-specific fire emissions for 2005 and 2006 ozone models