1One facility, two very different emissions

Module 5. Air Pollutant Emissions in the Mid-Atlantic United States

by K.G. Paterson, Ph.D., P.E. ©2007

www.mtu.edu

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Did You Know? For PM2.5 emissions in 2001, only 17 out

of the top 100 counties are in the Mid-Atlantic states (VA, WV, PA, MD, DC, DE, NJ)

2001 County Emissions Density (tons/mi2) of PM2.5

0 1.2-2.3

3.6-7 7+

0.7-1.2

2.3-3.6

>0-0.7

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Emission Module Goals

By the end of this module you should be able to: Classify emission types Identify emissions from major source types Describe the trends and patterns of air

pollutant emissions in the Mid-Atlantic U.S. Find the tools you need to estimate

emissions Find online resources of emission data

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WHAT ARE EMISSIONS?The amount of pollutant(s) a

source puts into the air during a fixed time.

Units: mass/timeEmissions vary – making air

quality management a challenge!Source activityEconomic healthPopulationClimateControlsTraffic

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.}These

influencesourceemissions:

TimeLocationPollutant

}Emissions varyover:

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Emissions classificationBy pollutant

By source type

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Classification – by PollutantSome general pollutant categories

includeCriteria air pollutants

Criteria Pre-cursor air pollutants

Hazardous Air Pollutants (HAPs) • There are 189 of these

• sulfur dioxide (SO2)• nitrogen oxides (NOx)• carbon monoxide (CO)• particulate matter (PM10, PM2.5)

• ammonia (NH3)• volatile organic compounds (VOCs)

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Classification – by PollutantAn Example: Emissions from North

Carolina in 1999:

* Point sources only

Pollutants Emissions* (lb/yr)

All criteria pollutants 1,930,000,000

All hazardous air pollutants (HAPs)

329,500,000

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Classification – by Source TypeStationary - sources with a fixed location

•Point: usually a large source, often a stack

•Area: sources that are considered as a groupMobile - sources

that move

•On-road: highway vehicles

•Non-road: non-highway vehicles

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Emissions from source types modeled differently

Mobilesource

Pointsource

Areasource

Gaussian plume model(e.g. ISC-AERMOD)

Roadway models(e.g. CALINE, CAL3QHC)

Flexible source models(e.g. CALPUFF)

Classification – by Source Type

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Analysis: Emission ClassificationQuestion: How many sources can

you think of?Action: In a small group, make

three lists for examples of air pollution sources: (1) point, (2) mobile, and (3) area

Time: 3 minutes

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Classification – by Source Type

Stationary sourcesMobile sources

Pointsource

Mobilesource

AreasourceExamples: on-road: gas, diesel;

off-road: marine, air, agricultural

Examples: power plant, chemical plant, etc.

Examples: gas stations,dry cleaners, fireplaces, lawn mowers, tanks farms, etc.

Stationary

Mobile

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Emission Classification Sulfur Dioxide (SO2)

Power plants are major sources of (SO2)

They are stationary (point) sources

0

0.2

0.4

0.6

0.8

1

1.2

DE DC MD NJ PA NC VA WV

Mill

ions

(to

ns/y

ear)

Point

On-Road

Non-Road

Area

(2002 data)

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Emission trends are not the same everywhere. Reductions in SO2

have been widespreadbut not universal.

http://www.epa.gov/airmarkets/cmap/mapgallery/mg_total_utility_so2.html

Emission Trend Sulfur Dioxide (SO2)

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Passenger vehicles are a major source of NOx.

These are mobile (on-road) sources.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

DE DC MD NJ PA NC VA WV

Mil

lio

ns

(to

ns/

year

)

PointOn-RoadNon-RoadArea

Emission Classification Nitrogen Oxides (NOx)

(2002 data)

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Trends in NOx emissionshave not been uniformin the Mid-Atlantic, butsome of the greatest reductions in the U.S.have been in the East

http://www.epa.gov/airmarkets/cmap/mapgallery/mg_total_utility_no3.html

Emission Trend Nitrogen Oxides (NOx)

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Analysis: Classification & Trend

http://www.epa.gov/airmarkets/cmap/mapgallery/mg_total_utility_no3.html

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Question: What are the temporal and spatial differences between NOX and SOX emissions in the Eastern United States? State why you think those temporal and spatial differences exist.

Action: In a small group examine the maps of the Eastern USA NOX and SOX emissions over time and report observations.

Time: 5 minutes.

Analysis: Classification & Trend

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MOBILE6 is a model for predicting emissions from vehicles. Capabilities:Pollutants predicted: CO, CO2, NOx, PM,

toxics, hydrocarbonsVehicle types: cars, trucks, motorcyclesOperating conditions: speed, temperature,

etc.Fuel types: gasoline, diesel

Emission Estimation

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Fugitive sources that often contribute to ambient particulate matter:Construction sitesAgricultureUnpaved roads

3% 2%

18%

9%

10%

5%7%

47%On-road vehicles

Off-road vehicles

Unpaved roads

Paved roads

Fuel combustion

Indiustrial processes

Waste disposal

MiscellaneousPM 2.5 Emissions

2000Source: Bureau of Transportation Statistics http://www.bts.gov/publications/national_transportation_statistics/2002/html/table_04_44.html

Emission Classification - Miscellaneous

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Emission EstimationAfter identifying possible sources of air

pollutant emissions, the next challenge is quantifying their magnitude.

Methods:Direct measurement CEM, stack testIndirect measurement Mass balanceProcess modeling Tanks and Mobile6Emission factor modeling AP-42

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MOBILE6 is a model for predicting emissions from vehicles. Capabilities:Pollutants predicted: CO, CO2, NOx, PM,

toxics, hydrocarbonsVehicle types: cars, trucks, motorcyclesOperating conditions: speed, temperature,

etc.Fuel types: gasoline, diesel

Emission Estimation - Example

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Further Learning Emissions Measurement Center, http://www.epa.gov/ttn/emc/ National Emission Inventory (NEI) Database for Criteria

and Hazardous Air Pollutants, http://www.epa.gov/oar/oaqps/emissns.html

Scorecard, an online tool to investigate pollution in your neighborhood, http://www.scorecard.org

Emission models, http://www.epa.gov/ttn/chief/software/ Compilation of Air Pollutant Emission Factors, Volume 1:

Stationary Point and Area Sources, AP 42, http://www.epa.gov/ttn/chief/ap42/index.html

AirData, online access to emissions at the county level and up, http://www.epa.gov/air/data/

A Guide to Mid-Atlantic Regional Air Quality, Part IV: Pollution Sources, pp. 47-58. http://www.marama.org/reports/Guide-MidAtlantic_RegAQ_Final.pdf

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Emission Module Goals

By the end of this module you should be able to: Classify emission types Identify emissions from major source types Describe the trends and patterns of air

pollutant emissions in the Mid-Atlantic U.S. Find the tools you need to estimate

emissions Find online resources of emission data

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Thanks for making this a great class!