Quantifying Emissions of Ammonia For Air Quality Analysis

Viney P. AnejaDepartment of Marine, Earth, and Atmospheric Sciences

North Carolina State UniversityRaleigh, NC 27695-8208, U.S.A.

2009 Science Meeting "Total Reactive Nitrogen: Regional Haze Impacts and Mitigation Options”July 28-29, 2009Baltimore, MD

U.S. Agricultural 2008 Preliminary Revenues

• Confined Animal Feeding Operations (CAFOs)Livestock receipts: ~$143.1 billion

• Crop receipts: ~$181.1 billion

Source: http://www.ers.usda.gov/Briefing/FarmIncome/Data/cr_t3.htm

National Media Attention

July 7, 2004

July 12, 2004

June 3, 2004

Emission, Transport, Transformation, and Deposition of Trace Gases

Source: Aneja et al., 2006, Eos

National Research Council, 2002Report “The Scientific Basis for Estimating Emissions from Animal Feeding Operations”

• “The stakes in this issue are large. More and more livestock are raised for at least part of their lives in AFO’s in response to economic factors that encourage further concentration. The impacts on the air in surrounding areas have grown to a point where further actions to mitigate them appear likely.”

• “EPA may use information from this project in determining how it will approach regulating both air and water quality impacts of AFOs. Substantial emissions of nitrogen (N), sulfate (S), carbon (C), particulate matter (PM), and other substances from AFOs do occur and cannot be ignored.”

Impacts of Enhanced Ammonia on the Environment

• Particulate matter (PM) formation• Visibility degradation• Nitrogen enrichment and eutrophication in

aquatic ecosystems• Impact on crop and forest production• Impact on ground water quality• Impact on biodiversity• Odors and odorants• Changes in rainfall chemistry

GasGas--ToTo--Particle Conversion ProcessesParticle Conversion Processes

HO2

NO23

SecondaryOrganicAerosol

CO, RH, RCHO

Gas-phaseProducts

Droplet Phase (Dp > 10um)

Aer

osol

Pha

se (D

p<

10um

)

Chemical coupling in the atmospheric gas, particle, and droplet phases (Meng, et al., 1997).

H2O2

HO2

NO

OHO3

NO3

NO3

PANRCO3

H2OHNO3

NH3

NH3

SO2

H2SO4

hv

N2O5

CO NOx PM2.5 PM10 SO2 VOC Pb NH3

1970 197.3 26.9 2.3(1990)

12.2 31.2 33.7 0.221 1.9

2005 89 19 2 2 15 16 0.003 2.6

Percent Change

-55% -29% -13% -84% -52% -53% -99% +27%

Source: http://www.epa.gov/airtrends/econ-emissions.html

U.S. Air Pollutant Emission Estimates (million tons/yr)

CO NOx PM2.5 PM10 SO2 VOC Pb NH3

1970 197.3

26.9 2.3(1990)

12.2 31.2 33.7 0.221 1.9

2005 89 19 2 2 15 16 0.003 2.6

Percent Change

-55% -29% -13% -84% -52% -53% -99% +27%

Percent Change(Europe)

-34% -76% -43% -22%

Source: http://www.epa.gov/airtrends/econ-emissions.html

U.S. and Europe Air Pollutant Emission Estimates (million tons/yr)

Nonattainment Areas in 2005

(Source: EPA Green Book, 2005)

Areas exceeding O3 Standard Areas exceeding PM2.5 Standard

(PM2.5: Particulate Matter with an aerodynamic diameter of up to 2.5 µm )

• Emission factors

• Emission based on inverse modeling

• Process based modeling

• Remote sensing

Methods to Quantify Ammonia Emissions

Commercial Hog Farm in North Carolina, USSampling Sites

Production Houses

Forage/Feed N, S, C

Waste Storage and Treatment Systems

Land Application

(i.e. spraying)

Biogenic Emissions

From Soil and Crops

e.g.NH3 VolatilizationUrine/feces

e.g.NH3 VolatilizationUrine/feces

e.g.NH3 VolatilizationUrine/feces

e.g.NH3 VolatilizationUrine/feces

Major Routes for N, S, and C Emissions from Intensively Managed Animal Operations in the USA

Ammonia Flux Micrometeorological Experiment

Dynamic Flow-Through Chamber System

Source: Aneja et al., 2000, JGR

U.S. EPA WATER9 Model

Ammonia Flux MeasurementsLog

(Program OPEN)

Program OPEN

Estimating Agricultural NH3 Emissions (Emission Factor Approach)

• Activity Data: U.S. Census of Agriculture for 2002 at county-level

Emission Rate (kg NH3 year-1) =

Activity Data (animal population) * Emission Factor (kg NH3 animal-1 year-1)

• Beef and Dairy Cattle• Hogs and Pigs• Chickens• Broilers

• Turkeys• Horses• Sheep• Fertilizer Application

(AAPFCO)

Volcanic emissions ?

Primary Sources of Ammonia Emissionsfor Animal Agriculture by Region

Based on current emission factor approach.

U.S. Ammonia Emission Factors for Animal and Crop AgricultureAnimal Agriculture Emission factor (kg-NH3/animal/ yr)

Animal Battye, Aneja, & Roelle, 20031 U.S. EPA: Battye et al., 19943

Dairy cow 28 40

Beef cow 10.2 27 (steers)

Sow 16.4 16

Finishing pig 6.4 7

Laying hen 0.31 0.31

Broiler 0.28 0.17

Sheep 1.34 3.4

Horses 8.0 12

Crop Agriculture Emission factor (kg NH3/Mg N)

Fertilizer Aneja et al., 20032 U.S. EPA: Battye et al., 19943

N-P-K 48 48

Nitrogen solutions 30 30

Ammonium phosphates 48 48

Anhydrous NH3 12 12

Urea 182 182

Ammonium nitrate 25 25

Other straight nitrogen 30 30

Ammonium sulfate 97 97

Aqua NH3 12 12

Ammonium thiosulfate 30 30

Fertilizer 27.9%

Non Agriculture 20.4%

Dairy Cattle 11.9%

Beef Cattle 14.0%

Poultry 14.2%

Swine 9.2%

Sheep 0.5%

Horses 1.5%

Goats 0.3%

U.S. Ammonia Emission Estimates (2002)

Total emissions: ~4 million tons/yr

Source: U.S. EPA 2002 National Emissions Inventory

2002 Ammonia Emissions

Based on current emission factor approach.Source: U.S. EPA, 2007

Ammonia Concentration CMAQ Output

• 36km grid

• 2001 emissions inventory and meteorology

• SAPRAC chemistry module

• Concentrations range from0-12 ppb

• Provides an idea of representativeness of sample locations

Source: U.S. EPA, 2007

Source: Gilliland et al., Atmos. Environ., 2006

Seasonal NH3 Emissions: Inverse Model EstimationComparison of model (CMAQ) and measured NH4

+ wet deposition

2003 20042002

NADP Ammonium Ion Wet Deposition

CMAQ Ammonium Ion Wet Deposition

CMAQ is able tocapture main spatial pattern and magnitudeof wet deposition

Courtesy: R. Dennis/R. Mathur (EPA)

Commercial Hog Farm in North Carolina, USSampling Sites

0

1000

2000

3000

4000

0:00 6:00 12:00 18:00 0:00

Time of Day

NH

3 -N

Flu

x ( μ

g m

-2 m

in-1

)

Observed Modeled

Measurements Compared with NH3 MTCR Model

October 31, 2004

NH3 flux from a swine waste lagoon system: Fall 2004

R2 = 0.41

1000

1500

2000

2500

3000

3500

1000 1500 2000 2500 3000 3500

MTCR Modeled NH3 Flux

Mea

sure

d N

H3 F

lux

Satellite Remote Sensing for Ammonia and Particulate Matter

Ammonia Emission Projections

0

100

200

300

400

500

600

700

800

900

1,000

2000 2005 2010 2015 2020 2025 2030

Year

NH

3Em

issi

on

s (t

ho

usa

nd

to

ns/

yr)

Beef Cattle

Dairy Cattle

Poultry

Swine

Based on current emission factor approach.Source: U.S. EPA, 2007

Cattle

• Addition of Alum or Zeolite to slurry to stop volatilization

Alum Reduction2.5% 58 ± 6%6.25% 57 ± 10%

Zeolite Reduction2.5% 22 ± 6%6.25% 47 ± 10%

• Acidifying liquid cow manure with lactic or nitric acid

pH Lowered emissions by

5.73 65 %5.14 72 %4.18 88 %

Lactic Acid

pH Lowered emissions by

5.20 29 %4.49 49 %

Nitric Acid

Swine• Manure additives

– 24% reduction• Biotrickling filters (Hansen, 2006)

– Reduce odor• Winter – 54%• Summer – 28%

– Reduce ammonia• Storage spreading system with biological

treatment of manure (Loyon, 2006)– Reduced NH3

• 30-50% with separated manure• 68% with unseparated manure

Nitrification

Denitrification

Module

Phosphorus

Removal

Module

EffluentEffluent

CalciumCalcium

PhosphatePhosphate

Solid-liquid

Separation

Module

Separated Separated SolidsSolids

The Process

Super Soil SystemsNorth Carolina’s

Swine Waste Treatment Solution

Reuse

Summary and Conclusions

• Emission factors approach– Easy to use, but results may have uncertainty

• Process based and inverse modeling approach– Complex but results have less uncertainty

• Remote sensing approach– Emerging area of gaseous and PM emission analysis

Challenges for the Community

What are the potential health effects from exposures to ambient levels of NH3?

How does NH3 react in the presence of other prevalent air pollutants such asSO2, NOX, etc.?

What are the sources of excess NH3 in the atmosphere? What is excess? How much is “natural”?

What do we know about reactions in the atmosphere?

Is there long range atmospheric transport?

Are current air monitoring methods sufficient for NH3 measurement?

Vertical bi-directional transport of ammonia ?

Are current air quality modeling techniques sufficient for analyzing the N cycle, including NH3?

Is it prudent to regulate NH3 and NOX or should we focus on the total N cycle?

How do we optimize and evaluate the impacts of reductions of the various forms of N and of other air pollutants?

Are control technologies for agricultural sources available? Are they feasible?

What are the proven methods (BMPs) and their associated costs for reducing NH3from agricultural sources?

Need for a network to monitor emissions from agricultural sources.

Challenges for the Community

• U.S. Department Of Agriculture – National Research Initiative,Contract No. 2004-35112-14253

• Phosphate Potash Institute, The Fertilizer Institute

• The National Science Foundation

• The Kenan Institute

• North Carolina Division of Air Quality, Contract No. EA 01001, and EA 8001

• Animal and Poultry Waste Management Center / Smithfield Foods

• Water Resource Research Institiute, Contract No. EA 7003

• Ms. Megan Gore

Acknowledgements

Quantifying Emissions of Ammonia For Air Quality Analysis

Viney P. AnejaDepartment of Marine, Earth, and Atmospheric Sciences

North Carolina State UniversityRaleigh, NC 27695-8208, U.S.A.

2009 Science Meeting "Total Reactive Nitrogen: Regional Haze Impacts and Mitigation Options”July 28-29, 2009Baltimore, MD

National Hog Farming Trends

States with most hogs

1992 2005Hog Population

58.2 million 61.3 million

Animals in Facilities > 2000 Head29% 79%

Changes in Production Facilities

0

5

10

15

20

1985 1990 1995 2000 2005

Year

Num

ber

of H

ogs

(Mill

ions

)

Iowa North Carolina Minnesota Illinois

Annual Average NH3 Emissions (2001)US EPA Emission Factor Based Inventory