Livestock and Air Quality CAFO Air Emissions Project

CSU-ARDEC Feb. 9, 2006

Animal Science (Johnson, Stanton, Marcillac)

NREL (Hannan)

ARS (Mosier/Follet

Atmospheric Sci. (Collet, Lee)

National Academy of ScienceNRC 03

Air Emissions from AFO’s• Commissioned by EPA and USDA

• Finding 7: methods and measurements needed for NH3, CH4, H2S, PM’s

• Finding 8: Emission factor estimates not adequate

• Finding 9: Process-based model development recommended

National Research Initiative USDA 2004 RFP

• $ for Air Quality studies

• ? How can AFO emissions be measured?

• Particularly variable, heterogeneous production systems; e.g., cattle, pens, dams, lagoons, composting of all shapes sizes, etc

• We have a team that thinks we can!

Air Emissions from dairy CAFO: multi-scale measurements and process-based modeling

• The overall aim: to measure potentially problematic air emissions from cattle production systems and develop process based methods to predict them.

Specific Objectives

• 1.   Measure emissions from 2 dairies:– Ammonia– PM2.5

– Nitrous oxide– Methane

• 2. Determine diurnal, seasonal variations • 3. Develop and challenge process model

estimates of emission fluxes

Objectives Contd:

• 4. Correlate downwind concentrations of spot sampled emissions - e.g.: H2S, VOC’s..

Approach

• Quantification of CAFO System Emissions– Mass Balance

F0

F1

Fe

Fd

FSx,y = dc/dtx,y,z + {F1y,z–F0y,z} + {Flx,z} + {Fex,y+Fdx,y}

dc/dt

x

yz

Whole-System Trace Gas Fluxes from Complex Agricultural Sources: Plume Characterization and Conservation of Mass

FS

Fl

Plume Lateral Vertical

Primary wind direction

indicates summation across plane or volume indicated by subscripts

F0

F1

Fd

Tethersonde Array

Ta, q, u, [CO2], [CH4], [N2O], [NH3], PM10, PM2.5

FSx,y = {F1y,z – F0y,z} + {Fdx,y}

1 sonde to characterize background profile, 3 (or more) to characterize plume, chemical trap array

Sonde telemetry to central computer. Balloon specs: >1 km height, 5 kg payload, auto-deflate

?

Tethersondes and Air Sampling

• Tethersondes at 5 heights; wind-speed, direction, humidity, temperature and pressure.

• Sample lines at 5 heights– draw samples to ground for non-reactive gases (CH4,

N2O, CO2)

– filters attached at each sample height collect NH3,

PM2.5, nitric acid.

• Sample; 1-2hr, 3X/d, 2 days, 7 seasons, 2yr

DW3

Upwind

DW2

DateTemp,

ºCRH, %

Wind Speed, mph

Wind Dir, º

Nov 18 11.3 26.8 2.3 348.3

Sample Dairy 1

DW1

Concentrations of NH3 by Height

0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 450.0

1

2

3

4

5

NH3, ppbv

Concentrations of NH4 by Height

0.0 0.1 0.2 0.3 0.4 0.5 0.6

1

2

3

4

5

NH4 ppb(w/ w)

Concentration of HNO3 by Location

1.4

1.5

1.6

1.7

1.8

1.9

2.0

UW DW1 DW2 DW3

Location

Concentration of NH3 by Location

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

UW DW1 DW2 DW3

Location

Concentration of NH4 by Location

0.0

0.1

0.2

0.3

0.4

0.5

0.6

UW DW1 DW2 DW3

Location

Concentration of CH4 by Location

1.8

1.9

2.0

2.1

2.2

2.3

2.4

2.5

2.6

2.7

UW DW1 DW2 DW3

Location

Concentration of CO2 by Location

370.0

375.0

380.0

385.0

390.0395.0

400.0

405.0

410.0

415.0

420.0

UW DW1 DW2 DW3

Location

Concentration of N2O by Location

314.0

316.0

318.0

320.0

322.0

324.0

326.0

328.0

330.0

UW DW1 DW2 DW3

Location

F0 = y ∫ uz cz dz F1 = ∫ ∫ uy,z cy,z dy dz

Fluxes F0 and F1: Planes Perpendicular to Wind Direction

Ta, q, u, [CO2], [CH4], [N2O], [NH3], PM10, PM2.5help

Fluxes estimated by fitting flux velocity planes to measured scalar concentration and wind speed profiles and estimating the integrals

0

50

100

150

200

250

300

350

400

450

500

0 5 10 15

0

50

100

150

200

250

300

350

400

450

500

0 5 10 15

0

50

100

150

200

250

300

350

400

450

500

0 2 4 6 8

0

50

100

150

200

250

300

350

400

450

500

0 5 10 15

dc/dt

x

yz

cz

cz

ApproachProcess-based Model

• Characterization of Emission Source Components – Animals, diets, pens, manure removal methods,

solids separation, lagoons, composting procedures

– Prediction of C and N flux through each

• Modify whole farm model:– No cropping, add composting, NH4

Products and GHG from Cattle Production

JW

Herd

100 cows+ others

Cropping

Feeds

Manure

CH 4 N20FuelC0 2

Soil Carbon

(+)

Figure 1. Estimates of source and intensity of greenhouse gas emissions per unit of milk, lbs/lb, by scenario from Colorado dairy cattle systems.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Base Milk+20% Milk-20% Aerobic Anaerobic

CO

2eq

per

mil

k

Carbon Dioxide

Nitrous Oxide

Manure Methane

Enteric Methane

Products and GHG from Cattle Production

JW

Herd

100 cows+ others

Cropping

Feeds

Manure

CH 4 N 20FuelC0 2

NH4 PM

(+)

Important questions

• NH3 amounts by source

• NH4, conversion to PM’s

• CH4 from lagoons, dams, composting

• N2O from each

• Variations: diurnal, season, temp, etc

Total cost of US livestock NH3 and CH4 (Sci. 05, 308:1901)

• NH3:• EPA 04 estimate

– 2,418,595 t/yr

• X $1.3 to $21/kg

• = 3 to 50 $Bill/yr

• Note: McCubbin 02; 10% Livstk NH3 $4B

• CH4:

• EPA 04 estimate:– 7.3 Tg/yr

• X $0.60 to $1.54/kg

• = 4 to 11 $Bill/yr

The next step: Mitigation

• Treatment effects; algae, aeration, CuSO4, etc, etc.

• Dietary comp: RDP, peptide, Bypass AA’s, CHO source and Kd, etc, etc

All Emission Mitigation Approaches Must:

• be based on a comprehensive, life cycle analysis that assesses all emissions; ammonia-PM2.5, greenhouse gases,etc.

Potential for Ammonia reduction

• Diet crude protein effect:

• Two research report examples:– Kulling,01 Dairy– Cole, 04 Beef

NH3 from manure of steers vs %CP in diet (Cole, et 05)

• Manure-soil incubations:

• Diet %CP NH3

• Control 14.5 0

• Med 13.0 - 37%

• Low 11.5 - 63%

Diet %CP vs Ammonia loss (Kulling,et. 01 J Ag Sci 137:235)

• Lactating Cows, 30.9 kg/d,

• 3 protein levels, +bypass Methionine12.5 %

15 %

17.5 %

Dairy % diet CP vs NH3 Emissions

(Kulling 01, J Ag Sci 137:235)78

0

10

20

30

40

50

60

70

80

NH3-N

17.5 15 12.5

Environmental Stewardship Strategies for Livestock production systems

• Reductions in excess N - Primary

• Reductions in feed/product

• Dilution of maintenance

• Reduction of maintenance

• Mitigation strategies should

consider all emissions