Livestock and Air Quality CAFO Air Emissions Project CSU-ARDEC Feb. 9, 2006

Transcription

1 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)

2 National Academy of Science NRC 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

3 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!

4 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.

5 Specific Objectives 1. Measure emissions from 2 dairies: Ammonia PM 2.5 Nitrous oxide Methane 2. Determine diurnal, seasonal variations 3. Develop and challenge process model estimates of emission fluxes

6 Objectives Contd: 4. Correlate downwind concentrations of spot sampled emissions - e.g.: H 2 S, VOC s..

7 Approach Quantification of CAFO System Emissions Mass Balance

8 Whole-System Trace Gas Fluxes from Complex Agricultural Sources: Plume Characterization and Conservation of Mass dc/dt z y x F e F l Primary wind direction F d F 0 F S F 1 F S x,y = dc/dt x,y,z + { F 1 y,z F 0 y,z } + { F l x,z } + { F e x,y + F d x,y } Plume Lateral Vertical indicates summation across plane or volume indicated by subscripts

9 Tethersonde Array T a, q, u, [CO 2 ], [CH 4 ], [N 2 O], [NH 3 ], PM 10, PM 2.5? F S x,y = { F 1 y,z F 0 y,z } + { F d x,y } F 0 F 1 F d 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

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14 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 (CH 4, N 2 O, CO 2 ) filters attached at each sample height collect NH 3, PM2.5, nitric acid. Sample; 1-2hr, 3X/d, 2 days, 7 seasons, 2yr

15 Date Temp, ºC RH, % Wind Speed, mph Wind Dir, º Nov Upwind Sample Dairy 1 DW1 DW3 DW2

16 Concentrations of NH3 by Height NH3, ppbv

17 Concentrations of NH4 by Height NH4 ppb( w/ w)

18 Concentration of HNO3 by Location Concentration of NH3 by Location UW DW1 DW2 DW3 Locat ion 0.0 UW DW1 DW2 DW3 Locat ion Concentration of NH4 by Location UW DW1 DW2 DW3 Location

19 Concentration of CH4 by Location UW DW1 DW2 DW3 Locat ion

20 Concentration of CO2 by Location UW DW1 DW2 DW3 Locat ion

21 Concentration of N2O by Location UW DW1 DW2 DW3 Locat ion

22 Fluxes F 0 and F 1 : Planes Perpendicular to Wind Direction T a, q, u, [CO 2 ], [CH 4 ], [N 2 O], [NH 3 ], PM 10, PM 2.5 help dc/dt z y x c z c z F 0 = y u z c z dz F 1 = u y,z c y,z dy dz Fluxes estimated by fitting flux velocity planes to measured scalar concentration and wind speed profiles and estimating the integrals

23 Approach Process-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

24 Products and GHG from Cattle Production Herd 100 cows + others Feeds Cropping Manure ( + ) CH 4 N 2 0 Fuel C0 2 Soil Carbon J W

25 Figure 1. Estimates of source and intensity of greenhouse gas emissions per unit of milk, lbs/lb, by scenario from Colorado dairy cattle systems Carbon Dioxide CO2eq per milk Nitrous Oxide Manure Methane Enteric Methane Base Milk+20% Milk-20% Aerobic Anaerobic

26 Products and GHG from Cattle Production Herd 100 cows + others Feeds Cropping Manure ( + ) J W CH 4 N 0 2 NH4 PM Fuel C0 2

27 Important questions NH 3 amounts by source NH 4, conversion to PM s CH 4 from lagoons, dams, composting N 2 O from each Variations: diurnal, season, temp, etc

28 Total cost of US livestock NH 3 and CH 4 (Sci. 05, 308:1901) NH 3 : EPA 04 estimate 2,418,595 t/yr X $1.3 to $21/kg = 3 to 50 $Bill/yr CH 4 : EPA 04 estimate: 7.3 Tg/yr X $0.60 to $1.54/kg = 4 to 11 $Bill/yr Note: McCubbin 02; 10% Livstk NH 3 $4B

29 The next step: Mitigation Treatment effects; algae, aeration, CuSO4, etc, etc. Dietary comp: RDP, peptide, Bypass AA s, CHO source and Kd, etc, etc

30 All Emission Mitigation Approaches Must: be based on a comprehensive, life cycle analysis that assesses all emissions; ammonia-pm2.5, greenhouse gases,etc.

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32 Potential for Ammonia reduction Diet crude protein effect: Two research report examples: Kulling,01 Dairy Cole, 04 Beef

33 NH 3 from manure of steers vs %CP in diet (Cole, et 05) Manure-soil incubations: Diet %CP NH 3 Control Med % Low %

34 Diet %CP vs Ammonia loss (Kulling,et. 01 J Ag Sci 137:235) Lactating Cows, 30.9 kg/d, 3 protein levels, +bypass Methionine 12.5 % 15 % 17.5 %

35 Dairy % diet CP vs NH 3 Emissions (Kulling 01, J Ag Sci 137:235) NH3-N

36 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