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Green Cheese
Energy Intensity and GHG Emissions of Integrated Dairy&Bio‐fuels Systems
in Wisconsin
Douglas Reinemann Horacio Aguirre‐Villegas
Louis Armentano
Victor Cabrera
John Norman
Simone Kraatz
Franco Milani
Josh Posner
Thais Passos Fonseca Oct 15th, 2010
Bio‐fuels Industry Dairy Herd
On‐Farm Processes
Dairy Feed
Milk
Dairy Feed
Manure
Biomass
Bio‐fuel
Milk
Milk
Dairy Products
Bio‐fuel
Manure
Bio‐fuel
Crops
BioGas, Electricity
GHG
GHG
GHG
GHG
GHG
GHG
GHG
FerSlizers
1) InvesSgate synergies and opportuni(es to reduce energy intensity and environmental impact of dairy and bio‐fuels producSon.
2) Provide guidance to: a) Individual farms to
i) choose technologies and management pracSces to reduce energy intensity and environmental burden of milk producSon; ii) prepare for carbon credits market b) Policy makers regarding implicaSons of specific technologies on WI energy and GHG balance, aiming beZer resource allocaSon
3) Compare efficiency and environmental impact of dairy producSon systems in WI vs. other regions
4) Expand Life Cycle Assessment database of agricultural products
Green Cheese Model ‐ Objec(ves
The “Green Cheese” Model
Informa(on Inputs
Lacta(ng cows forage intake
Desired milk produc(on
Model Components
1b.Diet composi(ons
1a.Dairy herd
Herd characteris(cs
3.Crop produc(on
Machinery
Outputs GHG Nutrient
losses
Inputs
Chemicals
Fuels and energy
Fer(lizers
2a.Manure handling
Milk
Meat Bio‐fuels
Process, embedded,
and cumula(ve energy and
GHG emissions Biogas
4.Bio‐fuels produc(on
2b.Biogas genera(on
System Boundary
Green Cheese: Model Components and Boundaries
Other characteris(cs of the system
CO2 for feed Land area
• 5 dairy diets – 3 forage bases
• 3 levels of co‐products from bio‐fuels – Dry disSllers grains and solubles (DDGS) – Soybean meal (SBM)
• 2 manure treatments – without anaerobic digesters – with anaerobic digesters (and biogas producSon)
Scenarios
Diet Corn silage DMI Alfalfa silage DMI Concentrates
CADS 29% 29% DDGS = Soybean meal
CSDG 36% 22% Max. DDGS
CSSB 36% 22% Max. Soybean meal
ASDG 22% 36% Max. DDGS
ASSB 22% 36% Max. Soybean meal
Results
• GHG emissions (kg CO2‐eq/kg ECM)
• Energy intensity (MJ/kg ECM)
• Net energy intensity = Energy inputs – Energy outputs
ECM = energy corrected milk to 4% fat and 3.3% protein CO2‐eq = carbon dioxide equivalent
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
CADS CSDG CSSB ASDG ASSB Diets
GHG emissions from Milk ProducSon (kg CO2‐eq/kg ECM)
AccounSng for bio‐fuels, displacement of fossil fuels; no biogas
AccounSng for bio‐fuels and biogas, displacement of fossil fuels and natural gas
‐2.5
‐1.5
‐0.5
0.5
1.5
2.5
CADS CSDG CSSB ASDG ASSB Diets
Net Energy Intensity of Milk ProducSon (MJ/kg ECM)
AccounSng for bio‐fuels energy and fossil fuels displacement; no biogas
AccounSng for bio‐fuels and biogas energy, displacement of fossil fuels and natural gas
Land use, GHG emissions, and energy intensity of milk production for selected diets. All values presented in relation to Diet CADS (100%).
0%
20%
40%
60%
80%
100%
120%
140%
CADS CSDG CSSB ASDG ASSB Diets
Land area use GHG emissions Energy intensity
Environmental Impacts of Integrated Milk and Bio‐fuels ProducSon (no biogas)
Land use, GHG emissions, and energy intensity of milk production for selected diets. All values presented in relation to Diet CADS (100%).
‐140% ‐120% ‐100% ‐80% ‐60% ‐40% ‐20% 0% 20% 40% 60% 80% 100% 120% 140%
CADS CSDG CSSB ASDG ASSB Diets
Land area use GHG emissions Energy intensity
Environmental Impacts of Integrated Milk and Bio‐fuels ProducSon (with biogas)
• Effects of anaerobic digesters for on‐farm biogas generaSon: – ReducSons in GHG emissions by 0.25 kg CO2‐eq/kg ECM
– ReducSons in energy intensity by 2.57 MJ/kg ECM
• The minimum GHG emissions and energy intensity per kg of milk occurred in the system that: – used anaerobic digesSon on the farm
and – maximized feeding of DDGS (and ethanol producSon)
• This scenario also resulted in the largest required land area; • Tradeoffs need to be considered.
Main Conclusions
PotenSal Impacts of Biogas
• Farms with more than 200 cows in Wisconsin: ~ 40% of WI milk producSon
~ 4.5 billion kg of milk/year
potenSal on‐farm energy producSon (from biogas): ~ 11.5 billion MJ/year
almost 3% of Wisconsin’s Natural Gas consumpSon (~ 400 billion MJ/year)
correspondent potenSal of savings on GHG emissions: ~ 1 billion kg CO2‐eq/year almost 10% of the 10.9 billion CO2‐eq from Wisconsin’s Agriculture sector (esSmated by the World Resources InsStute, 2007)
Thank you!
Thais Passos Fonseca: [email protected] Horacio Aguirre Villegas: [email protected]
Douglas Reinemann: [email protected]