Life Cycle Assessment for
Cheese Plants
FX Milani
UW-Madison
Wisconsin Dairy Products Association
September 28, 2010

FIL/IDF, UN-FAO dairy report

Nat’l Project Cheese & Whey LCA

Wisconsin cheese and whey
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Who: Rural development is VERY interested in the contribution of cheese/dairy manufacturing
What: Concern about sustainability issues, want to find “hot spots” and new potential returns

Wisconsin cheese and whey
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Where: Wisconsin based manufacturing
When: This year and next spring, beyond?
Why: Ultimately, dairy manufacturing is vital
How: Survey work to get baseline concerns and data, model potential ideas, investigate best ideas

The projects: 3 this year
◦ Sustain Metrics:
 UW Food Science, CDR,UW Biological Systems Engineering
 F. Milani, D. Reinemann, D. Sommer, students
 Modeling, Survey audits, Outreach program, Reports
◦ Whey Disposal:
 UW Food Science, CDR, Industrial Partners
 F. Milani, M. Molitor, D. Sommer, Contractors
 Survey audits, Whey/permeate data, Waste water data,
Reports/potential
◦ Sustainability Outreach:
 UW Food Science, Biological Systems Engineering
 F. Milani, A. Newenhouse
 Short course, Involvement with 2011 WCMA LaCrosse,
Outreach materials, Bus trips

Specific information to collect
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Energy use: gas, electric, wood, LP, etc
Transportation use
Refrigerant use
Raw material, chemical use
Packaging use
Water use, wastewater generated
Pounds and types of cheese produced

Milk composition
Water
Fat
(emulsion)
Protein
87.8%
3.7
3.1
( colloidal suspension)
Casein (2.5)
Lactoglobulin (0.3)
(true solution)
“
“ Lactalbumin
Others
(0.07)
(0.22)
Lactose 4.7
Minerals (ash) 0.7

Cheese Yield 10%, ~50% solids loss to whey
Percent milk constituents

Milk is high in phosphorous
Food item
Milk
Cream
Eggs
USDA Handbook 8 mg of P / Liter
930
710
1800

Cheese P loss to whey (50-90%)
Cheese Type mg of P / Liter
Cheddar 546
Colby
Jack
526
575
Mozzarella
Swiss
Brick
519
447
465
(Wendorff & Matzke, 1993)

The 4 F’s of whey
High
Value
$
Low
Value
$
FOOD
Feed
Fuel
Fertilizer

Options for whey
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Sell to aggregate processor
Land spread
Concentrate and sell (wet or dry)
UF concentrate, sell wet protein
◦ Permeate: sell wet or land spread
UF concentrate, sell dry protein
◦ Permeate: sell dry lactose, dry/landspd wet DLP
◦ (note: lactose market is very volatile)
UF concentrate, sell wet protein
◦ Permeate: biogas, dump minerals

Average Wisconsin cheese plant
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44.7 M pound cheddar cheese annually
28.8 M pounds sweet whey equivalent
447 M pounds milk (1.2 M pounds per day)
116 k gal per day water use, high vary
230 k gal per day wastewater flow, med vary
14,355 kWhr per day electric
6568 therms per day natural gas
459,801 pounds of caustic annual use
Citations listed at end of presentation

Wastewater and Carbon Footprint
Short Courses, November 9-11 http://www.foodsci.wisc.edu
http://www.cdr.wisc.edu

Citations for average cheese plant
 Cheese production: http:www.nass.usda.gov/Statistics_by_State/Wisconsin/ f
Publications/Annual_Statistical_Bulletin/annbull_2008.pd
 Whey conversion: USDA Handbook 8
 Milk Input: Van Slyke equation for cheddar cheese
 Water use: Fietz et al. Int. J. LCA 12(2) 109-17, 2007
 Wastewater output: Danalewich, et al. Wat. Res. 32(12)
3555-68, 1998
 Electric and natural gas use: C. Ling et al. USDA report,
2004
 Sodium Hydroxide use: Fernadez, et al. J. Food Eng 97,
319-28, 2010

How much energy is in permeate?
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Yield of pure carbohydrate is 0.38 cubic meter methane per kg lactose
1 kg lactose is 13,300 BTU, or 0.133 therm
1 therm is $0.475
1 kg lactose is $0.063, or $0.029 per pound
Current market lactose is $0.29-0.35, less drying cost at about $0.19, plus operational
3-12 cents, profitable now, but…
Wet permeate is 4.5% lactose

Carbon credits with lactose
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1 kg lactose produces 0.38 cubic meters methane, and 0.74 kg CO2
2685 kg of lactose produces mton CO2
Assume EU trading at $15 per mton, get additional $0.0055 per kg lactose ($0.0025 per pound)
$50,287 per year new revenue
Consumer milk is burdened with1.2 CO2 per kg milk. Milk contains 45 g lactose, potential 0.033 kg CO2 / kg milk carbon credit from lactose

Whey processing steps
Drained Whey
Fines Saver
Separator
Clarified whey
RO
Pasteurization
Evaporator
Cheese Fines
Whey Cream
Condensed
Whey
To Processor

Whey Processing steps
Condensed Whey
Crystallizer
Spray Dryer Dry Sweet Whey

Whey Protein Concentrate

Permeate processing

Important nutrients in whey
Nutrient Whole whey Whey permeate
N 12.2
2.0
P 4.0
3.8
K
Ca
Mg
Na
14.6
2.9
0.55
4.2
8.2
2.7
0.59
3.4

Benefits to landspreading
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Nutrient recycling
Residual fertility
Soil physical properties
Cost effectiveness
Pollution reduction

Land spreading, Chloride, WI
Ave. Cl (mg/L) Gal/A/yr.
Whey/permeate 1183 16,000
Salty whey
Used brines
56,900
187,000
500
89

Issues with landspreading
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Nitrogen content
Salt concentration
Soil oxygen levels
Odors
Soil limitations
Seasonal limitations (injection)