Life Cycle Assessment for Life Cycle Assessment for Cheese PlantsCheese PlantsFX MilaniUW-MadisonWisconsin Dairy Products AssociationSeptember 28, 2010

FIL/IDF, UN-FAO dairy FIL/IDF, UN-FAO dairy reportreport

Nat’l Project Cheese & Nat’l Project Cheese & Whey LCAWhey LCA

Wisconsin cheese and Wisconsin cheese and wheywhey

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

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

Wisconsin cheese and Wisconsin cheese and wheywhey

The projects: 3 this yearThe 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 Specific information to collectcollectEnergy use: gas, electric, wood,

LP, etcTransportation useRefrigerant useRaw material, chemical usePackaging useWater use, wastewater generatedPounds and types of cheese

produced

Milk compositionMilk composition

Water 87.8%

Fat (emulsion) 3.7

Protein 3.1

(colloidal suspension) Casein (2.5)

(true solution) Lactoglobulin (0.3)

“ Lactalbumin (0.07)

“ Others (0.22)

Lactose 4.7

Minerals (ash) 0.7

Cheese Yield 10%, ~50% Cheese Yield 10%, ~50% solids loss to wheysolids loss to whey

Percent milk constituents

Milk is high in phosphorousMilk is high in phosphorous

Food item mg of P / Liter

Milk 930

Cream 710

Eggs 1800

USDA Handbook 8

Cheese P loss to whey (50-Cheese P loss to whey (50-90%)90%)

Cheese Type mg of P / LiterCheddar 546

Colby 526

Jack 575

Mozzarella 519

Swiss 447

Brick 465

(Wendorff & Matzke, 1993)

The 4 F’s of wheyThe 4 F’s of whey

FOODFeedFuel

Fertilizer

HighValue

LowValue

$

$

Options for wheyOptions for wheySell to aggregate processorLand spreadConcentrate and sell (wet or dry)UF concentrate, sell wet protein

◦Permeate: sell wet or land spreadUF 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 Average Wisconsin cheese plantplant

44.7 M pound cheddar cheese annually28.8 M pounds sweet whey equivalent447 M pounds milk (1.2 M pounds per

day)116 k gal per day water use, high vary230 k gal per day wastewater flow,

med vary14,355 kWhr per day electric6568 therms per day natural gas459,801 pounds of caustic annual useCitations listed at end of presentation

http://www.foodsci.wisc.edu

http://www.cdr.wisc.edu

Wastewater and Carbon Wastewater and Carbon Footprint Short Courses, Footprint Short Courses, November 9-11November 9-11

Citations for average cheese Citations for average cheese plantplant

Cheese production: http:www.nass.usda.gov/Statistics_by_State/Wisconsin/Publications/Annual_Statistical_Bulletin/annbull_2008.pdf

Whey conversion: USDA Handbook 8Milk Input: Van Slyke equation for cheddar cheeseWater use: Fietz et al. Int. J. LCA 12(2) 109-17, 2007Wastewater output: Danalewich, et al. Wat. Res. 32(12)

3555-68, 1998Electric and natural gas use: C. Ling et al. USDA report,

2004Sodium Hydroxide use: Fernadez, et al. J. Food Eng 97,

319-28, 2010

How much energy is in How much energy is in permeate?permeate?

Yield of pure carbohydrate is 0.38 cubic meter methane per kg lactose

1 kg lactose is 13,300 BTU, or 0.133 therm1 therm is $0.4751 kg lactose is $0.063, or $0.029 per

poundCurrent 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 Carbon credits with lactoselactose

1 kg lactose produces 0.38 cubic meters methane, and 0.74 kg CO2

2685 kg of lactose produces mton CO2Assume EU trading at $15 per mton,

get additional $0.0055 per kg lactose ($0.0025 per pound)

$50,287 per year new revenueConsumer 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 stepsWhey processing steps

Clarified whey

Separator Whey Cream

Pasteurization

RO Evaporator

CondensedWhey

To Processor

Drained Whey

Fines Saver Cheese Fines

Whey Processing stepsWhey Processing steps

Crystallizer

Spray Dryer

Condensed Whey

Dry Sweet Whey

Whey Protein ConcentrateWhey Protein Concentrate

Permeate processingPermeate processing

Important nutrients in Important nutrients in wheywhey

Nutrient Whole whey Whey permeateN 12.2 2.0P 4.0 3.8K 14.6 8.2Ca 2.9 2.7Mg 0.55 0.59Na 4.2 3.4

Benefits to landspreadingBenefits to landspreading

Nutrient recycling Residual fertility Soil physical properties Cost effectiveness Pollution reduction

Land spreading, Chloride, Land spreading, Chloride, WIWI

Ave. Cl (mg/L) Gal/A/yr.

Whey/permeate 1183 16,000

Salty whey 56,900 500

Used brines 187,000 89

Issues with landspreadingIssues with landspreadingNitrogen contentSalt concentrationSoil oxygen levelsOdorsSoil limitationsSeasonal limitations (injection)