life cycle assessment: a simple overview of a complex process

Life Cycle Assessment:A simple overview of a complex process

Marty MatlockJennie PoppNathan KemperZara NiedermanCenter for Agricultural and Rural Sustainability

Mike FaupelMichele HalsellJon JohnsonApplied Sustainability Center

Greg ThomaDarin NutterTom CostelloInstitute for Sustainable Engineering Analysis

Everything is Connected

Source: R. E. Ricklefs’ Economy of Nature

Everything is changing

Every process has inputs and outputs

Manufacturing Process

Energy

Raw Materials

Raw Materials

Raw Materials

Water

Solid Waste Liquid Waste

Gas Waste

End Product

The more processes, the more complexity

Raw Materials

Raw Materials

Raw Materials


Energy Water

Solid Waste Liquid Waste

Gas Waste


Energy Water

Solid WasteLiquid Waste

Gas Waste


Energy Water


Gas Waste


Energy Water


Gas Waste

End Product

Life Cycle Assessment quantifies processes

Goal: Quantify inputs and outputs for a system in terms of a standardized unit of measure.

The scope and structure of the LCA are directly dependent upon the unit of measure (functional unit):

1. Energy embodied in a single product;2. Green house gasses produced per unit product;3. Tons of carbon produced per volume of product;4. Volume of water consumed per mass of product…

Goal and Scope of LCA must be formulated at the outset of the project, and the functional unit must be defined.

LCA Process is described in ISO 14040 and 14044 Standards.

Phase 1: Goal Definition and Scope

Four Phases of a Life Cycle Assessment

Phase 2: Life Cycle Inventory

Phase 3: Life Cycle Impact Assessment

Phase 4: Assessment/Scenario Analysis Inte

rpre

tatio

n an

d C

onte

xt

Life Cycle Assessment: Reconciling Functional Units

CO2

CH4

N2O

Green House Gas Potentials

1 g CO2 = 1g CO2-equiv.

1 g CH4 = 25 g CO2-equiv.

1 g NO2 = 310 g CO2-equiv.

• Develop a model

• Estimate the energy embodied in a unit (metric ton or 480 lb bale) of cotton produced (lint plus seed)

• Compare the total energy (MJ) required over varying cotton production strategies

Cotton LCA Case StudyPhase 1: Goal Definition and Scope

Cotton LCA Case Study Phase 2: LCA Inventory

RegionProduction Strategy Irrigation Fertilizer

North America East Mechanized Med High

North America West Mechanized High High

South America Mech Mechanized Medium Medium

South America Non-Mech Non-Mechanized Med Med

Australia Mechanized High High

Mediterranean - Mech Mechanized Medium High

Mediterranean - Non-Mech Non-Mechanized Medium Low

Asia - Mech Mechanized High High

Asia - Non-Mech Non-Mechanized Medium Medium

Africa - Non Mech Non-Mechanized Low Low

Field Preparation

Harvesting

Irrigation

Weed Control

Pest Control

Fertilization

Planting

Manual Application

Embodied Chemical

Tonne of CottonBale of Cotton

Yield

Manual Manual Manual

Manual Manual

Legend

Biofuels

Fossil Fuels

All values MJ/ha unless otherwise stated

98[5] (India),[6]

380[5] (India),[6],[19]

1066[5] India,[6], [19]

990[5] (India),[6]

618[4] (Turkey),[6]

103[5] (India),[6]

271[5] (India),[6],[19]

0Manure

0Rain‐Fed

Africa Cotton Production: Organic Fertilizer and Non-Irrigated

0.75 Tonne/ha [14](Africa)

Field Preparation

Harvesting

Irrigation

Weed Control

Pest Control

Fertilization

Planting

Mechanical Application

Embodied Chemical

Tonne of Cotton 1000kg

1895[2] Arizona

North America: Eastern United States

105[2] Arizona

105[2] Arizona

Yield

Mechanical

141[2] Arizona

282[2] Arizona

4023[8] New Mexico, [2]

338[8] New Mexico, [2]

1440[8] New Mexico, [2]

Mechanical Mechanical Mechanical

Mechanical Mechanical

1106[21] Arkansas, [2]

213[21] Arkansas, [2]

1895[2] Arizona

4023[8] New Mexico, [2]

1106[21] Arkansas, [2]

354[21] Arkansas, [2]

144(Embodied)

[21] Arkansas, [26]

24(Embodied)

[21] Arkansas, [26]

36(Embodied)

[2] Arizona, [21], [26]

72(Embodied)

[2] Arizona, [21], [26]

45(Embodied)

[2] Turkey, [21], [26]

782(Embodied)

[2] Turkey, [21], [26]

2.85tonne/ha

[2] Georgia

2.2tonne/ha

[21] Arkansas

2.5tonne/ha

[21] Mississippi

5293[21] Arkansas [13]

7449Water Amount [1] Greece, Energy Estimation [20], [2]

2328Water Amount [4] Turkey, Energy Estimation [20], [2]

5000[9] Turkey

4223[4] Turkey

AVG: 7564 STDEV: 822[16] ICAC,

[2],[4],[9],[10]

Legend

Biofuels

Fossil Fuels

All values MJ/ha unless otherwise stated

Cotton LCA Case StudyPhase 3: Impact Assessment

North America: Eastern United StatesField Preparation

Harvesting

Irrigation

Weed Control

Pest Control

Fertilization

Planting

Mechanical Application

Embodied Chemical

MJ/Tonne of CottonYield

MechanicalMechanical Mechanical Mechanical

Mechanical Mechanical

Simulated Cotton Energy Production, North America East

M ean = 7973.63

X <=5973.995%

X <=10526.195%

0

0.02

0.04

0.06

0.08

0.1

0.12

4 6.5 9 11.5 14

Energy Required, MJ/Tonne CottonValues in Thousands

Field PreparationX <= 1423

5.0%X <= 4386

95.0%

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5

Energy Required (MJ/Ha)Values in Thousands

Val

ues

x 10

^-4

PlantingX <= 146.7

5.0%X <= 390.6

95.0%

0

1

2

3

4

5

6

50 100 150 200 250 300 350 400 450 500

Energy Required (MJ/Ha)

Val

ues

x 10

^-3

IrrigationX <= 2239

5.0%X <= 12073

95.0%

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 2 4 6 8 10 12 14 16


Val

ues

x 10

^-4

Pest ControlX <= 116.5

5.0%X <= 237.5

95.0%

0

0.2

0.4

0.6

0.8

1

1.2

80 100 120 140 160 180 200 220 240 260 280


Val

ues

x 10

^-2

Weed ControlX <= 282

5.0%X <= 2163

95.0%

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.5 1 1.5 2 2.5


Val

ues

x 10

^-4

Fertilizer ApplicationX <= 99.3

5.0%X <= 535.8

95.0%

0

0.5

1

1.5

2

2.5

50 100 150 200 250 300 350 400 450 500 550 600


Val

ues

x 10

^-3

Fertilizer (Embodied)X <= 5652

5.0%X <= 7205

95.0%

0

1

2

3

4

5

6

7

8

9

5 5.5 6 6.5 7 7.5 8


Val

ues

x 10

^-4

HarvestingX <= 1946

5.0%X <= 3178

95.0%

0

0.2

0.4

0.6

0.8

1

1.2

1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6


Val

ues

x 10

^-3

YieldX <= 2.2987

5.0%X <= 2.7433

95.0%

0

0.5

1

1.5

2

2.5

3

3.5

2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9

Tonnes/Ha

Cotton LCA Case StudyPhase 4: Assessment/Scenario Analysis

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

North AmericaEast

North AmericaWest

South AmericaMechanized

South AmericaNon-Mech

Australia MediterraneanMech

MediterraneanNon-Mech

Asia Mech Asia Non-Mech Africa Non-Mech

Embo

died

Ene

rgy

of C

otto

n Pr

oduc

tion

MJ/

Tonn

e

Life Cycle Assessment Case Study:Carbon Equivalent GHG of Fluid Milk

Production Processing

DistributionConsumption

Life Cycle Assessment Case Study:Carbon Equivalent GHG of Fluid Milk

life cycle assessment: a simple overview of a complex process

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