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Life cycle assessment: Concepts & use

Rich Helling The Dow Chemical Company Sustainable Chemistry 5 December 2017

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Environmental challenges

Decisions are multi-attribute, complex & subjective

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$ Energy

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Life cycle assessment (LCA) provides environmental insights for decisions

Product life cycles

Know the inputs & outputs!

Ener

gy &

mat

eria

ls Em

issions & wastes

Calculate potential impacts

Σ Flow × Characterization Factor all stages all species

Potential Environmental Impact

=

Ene

rgy

& m

ater

ials

Em

issions & w

astes

*as defined by the international LCA standard ISO 14044

Key LCA concept: the functional unit

Functional Unit: The quantified performance of a product system, so that one can make valid comparisons of them.

Can of paint: not a

functional unit

Cover 1 m2 interior surface for 50 years;

a functional unit

LCA cannot tell if something is “green” or “sustainable”, only how A compares to B

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GHGs ENERGY ACID GAS

NUTRIENTS LAND WATER

Option A

Option B

Option A

Option B

Option A

Option B Option A

Option B

Option A

Option B

Option A

Option B

Simple carbon footprint example

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Raw material

extraction Refining Use End of

Life

2 kg CO2 5 kg CO2 1 kg CH4 10 kg CO2

Stage Emissions Characteri

zation Factor (CF)

Emissions x CF = GWP

Raw Matl’s 2 kg CO2 1 2

Refining 5 kg CO2 1 5

Manu-facturing 1 kg CH4 25 25

0.01 kg N2O 298 3

EOL 10 1 10

TOTAL life cycle GHG emissions (GWP) 45 kg CO2-eq

Characterization Factors (Global

Warming Potential)

GHG GWP

(kg CO2-eq/kg GHG)

CO2 1

CH4 25

N2O 298

0.01 kg N2O

ISO standards define process and expectations for comparative LCA claims

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ISO

ISO process reflects good project management

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ISO

In practice, start simple & iterate as needed

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Comparative Assertions

Information about our products

Internal decisions

Life cycle thinking & discussion

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Example: Polyurethane-Based Shoe Soles

Ref: Shawn Hunter, Rich Helling, Andrea Benvenuti, Renato Paludetto, Giuseppe Lista “The Green Footprint Project: Improving LCA in by Careful Bio-Feedstock Selection ” SusPolyUrethane 2013, 8 May 2013, Amsterdam

Many roads to shoe soles…

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Adipic acid

Azelaic acid

Why might bio-based materials have sustainability advantages?

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Σ add it up

Atmospheric CO2 incorporated into

product

But, GHGs also emitted throughout life

cycle

How does the total compare to fossil PU?

GHG advantage is not guaranteed – must conduct the LCA!

PU Shoe Sole LCA

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Goal: To assess the life cycle impacts of polyurethane shoe soles made from fossil-based and renewable-based polyesters

PU production

Polyester production

Adipic Acid production

Fossil feedstock

PU production

Polyester production

Azelaic Acid production

Bio-based feedstock

1 kg bio-based PU

?

1 kg fossil-based PU

Life Cycle Impact Assessment = sum of all potential impacts across the life cycle

Functional Unit: 1 kg of polyurethane foam

Significant GHG Advantage for PU from tallow (waste)

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Tallow-based PU is advantaged in all categories except water

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2

Sensitivity Analyses on the bio-feedstock options

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Waste fat for tallow is not a waste (has burdens)

Use of vegetable oil in place of tallow

EIO-LCA

Results depend on choice of feedstock & burdens

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Impact Category Fossil-based Tallow-based Tallow-based (with burdens)

Vegetable oil-based

Global Warming

Fossil Energy

Acidification

Eutrophication

Ozone Depletion

Smog Creation

Land Use

Water Use

highest impact potential

lowest impact potential

somewhere in the middle

Hefty® EnergyBagTM LCA

Ref: Han Zhang, Rich Helling, Jill Martin ” Scoping Life Cycle Assessment of Hefty® EnergyBagTM Program: An Innovative Plastic Waste Management System ” ACLCA XVII, Portsmouth, NH, October 4, 2017 ® ™ Hefty and EnergyBag are trademarks of Reynolds Consumer Products, LLC

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow

Flexible Plastic Packaging (FPP): Recycling Challenges

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Infrastructure Collection and Sortation

Technical Use of multiple materials

makes FPP difficult to recycle

Consumer Behavior Consumers want to do the right thing but are confused

End Markets Limited currently

Consumers receive Hefty® EnergyBagTM

When bag is full, put it in regular recycle bin/cart

Bags and other recyclables are picked up by local haulers

Bags are sent to and sorted at the local Material Recovery

Facility (MRF)

Sorted bags can be sent to energy recovery facilities, such as pyrolysis and cement kiln

Use energy to run plant and produce cement or to produce

new fuel or plastics

Hefty® EnergyBagTM Process

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M R F

Functional Unit The output of the system is to produce products (diesel, naphtha, fuel gas or cement) and manage non-recycled plastic (NRP) waste (feedstock for chemical recycling vs. landfill)

Therefore, the functional unit for today’s presentation is:

Produce 1kg of diesel and manage 1.11kg of NRP (cradle to gate)

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System Boundary, Diesel Case

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EnergyBag production

LLDPE

Extrusion

Pallet

Cardboard box

EnergyBag shipping

Curbside collection

MRF processing

Transport from MRF

to end user Pyrolysis Diesel

Convention diesel

production Diesel

Curbside collection

MRF processing

Transport from MRF to landfill

Landfill

Naphtha Fuel gas Char

Transport

Landfill

Diesel truck

operation

Diesel truck

operation

Bag distribution

Benchmark processes

Non-recycled plastic

Pyrolysis usually largest contributor

27 Method: TRACI 2.1 V1.01 / US 2008; Cumulative Energy Demand V1.08

Potential environmental impacts to produce 1kg diesel and manage 1.11kg of NRP

Hefty® EnergyBagTM diesel has lower potential impacts vs. conventional system

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Environmental impact to produce 1kg diesel and manage 1.11kg of NRP

Sensitivity Analysis – impact of distance from MRF on LCA metrics

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Use of nitrapyrin on US corn

Ref: Helling, Rich and Brian Wendelburg “Uncertainty & sensitivity in LCA: Use of nitrapyrin to reduce greenhouse gas emissions from US corn production” ACLCA XVII, Portsmouth, NH, October (2017)

Nitrification inhibitor

•Reduce N losses

•Improve N uptake by plants

•A meta-analysis of field studies give statistical measurements of benefits: • Lower greenhouse gas emission • Lower leaching of N • Improved yields

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Simple process map

Produce TG Produce

formulation

Ship to Iowa

Package in Iowa

Apply to field

Use phase emissions

End of life

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Corn farming models

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Kim, et al., IJLCA

Michigan State University

ecoinvent Agri-footprint

by

Blonk Consultants

Corn in Iowa – use of Instinct HL shows clear GWP advantage & some marine eutrophication

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Sensitivity analysis: Climate change benefit using different corn farming models

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kg CO2eq/kg w/o

kg CO2eq/kg with

Decrease, CO2eq/kg

Decrease, %

Kim, et al. 0.27 0.18 0.086 32%

Agri-footprint

0.51 0.42 0.096 19%

ecoinvent 0.64 0.56 0.070 11%

Uncertainty – climate change and eutrophication results are robust to uncertain model inputs

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Conclusions

Summary

• LCA is usefull to find & improve hotspots and make comparisons

• LCA does not determine greeness or sustainability • Always start simple and add complexity & detail as needed! • Polyurethane example: feedstock choices – both physical and

attribution – matter! • EnergyBag example: a two-part functional unit can be a useful

basis for waste-based processes • Nitrapyrin example: importance of sensitivity and uncertainty

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Questions?

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Acknowledgements

The “Green Footprint Project” was part of the EU “LIFE+” program:

LIFE07 ENV/IT/000412

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References • Helling, Rich “Life cycle assessment: Concepts & use” Michigan DEQ Sustainability Series Webinar,

22 June 2017 https://attendee.gotowebinar.com/recording/2505699422317413889 • Han Zhang, Rich Helling, Jill Martin ” Scoping Life Cycle Assessment of Hefty® EnergyBagTM

Program: An Innovative Plastic Waste Management System ” ACLCA XVII, Portsmouth, NH, October 4, 2017

• Shawn Hunter, Rich Helling, Andrea Benvenuti, Renato Paludetto, Giuseppe Lista “The Green Footprint Project: Improving LCA in by Careful Bio-Feedstock Selection ” SusPolyUrethane 2013, 8 May 2013, Amsterdam.

• Helling, Richard, Renato Paludetto, Andrea Benvenuti, and Giuseppe Lista “Life Cycle Assessment of polyurethanes for shoe soles with at least 20% renewable (bio-based) content: the Green Footprint Project” ISO 14044 Public Report, The Dow Chemical Company, August (2011)

• Pahola Thathiana Benavides, Pingping Sun, Jeongwoo Han, Jennifer B. Dunn, Michael Wang “Life-cycle analysis of fuels from post-use non-recycled plastics” Fuel 203 (2017) 11–22 http://dx.doi.org/10.1016/j.fuel.2017.04.070

• Helling, Rich and Brian Wendelburg “Uncertainty & sensitivity in LCA: Use of nitrapyrin to reduce greenhouse gas emissions from US corn production” ACLCA XVII, Portsmouth, NH, October (2017)

• Wolt, Jeffrey D., “A meta-evaluation of nitrapyrin agronomic and environmental effectiveness with emphasis on corn production in the Midwestern USA” Nutrient Cycling in Agroecosystems, vol. 69, pp 23-41 2004

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