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Life Cycle Assessment:Life Cycle Assessment:Critical PointsCritical Points

Prof O.Jolliet , T. Corbière, M. Thérézien

EPFL-Swiss Federal Institute of Technology-Lausanne

Ecosystem management, GECOS, CH-1015 Lausanne, SWITZERLAND

olivier.jolliet@epfl.ch, http://dgrwww.epfl.ch/GECOS/DD

In collaboration with Harvard School of Public Health (Harvard University), University of Medellin

and WBCSD (World Business Council for Sustainable Development).

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– To enhance both formal and informal learning opportunities through collaborative and cooperative processes;

1.1 1.1 Objectives of the LCA short courseObjectives of the LCA short course

The objectives of the “Life Cycle Assessment: Critical Points” distance-learning course are:

– To provide a quality and interactive distance education on LCA. More precisely, the course aims to enable participants:

–To know the relationships between Life Cycle Assessment (LCA) and other environmental tools, to know the existing LCA methodologies, the basic rules and frameworks for good LCA practice,

–To criticize an existing LCA, looking rapidly at the key issues,

–To identify the main environmental issues in a production process;

– To improve information and knowledge sharing as well as inter-university collaboration and tuition for industry collaborators.

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The aim of this unit is to achieve the following points:

– What LCA can achieve and what its main steps are through a case study on biomaterials;

– The position of LCA among others environmental impact assessment tools;

– A small review of LCA historical development.

1.2 Objectives of lesson 11.2 Objectives of lesson 1

What should be assimilated:

At the end of this lesson, you should be able to answer the following questions:

– What are the different steps of a LCA ?

– Why is an assessment needed and how is it structured ?

– What is the difference between natural and environmentally friendly ?

– What are the different kind of environmental assessment tools ?

– What are the LCA specificities ?

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2.2. Introductory case study Introductory case study22.1 How to replace Polystyrene ?.1 How to replace Polystyrene ?

What are the environmental problems with Polystyrene ?

Tips: Ask yourself what is Polystyrene made of ?

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As a replacement material, you may have thought of popcorn, and it has indeed been commercialized. This 100 % natural matter is renewable and biodegradable.

2.2 Popcorn as a possible alternative2.2 Popcorn as a possible alternative

The bestWorse Equivalent Slightly better Much better

According to your personal judgment, popcorn is :

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2.3 Popcorn versus Polystyrene2.3 Popcorn versus Polystyrene

Coming from natural resources, popcorn is intuitively seen as more ecological than petrochemical polystyrene – even if the ethical question of the use of food as a raw material remains raised. However, this alternative has still to be proven more environmentally friendly.

For popcorn, what are the key parameters from an environmental point of view ?

conventional polystyrene: extracted from non renewable fossil oil, this material is not biodegradable.

popcorn: extracted from renewable resources, this material is completely biodegradable.

Properties of the two matters:

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As a matter of fact, it is not possible to answer at that level. More information and a reflexion structure are needed.

To go beyond "a priori”, LCA can help to structure the required facts. LCA permits to target the relevant points in the life cycle of the considered product.

“LCA of biodegradable packing materials compared with polystyrene chips: the case of popcorn” has been published in 1994 (Agriculture, Ecosystem and Environment 49 (1994) 253-266). You can ask for us if you are interested in a copy of the article.

2.4 LCA to determine the environmental key 2.4 LCA to determine the environmental key parametersparameters

We will now have a quick overview of this study.

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2.5 LCA Steps2.5 LCA Steps

• Goal definition: enables to set the problem, to define the objectives and range of the study. Determining the limits of the system and the functional unit (the unit on which the study is performed) is crucial.

• Inventory: this is the full listing of the required raw materials and the air, water and soil emissions relative to the considered functional unit.

• Impact assessment: evaluates the environmental impacts of the above mentioned emissions.

• Interpretation: allows to interpret the results of each of the former steps and to point out the key factors for an environmental decision making.

LCA is a 4 steps tool defined in ISO standards.

Impact assessment

Goal

definition

Inventory of extractions and

emissionsInterpretation

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2.62.6aa Popcorn system boundaries Popcorn system boundaries

Now let’s come back to the examples of filling materials for packaging.

How would you imagine the system boundaries for popcorn?

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We can see on the former illustration that the system boundaries include all the processes but the tractor manufacture and the use phase of the popcorn as a filler. The tractor manufacture was not taken into account because life cycle data available for Polystyrene at that time did not include machinery and manufacturing so that it was decided to exclude both. As a matter of fact, this is a weakness, as the energy required and emissions could differ significantly.

2.62.6bb System boundaries, commentaries System boundaries, commentaries

Once the system is defined, emissions and extractions data for each production module are calculated, generating the inventory.

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2.72.7aa Inventory of the most important emissions Inventory of the most important emissions and extractionsand extractions

Emissions Popcorn

g/kg Polystyrene

g/kg Air CO2 620 5480 Particles 0.2 1.3 CO 1.0 3.4 NH3 3.1 0.0 Water Nitrates 31 0.0 Extractions MJ/kg MJ/kg Non renew. energy 7.2 81.3

At this stage of the study, what is the best scenario and why?

Popcorn is better for CO2, particles, CO and energy requirements. Polystyrene is better for NH3 and nitrates.

It is because of the agriculture phase! Indeed, the use of fertilizers in agriculture puts a high load of nitrogen on environment.

Do you guess why we have these results?

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2.72.7bb Inventory of the most important emissions Inventory of the most important emissions and extractionsand extractions

Which additional information would you need to answer “THE” question: what material is the best and why ?

It is too early to answer this question. All the emissions are considered the same. In reality some emissions are « worse » than others. It is necessary to give a relative weight to each emission to answer “THE” question.

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On the basis of this inventory, it is possible to get an evaluation of the relative environmental impact of each scenario. There is no universally accepted evaluation method. Therefore, it is recommended to apply several of them in parallel. You will learn more about some existing methods in unit 8.

2.8 Impact assessment2.8 Impact assessment

In that case, the methods Ecopoints, Critical Volumina and Critical Surface Time have been applied, and next graph presents the evaluation calculated per kg of materials.

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2.9 Popcorn impacts compared to Polystyrene 2.9 Popcorn impacts compared to Polystyrene impactsimpacts

Depending on the method, 1 kg popcorn turns out to be 3 to 4 times better than 1 kg polystyrene.

0%

20%

40%

60%

80%

100%P

S

PC

PS

PC

PS

PC

Phosphates

Nitrates

NH3

SO2

NOx

HC

CO

Part.

N2O

CO2Ecopoints Critical

voluminaCritical

surface-time

per kg materials

What do you think about this results? Any objection?

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As you can see in the picture, 100 g polystyrene have a much higher volume than 100 g popcorn. We measured half a cubic meter popcorn and it is indeed 4.6 times denser than polystyrene (and could feed the whole research institute during 3 days…).

2.10 Popcorn impacts compared to Polystyrene 2.10 Popcorn impacts compared to Polystyrene impactsimpacts

As the function fulfilled by the materials is the filling of the packaging, having chosen a mass reference is irrelevant. Volume is a better basis for comparison (defined as the functional unit later in the course).

Photo 100 g de chaque produit

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2.11a Popcorn impact compared to polystyrene 2.11a Popcorn impact compared to polystyrene impactsimpacts

The factor 4.6 is a direct multiplier of the relative impacts and popcorn turns out to be not better or even worse than polystyrene.

0%

50%

100%

150%

200%P

S

PC

PS

PC

PS

PC

Phosphates

Nitrates

NH3

SO2

NOx

HC

CO

Part.

N2O

CO2

per m3 materials

Ecopoints Critical volumina

Critical surface-time

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This would be even worse if the number of reuse were considered. In fact polystyrene is likely to have a bigger reusability potential than popcorn.

2.11b Popcorn impact compared to polystyrene 2.11b Popcorn impact compared to polystyrene impactsimpacts

Where would you act in priority to achieve this goal ? What is the environmental key parameter?

Therefore there is a need to improve popcorn in order to make it a good filling material.

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2.12 Conclusions2.12 Conclusions popcorn - polystyrenepopcorn - polystyrene

It is interesting to note that industrial products can be less damageable for the environment than natural products:

“Natural” is different from “environmentally friendly”!

Density is clearly the key parameter from an environmental point of view with a potential improvement of a factor 4.6… 460% ! By the way, this has now been achieved by a new material extracted from corn starch, currently on market. It is (3 times) lighter than popcorn and entirely biodegradable. Moreover it dissolves into water. But, as a possible counterpart, it requires more “industrial” steps.

Petit film : dissolution d'un chip d'amidon

This also shows that the chosen basis for comparing products, the so called functional unit, plays a crucial role and need to be properly defined. It should indeed reflect the product service or function (hence m3 instead of kg).

By the way, it was a tough task to announce the bad performance of the product to the farmer who helped carrying out this study!

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3. 3. Group formationGroup formation

Now that you see better what a LCA can achieve, we would like you to choose a case-study that interests you particularly. You have the choice among those proposed or you can suggest something of your own.

This will enable us to form exercise groups with the same interest. Three by three, during the next lessons, you will solve your case.

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4.14.1 Sustainable development and LCA Sustainable development and LCA

"Sustainable development satisfies needs of present generations while preserving the potential for future generation"

UNCED (Brundtland), 1987

"Such sustainable development is - technically appropriate,

- environmentally non-degrading,- economically viable and- socially favorable"

FAO, 1995

The greatest challenge is to link these different dimensions together. LCA is a tool which help to create this link.

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0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1er trim. 2e trim. 3e trim. 4e trim.time

4.24.2 LCA among different environmental impact LCA among different environmental impact assessment tools assessment tools

informationpotentialactions

Detailed LCALCA screeningEnergy balance

Design for environment

On this graph, one see that at the very beginning of the development of a new product, choices are still fully open. The designer has a very wide action potential, but little information is available, thus the difficulty to perform a full LCA.

As time goes by, product specification and available information grow, but it is too late to modify its design significantly. Therefore, different tools are required for different design stages. A conceptual approach such as Design For Environment is appropriate in the first design stage whereas LCA is appropriate later in the process.

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4.34.3 Environmental Assessment Methods Environmental Assessment Methods Indeed, LCA is “THE” tool, as you are learning it now. But several other tools are often used to perform an environmental assessment.

Next figure describes how different environmental tools are included in the decision process of firms. As for the environmental aspect, three kinds of tools can be distinguished:

–concepts that help to ask the right questions and find innovative and creative solutions;

–analysis methods that enable to quantify impacts;

–procedures of authorization or environmental management.

Which one do you know? (see next page)

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Environmental Aspects

Management, decisions making

Economical and social aspects

(Life cycle costing)

Technological System

Performances, life time

4.44.4 Environmental Assessment Methods Environmental Assessment Methods

ProceduresEnvironmental Impact AssessmentEcolabelEnvironmental Audit.

ConceptsLife Cycle ThinkingEnvironmental DesignIndustrial Ecology

Assessment MethodsLife Cycle AssessmentSubstance Flow Analysis Risk Assessment

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4.54.5 LCA compared to other environmental tools LCA compared to other environmental tools

We can have a look at particularities of LCA. This table compares LCA to other environmental tools.

Tools ObjectScale &

production cycle

Considered effects & substances

Effects Basic elements

SFA Substance

Flow Analysis

Polluting substance

Regional or global, subst.

cycle

No impact, single substance

Time and given region

Mass balance

EIA Environment

al Impact Assessment

New localised activity

Local effects Highly variableFor a given absorption capacity

Highly variable

Mass balance, environmental

multimedia models

Installation or chemical

Local or régional

ToxicityFor a given

periodMultimedia models,

effect evaluation

Product or system

Global, (regional) whole life

cycle

Multiples effects, large number of

substances

Per functional

unit

LCA Life Cycle

Assessment

RARisk

Assessment

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4.6a4.6a Environmental impact Assessment Environmental impact AssessmentLife Cycle AssessmentLife Cycle Assessment

Craddle Grave

Global

Local

On the following illustration, how and where would you sketch LCA and, for example, EIA?

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4.6b4.6b Environmental impact Assessment Environmental impact AssessmentLife Cycle AssessmentLife Cycle Assessment

Craddle Grave

Global

Local

LCA

EIA

Specificities of LCA:

• from cradle to grave,

• relate the impact to the function of a product,

• quantified approach.

From now on, we will focus on the LCA methodology.

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5.5. Historical review P. Hofstetter- SRA Historical review P. Hofstetter- SRA

1972 Fundation of the club of Rome:

Resources are limited

1973 Energy crisis energy balances

1977/90/97 Ecopoints (BUWAL 130/237)

1984/91/97 LCA of pakaging materials (BUWAL 24/132/250)

1992 20th anniversary of Club of Rome: the first limitation is the absorption capacity of the environment.

CML guide (Leiden University)

1993 "A code of Practice" SETAC (Society for Environmental Toxicity and Chemistry)

1994 Energy systems: inventory (ESU-ETH Zürich)

1995/99 Ecoindicator 95/99

Asian workshop SETAC working groups

ISO 14040-43

analysis framework UNEP best available factors

2001 Life Cycle Initiative

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6.6. Questions of understanding Questions of understanding

–What are the different steps of a LCA ? (describe the 4 steps)

–On which basis can you compare products or services?

–What are the criteria for natural and for environmental friendly ? (give an example)

–Give the different kind of environmental assessment tools ?

–What are the LCA specificities ?