Title: Life Cycle Assessment: Critical Points
1Life Cycle AssessmentCritical Points
- Prof O.Jolliet , T. Corbière, M. Thérézien
- EPFL-Swiss Federal Institute of
Technology-Lausanne - Ecosystem management, GECOS, CH-1015 Lausanne,
SWITZERLAND - olivier.jolliet_at_epfl.ch, http//dgrwww.epfl.ch/GEC
OS/DD - In collaboration with Harvard School of Public
Health (Harvard University), University of
Medellinand WBCSD (World Business Council for
Sustainable Development).
21.1 Objectives 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 enhance both formal and informal learning
opportunities through collaborative and
cooperative processes
- To improve information and knowledge sharing as
well as inter-university collaboration and
tuition for industry collaborators.
31.2 Objectives of lesson 1
- 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.
- 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 ?
42. Introductory case study2.1 How to replace
Polystyrene ?
What are the environmental problems with
Polystyrene ? Tips Ask yourself what is
Polystyrene made of ?
52.2 Popcorn as a possible alternative
As a replacement material, you may have thought
of popcorn, and it has indeed been
commercialized. This 100 natural matter is
renewable and biodegradable.
According to your personal judgment, popcorn is
The best
Worse
Equivalent
Slightly better
Much better
62.3 Popcorn versus Polystyrene
Properties of the two matters
conventional polystyrene extracted from non
renewable fossil oil, this material is not
biodegradable.
popcorn extracted from renewable resources, this
material is completely biodegradable.
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 ?
72.4 LCA to determine the environmental key
parameters
- 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.
We will now have a quick overview of this study.
82.5 LCA Steps
LCA is a 4 steps tool defined in ISO standards.
- 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.
92.6a Popcorn system boundaries
Now lets come back to the examples of filling
materials for packaging. How would you imagine
the system boundaries for popcorn?
102.6b System boundaries, commentaries
- 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.
Once the system is defined, emissions and
extractions data for each production module are
calculated, generating the inventory.
112.7a Inventory of the most important emissions
and extractions
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.
Do you guess why we have these results?
It is because of the agriculture phase! Indeed,
the use of fertilizers in agriculture puts a high
load of nitrogen on environment.
122.7b Inventory of the most important emissions
and 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.
132.8 Impact assessment
- 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.
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.
142.9 Popcorn impacts compared to Polystyrene
impacts
- Depending on the method, 1 kg popcorn turns out
to be 3 to 4 times better than 1 kg polystyrene.
What do you think about this results? Any
objection?
152.10 Popcorn impacts compared to Polystyrene
impacts
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
- 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).
162.11a Popcorn impact compared to polystyrene
impacts
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.
172.11b Popcorn impact compared to polystyrene
impacts
- 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.
Therefore there is a need to improve popcorn in
order to make it a good filling material.
Where would you act in priority to achieve this
goal ? What is the environmental key parameter?
182.12 Conclusions popcorn - polystyrene
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
- It is interesting to note that industrial
products can be less damageable for the
environment than natural products - Natural is different from environmentally
friendly!
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!
193. Group 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.
204.1 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.
214.2 LCA among different environmental impact
assessment tools
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.
224.3 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.
Which one do you know? (see next page)
- 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.
234.4 Environmental Assessment Methods
244.5 LCA compared to other environmental tools
- We can have a look at particularities of LCA.
This table compares LCA to other environmental
tools.
254.6a Environmental impact AssessmentLife Cycle
Assessment
- On the following illustration, how and where
would you sketch LCA and, for example, EIA?
264.6b Environmental impact AssessmentLife Cycle
Assessment
- 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.
275. 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
286. 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 ?