8- Análise de ciclo de vida

Prévia do material em texto

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Análise de ciclo de vida
LCA studies the environmental aspects and potential impacts
throughout a product’s life (i.e. cradle-to-grave) from raw
material acquisition through production, use and disposal.
Raw
materials
Production Use
Final 
disposal
Resources
Emissions to the environment
Environmental impacts
Life Cycle Assessment (LCA)
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APPLICATIONS
or ?
LCA of diapers - Franklin Associates Ltd, 1992
APPLICATIONS
Support decision making
At industrial level:
Example: what is the best alternative for the end-of-life of industrial
wastes?
At the consumer level:
Example: what is the best alternative for residencial heating: wood pellets
or wood split logs?
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APPLICATIONS
Marketing strategies
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http://www.google.pt/url?sa=i&rct=j&q=carbon+footprint+tesco&source=images&cd=&cad=rja&docid=QzkUgR1HP0h0tM&tbnid=_BhJYQEu8FdFAM:&ved=0CAUQjRw&url=http://www.mnn.com/your-home/at-home/blogs/wiping-away-carbon-emissions&ei=QhiJUbvfCqPw0gX3lIHICw&psig=AFQjCNHE9ZJswEGKds35Je0WXSm0K8lnww&ust=1368025125993819
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Incineration
and landfill
Energy
production
Emissions
Energy
consumption
Emissions
Recycling
Paper
production
from virgin
fibre
Forest
Consumption
/Production of
energy
Emissions
Example: what is the better alternative for the end-of-life of paper
from an environmental point of view?
Example: electric vehicles or internal combustion engine vehicles?
APPLICATION OBJECTS OF LCA
• Products
• Activities and services (e.g.: travel, music concert)
• Sector
• Organizations (e.g.: schools, companies, hospitals)
• Territories (e.g.: country, city)
STRENGTHS AND WEAKNESSES
• Strengths:
– Cradle-to-grave approach
– Avoidance of problem shifting, for example:
• from one life cycle stage to another (e.g., decreasing the impact at
the use stage but increasing at the impact at the end-of-life)
• from one geographic area to another (e.g., decreasing water use
at a region where water availability is not a problem but increasing
water use at a region with water scarcity)
• from one environmental medium (e.g. water) to another (e.g.
soil) (e.g., decreasing water pollution but increasing soil pollution)
– Multicriteria approach (several environmental impacts)
– Quantitative analysis
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STRENGTHS AND WEAKNESSES
• Weaknesses:
– Data requirements
– Relevance of results
– Time (and resource) consuming
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GOAL AND SCOPE DEFINITION
DATA
• Data on input flows:
– Consumption of raw materials
– Consumption of ancillary materials
– Consumption of electricity and fuels
– Consumption of water
• Data on output flows:
– Products and co-products
– Emissions to air (CO2, CO, SO2, NOx, particles, Hg, Fe, Zn, …)
– Emissions to water (N, P, …)
– Solid wastes
– Others (land use, radiation, …)
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Limite do sistema
Aquisição matérias primas
Produção (fabricação)
Utilização / Reutilização / 
Manutenção
Reciclagem / Gestão do 
resíduo
ENTRADAS
Matérias
Primas
Energias
SAÍDAS
Emissões para o ar
Descargas para a 
água
Resíduos sólidos
Co-produtos
Outras descargas 
ambientais
Example – Impact category selection
• Impact categories 
✓ global warming 
✓ acidification
✓ eutrophication
✓non-renewable resource depletion
✓photochemical oxidant formation
 stratosferic ozone depletion
 ecotoxicity
 human toxicity
 water use
 land use
No inventory data available
No consensual methodology available
Example – Impact category selection
• Impact categories 
✓ global warming 
✓ acidification
✓ eutrophication
✓non-renewable resource depletion
✓photochemical oxidant formation
 stratosferic ozone depletion
 ecotoxicity
 human toxicity
 water use
 land use
No inventory data available
No consensual methodology available
Caused by greenhouse gas emissions: 
• CO2
• CH4
• N2O
• SF6
• Halons
• CFCs (chlorofluorcarbons)
• HCFCs (hydrochlorofluorcarbons)
• HFCs (hydrofluorcarbons)
• PFCs (perfluorcarbons)
Example – Impact category selection
• Impact categories 
✓ acidification
✓eutrophication
✓non-renewable resource depletion
✓photochemical oxidant formation
 stratosferic ozone depletion
 ecotoxicity
 human toxicity
 water use
 land use
No inventory data available
No consensual methodology available
Deposition at the terrestrial surface of acid substances caused by the 
emission to air of acidifying gases such as:
• SO2
• NOx
• NH3
http://www.google.pt/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=rpOFD-AoesWwcM&tbnid=zc7CPMbWnoxWqM:&ved=0CAUQjRw&url=http://en.wikipedia.org/wiki/Acid_rain&ei=AURPUuerJeWM0wX0g4CwAg&bvm=bv.53537100,d.ZGU&psig=AFQjCNH08RrwRZ6k_arBtUZ8Vy8MOpGTHQ&ust=1381012859798062
http://www.google.pt/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=dEBMk3lapcflTM&tbnid=_-KHguWT6413fM:&ved=0CAUQjRw&url=http://www.glogster.com/andrew0314/transboundary-pollution/g-6mb5p84815ml3ntd83t1ua0&ei=aEVPUpSgE4rH0QXE-4GoCQ&psig=AFQjCNFb6Hi6_mlvvMNzVTro2KN1mD2TpA&ust=1381013028435943
Example – Impact category selection
• Impact categories 
✓ Eutrophication
✓non-renewable resource depletion
✓photochemical oxidant formation
 stratosferic ozone depletion
 ecotoxicity
 human toxicity
 water use
 land use
No inventory data available
No consensual methodology available
Surplus of 
nutrients in 
aquatic mediums
Growth of 
microorganisms
that decompose
the dead algae
Growth of algae
Decrease of 
dissolved O2
Death of aerobic
organisms
Increased amount
of organic matter
for decomposition
Development of 
anaerobic
microorganisms
that produce toxic
compounds
• Nitrogen
• Phosphorus
http://2.bp.blogspot.com/_ypnwZJvO0Jg/TCWcSpOYXjI/AAAAAAAAAEY/tqKJFJYT578/s1600/mirante3.jpg
Example – Impact category selection
• Impact categories 
✓non-renewable resource depletion
✓photochemical oxidant formation
 stratosferic ozone depletion
 ecotoxicity
 human toxicity
water use
 land use
No inventory data available
No consensual methodology available
• Fossil resources (crude oil, coal, natural gas)
• Mineral resources
Example – Impact category selection
• Impact categories 
✓photochemical oxidant formation
Formation of oxidants (mainly O3) through a complex set of chemical 
reactions involving organic compounds and NOx (mainly from the 
burning of fossil fuels), in the presence of sunlight
http://www.google.pt/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=2Za0yiledNMx0M&tbnid=UxlhK3r_ipzDUM:&ved=0CAUQjRw&url=http://www.theguardian.com/world/2013/jan/14/beijing-smog-continues-media-action&ei=0UVPUraKNeKW0AXixIGIDA&psig=AFQjCNG7u4U-Ee6acUGxwMA-mRoOkyW7Ag&ust=1381013309081913
http://www.google.pt/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=tzo0khZA_1hrsM&tbnid=XAbjc8aBZDIcxM:&ved=0CAUQjRw&url=http://www.secretsofthefed.com/guess-which-totalitarian-state-is-going-to-introduce-death-penalty-for-polluters/china-polluted-chinese-city-smog/&ei=akZPUr_uD9TJ0AXUr4HoCQ&psig=AFQjCNFuOY4HOdKsP9vQo1DwU8lzfzAz2g&ust=1381013420840023