What does LCA stand for
Life Cycle Assessment
Defenition
- life cycle means that a product is followed from its cradle where raw materials are extracted from natural resources, through production and use, to its grave the diposal
- env LCA - natural resources and pollutant emissions are described in quantitative terms
LCA model for use, flowchart
Flowchart (lådor i led neråt)
Raw material acquisition Process Transportation Manufacture Use Wastemanagement
In to them: Resources (ex raw material, energy, land resources)
Out from them: emissions (to air, water, ground)
- physical processes and flows of matter and energy
Term: Weighting
- used in the impact assessment (step 3 in LCA) to express the relative importance of different parameters
Term: index
- aggregated data in single dimension to express information eg GWP, footprint. Used in LCA to show the overall env. impact of a product in a single number/category
Term: Characterization
- In LCIA to calculate/evaluate the relevant contributes of emission and resources to each type of category
Term: classification
about grouping different substances into impact categories
Term: functional unit
To express the function of the system
General impact categories
- resource use
- human health
- ecological consequentces
Methodology of LCA, 4 steps
- Goal and scope defenition
- Inventory analysis
- Impact assessment (classification, characterization, weighting)
(pil mellan 3 och 1 med 4 emellen) - Interpretation
Describe step 1 in LCA methodology
- Goal and scope
- deciding product to be studied and purpose of the study
- state the intended application of the study, reason for carrying it out and fro whom the results are intended
- Goal - why, for whom, def of system,
- scope - modeling aspects, functional unit, system boundaries, allocation
Describe Functional Unit
- expressess the function of the system
- liter, kg/year,
- all flows related to the functional unit
- basis of comparison
What is included in system boundries
Geographical boundaries and time
What does allocation mean
- allocation in LCA tries to calculate how much one product that comes out has environmental load
- system expansion may be needed to look into what is happening around the system, where resources come from, to see full impact
- may need system expansion to fully see
Describe step 2 in LCA methodology
- Inventory analysis
- to build a system model according to the requirements of the goal and scope def.
- system model = a flow model of a technical system with certain types of system boundaries (“cradle-to-grave”)
- only env. relevant flows are concidered
- collecting and calculating data
Procedure:
- construction of flow model
- gather data
- Calculations - of resource use and pollutant emissions of the system
Describe step 3 in LCA methodology
- Impact assessment
- LCIA - Life Cycle Impact Assessment
- to describe the impacts of the env. loads quantified in the inventory analysis
Purpose
- to turn inventory results into more env. relevant info
- to aggregate the info into fewer parameters
3 steps:
- classification
- characteriszation
- weighting
Describe doing Classification
First step in LCIA
- sorting the inventory parameters according to type of environmental impact they contribute
Describe doing Characterisation
Second step in LCIA
- calculating the relevant contributes of the emissions and resource consumptions to each type of environmental impact
Describe doing weighting
Third step of LCIA
- models reflecting peoples values and preferences regarding the environment
- to express relative importance off different parameters
Most 4 critical choices of LCA methodology
- definition of functional unit
- system boundaries and allocation procedure
- type of data used
- Impact assessment - how results are presented
When to use LCA
- decision making: product or process design and dev., env policy making
- Learning: identification of improvement possibilities, risk management
- Communication: eco-labeling, carbon footprint
- LCA strives for completeness - many substances
MFA can be used to establish an inventory for LCA
