life cycle assessment a product-oriented method for ......life cycle assessment a product-oriented...
TRANSCRIPT
![Page 1: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/1.jpg)
1
Life Cycle AssessmentA product-oriented methodfor sustainability analysis
UNEP LCA Training KitModule g –Multifunctionality, allocation & system boundaries
![Page 2: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/2.jpg)
Contents
This module be used to expand on the presentation of LCI in module d.
• The problem
• Definitions and typologies
• Solving the multifunctionality problem
• Allocation according to ISO
• System boundary and allocation
• Economic allocation
![Page 3: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/3.jpg)
electricity productionwith cogeneration
of heat (CHP)
electricitycoal
generator fly ash
heat
function 1
function 2
not a functionD r a f t
Some processes have more than one function.– “multifunctional processes”
not a function
not a function
The problem
![Page 4: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/4.jpg)
electrolysis ofsodium chloride
chlorine(Cl2)
caustic soda(NaOH)
hydrogen gas(H2)
sodium chloride(NaCl)electricity
3 functions
D r a f t
The problem
![Page 5: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/5.jpg)
refinery process
naphtha kerosene heavy fuel oil
crude oil
3 functionsD r a f t
The problem
![Page 6: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/6.jpg)
66
• Two problems:
– How should the environmental impacts of these processes be allocated to the different product systems involved?
– Which processes belong to the product system studied and which do not?
The problem
![Page 7: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/7.jpg)
77
• Functional flow– any of the flows of a unit process that constitute its goal
• product outflows of a production process
• waste inflows of a waste treatment process
• Multifunctional process– a unit process yielding more than one functional flow
• co-production (multi-output)• combined waste processing (multi-input)
• recycling (input-output)
Definitions and typologies
![Page 8: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/8.jpg)
88
generalprocess
product
wasteproduct
product
product waste
single-output process
1 functional flow
Definitions and typologies
![Page 9: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/9.jpg)
99
generalprocess
product
wasteproduct
product
product product
multi-output process
2 functional flows
Definitions and typologies
![Page 10: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/10.jpg)
1010
generalprocess
waste
wasteproduct
waste
product waste
single-input process
1 functional flow
Definitions and typologies
![Page 11: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/11.jpg)
1111
generalprocess
waste
wasteproduct
waste
waste waste
multi-input process
2 functional flows
Definitions and typologies
![Page 12: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/12.jpg)
1212
generalprocess
product
wasteproduct
waste
product waste
input-output process
2 functional flows
Definitions and typologies
![Page 13: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/13.jpg)
1313
generalprocess
product
wasteproduct
waste
waste product
multi-input-output process
4 functional flows
Definitions and typologies
![Page 14: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/14.jpg)
1414
• Allocation problem– Partitioning (the inputs and outputs of) unit processes
among product systems can be a challenge.
• Multifunctionality problem– Across LCA inventory modelling
• what are the functional flows of every process?
• which processes are multi-functional processes?
• how to resolve the problems related to that?
Definitions and typologies
![Page 15: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/15.jpg)
1515
• Problem– When a product system needs product 1, it also produces
product 2.
• Possible solutions– more refined data collection– system expansion– substitution– partitioning (=allocation)– surplus
Definitions and typologies
![Page 16: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/16.jpg)
1616
• More refined data collection– … not allocation, but re-iteration of data collection
• System expansion– add extra function(s) to the functional unit– … but are you still doing the LCA of a product?
Definitions and typologies
![Page 17: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/17.jpg)
1717
• Substitution method– defining an “avoided” process with subsequent “avoided”
interventions/impacts– … but which process is avoided?
• Partitioning method– splitting the multifunctional process into several
monofunctional processes– … but what basis for splitting?
• Surplus method– ignoring co-products
Definitions and typologies
![Page 18: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/18.jpg)
1818
• The allocation problem is an artefact of isolating one function.
• Artefacts can only be cured in an artificial way; there is no “correct” way – not even in theory.
• A solution should be consistent in itself, and with main modelling principles.
Solving the multifunctionality problem
![Page 19: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/19.jpg)
• What to do with the extra heat?
electricity production
electricity
coal generator
fly ash
coal mining
equipment
generator production
steel
fly ash treatment
gypsum
waste heat
Solving the multifunctionality problem
![Page 20: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/20.jpg)
2020
• There are two main strategies for dealing with multifunctionality:
1 Accept extra functions as a composite reference fl ow(“system expansion”)
2 Eliminate extra functions by an extra modeling ste p(“allocation”)
• subtracting “avoided” burdens (“substitution”)
• allocating only part of burden to function needed (“partitioning”)
Solving the multifunctionality problem
![Page 21: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/21.jpg)
composite functional unit:
2 reference flowsD
r a f t
• System expansion– change system
boundary– include extra
function(s) in functional unit
– must also do this for the other alternatives
electricity production
electricity
coal generator
fly ash
coal mining
equipment
generator production
steel
fly ash treatment
gypsumD r a f t
waste heat
Solving the multifunctionality problem
![Page 22: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/22.jpg)
• Allocation-Substitution– change system
boundary– add extra process– subtract “avoided”
process– with
consequences upstream and downstream
heat production
coal
heat
avoids
avoided process
D r a f t
electricity production
electricity
coal generator
fly ash
coal mining
equipment
generator production
steel
flyash treatment
gypsum
waste heat
Solving the multifunctionality problem
![Page 23: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/23.jpg)
• Allocation-Partitioning– allocate only
a part of the process to the function considered
– with consequences upstream and downstream
allocate only part of the inputs and outputs to single
functionD r a f t
electricity production
electricity
coal generator
fly ash
coal mining
equipment
generator production
steel
fly ash treatment
gypsum
Solving the multifunctionality problem
![Page 24: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/24.jpg)
2424
• Comparison of solutions on three aspects:
changed(by multiplying with allocation factors)
samesamepartitioning
sameenlarged(with avoided processes)
samesubstitution
sameenlarged(for other alternatives)
revised(for all alternatives)
system expansion
process dataflow diagramfunctional unit
Solving the multifunctionality problem
![Page 25: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/25.jpg)
2525
• Problems with the three solutions:
what are the allocation factors?partitioning
which processes are avoided?substitution
you don’t answer the question you started withsystem expansion
problem
Solving the multifunctionality problem
![Page 26: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/26.jpg)
2626
D r a f t
Allocation according to ISO
![Page 27: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/27.jpg)
2727
• Step 1: Wherever possible, allocation should be avoided by:– dividing the unit process to be allocated into two or more
sub-processes and collecting the input and output data related to these sub-processes
– expanding the product system to include the additional functions related to the co-products
Allocation according to ISO
![Page 28: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/28.jpg)
2828
• Step 2: Partition inputs and outputs in a way which reflect s the underlying physical relationships between them.– This is not necessarily mass of molar flows.
• Step 3: Partition inputs and outputs in a way which reflect s other relationships between then.– For instance, they can be partitioned in proportion to the
economic value of the products.
Allocation according to ISO
![Page 29: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/29.jpg)
• System expansion versus substitution
A.-M. Tillman et al. Choice of system boundaries in life cycle assessment. Journal of Cleaner Production 2:1 (1994), p.24
Allocation according to ISO
![Page 30: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/30.jpg)
3030
electricity production
waste treatment TV use
electricityfly ash
price < 0
reference flow
System boundary and allocation
![Page 31: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/31.jpg)
3131
electricity production
chemical plant TV use
electricityheat
price > 0
reference flow
System boundary and allocation
![Page 32: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/32.jpg)
3232
electricity production
generator plant coal mining
coalgenerator
price > 0
reference flow
System boundary and allocation
![Page 33: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/33.jpg)
3333
electricity production
pallet production coal mining
coalwood waste
price < 0
reference flow
System boundary and allocation
![Page 34: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/34.jpg)
3434
• The price determines:– if a process is to be included– if allocation is needed for a process– extent to which a process in included
• Economic allocation determines for the price:– price<0: exclude– price>0: include a bit– price>>0: include a lot
System boundary and allocation
![Page 35: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/35.jpg)
3535
co-product
electricity production
downstream process TV use
electricity
by-product
price > 0
reference flow
price >> 0
price < 0
waste
System boundary and allocation
![Page 36: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/36.jpg)
3636
• Allocation factors are based on shares of outcomes.
– Absolute values are not needed.– Any monetary unit can be used, if it is the same.– Any base year can be used, if the same.
total amount produced × economic value/unit
Economic allocation
![Page 37: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/37.jpg)
3737
• Problems– market prices not known– fluctuating prices– inflation– trends in real prices– market distortions– markets not yet existing
• Some solutions are suggested in Leiden University Environmental Science Centre (CML) LCA Handbook.
Economic allocation
![Page 38: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/38.jpg)
3838
• Transparency is crucial in drawing system boundarie s and jn solving the multifunctionality problem.– what are the flow diagrams of the systems?– which flows are goods, which are wastes?– where are the multifunctional processes?– how is the multifunctionality problem solved in each of
these?• system expansion: what is the function added?
(also in the other alternatives)
• substitution: what is the avoided process?
• partitioning: what are the allocation factors?
Conclusions
![Page 39: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/39.jpg)
You may wish to review some segments of this module on allocation.
• The problem
• Definitions and typologies
• Solving the multifunctionality problem
• Allocation according to ISO
• System boundary and allocation
• Economic allocation
![Page 40: Life Cycle Assessment A product-oriented method for ......Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module g – Multifunctionality,](https://reader030.vdocuments.us/reader030/viewer/2022040112/5e76f6085eb8135cd033e109/html5/thumbnails/40.jpg)
The remaining modules explore these topics:
Module contents
h LCA mathematics
i LCIA mathematicsj Life cycle costing
k Uncertainty in LCA
l Carbon footprint