best practice lca - gabi software€¦ · best practice lca water ... (boiler feed water) water ......
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Welcome to the webinar!
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Your hosts
Jim Craig
Product Marketing
Daniel Thylmann
Consultant and
Water Expert
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Agenda
1. Terminology
2. GaBi Inventories
3. Balances and quantities
4. Water scarcity footprint
(Part 1 last week: Water assessment
methods)
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Agenda
1. Terminology
2. GaBi Inventories
3. Balances and quantities
4. Water scarcity footprint
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Terminology for Water inventories
• Water use umbrella term: all types of anthropogenic water uses
• Characterization of water use types - degredative vs. consumptive:
• Degradative use (water degradation): Water used and released into
the same watershed it was withdrawn from (wastewater, cooling
water) (possibly with degraded quality)
• Consumptive use (water consumption): Evaporation, product
integration, water transfers to different river basins, release to sea
water loss on watershed level
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Owens (2002); Koehler (2008), Int J LCA 13(6): 451–455;
Pfister, Koehler & Hellweg (2009), ES&T 43(11): 4098–4104
WithdrawalDegradative use
Consumptive use
Process
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• Characterization of water use types - green vs. blue:
• green water: rainwater and moisture stored in soil that evaporates during
production process, mainly during crop growth (evapotranspiration)
• blue water refers to surface and groundwater applied (e.g. irrigation in crop
cultivation)
• Characterization of water use types - in-stream vs. off-stream:
• In-stream use (hydroelectric generation, water transport, damming)
• Off-stream use: (total) withdrawal from water body (irrigation, water supply,
cooling)
Terminology for Water inventories
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Classification Examples
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Classification Examples
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Pictures (also from previous slide) from wikipedia, used under public domain
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Agenda
1. Terminology
2. GaBi Inventories
3. Balances and quantities
4. Water scarcity footprint
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Water input flows in GaBi
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• Make sure all relevant water inputs are tracked
• If the processing plant extracts water directly – use elementary flows (previous slide). Only these flows can be used. Do not create new elementary flows!
• Elementary flows can only be used at point of water extraction/water withdrawal
• If the processing plant uses tap water or something comparable – model as tracked flow (operating material, open input). In the model, these flows have to be connected with water provision processes (e.g. DE: Tap water). These processes will only have elementary water flows as input
• Think of special cases (e.g. rain water collection or large amounts of water contained in products)
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Water input flows in GaBi
• Water that is passed from one
processing step to another is an
operating material. Use operating
material flows. You can create your
own flows if necessary.
• Water that is looped back can be
modeled as such, but make sure to
track additional input to compensate
for losses (e.g. closed loop cooling)
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Water as operating material
List of operating materials (examples)
Water (desalinated; deionised)
Water (processed)
Water (cooling water)
Water (boiler feed water)
Water (process water)
Water (decarbonised, softened)
Water (tap water)
Water (process water)
Water (deionised)…
Water output flows in GaBi
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• Use elementary flows (see above) once the water leaves the system.
• Waste water treatment on site = last processing step Use elementary
flows
• Waste water treated elsewhere: use “Water (waste water, untreated)”
flow; this flow needs to be tracked (or marked with *) and to be
connected with a waste water treatment plant
• All water that is not tracked as output is assumed to be evaporated. Use
the elementary flow “Water vapour (inorganic emissions to air)”. This
flow is typically used to account for losses to close water balances.
• Water (evapotranspiration) is used to model evaporation of water
through plants
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Water output flows in GaBi
General remarks
• It is important to have a closed water balance, i.e. to know where water
used in a system comes from and where it goes to
• Correct usage of elementary flows is important. GaBi6 has new build
in quantities for calculating key figures used in water footprinting (e.g.
blue water consumption) that will only work when flows are used
correctly.
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Agenda
1. Terminology
2. GaBi Inventories
3. Balances and quantities
4. Water scarcity footprint
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Agenda
1. Terminology
2. GaBi Inventories
3. Balances and quantities
4. Water scarcity footprint
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• a set of different calculations, umbrella term rather than to
communicate a single number
Examples
• Water scarcity footprint: weighting of water consumption with
water scarcity index
• Water availability footprint: considers reduced availability due
to changes in water quality
• Water footprint profile: quality aspects considered through
standard LCA indicators like eutrophication, acidification and
toxicity
Water footprint (ISO 14046)
2020
Water Stress Index (WSI)
2112.12.2014
WSI based on withdrawal-to-availability ratio (m3/m3) (Pfister et al. 2009)
Takes into account water availability, use, and seasonal/annual variation in
precipitation
Pfister, Koehler & Hellweg (2009), ES&T 43(11): 4098–4104
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CWU: consumptive water use
WSIi : regional water stress index
WSIglobal : global average water stress index
(value: 0.602)
The Water Scarcity Footprint caused by consumptive use
𝑊𝑆𝐹 =
𝑖
𝐶𝑊𝑈𝑖 ×𝑊𝑆𝐼𝑖𝑊𝑆𝐼𝑔𝑙𝑜𝑏𝑎𝑙
„Amount of water as if it was consumed globally“
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Water use
Water Consumption
Water Footprint - Overview
Water scarcity
footprint
Application of
the WSI
Impact
Assessment
Endpoint?
Inventory Midpoint
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• ISO 14046: Water inputs or water outputs of different resource types,
different quality, different form, different location with different
environmental condition indicators or different timing shall not be
aggregated in the inventory phase. Aggregation may be performed at
the impact assessment phase.
Challenge: country level not sufficient; complexity of models (some
have several thousand processes involved); data availability;
confidentiality;
Approach: Hot spot analyses; PE to provide regionalization of
background processes on demand; test kit planed, stepwise update of
software and database
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Aggregated data and impact assessment
Example
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RegionDataset (GaBi
name)Unit
Blue water
consumption
Weighted
WSI
Water
Scarcity
footprint
Remark (percentages refer
to water consumption)
DEElectricity grid mix
(production mix)l/kWh 2.4 0.12 0.5
30% lignite, 22% nuclear; 13%
hard coal – cooling processes
NLElectricity grid mix
(production mix)l/kWh 1.1 0.298 0.5
28% biomass; 25% natural
gas, 21% coal 18% waste (all
cooling)
DE Hard coal mix 2010 l/kg 0.49 0.085 0.134% CIS; 26% Columbia; 13%
Germany; 10% Poland
NL Hard coal mix 2010 l/kg 0.59 0.102 0.158% Columbia; 25% RU; 6%
US, rest: Canada, South Africa
EU-27 Iron ore mix l/kg 0.84 0.41 0.675% US; 19% Canada; 1%
Australia
Electricity
Coal
Iron Ore
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Assessment of Quantity
(Water scarcity
footprint)
Water quality – Existing LCA impact categories
Eutrophication
Toxicity
Land Use
Acidification
Assessment of Quality (Impacts of water pollution)
Water Footprint Profile
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2712.12.2014
Contact
Annette Köhler
Daniel Thylmann