Unit 12.
Eco-selection
and the
Eco-audit tool
Introducing students to life-cycle thinking
Mike Ashby
Department of Engineering
University of Cambridge
© M. F. Ashby, 2013
For reproduction guidance see back page
This lecture unit is part of a set created by Mike Ashby to help introduce students to materials, processes and rational selection.
The Teaching Resources website aims to support teaching of materials-related courses in Design, Engineering and Science.
Resources come in various formats and are aimed primarily at undergraduate education.
Some of the resources are open access and students can access them. Others are only available to educators using CES EduPack.
www.grantadesign.com/education/resources
Outline, outcomes and resources
 The materials life-cycle
Outcomes
 Eco-audits and the audit tool

 Case study: PET bottles from France
An understanding of the
material life-cycle
 Ability to carry out ecoaudits of products
 DEMO
 Hands-on session, with exercises
Resources





Text: “Materials and the Environment”, 2nd Edition (2012) Chapters 1 - 10
Text: “Materials: engineering, science, processing and design”, 2nd Edition, Chapter 20
Text: “Materials Selection in Mechanical Design”, 4th Edition, Chapter 16
Software: CES EduPack with Eco-Audit tool
Poster: Wall chart of Eco-properties of materials
Mike Ashby, 2013
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The product life-cycle
Resources
Life cycle
assessment (LCA)
Emissions and waste
Combust
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Landfill
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Life cycle assessment (LCA)
ISO 14040 series
PAS 2050
Resource
consumption
Emissions
inventory
Impact
assessment


Typical LCA output
Aluminum cans, per 1000 units
• Bauxite
• Oil fuels
• Electricity
• Energy in feedstock
• Water use
• Emissions: CO2
• Emissions: CO
• Emissions: NOx
• Emissions: SOx
• Particulates
• Ozone depletion potential
• Global warming potential
• Acidification potential
• Human toxicity potential
59
kg
148
MJ
1572
MJ
512
MJ
1149
kg
211
kg
0.2
kg
1.1
kg
1.8
kg
2.47
kg
0.2 X 10-9
1.1 X 10-9
0.8 X 10-9
0.3 X 10-9
Roll up into an
“eco-indicator” ?
Full LCA is expensive, and requires great detail and experience –
and even then is subject to uncertainty
How can a designer used these data?
Mike Ashby, 2013
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Design guidance vs. product assessment
Market need
Problem statement
Alternative schemes
Concept
Layout and
materials
Embodiment
CAD, FE analysis,
optimization, costing
Detail
Design
guidance
Eco – audit
ability
Product
assessment
Product specification
Production
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Life cycle
assessment
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Eco-audit for design
Need: Fast Eco-audit with sufficient precision to guide decision-making
 1 resource – energy (oil equivalent)
Transport
 1 emission – CO2 equivalent
 Distinguish life-phases
Life-energy
600 16
14
Energy
Carbon
C02 equiv (kg)
Energy (MJ)
400
12
300 10
200
100
0
8
6
4
2
0
-100
-2
Potential benefits
Mike Ashby, 2013
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Analyse
results, identify
priorities
Fast
eco-audit
Explore options
with “What if..”s
Use CES to
select new Materials
and/or Processes
Recommend
actions & assess
potential savings
600
600
Initial
and
re-design
Initial
design
400
Energy (MJ)
Energy (MJ)
The steps
Eco-design: the strategy (1)
300
Use eco-audit to identify
Eco-design objective
200
200
100
100
0
-100
-100
Material
Minimize:
• material in part
• embodied energy
• CO2 / kg
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Manufacture
Minimize:
• process energy
• CO2/kg
Transport
Minimize:
• mass
• distance
• transport type
End of Life
Use
Minimize:
• mass
• thermal loss
• electrical loss
Select:
• recyclable materials
• non-toxic materials
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The CES Eco-audit tool
Data from CES
User inputs
User interface
Eco database
 Bill of materials
 Embodied energies
 Manufacturing process
 Process energies
 Transport needs
 CO2 footprints
 Duty cycle
 Unit transport energies
 End of life choice
 Recycling / combustion
Eco audit
model
Outputs
(including tabular
data)
Mike Ashby, 2013
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Typical record showing eco-properties
Mike Ashby, 2013
www.grantadesign.com/education/resources
The CES EduPack Eco-audit tool
Data from CES
User inputs
User interface
Eco database
 Bill of materials
 Embodied energies
 Manufacturing process
 Process energies
 Transport needs
 CO2 footprints
 Duty cycle
 Unit transport energies
 End of life choice
 Recycling / combustion
Eco audit
model
Outputs
(including tabular
data)
Mike Ashby, 2013
www.grantadesign.com/education/resources
The simple Audit tool: Levels 1, 2 and 3
New
Product name:
Super-Gizmo
^ 1. Material, manufacture and end of life
?
1
Component 1
Cast iron
30%
2.4
Casting
Recycle
1
Component 2
Polypropylene
0%
0.35
Molding
Landfill
v 2. Transport
?
Survey charts
v 3. Use
v 4. Report
?
?
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HELP at
each step
Full report
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Step 1. Material and process energy / CO2
Component name
Component 1
Material
Process
Aluminum alloys
2.3
End of life
Recycle
Polymer molding
1.85
Landfill
• Reuse
• Casting
• Refurbish
• Forging / rolling
• Recycle
Glass molding• Extrusion
3.7
Reuse
• Combust
• Wire drawing
• Powder forming
• Landfill
Total process energy
Total
• Vapormass
methods Total end of life energy
Component 2
Polypropylene
Component 3
Glass
Total embodied energy
Casting
Mass (kg)
End of life
options
CES EduPack
materials
tree
Mike Ashby, 2013
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Step 2. Transport
Transport stage
Transport type
Stage 1
32 tonne truck
Stage 2
Sea freight
Distance (km)
350
12000
Transport energy
Transport CO2
Table of transport types:
MJ / tonne.km
CO2 / tonne.km
Mike Ashby, 2013
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Step 3. Use phase – static mode
Energy input and output
Power rating
Fossil fuel to electric
1.2
kW
Energy conversion path
W
Fossil
fuel to heat, enclosed system
days per year
365
kW fuel to heat, vented system
Fossil
MW fuel to electric
Fossil
hours per day
0.5
hp fuel to mechanical
Fossil
ft.lb/secto heat
Electric
Total energy and CO2 for use
kCal/yrto mechanical (electric motor)
Electric
BTU/yr to chemical (lead-acid battery)
Electric
Usage
Usage
Electric to chemical (Lithium-ion battery)
Electric to light (incandescent lamp
Electric to light (LED)
Mike Ashby, 2013
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Bottled water (100 units)




PET bottle
Product name:
Number
1 litre PET bottle with PP cap
Blow molded
Filled in France, transported 550 km to UK
Refrigerated for 2 days, then drunk
Name
Material
Process
Mass (kg)
End of life
100
Bottles
PET
Molding
0.04
Recycle
100
Caps
Polyprop
Molding
0.001
Landfill
100
Water
1.0
Transport
Stage 1
14 tonne truck
550 km
Survey charts
Use - refrigeration
Fossil to electric
Mike Ashby, 2013
0.12 kW
2 days
24 hrs/day
Full report
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Output: summary charts
Toggle between energy
and carbon footprint
Copy or print
the chart
Reducing
Material-phase
impact
Material-phase
impact
LifeReducing
energy
Aim
Minimize embodied energy or CO2 footprint /
unit of function.
Which phase has
the largest impact?
Materials
Click on bar for help
on impact reduction
Select material with lowest embodied energy
Actions
and CO2 footprint per unit of function.
Use as large a 'recycled content' in the material
as possible.
Use as little material as possible while retaining
enough redundancy for safety.
Conflicts
Watch out for conflict with the Use phase. The
material with the lowest direct eco-impact may
not be the lightest or the cheapest. Use trade-off
methods to resolve the conflict.
Mike Ashby, 2013
www.grantadesign.com/education/resources
Actions and comparisons
The audit reveals the
most energy and
carbon intensive
steps…
… and allows rapid
“What if…”
PET
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Glass ?
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Change the materials




Glass
bottle
PET bottle
Product name:
Number
1 litre glass bottle with aluminum cap
Glass molded
Filled in France, transported 550 km to UK
Refrigerated for 2 days, then drunk
Name
Material
Process
Mass (kg)
End of life
100
Bottles
PET glass
Soda
Molding
Glass mold
Copy of current project
0.04
0.45
Recycle
100
Caps
Polyprop
Aluminum
New project
Molding
Rolling
0.002
0.001
Landfill
Saved project
100
Water
1.0
Transport
Stage 1
14 tonne truck
550 km
Use - refrigeration
Fossil to electric
Mike Ashby, 2013
0.12 kW
2 days
24 hrs/day
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Actions and comparisons
=
The fast comparison
allows design
decisions on-the-fly
Virgin PET
=
Reducing impact
Glass
Actions
 Use as large a 'recycled
content' in the material as
possible.
What if…….
100% recycled PET?
Mike Ashby, 2013
www.grantadesign.com/education/resources
Actions and comparisons
Click
Compare with….
Copy of current
content
Set Recycle content
to 100%
Can explore:
 Material choice
 Recycle content
 Transport mode
 Transport distance
 Use pattern
 Electric energy mix
 End of life choice
=
Virgin PET
Many projects available as
project files.
=
Glass
=
Recycled PET
Mike Ashby, 2013
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Electric kettle
Bill of materials and processes
2 kW electric kettle
 Made SE Asia
 Air freight to UK
 Life: 3 years
Transport
 12,000 km, air freight
 250 km 14 tonne truck
 6 minutes per day
Use
 300 days per year
 3 years
Mike Ashby, 2013
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Eco audit: the jug kettle
Use is 88%
of life-energy
What do we learn?
 Little gained by change of material for its own sake
 Much gained by insulation – double wall with foam or vacuum
 Or seek new concept: hot water on the fly – only as much as needed
Mike Ashby, 2013
www.grantadesign.com/education/resources
So what?
CES EduPack has two tools-sets to help explore the materials dimension of
environmental design
Tool 1. Eco-audits allows students to implement quick, approximate “portraits” of
energy / CO2 character of products. (This Unit)
Tool 2. Selection strategies allows selection to re-design products to meet ecocriteria, using systematic methods. (Unit 13)
Eco-audits reveal the eco-fingerprint of products and suggest approaches to making
them less environmentally damaging.
Project files for many of the audits shown in the spread of eco-fingerprints can be
down loaded from the Granta Website, allowing students to try alternative
assumptions.
Mike Ashby, 2013
www.grantadesign.com/education/resources
Pause for Demo
Mike Ashby, 2013
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Also Available for Sustainability
 Eco Design & Eco Audits
 Materials and Sustainable
Development
•
•
•
•
•
•
•
•
•
Exercises with Worked Solutions
Other Lecture Units
White Papers
Interactive selection case studies
Webinar recording
Poster
Sample Eco Audit Project Files
Links to other good resource sites
Eco Indicator Database
http://teaching.grantadesign.com/open/eco.htm
Mike Ashby, 2013
www.grantadesign.com/education/resources
Lecture Unit Series
These PowerPoint lecture units, as well as many other types of resources, are on the Teaching Resource Website.
Finding and Displaying Information
Unit 1
The Materials and Process Universe: families, classes, members,
attributes
Unit 2
Materials Charts: mapping the materials universe
Unit 3
The Elements: property origins, trends and relationships
Material Properties
Unit 4
Manipulating Properties: chemistry, microstructure, architecture
Unit 5
Designing new materials: filling the boundaries of materials
property space
Sustainability
Unit 12
Eco Selection: the eco audit tool
Unit 13
Advanced Eco Design: systematic material selection
Unit 14
Low Carbon Power: resource intensities and materials use
Special Topics
Unit 15
Architecture and the Built Environment: materials for
construction
Unit 16
Structural Sections: shape in motion
Unit 17
CES EduPack Bio Edition: Natural and man-made implantable
materials
Unit 18
Materials in Industrial Design: Why do consumers buy products?
Unit 19
Advanced Databases: Level 3 Standard, Aerospace and Polymer
Selection
Unit 6
Translation, Screening, Documentation: the first step in
optimized selection
Unit 7
Ranking: refining the choice
Unit 8
Objectives in Conflict: trade-off methods and penalty functions
Unit 9
Material and shape
Unit 10
Unit 11
Advanced Teaching and Research
Unit 20
Hybrid Synthesizer: modelling composites, cellular structures and
sandwich panels
Selecting Processes: shaping, joining and surface treatment
Unit 21
Database Creation: using CES constructor in research
The Economics: cost modelling for selection
Unit 22
Research: CES Selector and Constructor
Unit 23
Sustainability: sustainability and materials selection
Unit 24
The Polymer Edition
Unit 25
The Aerospace Edition
Mike Ashby, 2013
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Reproduction
Author
This work is licensed under a Creative Commons AttributionNonCommercial-ShareAlike 3.0 Unported License.
Professor Mike Ashby
University of Cambridge, Granta Design Ltd.
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www.eng.cam.ac.uk
Please make sure that Granta Design are credited on any
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purpose.
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and the logo for the University of Cambridge are not covered by
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Accuracy
We try hard to make sure these resources are of a high quality. If you have any suggestions for improvements, please contact us by email at
teachingresources@grantadesign.com
M. F. Ashby, 2013
Granta’s Teaching Resources Website aims to support teaching of materials-related courses in Engineering, Science and Design.
The resources come in various formats and are primarily aimed at undergraduate students.
This resource is one of 25 lecture units created by Professor Mike Ashby.
The website also contains resources donated by faculty at the 800+ universities and colleges worldwide using
Granta’s CES EduPack.
The teaching resource website contains both resources that require the use of CES EduPack and those that don’t.
Some of the resources, like this one, are open access.
www.grantadesign.com/education/resources
Mike Ashby, 2013
www.grantadesign.com/education/resources