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.
Unit 12.
Eco-selection and the
Eco-audit toolIntroducing students to life-cycle thinking
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Outline
Material consumption and life-cycle
Eco-audits and the audit tool
Strategy for materials selection
LCA - problems and solutions
Exercises
Resources Text: “Materials and the Environment”, Chapters 1 - 9 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
Demo
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Material production
Concern 1: Resource consumption, dependence
96% of all material
Usage
20% of Globalenergy
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Carbon to atmosphere
Concern 2: Energy consumption, CO2 emission
20% of all carbon to atmosphere
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The product life-cycle
LandfillCombust
Resources
Emissions and waste
Life cycle assessment (LCA)
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Typical LCA output
Aluminum cans, per 1000 units• Bauxite 59 kg
• Oil fuels 148 MJ
• Electricity 1572 MJ
• Energy in feedstock 512 MJ
• Water use 1149 kg
• Emissions: CO2 211 kg
• Emissions: CO 0.2 kg
• Emissions: NOx 1.1 kg
• Emissions: SOx 1.8 kg
• Particulates 2.47 kg
• Ozone depletion potential 0.2 X 10-9
• Global warming potential 1.1 X 10-9
• Acidification potential 0.8 X 10-9
• Human toxicity potential 0.3 X 10-9
Life cycle assessment (LCA)
Roll up into an“eco-indicator” ?
Full LCA expensive, and requires great detail and skill – and even then is subject to uncertainty
How can a designer used these data?
Resource consumption
Emissionsinventory
Impactassessment
ISO 14040 seriesPAS 2050
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Design guidance vs. product assessment
Product specification
Concept
Embodiment
Detail
Market need
Problem statement
Alternative schemes
Layout and materials
CAD, FE analysis, optimization, costing
ProductionLife cycle
assessment
Eco – audit ability
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Eco-audit for design
Need: Fast Eco-audit with sufficient precision to guide decision-making
Distinguish life-phases
1 resource – energy (oil equivalent) 1 emission – CO2 equivalent
600
400
300
200
100
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-100
Ene
rgy
(MJ)
Mat
eria
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Man
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Tran
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se
Dis
posa
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EoL
cred
it
16
14
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8
6
4
2
0
-2
C0 2
equ
iv (
kg)
Mat
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l
Man
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Tran
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Use
Dis
posa
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EoL
cred
it
This is the life-energy and life-CO2 (as prescribed in ISO 14040 and PAS 2050)
These are potential benefits (could be recovered at end of life)
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Fast eco-audit
Eco-aware design: the strategy (1)
The stepsAnalyse
results, identifypriorities
Explore options with “What if..”s
600
400
300
200
100
0
-100
Ene
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(MJ)
Mat
eria
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Man
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ture
Tran
spor
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Use
Dis
posa
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EoL
cred
it
Initial design600
400
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Ene
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Mat
eria
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Use
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it
What if ..Different material?
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Fast eco-audit
Eco-aware design: the strategy (2)
The stepsAnalyse
results, identifypriorities
Use CES to select new Materials
and/or Processes
Recommend actions & assesspotential savings
Explore options with “What if..”s
600
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300
200
100
0
-100
Ene
rgy
(MJ)
Mat
eria
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Man
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ture
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Dis
posa
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EoL
cred
it
Use eco-audit toindentify
design objective
Minimize: • material in part
• embodied energy
• CO2 / kg
MaterialMinimize:
• process energy
• CO2/kg
ManufactureMinimize:
• mass
• distance
• transport type
TransportMinimize:• mass• thermal loss• electrical loss
UseSelect:
• non-toxic materials• recyclable materials
End of life
Look at the first three steps
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The CES Eco-audit tool
User interface
Bill of materials
Manufacturing process
Transport needs
Duty cycle
End of life choice
User interface
Bill of materials
Manufacturing process
Transport needs
Duty cycle
End of life choice
User inputs
Eco database
Embodied energies
Process energies
CO2 footprints
Unit transport energies
Recycling / combustion
Eco database
Embodied energies
Process energies
CO2 footprints
Unit transport energies
Recycling / combustion
Data from CES
Eco audit model
Eco audit model
Outputs(including
tabular data)
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Typical record showing eco-properties
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Total embodied energy Total process energy Total mass Total end of life energyAvailable processes
• Casting
• Forging / rolling
• Extrusion
• Wire drawing
• Powder forming
• Vapor methods
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Transport
Transport stage Transport type Distance (km)
Stage 1 32 tonne truck 350
Stage 2 Sea freight 12000
Table of transport types: MJ / tonne.kmCO2 / tonne.km
Transport energy
Transport CO2
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Use phase – static mode
Energy input and output
Power rating
Usage
Usage
Fossil fuel to electric
days per year
hours per day
1.2 kW
365
0.5
Energy conversion path
Fossil fuel to heat, enclosed system
Fossil fuel to heat, vented system
Fossil fuel to electric
Fossil fuel to mechanical
Electric to heat
Electric to mechanical (electric motor)
Electric to chemical (lead-acid battery)
Electric to chemical (Lithium-ion battery)
Electric to light (incandescent lamp
Electric to light (LED)
Total energy and CO2 for use
W
kW
MW
hp
ft.lb/sec
kCal/yr
BTU/yr
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Bottled water (100 units)
Fossil to electric 0.12 kW 2 days 24 hrs/day
Use - refrigeration
1 litre PET bottle with PP cap
Blow molded
Filled in France, transported 550 km to UK
Refrigerated for 2 days, then drunk
Number Name Material Process Mass (kg) End of life
100 Bottles PET Molding 0.04 Recycle
100 Caps Polyprop Molding 0.001 Recycle
100 Water 1.0
Transport
14 tonne truckStage 1 550 km
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The output: drink container
The audit reveals the most energy
and carbon intensive steps…
… and allows rapid “What if…”
Material Manufacture Transport Use
End of life
12
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6
4
2
0
-2
-4
-6
Car
bon
(kg)
100% virgin PETwith recycling
PET Glass ?
Material Manufacture Transport Use
End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PETwith recycling
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Change the materials
Fossil to electric 0.12 kW 2 days 24 hrs/day
Use - refrigeration
1 litre glass bottle with aluminum cap
Glass molded
Filled in France, transported 550 km to UK
Refrigerated for 2 days, then drunk
Transport
14 tonne truckStage 1 550 km
Number Name Material Process Mass (kg) End of life
100 Bottles PET Molding 0.04 Recycle
100 Caps Polyprop Molding 0.0001 Recycle
100 Water 1.0
Soda glass Glass mold 0.45
Aluminum Rolling 0.002
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Glass bottle replacing PET
Material Manufacture Transport Use
End of life
12
10
8
6
4
2
0
-2
-4
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Car
bon
(kg)
100% virgin PETwith recycling
Material Manufacture Transport Use
End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PETwith recycling
Material Manufacture Transport Use
End of life
800
600
400
200
0
-200
-400
Ene
rgy
(MJ)
Change of scale
100% virgin glasswith recycling
Material Manufacture Transport Use
End of life
60
50
40
30
20
10
0
-10
-20
-30
Car
bon
(kg)
Change of scale
100% virgin glasswith recycling
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Use recycled PET instead of virgin?
Material Manufacture Transport Use End of life
12
10
8
6
4
2
0
-2
-4
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Car
bon
(kg)
100% recycled PETwith recycling
100% recycled PETwith recycling
Material Manufacture Transport Use End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PETwith recycling
Material Manufacture Transport Use
End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
Material Manufacture Transport Use
End of life
12
10
8
6
4
2
0
-2
-4
-6
Car
bon
(kg)
100% virgin PETwith recycling
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Is it practical to use recycled PET?
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Combust instead of recycle
Material Manufacture Transport Use
End of life
12
10
8
6
4
2
0
-2
-4
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Car
bon
(kg)
100% virgin PETwith recycling
Material Manufacture Transport Use
End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PETwith recycling
Material Manufacture Transport Use
End of life
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PET with combustion
Material Manufacture Transport Use End of life
12
10
8
6
4
2
0
-2
-4
-6
Car
bon
(kg)
100% virgin PET with combustion
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Ship by air freight, refrigerate 10 days
Material Manufacture Transport Use
Disposal
12
10
8
6
4
2
0
-2
-4
-6
Car
bon
(kg)
100% virgin PETwith truck transport
Material Manufacture Transpt Use
Disposal
60
50
40
30
20
10
0
-10
-20
-30
Car
bon
(kg)
100% virgin PETwith air freight
Change of scale
Material Manufacture Transpt Use
Disposal
1000
800
600
400
200
0
-200
-400
Ene
rgy
(MJ)
Change of scale
100% virgin PETwith air freight
Material Manufacture Transport Use
Disposal
400
300
200
100
0
-100
-200
Ene
rgy
(MJ)
100% virgin PETwith truck transport
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Teaching with the CES Eco-audit tool
• Overview of the life cycle
• Shown how Eco Audit Tool works
• Pre-loaded projects
Which life phase dominates?
What could you do about it?
• Self-made projects
Bottled mineral water.prd
Hair dryer.prd
Electric kettle.prd
Portable space heater.prd
Family car.prd
Wind turbine.prd
Pre-loaded in CES Edu 2011
Material
Recycle content
Transport mode
Transport distance
Use pattern
Electric energy mix
End of life
Students can explore change of
Introductory level teaching
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Jug kettle
2 kW jug kettle
Made SE Asia Air freight to UK Life: 3 years
6 minutes per day
300 days per year
3 years
Use
12,000 km, air freight
250 km 14 tonne truck
Transport
Bill of materials and processes
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Eco audit: the jug kettle
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 make hot water on the fly – only as much as needed
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The enhanced Audit tool: Eco Design
Add record
Eco AuditSynthesizer
Options….
v 2. Transport ?
v 3. Use ?
v 4. Report ?
Joining and finishing
^ 1. Material, manufacture and end of life ?
Same as the simple model
Machining, grinding, %
removed
% recovered at end of life
1 Component 1 Cast iron 30% 2.4 Casting Fine machining 10% Recycle 95%
Component 1 Painting 0.55 m2
Component 1 Welding 0.7 m
Choose joining(adhesives, fastners,
welding)
and finishing(painting, plating, powder coating)
Set parameters
For advanced teaching the Enhanced Eco Audit Tool is available in the Eco
Design Edition of CES EduPack
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So what?
Tool 1. Eco-audits allows students to implement quick, approximate “portraits” of energy / CO2 character of products.
CES has two tools-sets to help explore the materials dimension of environmental design
Tool 2. Selection strategies allows selection to re-design products to meet eco-criteria, using systematic methods
They allow fast audits and systematic materials selection for redesign
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Lecture Unit Series
These PowerPoint lecture-units are on the Teaching Resource Website
Each frame of each unit has explanatory notes. You see them by opening the PowerPoint slide in Notes view (View – Notes pages) or by clicking this icon in the bottom toolbar of PowerPoint
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Also Available for Sustainability
• 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
On the topics of:
Eco Design & Eco Audits
Low Carbon Power Systems
http://teaching.grantadesign.com/open/eco.htm
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www.grantadesign.com/education/resources
M. F. Ashby, 2011
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 23 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.
AuthorProfessor Mike Ashby
University of Cambridge, Granta Design Ltd.
www.grantadesign.com/education
www.eng.cam.ac.uk
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