View
2.159
Download
0
Category
Tags:
Preview:
DESCRIPTION
Engineers are leading the push to create greener products that will help us meet current and future sustainability challenges. Stanford Engineering Professor Mike Lepech discusses the impact of green engineering on our planet and on our daily lives.
Citation preview
© 20112011 Stanford eDay 16 July 2011
Green Engineering 101
Michael LepechDepartment of Civil and Environmental Engineering
Stanford University
2011 Stanford Engineering eDay
16 July 2011
© 20112011 Stanford eDay 16 July 2011
Our Environment
© 20112011 Stanford eDay 16 July 2011
Our Behavior
© 20112011 Stanford eDay 16 July 2011
Why do we do this?
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final Assessment
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final AssessmentInputs Outputs
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
Inputs Outputs
Impacts
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final Assessment
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
Inputs Outputs
Value, $$$$$$
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final Assessment
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
Inputs Outputs
Value, $$$$$$
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final Assessment
© 20112011 Stanford eDay 16 July 2011
Engineering a greener world
Inputs Outputs
Impacts, Value, $$$$$$
• Systems Modeling
• Flow Accounting
• Impact Assessment
• Valuation
• Guided Design
• Environmental Looping
• Final Assessment
© 20112011 Stanford eDay 16 July 2011
Case Study
© 20112011 Stanford eDay 16 July 2011
What does it take to make chocolate chip cookies?
• Flour
• Baking Soda
• Salt
• Butter
• Sugar (and Brown Sugar)
• Vanilla
• Eggs
• Chocolate Chips?
© 20112011 Stanford eDay 16 July 2011
What does it take to make chocolate chip cookies?
• Flour
• Baking Soda
• Salt
• Butter
• Sugar (and Brown Sugar)
• Vanilla
• Eggs
• Chocolate Chips
© 20112011 Stanford eDay 16 July 2011
Sugar Production
Sugar Production Video
Fields & Harvest Sugar Cane Transportation
GrindingPressingRefiningBagging
Energy and
Materials
© 20112011 Stanford eDay 16 July 2011
ISO 14040 Life Cycle Modeling
Material
Processing
Use
Manufacture
& Assembly
Retirement
& Recovery
ServiceDisposal
Raw Material
Acquisition
Reuse
Primary
Materials(e.g., ores, biotic
resources)
Recycled
Materials(open loop recycling)
Primary
Energy(e.g., coal)
Air pollutants(e.g., Hg)
Water
pollutants(e.g., BOD)
Solid waste(e.g., MSW)
Products(e.g., goods, services)
Co-products(e.g., recyclables, energy)
RemanufactureRecycling
Center for Sustainable Systems (2003)
T
T
T
T
T
T
© 20112011 Stanford eDay 16 July 2011
Bill of Materials (Batch Recipe)
• Flour 2.25 cups
• Baking Soda 1 teaspoon
• Salt 1 teaspoon
• Butter 1 cup (2 sticks)
• Sugar (and Brown Sugar) 1.5 cups
• Vanilla 1 teaspoon
• Eggs 2
• Chocolate Chips 2 cups
© 20112011 Stanford eDay 16 July 2011
US Electricity Life Cycle Inventory
Kim. S. and Dale, B. (2005)
© 20112011 Stanford eDay 16 July 2011
Environmental Footprint of a Batch (24)E
coP
oin
ts
Flour
ButterChocolate
Eggs
Sugar
Baking Soda, Salt, Vanilla
Greenhouse Gases
Ozone Depletion
Acidification
Eutrophication
Heavy Metals
Carcinogens
Summer Smog
Winter Smog
© 20112011 Stanford eDay 16 July 2011
Carbon Footprint of a Batch of Cookies
78g CO2-eq per cookie
© 20112011 Stanford eDay 16 July 2011
Environmental Impact Flow
One Chocolate Chip Cookie
© 20112011 Stanford eDay 16 July 2011
Environmental Impact Flow
© 20112011 Stanford eDay 16 July 2011
ISO 14040 Life Cycle Modeling
Material
Processing
Use
Manufacture
& Assembly
Retirement
& Recovery
ServiceDisposal
Raw Material
Acquisition
Reuse
Primary
Materials(e.g., ores, biotic
resources)
Recycled
Materials(open loop recycling)
Primary
Energy(e.g., coal)
Air pollutants(e.g., Hg)
Water
pollutants(e.g., BOD)
Solid waste(e.g., MSW)
Products(e.g., goods, services)
Co-products(e.g., recyclables, energy)
RemanufactureRecycling
Center for Sustainable Systems (2003)
T
T
T
T
T
T
© 20112011 Stanford eDay 16 July 2011
Environmental Footprint of a Batch (24)E
coP
oin
ts
Flour
Butter Chocolate
EggsSugar
Baking Soda, Salt, Vanilla
Greenhouse Gases
Ozone Depletion
Acidification
Eutrophication
Heavy Metals
Carcinogens
Summer Smog
Winter Smog
MixingTrucking
Baking
© 20112011 Stanford eDay 16 July 2011
Carbon Footprint of a Batch of Cookies
310g CO2-eq per cookie
© 20112011 Stanford eDay 16 July 2011
Environmental Impact Flow
One Chocolate Chip Cookie
US Energy
Production
© 20112011 Stanford eDay 16 July 2011
Our First Design Conclusion…
NO BAKE COOKIES!
© 20112011 Stanford eDay 16 July 2011
Design Challenge
© 20112011 Stanford eDay 16 July 2011
Design Challenge
• Designing a “green” no bake dessert…
– Design constraint
CO2-eq < 78g
– Must use one graham cracker and one spoon of frosting!
© 20112011 Stanford eDay 16 July 2011
Design Challenge
• Designing a “green” no bake dessert…
– Parts list….
Item Impact (g CO2-eq)
Graham Cracker 25
Chocolate Frosting (1 spoon) 15
Vanilla Frosting (1 spoon) 13
Marshmallow 6
Chocolate Chips 1
Sprinkles (1 spoon) 5
Hershey Kiss 8
© 20112011 Stanford eDay 16 July 2011
How do we use this at Stanford?
© 20112011 Stanford eDay 16 July 2011
Advanced Materials for Green Infrastructure
ECC (Engineered Cementitious Composite)
© 20112011 Stanford eDay 16 July 2011
Ductile Cement-based Materials
Concrete
Normal Fiber
Reinforced Concrete
HPFRCC (ECC)
w or
© 20112011 Stanford eDay 16 July 2011
1
0
cos2/
0
)()()(),()(
fL
z
e
f
fdzdzppgLP
A
V
Stress vs. Crack Opening Relation
0
1
2
3
4
5
6
7
0 0.1 0.2 0.3 0.4 0.5
Crack Opening, d (mm)
Str
ess,
s (
%)
M45
8%
14%
21%
Stress vs. Crack Opening Relation
0
1
2
3
4
5
6
7
0 0.01 0.02 0.03 0.04
Crack Opening, d (mm)
Str
ess, s (
MP
a)
M45
21%
13%
8%
`
Nanotailoring of Green ECC
• Increasing carbon content decreases interfacial friction
• 40% reduction in complimentary energy
Str
es
s,
(MP
a)
Crack Opening, (mm)
Increasing Carbon Content
Virgin PVA Fiber Nanocoated PVA
Str
ess,
(MP
a)
© 20112011 Stanford eDay 16 July 2011
ECC Link Slab Concept
Links two adjacent bridge
spans through continuous
deck
ECC material accommodates
adjacent span deformations
Combined flexural, axial, and
environmental loads
Concrete DeckContinuous Reinforcement Shear Stud ECC Link Slab Deck Interface
Steel Beam Debonding Paper Concrete SidewalkConcrete Railing
Concrete DeckContinuous Reinforcement Shear Stud ECC Link Slab Deck Interface
Steel Beam Debonding Paper
Concrete DeckContinuous Reinforcement Shear Stud ECC Link Slab Deck Interface
Steel Beam Debonding Paper Concrete SidewalkConcrete Railing
Concrete DeckContinuous Reinforcement
Shear Stud Deck Interface
Steel Beam Debonding Paper
ECC Link Slab
© 20112011 Stanford eDay 16 July 2011
Life Cycle Model
MOBILE6.2
Emissions
Model
NONROAD
Emissions
Model
KyUCP
Traffic Flow
Model
Life Cycle Assessment Model
Life Cycle Cost Model
Model ParametersUser Input and System
Definition
Environmental
Sustainability Indicators
- Resource Depletion
- Energy Use
- Global Warming Potential
Social Cost Factors
- Agency Activity Emissions
- Vehicle Emissoins
- Vehicle Operating Costs
- User Delay
Agency Cost Factors
- Construction Material
- Distribution
- Construction (Labor & Equip)
- End of Life Costs
Agency Costs Social Costs
Keoleian et al, Journal of Infrastructure Systems March 2005 51-60
© 20112011 Stanford eDay 16 July 2011
Detailed Impact Flow (CO2-eq)
• Full life cycle model is comprehensive and detailed
– 203 nodes visible of 36 908
© 20112011 Stanford eDay 16 July 2011
Infrastructure Sustainability Indicators
• Total primary energy consumption is dominated by traffic-related energy
Total Primary Energy Consumption
by Life Cycle Stage
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
ECC Conventional
Gig
ajo
ule
s (
GJ
)
EOL
Distribution
Materials
Construction
ΔTraffic
Keoleian et al, Journal of
Infrastructure Systems
March 2005 51-60
© 20112011 Stanford eDay 16 July 2011
Plastics from Waste Methane
© 20112011 Stanford eDay 16 July 2011
OFU Gimsøystraumen Bridge
Total span: 839 meters Maximum clearance to the sea: 30 meters
Spans: 9 Opened in 1981
Main span: 148 meters
© 20112011 Stanford eDay 16 July 2011
Management Results
Environmental Impact
Budgets
CO2 Impact Budget
CO2 Accrual
© 20112011 Stanford eDay 16 July 2011
Targeting “Sustainability”
• Target reductions to achieve a stabilized atmospheric carbon-equivalent concentration of 490ppm -535ppm (Scenario II) by Year 2050 (Year 2000 baseline).
IPCC AR4
© 20112011 Stanford eDay 16 July 2011
Design Challenge
• Designing a “green” no bake dessert…
– Design constraint
CO2-eq < 78g
– Must use one graham cracker and
one spoon of frosting!
© 20112011 Stanford eDay 16 July 2011
Final Thoughts…
• We need to take better care of our planet.
• Engineers are a big part of that!
–Green design is a big part of Stanford Engineering
– Lots of ways to design “green” that respect the choices and values of many people
© 20112011 Stanford eDay 16 July 2011
Thanks!
Questions?
Michael D. Lepech
mlepech@stanford.edu
stanford.edu/~mlepech
© 20112011 Stanford eDay 16 July 2011
Recommended