Transcript Green Engineering

Green Engineering
Jess Everett
A number of the slides were adopted
from a presentation by Dr. Robert Hesketh
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Green Engineering
• Design, commercialization and use of
processes and products that are feasible
and economic while minimizing
– Generation of pollution at the source
– Risk to human health and the environment
• US EPA
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Sustainable Development
• Sustainable development meets needs
of present without compromising ability
of future generations to meet needs
– World Energy Council
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Industrial Ecology
• Systematic examination of
–
–
–
–
local/regional/global
uses/flows of
materials/energy in
products/processes/industrial sectors/economies
• Focuses on potential role of industry in reducing
environmental burdens throughout product life
cycle
Journal of Industrial Ecology
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Life Cycle Assessment
Materials
LifeCycle
Stages
Materials
Energy
Materials
Energy
Energy
Materials
Energy
Raw
Materials
Extraction
Material
Processing
Product
Manufacturing
Use, Reuse,
Disposal
Wastes
Wastes
Wastes
Wastes
other toxic
releases
Human health
and ecosystem
damage
LifeCycle
Impacts
global
warming
ozone
depletion
smog
formation
acidification
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-Robert Hesketh
20W compact fluorescent
lamp compared to 75W
incandescent lamp
75W
Standard
Incandesc
ent
Watts per
Lamp/Fixture
Purchase Cost
Lamp/Fixture
Cost to Change
Lamp/Fixture
Life of Lamp in
Hours
Lumens Output
75
20-W
Compact
Fluoresce
nt lamp
(CFL)
20
$0.50
$15.00
$1.00
$1.00
750
10,000
1,190
1,200
Rate Data
Hours per Year
Lamp On
Months CFL Lamp Will Last
No. of standard lamps needed to
equal
one CFL (lifetime)
Electricity
Calculations
Total kWh Used
CO2 Calculations
Coal Generation*
All Generation**
$-Saving Calc.***
$ for Purchasing
Lamps
$ for Changing
Lamps
$ for kW
$ for kWh
$ Total
75-W 20-W
Std. CFL
200
kWh,
kW
Savings
550
75-W 20-W
Std. CFL
1,778
474
1,155
308
CO2
Savings
1,304
847
75-W 20-W
Std. CFL
$7
$15
Dollar
Savings
-$8
750
$13
$1
$12
$24
$45
$89
$6
$12
$34
$18
$33
$55
3,000
40.0
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-Robert Hesketh
Green Design Initiative
• Reduce environmental damage by
– Minimizing use of non-renewable
resources
– Reducing use of renewable resources to
sustainable levels
– Lowering environmental discharges
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Engineers and Environmental
Regulations
Major Laws/Amendments
Environmental Regulations
Bishop, “Pollution Prevention: Fundamentals and Practice”, McGraw-Hill, 2000
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-Robert Hesketh
U.S. Energy Flows, 1997
Annual Energy Review 1997, U.S. DOE, Energy Information Administration, Washington, DC, DOE/EIA-0384(97)
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-Robert Hesketh
Global Warming and Related
Impacts
Materials Energy
Products
Process of
Concern
O3
Cause and Effect Chain
greenhouse
gas emissions
CO2, CH4, N2O
climate change;
sea level change
human mortality
or life adjustments
N2 O
CH4
CO2
CFCs
Contribution to global
Warming; Phipps, NPPC,
http://www.snre.umich.edu/nppc/
Climate Change 1995, Intergovernmental Panel on Climate Change, WMO and
UNEP, Cambridge University Press, 1996.
-Robert Hesketh
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Stratospheric Ozone and Related
Impacts
Materials
Cause and Effect Chain
Energy
Products
Process of
Concern
ozone depleting
substances
CFCs, HCFCs
ozone layer loss
increase in uv
human mortality
or life adjustments
ecosystem damage
Toxics Release Inventory Data
Climate Change 1995, Intergovernmental Panel on
Climate Change, WMO and UNEP, Cambridge 11
University Press, 1996.
-Robert Hesketh
Smog formation and related
impacts
Materials
Energy
Process of
Concern
Products
Cause and Effect Chain
NOx and volatile
organic substances
NOx
photochemical
oxidation reactions
VOCs
human/ecological
damage from O3
and other oxidants
1 - Chemical & Allied Processing
2 - Petroleum & Related Industries
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7
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5
NOx
Miscellaneous
Transportation
2
4
3
3 - Metals Processing, 4 - Other Industrial Processes
5 - Solvent Utilization, 6 - Storage & Transportation
7 - Waste Disposal & Recycling
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6
2
3
4
Industrial Processes
Fuel Combustion
1997
VOCs
1997
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National Air Quality and Emissions Trends Report, 1997, U.S. EPA Office of Air Quality Planning and Standards, http://www.epa.gov/oar/aqtrnd97/chapter2.pdf
-Robert Hesketh
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Acid rain / Acid deposition
Materials
Energy
Process of
Concern
Products
Cause and Effect Chain
SO2 and NOx
emission to air
Acidification rxns.
& acid deposition
human/ecological
damage from H+
and heavy metals
SO2
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6
7
1997
Miscellaneous
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Transportation
Industrial Processes
1 - Chemical & Allied Processing
2 - Petroleum & Related Industries
3 - Metals Processing
4 - Other Industrial Processes
5 - Solvent Utilization
6 - Storage & Transportation
7 - Waste Disposal & Recycling
Fuel Combustion
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National Air Quality and Emissions Trends Report, 1997, U.S. EPA Office of Air Quality Planning and Standards, http://www.epa.gov/oar/aqtrnd97/chapter2.pdf
-Robert Hesketh
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Human Health Toxicity
Materials
Energy
Process of
Concern
Transportation
Equipment
7%
RCRA
Hazardous
Waste
Primary
Metals
8%
Petroleum
Refining
9%
Products
Toxic releases to
air, water, and soil
Transport, fate,
exposure pathways
& routes
All Other
Industries
16%
EPCRA
Toxic
Rubber
Waste and Miscel-
Chemical /
Allied
Products
51%
Electronic
Equipment
9%
Allen and Rosselot, 1997
laneous
Petroleum Plastics
3%
Refining
3%
Human health
damage; carcinogenic & non...
All Other
Industries
23%
Paper and
Allied
Products
5%
Transportation
5%
Chemical
and Allied
Products
27%
Primary
Metals
22%
Fabricated
Metals
6%
Electronic
Equipment
6%
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-Robert Hesketh
Green Design Tools
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Mass balance analysis
Green indices
Design for disassembly and recycling aids
Risk analysis
Material selection and label advisors
Full cost accounting methodologies
Introduction to Green Design, By Chris Hendrickson, Noellette Conway-Schempf, Lester Lave
and Francis McMichael, Green Design Initiative, Carnegie Mellon University, Pittsburgh, PA
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Mass balance analysis
• Trace materials or energy in and out of
an analysis area
– manufacturing process or plant,
watershed…
• Ideally based on measured inflows,
inventories, and outflows
– problems with data availability and
consistency
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Green Indices
• Summarize various environmental impacts
into simple scale
– E.g., compare pound mercury dumped into the
environment with pound dioxin?
– Designer compares green score of alternatives
and choose one with minimal environmental
impact
– Provide at least rudimentary guidance in choosing
materials, components, or processes
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Design for disassembly and
recycling aids
• Making products that can be taken apart
easily for subsequent recycling and parts
reuse
– Kodak’s ‘disposal’ cameras snap apart, allowing
87% of the parts (weight) to be reused or recycled
– DFD/R acts as a driver for recycling and reuse
• Disassembly $ may exceed value of materials
– DFD/R software generally calculate potential
disassembly pathways, point out fastest pathway,
and reveal obstacles to disassembly that can be
"designed out"
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Risk analysis
• Tracing through chances of different effects
occurring
– E.g., risk of toxic emissions estimated by
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•
•
•
estimating amount and type of emissions
transport in the environment
ecological and human exposure
likely damage (such as cancer) as a percent
– All steps have uncertainty
– Integrate effects over several media
• air, water and land
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Basic Concepts: Risk Assessment
Risk
=
Exposure
Hazard
-Robert Hesketh
Basic Concepts: Risk Assessment
Risk
=
Exposure
Hazard
Concentration in
Air,
Water
Soil
(g/m3)
Transmission Rate
(m3/s)
Duration
(s)
-Robert Hesketh
Basic Concepts: Risk Assessment
Risk
=
Exposure
Hazard
Permissible Exposure Limit (PEL)
Threshold Limit Value (TLV)
No Observable Adverse Effects Level (NOAEL)
Reference Dose (RfD)
Reference Concentration (RfC)
Cancer Slope Factors
Human Health &
Ecosystem Effects:
Carcinogenic
Toxicity
-Robert Hesketh
Material selection
• Different materials can produce a particular
quality component or product, but with
different environmental implications
• Material selection guidelines attempt to
guide designers towards the
environmentally preferred material
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Material Selection Principles
• Graedel and Allenby [1995]
– Use abundant, non-toxic materials where possible
– Use materials familiar to nature (e.g. cellulose),
rather than man-made (e.g. chlorinated aromatics)
– Minimize number of materials used in product or
process
– Try to use materials that have an existing
recycling infrastructure
– Use recycled materials where possible
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Label advisors
• Marks on materials or products that reveal
information about material content relevant to
environment or conservation
– Plastic identification symbol that can be used in
plastics resorting and recycling efforts
– Eco-labels provide “unbiased” appraisal of
environmental benefits of products
• Recycled Content, Energy Saving, Organic, Pest
Management, Social Responsibility, Sustainable
Agriculture, Sustainable Fishing, Animal Welfare,
Sustainable Wood
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Full cost accounting methodologies
• Provide methods to account for ALL costs
associated with a product, process, activity
– Companies may incur high costs from using a material
or process that creates environmental problems when an
environmentally benign material or process exists
– Consumers purchase products that create environmental
problems because they do not know about green
alternatives
• Example: protect bolt from corrosion
– plate with cadmium or use stainless steel bolt
• purchase price of the two bolts
• additional costs to the company of using a toxic material
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Green Engineering WEBSITE
http://epa.gov/oppt/greenengineering/