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Green EngineeringGreen 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
Raw MaterialsExtraction
Energy
Wastes
MaterialProcessing
Wastes
ProductManufacturing
Wastes
Use, Reuse,Disposal
Wastes
Materials
Energy
Materials
Energy
Materials
Energy
MaterialsLife-CycleStages
global warming
ozone depletion
smog formation
acidifi-cation
other toxicreleases
Human healthand ecosystem damage
Life-CycleImpacts
-Robert Hesketh
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Electricity Calculations
75-W Std.
20-W CFL
kWh, kW
Savings Total kWh Used 750 200 550 CO2 Calculations 75-W
Std. 20-W CFL
CO2 Savings
Coal Generation* 1,778 474 1,304 All Generation** 1,155 308 847 $-Saving Calc.*** 75-W
Std. 20-W CFL
Dollar Savings
$ for Purchasing Lamps
$7 $15 -$8
$ for Changing Lamps
$13 $1 $12
$ for kW $24 $6 $18 $ for kWh $45 $12 $33 $ Total $89 $34 $55
20W compact fluorescent lamp compared to 75W
incandescent lamp
-Robert Hesketh
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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
Bishop, “Pollution Prevention: Fundamentals and Practice”, McGraw-Hill, 2000
Major Laws/Amendments
Environmental Regulations
-Robert Hesketh
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U.S. Energy Flows, 1997Annual Energy Review 1997, U.S. DOE, Energy Information Administration, Washington, DC, DOE/EIA-0384(97)
-Robert Hesketh
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Global Warming and Related Impacts
Process of Concern
EnergyMaterialsProducts
greenhousegas emissions CO2, CH4, N2O
climate change;sea level change
human mortalityor life adjustments
Cause and Effect Chain
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
EnergyMaterialsProducts
ozone depleting substancesCFCs, HCFCs
ozone layer lossincrease in uv
human mortalityor life adjustmentsecosystem damage
Cause and Effect Chain
0.E+00
2.E+05
4.E+05
6.E+05
8.E+05
1.E+06
1.E+06
1995 1996 1997
Year
Total On- and Off-site Releases
Toxics Release Inventory Data
Process of Concern
Climate Change 1995, Intergovernmental Panel on Climate Change, WMO and UNEP, Cambridge
University Press, 1996. -Robert Hesketh
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Smog formation and related impacts
EnergyMaterialsProducts
NOx and volatileorganic substances
photochemical oxidation reactions
human/ecologicaldamage from O3
and other oxidants
Cause and Effect Chain
NOx VOCs
12 3
4
5
6
7
1
2
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6 7
1 - Chemical & Allied Processing2 - Petroleum & Related Industries
3 - Metals Processing, 4 - Other Industrial Processes5 - Solvent Utilization, 6 - Storage & Transportation7 - Waste Disposal & Recycling
VOCs
NOx 1997
1997
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
Fuel Combustion
Industrial Processes
Transportation
Miscellaneous
Process of Concern
-Robert Hesketh
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Acid rain / Acid deposition
EnergyMaterialsProducts
SO2 and NOxemission to air
Acidification rxns.& acid deposition
human/ecologicaldamage from H+
and heavy metals
Cause and Effect Chain
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
SO2
1
23
5 7
4
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1 - Chemical & Allied Processing2 - Petroleum & Related Industries3 - Metals Processing4 - Other Industrial Processes5 - Solvent Utilization6 - Storage & Transportation7 - Waste Disposal & Recycling
1997
Fuel Combustion
Industrial Processes
Transportation
Miscellaneous
Process of Concern
-Robert Hesketh
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Human Health ToxicityEnergyMaterials
Products
Toxic releases to air, water, and soil
Transport, fate, exposure pathways& routes
Human health damage; carcino-genic & non...
Petroleum Refining
9%
Chemical / Allied
Products51%
Transport-ation
Equipment7%
All Other Industries
16%
Primary Metals
8%
Electronic Equipment
9%
Chemical and Allied Products
27%
Primary Metals22%
All Other Industries
23%
Paper and Allied
Products5%
Petroleum Refining
3%
Rubber and Miscel-
laneous Plastics
3%
Transport-ation5%
Fabricated Metals
6%
Electronic Equipment
6%
RCRA HazardousWaste
EPCRAToxicWaste
Allen and Rosselot, 1997
Process of Concern
-Robert Hesketh
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Green Design Tools
• Mass balance analysis
• Green indices
• Design for disassembly and recycling aids
• Risk analysis
• Material selection and label advisors
• Full cost accounting methodologiesIntroduction 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
• 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
Exposure HazardRisk =
Basic Concepts: Risk Assessment
-Robert Hesketh
Exposure HazardRisk =
Transmission Rate(m3/s)
Concentration in Air,
Water Soil
(g/m3)
Duration(s)
Basic Concepts: Risk Assessment
-Robert Hesketh
Exposure Hazard
Human Health & Ecosystem Effects:
CarcinogenicToxicity
Risk =
Basic Concepts: Risk Assessment
-Robert Hesketh
Permissible Exposure Limit (PEL)
Threshold Limit Value (TLV)No Observable Adverse Effects Level (NOAEL)
Reference Dose (RfD)Reference Concentration (RfC)Cancer Slope Factors
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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
Green Engineering WEBSITE
http://epa.gov/oppt/greenengineering/