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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

34

5

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/