Download - Environmentally Conscious Design & Manufacturing (ME592) Date: March 8, 2000 Slide:1 Environmentally Conscious Design & Manufacturing Class 2: Industrial

Environmentally Conscious Design & Manufacturing (ME592)

Date: March 8, 2000 Slide:1

Environmentally Conscious Design & Manufacturing

Class 2: Industrial Ecology & Manufacturing

Prof. S. M. Pandit



Industrial Ecology and Manufacturing Case Study: The Automobile - A Discrete Manufactured Product

Agenda Environmental Impact “The Master Equation” Automobile sub-systems & Environmental Impact Environmental interactions during manufacturing Energy consumption & Motive energy options Infrastructure: Embedded energy in roads Environmental interactions during product useReferences:

Graedel & Allenby “Industrial Ecology and the automobile”

EPA

Web



The Master EquationQuantitative estimates of the environmental impact in a

particular locality (or eco - system)

Population Gross Domestic Product

Env. impactper unit of GDP



The Master Equation

E = [P] [ip

E = Environmental ImpactP = Population (temporal) ip= Gross Domestic Product(GDP) / person = Environmental Impact / GDP

Po = Initial populationt = TimeR = Net rate of growth = (Rb - Rd) + (Ri - Re)

P = P0 exp {Rt}



The Master Equation

Pip

E

Time



The Master Equation

As we move towards sustainable manufacturing,

The environmental impact surface should become flatter.

d/dt [Pollutant generation] < d/dt [Pollutant processing]

Short / Long term implications



Automobile Sub-systems & Environmental Impact

Environmental impactConstituents

Design

Societal & Cultural Factors

Sub-systems ?

Questions Addressed

Impact of design and materials - Technology focus




ChassisFrameEngineBrakesCooling systemsLubricationTiresFuelPaintEmission ControlElectrical powerElectronics

Mechanics,Thermofluids

Tribology

Chemical processing,Thermofluids

Machines,Signal processing

Overview ofSub-Systems




Materials selected (how do we look at properties?) : Ferrous

Cast IronsSteelAlloy steels

Aluminum alloysCeramicsComposites PolymersFluids

Engine / Transmission / Brake / Battery

Time - Temperature dependent diffusion of C in Fe

Ref: http://ate.cc.vt.edu/eng/materials/classes



EnvironmentalImpact

• Raw Material depletion• Combustion by-products• Manufacturing Process Waste Streams




Design factors and Environmental Impact

• Combustion Efficiency• Weight• Corrosion resistance• Ease of Manufacturing• Functionality• Cost• Recyclability




Environmental Interactions during Manufacturing

Upstream Input(s)

RawMaterials&Energy

WasteStreams

Downstream Output(s)

Manufacturingprocess




Typical Manufacturing Processes, inputs and outputs

• What can we do with these?Develop analytical I/O models

- Based on experimental data (Regression,DDS)- Based on a physical understanding of the process(still using models developed to describe basic

interactions; e.g. rate phenomenon in chemicalmetallurgy to describe chemistry change and

effluents in welding processes)




Casting & Forming:Aromatic hydrocarbonsreleased from binder.

&Heat released

- Sand discarded after use

Other Processes: Die Casting, Injection molding, Welding and Brazing, Metal Plating, Painting



Environmental interactions during manufacturing

“Greening” the manufacturing processes (How)

- Energy management- Better mold utilization- Reuse of contaminated water- Waste water treatment options

- TRANSITION TO NEW PROCESSES?



Energy Consumption (urban use)

Engine

Standby (3.6%) Accessories (1.5%)

Engine Losses (69.2%) Driveline losses (5.4%)

Other losses

Aero: 10.9%Rolling: 7.1%Braking: 2.2%



Energy Consumption (options)

C - Based Fuels

CH3OH High Cost, Smog, Global WarmNat. Gas High Cost, Smog, Global Warm C2H5OH High Cost, Smog, Bio.

Corn-based: 5% of needs




Electric Vehicles: - Electro-Chemical Batteries- Electromechanical Batteries

Hybrid power

Fuel Cells



Hybrid:

Fuel economy of 66 mpg and emission reductions of 50% for carbon dioxide and 90% for carbon monoxide, hydrocarbons and nitrogen oxide





About Fuel Cells

Ref: http://www.benwiens.com/energy1.html



Infrastructure: Embedded Energy in Roads

Material Embedded Energy(J/kg)

Bitumen 0.63

Cement 6.70

Aggregate 0.07

Reinforcing steel 23

Steel Beams 18



Infrastructure: Embedded Energy in Roads

Energy / km of urban roads8.4 x 1012J

Total Embedded Energy: (x1018J)

Roads: 190Bridges: 1.5

Estimated worldwide“embedded energy”in roads



Environmental Interactions

during Product Use

Auto use residues or potential waste streams

{Principal Environmental Impact occurs during use, and

this is therefore the most “significant” life cycle stage}

• Solids• Liquids• Gaseous




during Product Use

Solids:

Batteries (10% lead loss)Tires (freeze and grind?)Scrap - How do you quantify?

Liquids:

OilAntifreezeBattery Acids




during Product Use

Gaseous Emissions:In many urban areas, motor vehicles are the single largest contributor to ground-level ozone, a major component of smog. Ground-level ozone is the most serious air pollution problem in the northeast and mid-Atlantic states. - EPA

http://www.dieselnet.com/standards/cycles



Cars also emit several pollutants classified as toxics, which cause as many as 1,500 cases of cancer in the country each year. Auto emissions also contribute to the environmental problems of acid rain and global warning. - EPA

Ref: http://www.nsc.org/ehc/mobile/mse_fs.htm


during Product Use



CxHy:

Hydrocarbons react with nitrogen oxides in the presence of sunlight and elevated temperatures to form ground-level ozone.

It can cause eye irritation, coughing, wheezing, and shortness of breath and can lead to permanent lung damage.


during Product Use




during Product Use

NOxNitrogen oxides also contribute to the formation of ozone and contribute to the formation of acid rain and to waterquality problems.

COCarbon monoxide is a colorless, odorless, deadly gas. It reduces the flow of oxygen in the bloodstream and can impair mental functions and visual perception. In urban areas, motor vehicles are responsible for as much as 90 percent of carbon monoxide in the air.




during Product Use

Clean - upthe toxins (How?)

•Chemical Catalysis•Absorption•Adsorption

How about bio-degradation?

http://news.pollutiononline.com/common




during Product Use

Where From?

• When outside temperatures on hot, sunny days cause a car's fuel to evaporate

• Hot engine and exhaust system of a running car cause the fuel to become heated

• When the car is shut off and remains hot enough to cause fuel to evaporate

• During refueling, when gasoline vapors escape into the air from the gas tank and the nozzle

Download - Environmentally Conscious Design & Manufacturing (ME592) Date: March 8, 2000 Slide:1 Environmentally Conscious Design & Manufacturing Class 2: Industrial

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