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Lecture 10

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    • 1. Today’s objectives- Environmental Issues
      • e-waste
      • Silicon Valley: super successful, super toxic
      • Heat protection
      • Alternative energy
    • 2. Processing Waste http://www.chrisjordan.com/
    • 3. Cables http://www.chrisjordan.com/
    • 4. Hard Drives http://www.chrisjordan.com/
    • 5. Circuit Boards http://www.chrisjordan.com/
    • 6. Cell Phones http://www.chrisjordan.com/
    • 7. More Cell phones http://www.chrisjordan.com/
    • 8. Computers-everybody wants them
    • 9. How much ewaste is there?
      • In the year 2000, 4 Billion tons of e-waste were generated.
      • This amounts to 15 pounds of ewaste/person:
        • Telecommunications Equipment
        • Video Products
        • Audio Products
        • Computers
      2'124'400 Total 93473.6 PC's 125339.6 Monitors 129588.4 Household Electronics 214564.4 Commercial Electronics 380267.6 Packaging 1181166.4 TVs Weight (tonnes) Equipment 1 tonne = 2 tons = 4000 pounds = 8 TRILLION POUNDS OF WASTE
    • 10. http://www.ewaste.ch/welcome/ Computer Equipment (computers, printers etc) & Consumer Electronics (TVs) 67,000 Canada Electronic and Electrical Appliances including Refrigerators 118,000 Denmark Refrigerator, Air Conditioners, Televisions, Washing Machines, Computers 60,000 Thailand Computers, Home electrical appliances (TVs, Washing Machines, Airconditioners, Refrigerators) 14,036 Taiwan Video Products, Audio Products, Computers and Telecommunications Equipment 2,124,400 USA Office & Telecommunications Equipment, Consumer Entertainment Electronics,Large and Small Domestic Appliances, Refrigerators, Fractions 915,000 United Kingdom Office & Telecommunications Equipment, Consumer Entertainment Electronics,Large and Small Domestic Appliances, Refrigerators, Fractions 1,100,000 Germany Office & Telecommunications Equipment, Consumer Entertainment Electronics,Large and Small Domestic Appliances, Refrigerators, Fractions 66,042(*) Switzerland Categories of Appliances counted in e-waste Ewaste (tonnes / year) Country
    • 11. Bad stuff I Medical equipment, fire detectors, sensing element in smoke detectors Radio-active substances - Americium Toner cartridges for laser printers / copiers - Toner Dust Others: Cable insulation - PVC (polyvinyl chloride) Cooling unit, Insulation foam - Chlorofluorocarbon (CFC) Fire retardants for plastics (thermoplastic components, cable insulation) TBBA is presently the most widely used flame retardant in printed wiring boards and casings. - TBBA (tetrabromo-bisphenol-A) - PBB (polybrominated biphenyls) - PBDE (polybrominated diphenyl ethers) Condensers, Transformers - PCB (polychlorinated biphenyls) TCE :trichloroethylene. Its vapor is used as a source of chlorine in Si processing, most notably during thermal oxidation of Si to complex metallic contaminants potentially present on the Si surface. Halogenated compounds: Occurrence in e-waste Substance
    • 12. Bad stuff II Li-batteries - Lithium Rechargeable NiCd-batteries or NiMH-batteries, electron gun in CRT - Nickel Fluorescent lamps that provide backlighting in LCDs, in some alkaline batteries and mercury wetted switches - Mercury CRT screens, batteries, printed wiring boards - Lead Rechargeable NiCd-batteries, fluorescent layer (CRT screens), printer inks and toners, photocopying-machines (printer drums) - Cadmium Power supply boxes which contain silicon controlled rectifiers and x-ray lenses - Beryllium Getters in CRT - Barium Small quantities in the form of gallium arsenide within light emitting diodes - Arsenic Heavy metals and other metals:
    • 13. materials worth recovering in a computer CRT,PWB Glass, solid state devices 6.8 24.8803 Silica PWB Wetting agent in thick film < 0.1 0.0063 Bismuth Housing, PWB, CRT Diodes < 0.1 0.0094 Antinomy Conductivity/PWB, connectors Conductivity < 0.1 0.0189 Silver PWB, connectors Connectivity, Conductivity < 0.1 0.0003 Palladium PWB Resistive circuit < 0.1 0.0016 Ruthenium Connectivity, conductivity/PWB, connectors Connectivity, Conductivity < 0.1 0.0016 Gold  PWB, CRT Battery, Phosphor emitter 0.6 2.2046 Zinc Housing, CRT, PWB Structural, Magnetivity 0.23 0.8503 Nickel CRTs, PWBs, connectors Conductivity 1.91 6.9287 Copper PWBs, CRTs Metal joining 0.27 1.0078 Tin Housing,CRTs, PWBs Structural, Magnetivity 5.58 20.4712 Iron Housing, CRT, PWB, connectors Structural, Conductivity 3.86 14.1723 Aluminum Cable, Housing Insulation 6.26 22.9907 Plastics Location Use kg % Material
    • 14. Recycled tons
    • 15. Ewaste recycling
      • First tier recycling collects items, refurbishing and reselling/donating whenever possible.
      • Second tier processor begins tearing the product apart. Metals, electronic components, CRTs, and plastics are separated and shipped in bulk to specialized refiners.
      • Third tiers are refineries specializing in base material recapture.
        • Leaded Glass: Cathode ray tubes are heavily leaded and are considered hazardous waste. However, there is an economically viable recycling method which grinds the leaded glass to a powder which is resold to cathode ray tube manufacturers creating a true circular life cycle.
          • LCD and plasma technology make these obsolete, though.
        • Precious Metals: Electronic boards are sent to precious metal smelters. Here precious metal and copper are recaptured and all other non desirable material is burned off.
          • To reduce costs, precious metals are being removed from the product wherever possible—thus less incentive to recycle.
        • Metals and Plastics: What is left (approximately 80% of the scrap volume) are intermixed, miscellaneous metals and plastics.
          • The labor cost for dismantling/separating far exceeds the value of the separated recyclable materials.
          • For this reason significant amounts of non reusable computer equipment are shipped to the Far East for further processing.
    • 16. Harpers Magazine, January 2005
    • 17. Recycling copper
    • 18. The Superfund
      • Congress passed the Superfund law in 1980.
        • Under the law, EPA was empowered to order polluters to clean up contamination resulting from their business activities or other ventures.
        • The Superfund also created a trust, funded by industry fees, for EPA to clean up &quot;orphan sites&quot;--sites where polluters refused to clean up, where the company was no longer in existence, or where a polluter could not afford to pay for the clean-up.
      • Superfund funding has dropped by 25% from 2001-2004 compared to 1992-2000.
      • Because of this shortfall, 30% of cleanups at orphan sites are now paid for entirely by taxpayers.
      • The government opposes reinstatement of the industry fees that would restore the trust fund.
      • Superfund consumes 25% of the E.P.A.'s budget.
      • Even with $20 billion spent over the last 15 years, more than 75% of sites still haven't been cleaned up.
    • 19. Silicon Valley
      • In the 60s-70s, semiconductor companies used TCE to clean silicon wafers
      • Thousands of gallons of TCE disposed in underground tanks.
      • The tanks corroded and leaked, though damage wasn’t discovered for years.
      • One of the first and largest detected leaks, from the Fairchild Camera and Instrument Corp., contaminated a public drinking well with 1,700 to 8,800 parts per billion TCE (the state standard for TCE is 200 parts per billion.)
        • California Department of Health Services reported three times as many birth defects and twice as many miscarriages in the neighborhood effected.
      • Silicon Valley currently has 29 Superfund sites (mostly TCE).
        • This is more than any other area in the country.
      • High-tech manufacturing created 24 of the 29 sites
        • 18 are tied to the computer chip industry.
        • At one time, the largest mercury mine in the U.S. was located in the New Alma den hills in the back of San Jose. Mercury, which is used to separate silver from base ore, seeps from this 100-year year old open sore and poisons the Guadalupe River and San Francisco Bay.
        • The Hispanic hamlet of Alison lies partly on a landfill created by the dumping of asbestos-lined pipes in the 1950’s by the Certainteed Corporation.
      http://rwor.org/a/v21/1020-029/1026/silicon.htm
    • 20. Super-fund Sites In Si Valley Http://Www.Svtc.Org/ 5 Miles Apple Intel Hp Applied Materials Lockheed Stanford
    • 21. Si valley
      • Since low income housing often exists in industrial areas, those in poverty (and many children) are exposed to extensive health risks.
    • 22. Keeping things cool
      • On a 90 degrees F / 32.2 C clear, sunny day in Austin, Texas:
        • a white roof had a temperature of 110 degrees F / 43.3 C.
        • an aluminum coated roof had 140 degrees F / 60 C.
        • a black, single ply roof had a temperature of almost 190 degrees F / 87.8 C.
      • A study in Florida revealed that by increasing heat reflectivity, homeowners saved an average of 23% of their cooling costs.
      • Maximum savings for a nationwide project to decrease heat absorbed by homes (U.S.A.) could be $10 billion in energy and equipment costs.
    • 23. Color and Reflectivity
      • The Environmental Protection Agency reports that electric lighting accounts for 25% of US electricity use.
        • The lighter the color the higher the reflectivity can be applied (white=80%).
        • Dark walls absorb more light and reflect less (black=5%).
        • Consequently, far more lighting is required for rooms with dark walls than those with light walls.
      • The color of a room will affect your perception of temperature.
        • People estimate the temperature of a room with cool colors, such as blues and greens, to be 6-10 degrees Fahrenheit cooler than the actual temperature.
        • Warm colors, such as reds and oranges, will result in a 6-10 degrees Fahrenheit warmer estimate.
    • 24. Alternative Energy • p-n junction: • Operation: --incident photon produces hole-elec. pair. --typically 0.5V potential. --current increases w/light intensity. • Solar powered weather station: polycrystalline Si Los Alamos High School weather station (photo courtesy P.M. Anderson)
    • 25. Advantages of solar
      • ¼ of world’s population has no access to electricity.
      • Those without spend more money on kerosene/candles then on electricity
        • High capitol cost of building a power grid limits their future options.
      • Sunlight provides about 1 kilowatt per square meter at the Earth's surface
      • Most solar cells are between 8 and 12 percent efficient.
      • In desert areas, they can operate for an average of 6 hours per day when mounted in nonrotating brackets.
      J. Trancik, Columbia Earth Institute
    • 26. Alternative energies
      • As of 2001, with batteries to provide power at night, desert climates can get power for about 8 cents per kilowatt hour using solar cells and batteries.
      • By contrast, nuclear and hydroelectric power plants can provide power at 1.5 to 3 cents per kilowatt hour.
      • Electric company charges 5 to 10 cents / kWhr for standard power
      • Solar power is already cheaper than internal combustion generators that use natural gas, diesel or gasoline, and is becoming competitive with the costs of coal power in some areas.
        • The problem is paying for the solar cells themselves.
      http://en.wikipedia.org/wiki/Solar_cell
    • 27. How many solar panels do you need for your home?
      • 25 kWhrs/day
      • 10% efficiency * 1 kW/m^2 * 5 hours/day = 0.5 kWhr/daym^2
        • Thus, requires 25 kWhrs/day / 0.5 kWhr/daym^2
        • 50 m 2
      • You could save $80/month on your electric bill
      http://www.ravallielectric.com/d5.htm
    • 28. Farming vs. collecting rays
      • In an average year, a Maryland farmer makes about $50 per acre for corn.
      • An acre receives about 6 million kilowatt-hours of energy per year.
      • Covered with solar panels with 10% efficiency, 0.6 million kW-hours of electricity could be recovered.
      • At $0.10 per kW electric price, this is $60,000 in electric energy revenue.
      • Just by not farming.
      • But, to cover the acre with solar panels, it will cost $2 million.
      • The answer—heavy subsidies and lower cost solar cells.
      http://solstice.crest.org/renewables/solar-concentrator-list-archive/msg00795.html
    • 29. Consumer choice
      • Green electricity is available in Connecticut today
      • But it costs an extra $5.50 a month for the average home.
    • 30. Wind power
      • Denmark, windmills everywhere…
        • Employs 20,000 people
        • Generates 2 B dollars
        • Provides 20% of national power consumption
      • Major advances in materials are allowing bigger, more efficient turbine blades.
    • 31. Efficient engines?
      • Electric Cars are dead
        • Pilot program in California officially shut down in January, 200 cars mothballed despite having multiple customers who wanted to buy them.
      • Hybrid vehicles
        • Toyota cannot make hybrid cars fast enough—1 year wait list.
        • Ford, Toyota, Honda, Lexus, others all coming out with hybrid vehicles.
          • Fuel economy improves by 25 to 100%
        • The industry is being given a boost by continued congressional support in the form of tax breaks ($2000 for buying a new one).
      • ‘corn oil’ based fuel additives (ethanol)
        • common additive in gasoline, sometimes even legislated
        • great example of a pure political ‘pork’ project
          • Totally inefficient, unless the goal is to give farmers something to do.
    • 32. Other energy systems
      • Fuel cell technology, wind power generation, hydroelectric
        • Each of these requires heavy governmental subsidies.
        • Most efficient if put together in ‘farms.’
          • Plans considered for putting windmills off Nantucket.
          • True bipartisan support fought (and likely killed) the project.
      • Models exist for success
        • A single offshore wind farm near Lolland, (joint Denmark/Sweden venture)
        • 166 MW produced, out of 530 MW worldwide
        • 72 turbines
        • Supplies 145,000 Danish homes
        • Saves 1 million tons of CO 2 emissions
      http://www.scandinavica.com/culture/nature/wind.htm
    • 33. Materials impacts
      • Thermal protection
      • Solar panel shingles which replace ordinary shingles have recently become available.
      • Enhanced solar panel efficiency (16.5% is the best thus far, 30% with optics to concentrate the light)
      • Enhanced solar panel lifetime
    • 34. SUMMARY
      • e-waste
      • Silicon Valley: super successful, super toxic
      • Heat protection
      • Alternative energy
        • Solar
        • Wind
        • Fuel cells
        • Hybrid engines
      • For each of these, there are important materials related discoveries waiting to be made.
      Reading for next class Something trashy on the beach…

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