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Environmentally Conscious Design & Manufacturing. Class 21,22: Energy Aspects. Prof. S. M. Pandit. Agenda. Environmental Burden: Energy Energy and industry Energy and automobile General approach to minimizing energy use. Environmental Burden: Ranking.
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Environmentally Conscious Design & Manufacturing Class21,22: Energy Aspects Prof. S. M. Pandit
Agenda • Environmental Burden: Energy • Energy and industry • Energy and automobile • General approach to minimizing energy use
Environmental Burden: Ranking Consumer Consumer Scientific Government perception perception (LCA) policy 1996 1991 (Netherlands) Energy consumption 1 4 1 3 Water/recycling 2 5 4 2 Materials use 3 1 3 6 Packaging 4 2 5 5 Sustainability 5 6 N/A 1 Production processes 6 3 2 4 Source: A. Stevels, Stanford Ecodesign short course, 1999
Incentives • The three incentives to encourage efficiency and renewable energy are: • Avoided emissions • Conservation and renewable energy reserve • The reduced utilization provision Source: EPA
Energy and Industrial Ecology • Tracking energy flows and transformation is a fundamental approach of industrial ecology • Energy accounting is essential for identifying and assessing environmental consequences of industrial activities.
Environmental Performance: Energy • Quality of energy used per year or per unit of product • Quality of energy used per service or per customer • Quality of each type of energy used • Quality of energy units saved due to energy conservation • Source: International Organization for standardization, Annexes Testing committee.(1996)
Energy Use in Industries Source: U.S. DOE (1990)
Analyzing Energy Use is the fraction of output material from primary production. Schematic diagram of a metal processing system using only virgin materials
Analyzing Energy Use (cont.) is the fraction of output material from primary production is the amount of the material entering the process in the ore is the amount of the material entering the process as consumer scrap Schematic diagram of a metal processing system using both virgin materials and consumer scrap
Checklist for Energy Analysis • For facility engineers • Replace incandescent lighting with high-efficiency • fluorescent lighting • Install an automatic lighting control system • Check boilers and furnaces for leaks • Utilize cogenerated heat and electricity from within the • facility or nearby • Use waste heat • Encourage good energy housekeeping
Checklist for Energy Analysis(Cont.) • For Process designer • Minimize the use of energy-intensive process steps • Optimize the use of heat exchangers and similar devices to utilize otherwise wasted heat • Use the maximum possible amount of recycled material • Utilize energy management approaches and equipment • Utilize energy variable speed motors and other automated load control
Automobiles Energy Options • Alternative carbon-based fuels • Electric vehicles • Hybrid-powered vehicles • Fuel cell-powered vehicles
Schematic Diagram of a Fuel Cell Reference: P.M. Eisenberger, Basic Research Need for Vehicles of the Future
Fuel Cells - Why • Direct conversion of chemical to electrical energy • Environmental considerations: • Clean power source • Non toxic emissions • Efficient
Types of Fuel Cells • Phosphoric acid • Most commercially developed type of fuel cell • Generate electricity at more than 40% efficiency • Nearly 85% of steam this fuel cell produces is used for cogeneration (compared to 30% for the most efficient internal combustion engine)
Types of Fuel Cells - Phosphoric Acid • Operating temperatures are in the range of 400 degrees F. • These fuel cells also can be used in larger vehicles, such as buses and locomotives.
Types of Fuel Cells - Efficiencies A. Phosphoric Acid 40% 400 F B. Proton Exchange 200 F C. Molten Carbonate 1200 F D. Solid Oxide 60% 1800 F E. Alkaline 70% F. Others (i)Direct Methanol 40% 150 F (ii)Regenerative
Types of Fuel Cells - Emissions Engine Type Water Vapor/mile Carbon Dioxide/mile Gasoline Combustion 0.39 lb. 0.85 lb. Fuel Cell Running on Hydrogen from Gasoline 0.32 lb. 0.70 lb. Fuel Cell Running on Hydrogen from Methane 0.25 lb. 0.15 lb. Fuel Cell Running on Renewable Hydrogen 0.25 lb. 0.00 lb.
General Approaches to Minimizing Energy Use • Heating, Ventilating, Air Conditioning (HVAC) • Lighting • On-site energy generation • Energy housekeeping
Energy Housekeeping • Make the existing industrial situation more energy-efficient • e.g. • More efficiently design computer • Improve heat-transfer efficiency • Employ point-of-use fluid heaters
Energy Consumption in EU • Strong pressure by the EU on national authorities to bring energy consumption down • Planning difficulties to build new generating plants • Opposition to nuclear energy • Dependence on imports of fuel • Declaration of energy consumption on products for sale e.g. refrigerators • Reduction of stand-by energy, e.g. TVs,VCRs, computers Source: A. Stevels, Stanford Ecodesign short course, 1999
Energy Consumption in Japan • Targets • Standard for standby power for all CE products=1 watt • Energy reduction in operational modes • 1/6 for TV, air conditioner • 1/3 for refrigerator • 1/2 for washing machine Source: A. Stevels, Stanford Ecodesign short course, 1999
New Energy Technologies • Solar power, photovoltaics • Pulsed combustion • Waste pyrolysis systems • Waste to energy conversion • Gasification and wet thermal oxidation
Homework #7 1. Give a chart showing the performance hierarchy of recycling options 2. Discuss the primary considerations in recycling economics. 3. Graphically illustrate the cost benefits of recycling against the competition. 4. Discuss an example of successful reuse effort.
Homework #7 5 Compare the costs of new, reused and remanufactured product. What is needed to improve the status of reused product? How is it accomplished in your example given in #4. 6 Discuss an example of successful remanufacture effort.
