environmentally conscious design & manufacturing (me592) date: april 26, 2000 slide:1...

Environmentally Conscious Design & Manufacturing (ME592)

Date: April 26, 2000 Slide:1

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

Consumer Consumer Scientific Government perception perception (LCA) policy 1996 1991 (Netherlands)

Energy consumption 1 4 1 3Water/recycling 2 5 4 2Materials use 3 1 3 6Packaging 4 2 5 5Sustainability 5 6 N/A 1Production 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 Emission



Energy and Emission (cont.)



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)



Gaseous Species Emitted by Energy

Generation Processes



Energy Use in the Production of Aluminum Cans



Energy Use for the Production of Metals



Analyzing Energy Use

Schematic diagram of a metal processing system using only virgin materials

is the fraction of output material from

primary production.



Analyzing Energy Use (cont.)

Schematic diagram of a metal processing system using both virgin materials and consumer scrap

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



Life Cycle of a Typical Automobile



Energy Consumption for Automobile



Life Cycle Energy Use for Various Automobiles



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



Distribution of Input Energy for a Midsize Automobile



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



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.

Types of Fuel Cells - Emissions



General Approaches to Minimizing Energy Use

• Heating, Ventilating, Air Conditioning (HVAC)

• Lighting

• On-site energy generation

• Energy housekeeping



Energy Efficiency of Light Source



On-site Energy Generation



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



• 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


Energy Consumption in EU



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




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.

environmentally conscious design & manufacturing (me592) date: april 26, 2000 slide:1...

Documents

energy energy

energy use slide

energy quality of energy

emission slide

epa slide

pandit slide

renewable energy

industry energy