Environmentally Conscious Design & Manufacturing (ME592) Date: March 17, 2000 Slide:1 Environmentally Conscious Design & Manufacturing Class 6: Reuse

Environmentally Conscious Design & Manufacturing (ME592)

Date: March 17, 2000 Slide:1

Environmentally Conscious Design & Manufacturing

Class 6: Reuse / Recycle

Prof. S. M. Pandit



Reuse / Recycle

Agenda

Motivation Design issues & inverse manufacturing Discrete product recycling Tools Expert systems



Motivation

1991Carnegie Mellon Report Projection:

• 150,000,000 obsolete PCs by 2005

• None with readily recoverable materials

• Landfilled!

• Cost: $ 400,000,000

• What about washing machines, refrigerators, etc.?



Design Issues - 1

Inverse Manufacturing

Not limited to reusing and recycling

-- Develop methods for the creation of designs with thought given to reuses and recycling from the very early stage

-- Improve the functions of a product along with prolonging its product life through use and maintenance

-- Lower the amount of abandoned artifacts.

http://amstel.t.u-tokyo.ac.jp/~umeda/yoshikawa.html



Design Issues - 2

• Green Design

-- How to arrange the information for design and

development leading to the formation of an

artifact system symbiotic with the

environment.

-- New artifacts born out of this sort of

methodology will have considerable effect in

creating the new industries of the future.



Design Issues - 3

Extension of Reuse / recycle concepts: Maintenance Issues

-- The manufacturing industry will turn into a life cycle industry

-- The artifacts produced will quantitatively decrease

-- But they will, instead, have » A long life and» Give rise to higher added values

and the manufacturing industry will become sustainable.



Design Issues - 4

Reuse / Recycling in sustainable manufacturing

-- Develop methods serving toward the creation of

designs with thought given to reuse and

recycling from the very early stage

-- Improve the functions of artifacts, while decreasing the production volume but

maintaining the level of economic activities.



Recycling - Options & Hierarchy

• Maintenance

• Recycle subassemblies

• Recycle components

• Recycle materials



Hierarchy of Preference in Recycling - 1









Closed-loop Recycling



Open-loop Recycling



Recycling Materials - 1

• Avoid

-- Too many different materials

-- Toxic materials

-- Joining dissimilar materials hard to

separate

• Metals

-- Dilution factors affect price (of Extraction)



Relation between Dilution and Price




• Plastics

-- Composition affects chemistry for recycling

• Tag with symbol

• Fastening methods




• Priorities for recycling:

-- Reduce materials content

-- Reuse / refurbish

-- Remanufacture

-- Recycle

-- Incinerate

-- Dispose of as waste

Preference



Tools - 1

• Hierarchy for recycling / Reprocessing

-- pairwise comparison techniques

• Look at available technology

• Feasibility of developing technology

• Cost and time factors



Tools - 2

• Choosing between alternatives:

-- Reprocessability index for products &

subassemblies

-- Pairwise comparison



Tools - 3

• Disassembly options (operations planning)

• Engineered materials

• Adsorb/ absorb contaminants

• Bio- degradation

• Experimental & analytic tools

-- Effluent gases, caloric values, incineration

options



Tools - 4



Recycling Program Steps

• Evaluation

• Design & Development

• Education

• Implementation

• Monitoring & Management

• Transportation, Processing & Marketing



Expert SystemsInference Engine

• Tree structure “If-Then-Else” Rules• Analytic models• Hybrids• Empirical models• Learning algorithms• Imprecision “fuzzy”

Inputs

External Data

Output Processor Structured Data Base



Homework #2The following problems are out of the textbook “Industrial Ecology”

1. Problem 2.3

Answer: (Example of aluminum)

year Pop(billion) Al(million tons) Al per capita (g/person)

1950 2.5 1.25 4501960 3.2 2.60 7401970 2.8 7.0 16701980 4.7 11.0 21301985 5.0 11.5 2090

2. Problem 2.4

Answer: 2000: 23; 2010: 14 g; 2020: 6.2 g SO2/dollar

Hint: Use extrapolation beyond the curves of Fig. 2.8)



Homework #23. Problem 3.2

Answer: 1.5%(current fraction),

1.0%( 2020 fraction).

4. Problem 4.1

Answer:Draw a vertical line from 1.1 mg/l, and picture moving all of

the curves to the right by half a division (i.e., factor of three in the

log). The intersection is with the log probit curve. The Weibull model

would have given approximately 2*104 µg/l as the standard, the logit

model approximately 0.3 µg/l, and the multistage model approximately

30 µg/l.

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Environmentally Conscious Design & Manufacturing (ME592) Date: March 17, 2000 Slide:1 Environmentally Conscious Design & Manufacturing Class 6: Reuse