costs of materials usage

Costs of Materials Usage

Professor Randolph Kirchain Department of Materials Science & Engineering and

Engineering Systems Division

Massachusetts Institute of Technology Cambridge, Massachusetts Materials Systems Laboratory

Materials & Sustainability: Slide 1

Overview

• Context – Indirect Costs • The role of materials in the environment

– Direct – Indirect

• Is this really a problem? – How much do we consume?

• What can be done – Changing the rules of the game

• Research at MIT – Enabling materials substitution – Improving materials reuse



1

Review

• Manufacturing cost – Materials, labor, energy – Capital

• Other costs – R&D – Marketing – Managerial – Social?

• Social costs – Environment – Social



How do Materials Drive Social Cost? Environment

• Direct – Manufacturing burden

• Consumption of energy • Emissions to the environment

– Concentration in the environment • Most materials still eventually in up in landfills • Toxicity for some materials

• Indirect – Performance of the products into which they are

transformed • Energy Efficiency • Recyclability



2

Is this really a problem?

How much do

YOU

consume per day?



/ /

2 3 3 7

2 6



How much do YOU use per day (kilograms)?

Inputs 3 Recycled

> 50 kg person day

21 21

Metals Minerals Forestry products Agriculture Energy materials Construction

Outputs

19 21

Dissipated Wastes Air emissions In use

Figure by MIT OCW.

3

Courtesy of Annual Review, Inc. Used with permission.Source: Figure 3 in Matos, G., and L. Wagner. "Consumption of Materials in the United States, 1900-1995." Annu Rev Energy Environ 23 (1998): 107–22.

Steel

Steel

Materials Substitution:

Which Material would you Choose?

CO2 11 kg / kg

SO2 0.4

NOx 0.3

CO2 2 kg / kg

SO2 0.008

NOx 0.007



Making Better Material Choices

Material B Material A

CO2 SO2 NOx NM VOC Dust 1e-05

0.0001

0.001

0.01

0.1

1

10

100 Aluminum

Emissions from Production

Aluminum 0

2

4

6

8

10

12

kg

Emissions from Production CO2

A B

A B



Which would you choose?

kg R

elea

sed

per k

g Pr

oduc

ed

Why does A advertise itself as Environmental?

5

What is Life-cycle Assessment?

• SETAC Definition: “The life cycle assessment is an objective process to evaluate the environmental burdens associated with a product, process, or activity by identifying and quantifying energy and materials usage and environmental releases, to assess the impact of those… and to evaluate and implement opportunities to effect environmental improvements…”



LCA: Methodology

• Goal & Scope Definition – What is the unit of analysis? – What materials, processes,

or products are to be considered?

• Inventory Analysis – Identify & quantify

• Energy inflows • Material inflows • Releases

• Impact Analysis – Relating inventory to impact

on world

Massachusetts Institute of TechnologyCambridge, Massachusetts Materials Systems Laboratory

Goal & Scope

Definition

Inventory Analysis

Impact Analysis

Interpretation


6

Example:

Comparing Beverage Packages



Goal & Scope Definition

• Purpose • Scope of study: – Identify preferred material – Various container

• Target group – materials • Steel

– Package manufacturers • Aluminum – Policy makers • Polyethylene

• Unit of analysis • Glass • Polystyrene – One beverage package • Paper

• Time period – life cycle of one package



7

What would we include?



Goal & Scope Definition: How far do we go?

• Defining boundaries – No theoretical basis for exclusion – Often broken at environmental flows or economic

flows of + value – Generally includes only processes in direct contact

with product & raw materials entering that product

• Example: Oil Use – Combustion

• If electricity, consider:conversion efficiency & transmission eff.

– Extraction – Transport – Refining



8

Inventory Analysis

• Data collection – Inflows of materials – Inflows of energy – Releases to land, water and air

• Typically the most time consuming stage

• Data sources – Scientific literature, Published studies – Industry & government records – Industry associations – Private consultants





Inventory Analysis: Glass

9



Life-cycle Inventory: Glass

No Recyc 70% Recyc 97% Reuse

Impact Assessment

• Classification – Environmental stressors are correlated with specific

environmental issues• Resource depletion • Global warming • Photochemical oxidation • Acidification • Human & Ecosystem toxicity • Nutrification • Ozone depletion

• Characterization – Quantify contribution of stressor to specific issue

• Valuation



10

Use

List of Top Process Concerns

• Toxics – Can I reduce the use of toxic feedstocks or products?

• Waste – Can I improve material usage efficiency? – Can I utilize waste streams of other processes?

• Energy (Water) Efficiency – Can I drive down energy (water) usage?

• Supply Chain Awareness – Can I select environmentally conscious suppliers?





Environmental Burdens of Microelectronics

0

500

1000

1500

2000

2500

Cum

ulat

ive

Ener

gy (k

Wh

/ kg

chi

p)

1 kg of Si chips10 - 50

kg Si Materials Use

EnergyEnergyUse

Æ Si Die Production Æ

0

400

800

1200

1600

Inflo

ws

(g /

chip

)

Fossil Fuel Chemicals

Inflows per 2g RAM Chip

11

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