Life Cycle Assessment (LCA)

offbeatnothingSoftware and s/w Development

Dec 2, 2013 (3 years and 9 months ago)

61 views

Life Cycle Assessment (LCA)

Sustainable Operations

Prof. Gil Souza

1

Life Cycle Assessment (LCA)

Quizzes


For each pair of products / processes below,
which one has the lowest environmental
impact?


PET or aluminum packaging for soft drinks?


Remanufacturing or recycling?


Paper or plastic bags?


Ethanol or gasoline for powering automobiles?


Compact dish detergent or regular dish detergent?


LED lights or CFL lights or incandescent lights?




Life Cycle Assessment (LCA)

2

Answer: You Need Life Cycle
Assessment (LCA)


LCA’s goal is to find the full range of environmental
(and societal) damages assignable to products (or a
process) through its entire life cycle


Raw material extraction and processing, manufacturing,
distribution, use, and disposal / recycling


Common categories of assessed damages (but not
limited to)


Global warming, toxicity (air, water, and land), ozone layer
depletion, acid rain, depletion of minerals and fossil fuels


Data intensive process, usually done through software
and existing databases

Life Cycle Assessment (LCA)

3

Structure / Scope of LCA

Life Cycle Assessment (LCA)

4

Source: P&G website

Cradle to Gate

Includes 4 stages

Cradle to Grave

Includes 6 stages

LCA Phases (ISO 14040 and 14044)

Life Cycle Assessment (LCA)

5

Goal and Scope
Definition

(Determining
boundaries for study)

Inventory Analysis
(Data on inputs and
outputs quantities for
all relevant processes)

Impact Assessment
(Contribution to impact
categories, such as
energy consumption,
through normalization
and weighing

Interpretation

(Major
contributions,
sensitivity analysis:
what can be learned
from study?)

Step 1: Determining Goal


Level of specificity
in the study


Is the product being analyzed specific to a company or a plant? Two
different plants producing the same type of product could have
different emission levels, for example


This requires an additional level of data collection that may be impractical


Or, will we focus on industrial averages (e.g., impacts of using
recycled aluminum in a design)?


Level of accuracy
in data collection / analysis


Should be high if used in driving public policy


If used in internal decision making for a firm, a reasonable estimate is
generally enough


How to display the results. Example: comparing two products


Comparison should be made in terms of equivalent use


Example: bar soap vs. liquid soap; the basis should be an equal
number of hand washings


Life Cycle Assessment (LCA)

6

Life Stage
Materials
choice
Energy use
Solid
residues
Liquid
residues
Gaseous
residues
Resource
extraction
Product
manufacture
Packaging and
transportation
Product use or
consumption
Maintenance,
recycling and
disposal
Product Assessment Matrix
Environmental concern
Step 1: Determining Scope

Example

Step 2: Inventory Analysis


Collect data on the impact of inputs and outputs
generated by each row (life cycle stage) on the
assessed category of interest. Categories on
previous example:


Materials choice


Energy use


Solid residues


Liquid residues


Gas residues


Many databases exist for common materials and
processes used (industry averages)


Mostly done through software


8

MOT

Sustainability

9

Materials Choice


Recommendations based on availability on
Earth, rate of depletion and toxicity


Recommended
:


Al, Br, C, Fe, H,
Mn
, N, O, S, Si, and Ti


Supplies are ample, potential for recycling is
good, and have no significant toxicity issues


Limit or avoid
:


Ag, As, Au,
Cd
,
Cl
, Cr, Hg, Ni,
Pb


Short supply and/or toxicity problems

10

Life Cycle Assessment (LCA)

Energy Use (GJ / Mg) in Production of
Various Metals

Metal

Primary
Production

Secondary
Production*

Steel

31

9

Copper

91

13

Aluminum

270

17

Zinc

61

24

Lead

39

9

Titanium

430

140

* Consumer recycled material

Source: P. Chapman and F. Roberts, 1983

11

Life Cycle Assessment (LCA)

Solid Residues


Process residues


A result of manufacturing process


Example: fly ash from coal combustion


Product residues


Intended to be part of the product


Example: plastic molding


Packaging residues


30% of all municipal solid waste…but


40% of all U.S. goods are purchased by corporations


Liquid Residues of Common Industrial Processes and
Products

Process

Liquid Species

Trace
Metals

Nutrients

Solvents,
Oils

Organics

Acids

Suspended
Solids

Agriculture







Chemical Mfg.

+

*

*

+

Electronics

*

+

Electroplating



*

+

Fertilizer

*

+

Food production

+

Leather making

+

*

Metal cleaning

*

*

*

*

Mining, smelting

*



Pesticides

*

* = Modest influence on local, regional or global scale; + = minor influence on local,
regional, or global scale; • = major influence on local, regional, or global scale

Source: T. Graedel and B. Allenby, “Design for
Environment”.

Example of LCA 1: Paper vs. Plastic Bag

Category

Paper Bag

Plastic Bag

Raw

materials

Wood (renewable)

Oil / gas (non
-
renewable)

Energy to make

1.7
mJ

1.5
mJ

Solid waste

50 g

14 g

Total emissions to air

2.6 kg

1.1 kg

Global warming
equivalents

(CO2
equivalents)

0.23 kg

0.53 kg

Life Cycle Assessment (LCA)

13

Source: Institute for Lifecycle Energy Analysis

Compares one paper bag with two plastic bags (similar carrying capacity)

Assumes current recycling rates

It depends!

Example of LCA 2: Impact on
Global
Warming

of Different NEC Products

Life Cycle Assessment (LCA)

14

Purchased
parts

88%

Assembly
at NEC

7%

Electricity
cons. (use)

4%

Distribution

0.5%

Disposal

0.5%

Cell Phones

Purchased
parts

23%

Assembly
at NEC

1%

Electricity
cons. (use)

76%

Distribution

0.4%

Disposal

0.1%

Fax Machines

Purchased
parts

59%

Assembly at
NEC

1%

Electricity
cons. (use)

39%

Distribution

1.0%

Disposal

0.2%

Desktop PCs

Purchased
parts

2%

Assembly
at NEC

1%

Electricity
cons.
(use)

98%

Switching Equipment

Source: www.nec.co.jp

Example of LCA 3: Lamps (Energy Consumption)

Life Cycle Assessment (LCA)

15

Source: www.osram
-
os.com

25 x GLS
2.5 x GFL
1 x LED
Use [kWh]
3290
658
658
Production [kWh]
15.3
10.2
9.9
0
500
1000
1500
2000
2500
3000
3500
Energy [kW]

Lamps in Comparison

(Use During 25,000 Hours)

Example of LCA 3: Lamps (Toxicity Potential)

Life Cycle Assessment (LCA)

16


Toxicity here is mainly caused by power
consumption due to by
-
products: arsenic, sodium
dichromate, hydrogen fluoride


Measured in 1,4 dichlorobenzene equivalent

Example of LCA 4: Corrosion
Protection Systems (After Scaling)

Life Cycle Assessment (LCA)

17

Source: Technical University of Berlin

Example of LCA 5: Materials for
Residential Construction

Life Cycle Assessment (LCA)

18

Source: Kozak and Galston (2001)

Application of LCA

Which option is better for the environment:
remanufacturing or recycling
?

Answer:
It depends
!

(But remanufacturing is typically better)

19

Life Cycle Assessment (LCA)

Example A. Two
Automotive Parts
(Low Level of
Technological Obsolescence)

6205
3150
742
0
1000
2000
3000
4000
5000
6000
7000
Disposal
Recycling
Remanuf.
Energy consumption (KWh/ton) for steel part:
(gear) alternatives for end-of-life
29450
4405
2597
0
5000
10000
15000
20000
25000
30000
Disposal
Recycling
Remanuf.
Energy consumption (KWh/ton) for aluminum part
(transmission): alternatives for end-of-life
Source: Bert Bras (2009)


In “disposal” a new part has to be produced from virgin raw materials


In recycling, a new part is produced from recycled materials


In remanufacturing, the part is remanufactured and reused

20

Life Cycle Assessment (LCA)

Remanufacturing

is clearly better!

Example B.
Cell Phones
: Impact on
Global
Warming

(
Primarily Energy Consumption
)

Life Cycle Assessment (LCA)

21

Most carbon footprint (and also energy use) occurs in
purchased pars (manufacturing and raw material extraction.)
Remanufacturing

is best!

Purchased
parts

88%

Assembly at
NEC

7%

Electricity
cons. (use)

4%

Distribution

0.5%

Disposal

0.5%

Cell Phones

Example C.
Desktop PCs
: Impact on
Global
Warming

(
Primarily Energy Consumption
)

Life Cycle Assessment (LCA)

22

Purchased
parts

59%

Assembly at
NEC

1%

Electricity
cons. (use)

39%

Distribution

1.0%

Disposal

0.2%

Desktop PCs

Most carbon footprint (and also energy use) occurs in
purchased pars (manufacturing and raw material extraction.)
Remanufacturing

is best!

Example D.
Internet Switching Equipment
: Impact on
Global Warming

(Primarily Energy Consumption)

Life Cycle Assessment (LCA)

23

Most carbon footprint (and also energy use) occurs during the use.
Recycling

is best, if newer equipment is more energy efficient!

Purchased
parts

2%

Assembly
at NEC

1%

Electricity
cons. (use)

98%

Switching Equipment

Example E.
Refrigerators
: Impact on Cumulative
Energy Consumption

Source: Quariguasi Frota Neto et al. 2008

Again, most energy consumption occurs in usage. Best to replace
old appliances with energy efficient new appliances.


Recycling

is best!

24

Sustainable Operations

Distribution

Manufacturing

Use

Limitations of LCA: Examples


Weights given to different impacts


What is more important? Use of water resources or CO2
emissions?


Drawing the boundaries


Cradle to Gate or Cradle to Grave
?


Do we consider supporting activities for the system?


Example: a warehouse stores the product. Direct energy consumption
for the warehouse should be part of the system, but emissions
associated with garbage pickup for the facility probability shouldn’t be.


Social and economic impacts


Environmental impacts are relatively easy to measure, but socio
-
economic impacts are difficult to quantify


Renewable vs. non
-
renewable resources


Remanufacturing, recycling, and reuse


Consideration of recycling makes significant impact, even though
that depends on recycling rates

Life Cycle Assessment (LCA)

25

Further Resources


The web has an incredible amount of
information on LCA


For starters, please check the document
“LCA_guide_EPA.pdf” on Angel, which has a
more detailed guide to LCA (by the EPA), and it
includes a list of software vendors


See
http://www.life
-
cycle.org/


Life Cycle Assessment (LCA)

26