Centre of Environmental Science CML, Leiden University Prepared for NATO workshop Budapest, Hungary September 2003 Hybrid Life Cycle Assessment Sangwon

Centre of Environmental ScienceCML, Leiden University

Prepared for NATO workshop Budapest, Hungary September 2003

Hybrid Life Cycle Assessment

Sangwon Suh

Centre of Environmental Science (CML)Leiden University, the Netherlands



Truncation in LCA

Hybrid input-output LCA

Case Study

Conclusion

Contents



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Reference

Lave et al., 1995

Lenzen, 2001

Estimated truncation

66%

9~52%

Method

1st order upstream

3rd order (energy)

Truncation in Process LCATruncation in Process LCA



1st 2nd 3rd 4th 5th 6th

[Lave et al., 1995] [Lenzen., 2001]



[Donhomae, 1994][Lave et al., 1995][Hendrickson et al, 1998]

Input-output based LCI



Activated carbon and charcoal Alkali metals

Alumina Aluminum chloride Aluminum compounds Aluminum hydroxide (alumina trihydrate) Aluminum oxide Aluminum sulfate Alums Ammonia alum Ammonium chloride, hydroxide, and molybdate

Ammonium compounds, except for fertilizer Ammonium perchlorate Ammonium thiosulfate Barium compounds Bauxite, refined Beryllium oxide Bleach (calcium hypochlorite), industrial Bleach (sodium hypochlorite), industrial Bleaches, industrial Bleaching powder, industrial Borax (sodium tetraborate) Boric acid Boron compounds, not produced at mines Borosilicate Brine Bromine, elemental Calcium carbide, chloride, and hypochlorite Calcium compounds, inorganic Calcium metal Carbide Catalysts, chemical Cerium salts Cesium metal Charcoal, activated

SIC 2819-Industrial inorganicchemicals, NEC

182 items



Engineering ModelMeso/Macro

Economic Model

Why Hybrid ?

Integrated hybrid LCAAccurateDisaggregatedPartial

CompleteAggregated

General



Hybrid Life Cycle Assessment

[Moriguchi et al., 1993]

Utilized Japanese input-output table and process datafor life cycle CO2 emission of automobile



Process analysis

Input-output analysis

Bullard et al. (1978)Engelenburg et al. (1994)Moriguchi et al (1993)

Tired hybrid modelTired hybrid model



Input-output based hybrid modelInput-output based hybrid model

+ Use + Use + Disposal+ Disposal

Joshi (1999)Gibbson et al. (1982)



Integrated Hybrid LCI modelingIntegrated Hybrid LCI modeling

LCI [Heijungs & Suh, 2002] : Physical unit/operation time

IOA [Stone, et al., 1963] : Monetary unit/total production

Integrating the computational structure of

Full interaction between process and economy



SteelSteel SteamSteam

Production of ToasterProduction of Toaster

Use of ToasterUse of Toaster

Disposal of toasterDisposal of toaster

1 kg CO2/kg steel

4 kg CO2/ MJ Steam

1 kg 0.5 MJ

1 unit

1 unit

2 kg CO2/unittoaster production

0.001 kg CO2/piece of bread toasted

0.5 kg CO2/unit toaster disposal

0.5 MJ

0.25 kg




11000

01000000

01100

005.015.0

0015.01

~A

5.01241~ B

0

1000

0

0

0

~k

5.17~~~~ 1 kABM




0

2

4

6

8

10

12

Steel Electricity Toaster Toasteruse

Wastedisposal

LC CO2 Contribution by processes



yAB

0

y

AIC

CABBq

1

1

u

d

~

***

*~

***

~

***

~

***

*~

***

~ 1

u

d

f

f

AIC

CA

g

g




IKICDKDC*AAAAA

1ˆ *

ˆ**

pApA

)*

~ *

~ˆ *

~ˆ( ***** P

udFPF PZZPmPUPmUU

TF

TP )(~)(ˆ

*****PVPmVV

Pretreatment of IO table for integration



Hybrid matrixHybrid matrix



0.263$ Sub Bitumen

Steam

0.031$ Ind.Bld

Coal mining

Ind. Installat’n





Case StudyCase Study

- Baseline (Existing LCI)

- Hybrid (Cut-offs and capitals : 38 links)

- IO LCI (Miscellaneous floor coverings)

yAPM ~~~~ 1

yAIPM 1)(

yABM 1

Linoleum (a flooring material by Forbo BV)



0%

50%

100%

150%

200%

250%

POC OD GW HT AEF AES SEF SES TE AD EUT ODR

Baseline Hybrid IO LCI



Baseline

Hybrid Max

IO LCI

0%

5% ~ 73% (avg. 18%)

-85% ~ 124% (avg. 3%)

Percent change



Process LCAProcess LCA

Input-Output Input-Output LCALCA

ModelModel

Process specificProcess specific

EncompassingEncompassingsystem boundarysystem boundary

StrengthsStrengths WeaknessWeakness

TruncationTruncation

AggregationAggregation

HybridHybrid

LCALCA

HybridHybrid

LCALCA









Approaches in Life Cycle Inventory ModellingApproaches in Life Cycle Inventory Modelling



0 200 400 600 800 1000

Product B

Product A

kg CO2-eq.

Uncertainties in LCIUncertainties in LCI

0

50

100

150

200

250

0 200 400 600 800 1000

Fre

qu

en

cy

0

50

100

150

200

250

0 200 400 600 800 1000

Fre

qu

en

cy



Uncertainty analysesUncertainty analyses

Perturbation Analysis Perturbation Analysis (Heijungs and Suh, 2002)(Heijungs and Suh, 2002)

Monte Carlo simulation Monte Carlo simulation (Hendry, 1984, Huijlbregts, 2001)(Hendry, 1984, Huijlbregts, 2001)

Changes in results due to change in a parameter

Location and dispersion of the results due tosimultaneous changes in all parameters



Monte Carlo simulationMonte Carlo simulation

Computation of LCIComputation of LCI

yBAE 1E: Life Cycle InventoryB: Environmental intervention matrixA: Technology matrixy: Functional unit




Basic conceptBasic concept

yAABBE 1))(( kkk

nEEEEE ,...,, 321Randomly distributed noise onEnvironmental intervention matrix

Randomly distributed noise onEnvironmental intervention matrix

Randomly distributed noise onTechnology matrix

Randomly distributed noise onTechnology matrixStatistical property, location and dispersionStatistical property, location and dispersion



Model buildingModel buildingModel buildingModel building

Data gatheringData gatheringData gatheringData gathering

Extraction of Extraction of distribution distribution propertiesproperties

Extraction of Extraction of distribution distribution propertiesproperties

Coding and Coding and running running

a programa program

Coding and Coding and running running

a programa program

Analyse Analyse the resultsthe results

Analyse Analyse the resultsthe results

Steps for Monte Carlo simulationSteps for Monte Carlo simulation



0

~~~

1y

AIN

SAPPM

yAPM ~~~~ 1

yAIPM 1)(

Process LCAProcess LCA

Input-output LCAInput-output LCA

Hybrid LCAHybrid LCA


Model buildingModel building




Data gatheringData gathering

Linoleum

1996 US. IO data and environmental statistics640900 Hard surface floor coverings, n.e.c.

38 missing flows linked with IO table

Process LCAProcess LCA (Gorree et al., 2001)(Gorree et al., 2001)

Input-output LCAInput-output LCA (Suh and Huppes, 2001)(Suh and Huppes, 2001)

Hybrid LCAHybrid LCA (Suh and Huppes, 2001) (Suh and Huppes, 2001)



Considered uncertaintyConsidered uncertainty

IO partIO part

Aggregation UncertaintyUncertainty due to data ageSource data uncertainty in IO tableSource data uncertainty in environmental data

Process partProcess part

Uncertainty due to data ageSource data uncertainty in technology matrixSource data uncertainty in environmental data




Extraction of distribution propertyExtraction of distribution property

Ex) Aggregation Uncertainty in IO LCA

496 X 496

9510 1




Data preparationData preparation

Ex) Aggregation Uncertainty in IO LCA

y = 0,6937x0,6914

0

20

40

60

80

100

1 10 100 1000

log [n/n*]

Sta

nd

ard

err

or

(Ix

*-x

I)/x



0%

50%

100%

150%

200%

250%

POC OD GW HT AEF AES SEF SES TE AD EUT ODR

Baseline Hybrid IO LCI



0

10

20

30

40

50

0 50 100 150 200 250 300

Fre

que

ncy



0

10

20

30

40

50

0 50 100 150 200 250 300

Fre

que

ncy

Narrow distributionNarrow distributionbut relatively underscoredbut relatively underscored

More provable toMore provable tocontain the ‘true values’contain the ‘true values’

but rather wider distributionbut rather wider distribution

Wider than process analysis butWider than process analysis butmuch narrower than IO resultsmuch narrower than IO resultsand closer to the target valueand closer to the target value







Accuracy Accuracy vs.vs.

precisionprecision



APPLAUSEAPPLAUSE



‘Which is the better’ arguments between process LCA and IO LCA

Two sides of a coin: Accuracy vs. precisionTwo sides of a coin: Accuracy vs. precision

Process LCA

High precision but less accuracyHigh precision but less accuracy

IO LCA

High accuracy but less precisionHigh accuracy but less precision



Conclusions

In engineering terms, pure process-LCA is precise but lacksaccuracy, while pure IO-LCA is more likely cover the true valuebut lacks precision.

Hybrid LCA combines the two and improves the accuracy whilemaintaining the overall precision.

Hybrid approach generally solves the problem of system boundaryin process-LCA conserving process-specificity as much as possible



Thank You

Documents

Centre of Environmental Science CML, Leiden University Prepared for NATO workshop Budapest, Hungary September 2003 Hybrid Life Cycle Assessment Sangwon