Sustainability Assessment of H 2 Pathways

Sustainability Assessment Sustainability Assessment of Hof H22 Pathways Pathways

Ben MBen MccLellanLellan Chemical EngineeringChemical Engineering

ARC Centre forFunctional Nanomaterials


IntroductionIntroduction

Why Hydrogen?Why Hydrogen?

Why Sustainability Metrics?Why Sustainability Metrics?

Purpose of this workPurpose of this work



General Life Cycle FlowsheetGeneral Life Cycle Flowsheet

Extraction Production Purification Utilisation

Transport

Transport

Transport Transport / Storage

CO2 Capture Sequestration



Sustainability MetricsSustainability MetricsAim:Aim: to assess and compare the different to assess and compare the different

pathways in terms of environmental pathways in terms of environmental sustainabilitysustainability

Potential Environmental ImpactsPotential Environmental Impacts

Not location-specific Not location-specific (IChemE, TRACI)(IChemE, TRACI)

n

iNiNi PFWEB

1, ))((

n

i H

n

W

EBEBEBPEI

1 2

21 )...(



EB = Environmental burden

WN = Mass of emission

WH2 = GJ Hydrogen Produced

PF = Potency Factor

PEI = Potential Environmental Impact

Sustainability MetricsSustainability Metrics

Specific Sustainability MetricsSpecific Sustainability Metrics

Take location-specific factors into Take location-specific factors into accountaccount

n

i

high

n

n

i

n

iiii

n

nK

KEBSEB

1 21

21

1

...

...

)(

n

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n

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SEBSEBSEBSEI

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SEI = Specific Environmental Impact

SEB = Specific Environmental Burden

K = unitless location-specific coefficient

Case StudyCase StudyTwo Source Extraction Points – Two Source Extraction Points – one for NG, one for Coalone for NG, one for CoalOptions of on-site hydrogen Options of on-site hydrogen production or at point of usage production or at point of usage hydrogen productionhydrogen productionComparison of Source Comparison of Source Transport, Source Extraction Transport, Source Extraction and Hydrogen Production and Hydrogen Production ImpactsImpacts



Case Study - DetailsCase Study - DetailsTable 1: Hypothetical Test Case Data

Feedstock Coal Coal NG NG

Process

Gasification (IGCC)

Gasification (IGCC)

Steam Reforming

Steam Reforming

Location #1 #2 #3 #4

Distance from Source

Onsite (3km)

200km Onsite (3km)

450km

Transport Type Rail Rail Pipeline Pipeline

Mean Annual Days of Rain

92 66 95 53

Average soil pH 5.8 7.3 5.7 6.4

Population within 20km

1075 274955 812 5749



Global Warming ImpactsGlobal Warming Impacts

CO2 and hydrocarbon emissions from each stage given as CO2 equivalenceK value based directly on emissions






Production (P), Extraction (E) and Feedstock Transport (T) CO2 Emissions

1 E -05

0.0001

0.001

0.01

0.1

1

1 0

1 00

P # 1 P # 2 P # 3 P # 4 E # 1 E # 2 E # 3 E # 4 T # 1 T # 2 T # 3 T # 4

Situation

PEI

SEI

OnsiteOnsite OffsiteOffsite

CoalCoal #1#1 #2#2

NGNG #3#3 #4#4





CoalCoal #1#1 #2#2

NGNG #3#3 #4#4

Environmental Impacts (Global Warming)

0

5

1 0

1 5

20

25

30

35

40

45

PEI #1 SEI #1 PEI #2 SEI #2 PEI #3 SEI #3 PEI #4 SEI #4

Situation

kg C

O2-eq

/ GJ H

2

Transport

Extraction

Production

Acidification PotentialAcidification Potential

NOx and SOx emissions weighted in NOx and SOx emissions weighted in terms of SOterms of SO22 equivalence equivalence

PEI from simple addition of PEI from simple addition of emissions (factor of 0.7 for NOx)emissions (factor of 0.7 for NOx)

K value based on annual rainfall and K value based on annual rainfall and soil pH in the regionsoil pH in the region

Rain factor:

Where frain is the mean annual days of rain.

Soil factor:

days

f rainrain 365

71

pH

pH soilsoil



(pH >0)

Acidification PotentialAcidification Potential



Acidification Impact of H2 Production (P) and Feed Extraction (E)

1 E -1 1

1 E -1 0

1 E -09

1 E -08

1 E -07

1 E -06

1 E -05

0.0001

0.001

0.01

0.1

1

P # 1 P # 2 P # 3 P # 4 E # 1 E # 2 E # 3 E # 4

Situation

kg S

O2-e

q / G

J H2

(log

sca

le) PEI

SEI


CoalCoal #1#1 #2#2

NGNG #3#3 #4#4

Human Health ImpactsHuman Health Impacts

Mainly from H2 Production Mainly from H2 Production – only emissions – only emissions assessed hereassessed here

ParticulatesParticulates

Assumed to have a major Assumed to have a major impact only in the impact only in the surrounding 20km radiussurrounding 20km radius

K value based on K value based on population in surrounding population in surrounding areaarea

Kmpop Pf 20)(



Human Health ImpactsHuman Health Impacts



Human Health Impact of Hydrogen Production

0.0001

0.001

0.01

0.1

1

# 1 # 2 # 3 # 4

Situation

kg P

M10

/ GJ H

2 (l

og s

cale

) PEI

SEI


CoalCoal #1#1 #2#2

NGNG #3#3 #4#4

Global Warming Potential - Global Warming Potential - Comparison of StagesComparison of Stages



Situation Extraction Transport Production

# 1 0.22 5.05E-07 34.54

# 2 0.22 3.50E-03 34.54

# 3 2.59E-03 4.45E-07 22.05

# 4 2.59E-03 8.80E-03 22.05

Global Warming Specific Environmental Impacts

(kg CO2-eq / GJ H2)


CoalCoal #1#1 #2#2

NGNG #3#3 #4#4

Summary of ResultsSummary of Results

Global Global WarmingWarming

AcidificationAcidification Human Human HealthHealth

PEIPEI SEISEI PEIPEI SEISEI PEIPEI SEISEI

#1#1 22 22 11 11 11 33

#2#2 11 11 11 44 11 11

#3#3 44 44 22 22 22 44

#4#4 33 33 22 33 22 22

Ranking of Overall Environmental Impacts (1- Highest, 4- Lowest)

As expected because Global Warming is non-location-specific

Ranking changes with SEI due to local population

Ranking changes with SEI due to different soil pH / rainfall conditions


CoalCoal #1#1 #2#2

NGNG #3#3 #4#4



ConclusionsConclusions

Sustainability metrics were used Sustainability metrics were used successfullysuccessfullySome adjustments need to be made to Some adjustments need to be made to enable more wide-ranging use enable more wide-ranging use

(inclusion of social/economic factors, distance/time variable models)(inclusion of social/economic factors, distance/time variable models)

The data and model require refiningThe data and model require refiningThe importance of specific indicators The importance of specific indicators demonstrateddemonstrated



ConclusionsConclusions

Sustainability Metrics can be used Sustainability Metrics can be used to compare different technology to compare different technology impacts, different life cycle stages impacts, different life cycle stages and different locationsand different locations

A useful tool, but the process A useful tool, but the process needs to be improved so that it is needs to be improved so that it is more scientificmore scientific



Hydrogen Production – Hydrogen Production – Summary of ResultsSummary of Results



Global Warming Acidification Human Health

Situation PEI SEI PEI SEI PEI SEI

#1

34.54 34.54

0.0291 0.027 0.1925 0.0008

#2

34.54 34.54

0.0291 0 0.1925 0.1925

#3

22.05 14.07

0.0075 0.0075 0.064 0.0002

#4

22.05 14.07

0.0075 0.0039 0.064 0.001

Transport and Extraction – Transport and Extraction – Summary of ResultsSummary of Results



Global Warming

Situation

PEI SEI

#17.62 7.62

#27.62 7.62

#30.239 0.0075

#40.239 0.0075

Global Warming Acidification

Situation

PEI SEI PEI SEI

#1

0.0042 3.96E-05 8.18E-08 7.47E-08

#2

0.35 0.27 6.82E-06 0

#3

0.0031 2.23E-05 5.25E-11 5.25E-11

#4

0.44 0.44 7.89E-09 4.11E-09

Transport Impacts

Extraction Impacts

Sustainability Assessment of H 2 Pathways

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