Environmental Footprint Profiles of Hydrogen as Automotive Energy

Yuki Kudoh, Naomi Kitagawa, Ryoji Muramatsu, Akito Ozawa and Yutaka Genchi

Research Institute of Science for Safety and Sustainability,

National Institute of Advanced Industrial Science and Technology

Presented at LCM2017, Session “MO-101: LCM for transport and mobility”

3-6 September 2017, Luxembourg

Importance of focusing on H2 supply chain

2

Energ

ies

Mate

rials

Energ

ies

Mate

rials

environmental emissions are attributed to H2

if the system boundary is set to the whole supply chain

Energ

ies

Mate

rials

Energ

ies

Mate

rials

Energ

ies

Mate

rials

Energ

ies

Mate

rials

End usetechnologies

Environmental footprint profiles of H2 useshould be evaluated throughout the supply chain

H2 technologies do not have carbon emissions in their use phase

1. Introduction

Fossil fuelsRenewablesLignite+CCS

CCS

H2

H2production

Energycarrier

production

Storage H2

H2 is an energy carrier (not an energy source) Should be produced from

other energy sources

Aim of the study

• Variety of studies for H2 supply chains LCA

– WtW studies by CONCAWE/EUCAR/JRC (EU), ANL GREET model (US), JHFC (Japan Hydrogen and Fuel Cell Demonstration Program) …

• Different assumptions, system boundaries LCA database, etc. The mere use of the combinations of

these results does not make sense

• Conducted a WtW analysis on an equal footingto identify the environmental hotspots in R&Ds of H2 technologies

– Foreground data: Input data to the processes comprising the supply chain (collected from literatures)

– Background data: Japanese LCA database

3

System boundary

4

• Supplying cheap and low carbon H2 to Japan in quantity

Import renewable H2 using energy carriers and drive FCVs

Select natural gas steam reforming H2 as a reference

ReformingNatural gas Storage

HC->H2

H2 station

H2

Renewableenergy

H2 production Energycarrier

production

Storage

FCV

H2 station

RefineryCrude oil Storage Refuellingstation

GV

HV

• Select gasoline vehicle (GV) and gasoline hybrid vehicle (HV) as the conventional counterparts

2. Assumptions and Methodology

Major WtT assumptions

• H2 producing countries:

– Australia: 10,000 km one way distance to Japan;

– electrolysis by wind turbine and solar PV

– Norway: 20,000 km one way distance to Japan;

– electrolysis by wind turbine

– Renewable power plants are constructed dedicated for H2 production

Whole life cycle considered (materials production, construction,

transport and maintenance)

• H2 carriers assumed:

Liquid hydrogen (LH) and Methylcyclohexane (MCH)

• Emissions due to energy and material inputs to the whole supply chain are calculated

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C7H8 (Toluene) + 3H2 ⇄ C7H14 (MCH)

Imported renewable hydrogen supply chain using LH

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H2 production

LH production (Liquefaction)

LH storage (Loading)

LH transport (Tanker)

LH storage (Discharging)

LH distribution(Tank truck)

Water0.80

kg/Nm3

Ren. ele.(Fixed)

3.7~5.2~7.3kWh/Nm3

Electricity0.55~0.91~1.3

kWh/Nm3

Electricity0.055kWh/Nm3

Grid ele.0.055kWh/Nm3

Overseas Japan

(≈ LNG tanker)

Unloaded tanker

Boil-off0.2~0.3~0.4%/day

LH storage (H2 station)

H2 compression and storage(H2 station)

CH charge

(23kL tank truck)Grid ele.0.055kWh/Nm3

Grid ele.0.28kWh/Nm3

Grid ele.0.092kWh/Nm3

FCV

3. Results

WtT GHG emissions from imported renewable hydrogen using LH

• Large electricity input required for H2 liquefaction

Large emissions from Australian H2 (coal being the main electricity source)

• Renewable electricity case: Substitute grid electricity inputs to overseas process for the same renewable electricity as H2 production

Significant reduction expected for H2 from Australia

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Base case

Renewable electricity case

Reduction from base case69% 68% 56% 1% 1%

Imported renewable hydrogen supply chain using MCH

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H2 prod.

MCH prod.Yield 99.8%H2 util. rate

97.85%

MCH storage (Loading)

MCH transport (Tanker)

MCH storage

(Discharge)

MCH distrib.

(Tank truck)

Electricity7.5~41~93kWh/t-MCH

Electricity0.83~0.92~1.0

kWh/t-MCH

Grid ele.0.83~0.92~1.0

kWh/t-MCH

Overseas Japan

(≈ Oil tanker> 80kDWT)

DeH2Yield 94.9%H2 recov. Rate 90%

Grid ele.0.24~0.31~0.35

kWh/Nm3

Heat (City gas)9.2 MJ/Nm3

C7H8

storage (Loading)

C7H8

transport (Tanker)

C7H8

storage (Discharge)

Virgin C7H83% of the

initial amount

H2 comp. and stor.(H2 station)

CH charge

FCV

C7H8

distrib.(Tank truck)

(20kL tank truck)

(20kL tank truck)

WtT GHG emissions from imported renewable hydrogen using MCH

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• Large amount of heat required for dehydrogenation C7H14 (MCH) C7H8 (Toluene) +3H2

∆H=+205kJ/mol

• City gas combustion assumed for base case (accounting for 50~58% of the total emissions)

• Waste heat case: Dehydrogenation heat by waste heat utilisation from neaby plants

39~46% reduction from H2 supply chain using MCH

Reduction from base case46% 46% 39% 44% 44%

Base case

Waste heat case

H2 WtT GHG emissions at a glance

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Bar charts: AverageError bars: Potential range due to difference of inventories

TtW assumption

Fuel consumption data by Japanese type-approval test cycle assumed in Toyota Motor Corporation’s

“The MIRAI Life Cycle Assessment Report for Communication”

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FCV152.17 [km/kg-H2]

(0.66 [kg-H2/100km])0.79

[MJ-LHV/km]

HV23.2 [km/L]

(4.3 [L/100km])1.4

[MJ-LHV/km]

GV11.4 [km/L]

(8.8 [L/100km])2.9

[MJ-LHV/km]

JC08 mode test cycleCycle time: 1204 secCycle distance: 8.17 kmAverage velocity: 24.4 km/h

WtW GHG emissions

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• FCVs prevails over GV

• If FCVs are to compete with HV, the followings become necessary

Selection of low carbon pathways

Progress in TtW energy performance of FCVs

#H2 from offshore WT not shown in this chart(Almost the same with onshore WT)

Summary and the way forward

• In terms of WtW GHG emissions, FCVs have the advantage towards GV but whether FCV can prevail over HV depends upon the choice of low carbon hydrogen supply chain and TtW performance

• Process designing as well as technology improvement is indispensable for the renewable H2 supply chain from overseas to contribute to GHG emissions

– H2 liquefaction for LH supply chain

– Dehydrogenation for MCH supply chain

The way forward

• Calculation of other environmental emissions

• Calculations for byproduct H2 and H2 from lignite with the combination of CCS technology, etc.

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Right H2 source, right H2 energy carrier, right H2 technologyin the right place

4. Summary

WtT NOx and SOx emissions

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NOx emissions

SOx emissions

Thank you very much for your kind attention!

Yuki Kudoh (kudoh.yuki@aist.go.jp)

AcknowledgementThis study was supported by “Advancement of Hydrogen Technologies and Utilization Project” funded by the New Energy and Industrial Technology

Development Organization (NEDO)

GHG intensity of renewable power• Renewable power plant is newly constructed for renewable

hydrogen production

The whole life cycle of the power plant is considered (materials production, construction, transport and maintenance)

• Renewable power plant is constructed overseas but IDEA only covers Japanese industries

GHG intensities of overseas processes approximated using IDEA are used for calculation

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Type[g-CO2eq./kWh]

Load factor Australia Norway

Wind turbine, 40MW

Offshore 35% 15.5 11.0

Onshore, bottom-mounted 45% 17.3 10.1

Solar PV, 10MW 18% 64.6

Grid electricity 995 13.6

Other target supply chains

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H2 production

H2 compression

GH transport

(Tank truck)

H2 comp. and stor.

(H2 station)

GH charge

Grid ele.0.12~0.27~0.44

kWh/Nm3

(2330 Nm3GH tank truck)

FCV

Gasoline from

refinery

Gasoline transport

(Tank truck)

GV / HV

(20kL tank truck)

Natural gas steam reforming hydrogen

Gasoline

(Data from IDEA)

Natural gas14.8~15.1~15.3

MJ/Nm3

Grid ele.0.10~0.44~0.78

kWh/Nm3

Process water0.0020

m3/Nm3