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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
5
C7H8 (Toluene) + 3H2 ⇄ C7H14 (MCH)
Imported renewable hydrogen supply chain using LH
6
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
7
Base case
Renewable electricity case
Reduction from base case69% 68% 56% 1% 1%
Imported renewable hydrogen supply chain using MCH
8
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
9
• 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
10
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”
11
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
12
• 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.
13
Right H2 source, right H2 energy carrier, right H2 technologyin the right place
4. Summary
WtT NOx and SOx emissions
14
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
16
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
17
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
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