Post on 26-Mar-2021
Advanced Alkaline Electrolysis
Richard Bourgeois, P.E.GE Global Research Center
Niskayuna, NY
This presentation does not contain any proprietary or confidential information
Project #PDP16
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Acknowledgements
Acknowledgment: This material is based upon work supported by the Department of Energy under Award Number DE-FC-0706-ID14789
Disclaimer: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
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OverviewTimelineStart: 30 September 2006End: 30 December 200820% complete
BudgetTotal Funding: $1,239,479DOE Share: $ 973,783Contractor: $ 265,696
funded by both the DOE Nuclear Hydrogen Initiative and DOE HFCIT programs
Received in 2006: $542,5462007 Funding (to date) : $ 92,478
Barriers AddressedG. Capital Cost of Electrolysis SystemsI. Grid Electricity Emissions
PartnersGE Global ResearchGE Energy NuclearEntergy NuclearNational Renewable Energy Laboratory
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ObjectivesStudy the feasibility of using alkaline electrolysis technology with current-generation nuclear power for large scale hydrogen production:
Economic Feasibility : Market study of existing industrial H2 usersTechnical Feasibility : Developing pressurized low cost electrolyzerCodes and Safety: Environmental and regulatory impact assessment
Units DOE 2012 TargetCell Efficiency % 69% (1.8V)System Cost $/kg H2 $0.70 ($400/kW)Electricity Cost $/kg H2 $2.00O&M Cost $/kg H2 $0.60
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ApproachTask 1: Define market and requirements
• Industrial users survey• Technical and pricing requirements • Nuclear regulatory and environmental impact issues
Task 2: Design and build pressurized electrolyzer stack• Develop plastic stack technology • Low cost electrode methods
Task 3: Plastics oxidation lifing• Creep resistance• Oxidation
Task 4: Demonstrate electrolyzer performance and capital costsTask 5: System operation testing
• O&M cost assessmentTask 6: Create industrial-scale system conceptual designTask 7: Create 1-kg-per-second demonstration system
conceptual design
80% complete
10% complete
5% complete
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• $ 1 BSize:Growth:
• $ 15.5 B• 10 % CAGR
• $ 17 B• 1.5 % CAGR
• >$0.5 B• 5% CAGR
• Flat Demand
• Key Use: Fertilizer
• Captive H2 Production
Facilities
• 1.5% CAGR • 5% CAGR
• >$0.5 B
Captive (90%) Merchant (10%)
• Hydrogen Used to Remove Sulfur
• EU & US Regulations Mandating Lower Sulfur Content in Gas, Diesel
• Captive H2 Production Facilities
• Hydrogen Used for High Heat Processes i.e. Plasma Spray
• Batch type process
• Manufacture of Specialty Chemicals for a Variety of Industries
• Methanol
• Hydrogenating Oils for a range of applications:
Source: HSBC, 2004
RefineriesAmmonia
ProductionMetals Fab. &
Treatment Chemical Mfr’gFood &
Personal Care
Global Hydrogen Market
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Industrial market infrastructure can lead fueling infrastructure
Distributed Industrial (250kWe – 1MWe)
Sources: Chemical Economics Handbook (SRI, 2004) US Census (2002)1
10
100
1000
10000
100000
1000000
0 50 100 150 200 250 300 350
Number of Sites (US)
Site
Cap
acity
, kg
H2/
day
Ammonia Production
Petroleum RefiningFloat
Glass
FoodHydrogenation
Electronics
Metals
BWR Water Chemistry
GeneratorCooling
Large-Scale Commercial (200 MWe electrolysis)
Industrial Hydrogen Market Segments
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$446$5,000Production$1,426$16,000Prototype
Per Nm3/h
Per kg/h
Projected CapEx, 5 kg/hr stack :
$446Production$1,426Prototype
Per Nm3/hr
Per kg/hr
GE Technology Capital Costs
At 50 kWh/kg H2 , production stack cost is $100/kW
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$0.00
$0.50
$1.00
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
$4.50
$5.00
0 1 2 3 4
Electricity Cost, Cents / kWh5 6
Hyd
roge
n C
ost p
er k
gFeedstockO&MBOP CapitalStack Capital
$0.00
$0.50
$1.00
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
$4.50
$5.00
0 1 2 3 4 5 6
FeedstockO&MBOP CapitalStack Capital
Source: GE Global Research, NREL H2A Model
Projected H2 Cost with GE Electrolyzer:1000 kg/day, 30 bar pressure
Low-cost electricity still key to meeting targets.
*electricity, water
*
DOE Target $3/kg
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existing fleet - US 1995-2005
0.01.02.03.04.05.06.07.08.09.0
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
Nuclear 1.72Coal 2.21
Gas 7.51Oil 8.09
Cen
ts /k
Wh
(200
5)
Source: NEI, 2006
Electricity Production Costs
Lowest cost electricity available from existing nuclearElectricity market demands set actual price
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GE Alkaline Electrolysis Technology
1 10 100
base metals
GE electro –deposited
GE spray
precious metals
Cell
Ove
rpot
entia
l
Relative Cost per Unit Area
TargetZone
dimensionallystabilized anode (DSA)
1 10 100
base metals
GE electro –deposited
GE spray
precious metals
Cell
Ove
rpot
entia
l
Relative Cost per Unit Area
TargetZone
dimensionallystabilized anode (DSA)
High Surface Electrode
1000x electrode surface: performance at 1/10 traditional electrode cost
• Wire arc electrode system• Electrodeposition
Plastic Stack• One piece stack assembly:
minimal part count • Molded passages, not
machined…
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OHH
OO
e-
H+H+
H+H+
HHHH
e-e-
e-
e-
e-e-
e-
electrolyte
O2 H2H2
OHH
current
2 H2O + ELECTRICITY → O2 + 2 H2
electrode electrode
oxygen hydrogen
waterO
HHO
HH
OO
e-
H+H+
H+H+
HHHH
e-e-
e-
e-
e-e-
e-
electrolyte
O2 H2H2
OHH
OHH
current
2 H2O + ELECTRICITY → O2 + 2 H2
electrode electrode
oxygen hydrogen
water
+ _
Diaphragm Bipolar conductor
Porous Cathode Porous Anode
Multicell Bipolar Stack
catholyte passage
anolyte passageanode
separation diaphragm
cathode other side
Bipolar type half-cells
Cathode (-):2H2O + 2e- 2OH- + H2
Anode (+):2OH- H2O + 2e- + ½ O2
Electrolysis Cell Basics
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Technical Details - Electrode
1 10 100
base metals
GE electro –deposited
GE spray
precious metals
Cell
Ove
rpot
entia
l
Relative Cost per Unit Area
TargetZone
dimensionallystabilized anode (DSA)
2004-2005 Project : Wire-arc sprayed high surface electrodes
Higher Efficency
Lower Cost
Today : Electrodeposition
1 10 100
base metals
GE electro –deposited
GE spray
precious metals
Cell
Ove
rpot
entia
l
Relative Cost per Unit Area
TargetZone
dimensionallystabilized anode (DSA)
2004-2005 Project : Wire-arc sprayed high surface electrodes
Higher Efficency
Lower Cost
Today : Electrodeposition
• Achieved target performance with hot spray technique in 2005.
• Researching electrodeposition for additional cost and performance advantage:
- Thinner bipolar plate- Eliminates warping- Coats 3D electrode surface
GE electrode technology applies a high effective surface area, nickel-based coating to the base metal bipolar plate for high performance at low cost.
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Technical Details – Electrode
CELL
Tank/ Heater
TEST SETUP
MESH ELECTRODE
•Single flow cell•Ambient pressure, 80°C
FLAT PLATE ELECTRODES
•Plastic mesh for flow distribution
• Some oxide left – leaching blocked by plastic mesh
•Cathode mesh applied•Higher coated surface area
FLAT PLATE
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1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
Current, mA/cm2 (Scale removed to protect proprietary information)
Volta
ge, V
/cel
l
Flat, Pre-depositionFlat, Post-depositionMesh, Pre-depositionMesh, Post-deposition
GOAL
Single Cell Performance
Target Current Density
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Electrode Results- First Quarter
• Test results meeting target current density for single cell.
• Additional performance margin needed: large cell and multi-cell stack voltages are typically higher than small single cell.
• Additional mV reductions possible from anode side mesh, method optimization, catalyst additives.
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Electrode Assembly
Plastic weld
Diaphragm cartridge
Diaphragm cartridge
x9
Stack end assembly (machined from molded blanks
Stack end assembly (machined from molded blanks
9 cell stack core
Plastic Stack Construction
10-cell Stack module
(shell, bolts, current straps not shown)
15 bar pressure stack under construction for 2007 test
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Resistance Wire Welding
Test plan to determine process parameters and abate risks:• wire size, current, voltage• weld spacing – in-plane and stacking of plates• weld strength – tensile and crack opening• clamping strategy• wire placement and tacking• weld closure
• Robust method to join plates for test stack
• Wire path determines weld location• Allows “blind” welds along passages• Heat management, inspection method
biggest challenges
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Welding – Experimental Setups
Coupon
Pressure Test
Full Plate with Manifolds
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Plastic Oxidation Lifing
1) Hot KOH and bubbling air at ambient pressure2) Ambient pressure electrolysis 3) high pressure O2 in reactor vessels
Approach: Exposing test samples to oxidant in three experiments:
Risk: Oxidation reduces strength of plastic over time. Electrolysis produces high-pressure oxygen and other oxidative species such as ozone.
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Peristaltic Pump
ReplenishingH2O Jug
4L of 30%KOH @ 80° CDC volts =2
DC current = 6.0
Oxidation Exposure Testing
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• 3-Point bend notched samples tested at 80C• No difference between oxygen-only and electrolyzer-exposed samples after 5 days• Continue sampling at 1 wk intervals
Fracture Toughness Test
If there is no difference in strength between oxygen-only and electrolysis exposed samples, the high pressure oxygen-only experiment is validated.
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2007: Regulatory assessmentComplete industrial market technical requirementsComplete electrolyzer stack technical developmentBuild and begin testing of 10-cell pressurized stack
2008: Conceptual design of reference plants
Future Work
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RelevanceTechnology for a sustainable hydrogen economy, built on current industrial markets with existing technology.ApproachCombine GE’s low cost electrolyzer stack technology, Entergy’s experience in nuclear electricity markets, and NREL’s economic modeling expertise to evaluate the feasibility of nuclear electricity and electrolysis for large-scale hydrogen generation.Technical Accomplishments and ProgressSegmented industrial market and estimated hydrogen costs for developed product. Completed conceptual design for prototype electrolyzer stack.Technology Transfer and CollaborationsCompleting market case and technology development for commercialization. Collaboration between electrolyzer developer and nuclear utility fosters a well-ordered approach to entering the industrial market.
Summary