progress report on performance and reliability
TRANSCRIPT
Progress Report on Performance and Reliability Advancements in a Durable Low Temperature Tubular SOFC
14th June 2018Praveen Cheekatamarla
Agenda About Atrex Energy, Inc.
Applications of remote power generators
Technical progress Cell technology improvements 5kWEL stack Manufacturing automation
Further work
Acknowledgements
About Atrex Energy “Powder to Power”
Commercially developed tubular Solid Oxide Fuel Cell (SOFC) technology and systems with ~ 600 stacks shipped – NG, Biogas & Propane, accumulating >6 Million hours of run time Fielded units include configurations up to 1.5kW but
demonstrated up to 10kW prototypes Customers include oil and gas, telecommunications, rail,
environmental monitoring, mining, construction, maritime and US Coast Guard
Units running in remote environments for >35,000hrs FC1 certification from the Canadian Standards Association
Military Technology Product Development – Fuel Flexible Solutions using JP8, DF2, F24, S8, GTL – 2nd generation technology with >40% net DC efficiency
Hybrid Energy Storage Module – Intelligent power management with ability to connect 6 different power sources for optimal fuel efficiency
Atrex Energy continues to transition its commercially available SOFC technologies for advanced power applications with fuel flexible solutions
Remote NG and Propane Applications
LPG, Alaska
NG, TX LPG, Wyoming
NG, PALPG, Alaska
3+ yr operation on well head natural gas (Texas) C
urr
en
t/A
or
Vo
lta
ge
/V
Technical Progress: Performance and Durability
Enhancements
SOFC Improvements
Sub-stoichiometric O/C (POX) for fuel efficiency and cell performance improvement
Integral/internal reforming catalyst – high carbon tolerance
Tailored catalyst to enhance oxidation reactions and suppress fuel decomposition
Fuel LHV-to-electricity efficiency of >55%
Intermediate operating temperature for cost reduction and stack longevity
Enabled by enhanced electrode performance
Cathode infiltration for improved ORR
Anode infiltration for improved kinetics and conductivity
Internal solid fuel element for durability enhancement
Resilient against high fuel utilization operation
Low Temperature, O/C< Substoich. – Cell Performance Improvement
O/C = 1.2 O/C = 0.6
Major improvement by combining electrode infiltration and low O/C fuel processing Electrode infiltration
Cell performance improvement at lower temperature Lower impact of thermal gradients across the stack
Lower O/C fuel processing Further improvement in cell performance at all temperatures with bigger
boost at lower temperatures
9% in
crea
se
Sub-stoich. O/C Operation at Low Temperature
48 cell stack Stack temperature: 730-760 deg C Partial Oxidation of Natural gas at
O/C < stoichiometry (0.5-0.6) No degradation over the course of
the test - >5000 hours
20 cell stack Stack temperature: 680 deg C Partial Oxidation of Natural gas at
O/C < stoichiometry (0.5-0.6) 1800+ hours of operation without
carbon fouling or degradation
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10/17/2017 12/6/2017 1/25/2018 3/16/2018 5/5/2018 6/24/2018
O/C
Mol
ar R
atio
Stac
k Vo
ltage
and
Cur
rent
Stack Voltage
Stack Current
O/C Ratio
Integrated Solid Fuel Element
Anode protection: Redox chemistry supplements the fuel requirement under high Ufconditions
Peak shaving: The response time of the solid fuel has been demonstrated to be less than 1 sec. The solid fuel element can actively respond during sudden load changes
Flow fixed / flow dropped
Load increased / load fixed
Load
injector
Fe (Redox)
Combined Impact of SOFC Improvements (Stack) – High Uf, Low O/C
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Aver
age
Cell
Volta
ge
Stk
V/Cu
rren
t/T,
Uf (
%)
Time, Minutes
Fuel Utilization
Average Cell Volt
Stack Amps
Stack Voltage
Average Stk Temp (C)/10
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2875 2880 2885 2890 2895 2900
Aver
age
Cell
Volta
ge, O
/C M
olar
Rat
io
Stk
V/Cu
rren
t/T,
Uf (
%)
Time, Minutes
Fuel Utilization
Average Cell Volt
Stack Amps
Stack Voltage
Average Stk Temp (C)/10
O/C
Stack: 20 cells O/C: 1.2 Uf: 45-100% T: 700-750 C Avg Cell V: 0.86 –
0.8V
Stack: 20 cells O/C: 0.8 Uf: 70-100% T: 700-750 C Avg Cell V: 0.84 – 0.81V (30mV drop) Sustainability: >12 minutes @ 100% Uf
Combined Impact of SOFC Improvements (Stack) – Low Temp., High Uf, Low O/C
Stack: 20 cells O/C: 0.7 - 0.8 Uf: 70-120% T: 700-725 C Avg Cell V: 0.80 – 0.77V (30mV drop) Sustainability: >5 minutes @ 120% Uf
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4110 4115 4120 4125 4130 4135 4140
Aver
age
Cell
Volta
ge
Stk
V/Cu
rren
t/T,
Uf (
%)
Time, Minutes
Fuel Utilization
Average Cell Volt
Stack Amps
Stack Voltage
Average Stk Temp (C)/10
Stack: 20 cells O/C: 0.5-0.6 Uf: 90 - 100% T: 630-680 C Avg Cell V: 0.80 – 0.77V (30mV
drop) Sustainability: >5 minutes @
100% Uf0
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4150 4155 4160 4165 4170 4175 4180 4185
Aver
age
Cell
Volta
ge
Stk
V/Cu
rren
t/T,
Uf (
%)
Time, Minutes
Fuel Utilization
Average Cell Volt
Stack Amps
Stack Voltage
Average Stk Temp (C)/10
5KW Natural Gas SOFC Generator
Fuel Inlet
Stacks
Exhaust 2.5kW sub-module tests complete Developed an 85% effective heat
exchanger Balance of plant design complete Design based on the commercial
platform Spatial thermal gradient <50deg C ~ 30” * 50” * 37”
5KW Natural Gas SOFC Generator Baseline tests complete Construction of enhanced stacks underway
500
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Pow
er, W
; Tem
pera
ture
, C
Volts
, V; A
mps
, A
Time, Hours
Power, kW
Stack Current
Stack Voltage
Average Stk Temp
Process Modification – Automation & Cost Reduction
Cell fab. process modification for automation and cost reduction Thinner anode wall
Simplified functional layer deposition
Process Automation Tasks Improved anode powder filling
Cathode and anode infiltration
Fuel processor tube fabrication
Thinner Anode Cell Performance
Thinner anode cell showed moderate improvement in performance
600+ hours of operation at O/C of 0.5, Temperature of 700 deg C, and with infiltrated Cathode showed stable performance
Manufacturing yield is comparable to the current standard process
Cost Reduction via Process Improvements Cell fabrication process modification for cost savings
Printed barrier, cathode and current collection layers 48% cost reduction 4500+ hours of continuous operation under aggressive operating conditions shows
stable performance 825 deg C, thermal cycling, load cycling
Semi-Automatic Anode Infiltration
Features: Automatic solution
dispense with precise quantity control
Manual cell handling
Optional automatic cell handler for higher capacities
fixture
Solution dispensing system
Powder Filling - Process Automation
Features: Completely automated
process for dispensing, packing the high durometer bag
Improved quality control
High throughput processing
Bag
Plug
Automatic Cathode Infiltration
Features: Automatic slurry spray Automatic or manual cell loading Automatic purge for the slurry delivery line
Verified to be compatible with NETL’s process/materials
Improved SOFC performance at lower temperatures
Stability tests in progress, >2000 hours
Automatic Cathode Infiltration
Major Forward Activities
Integration and evaluation of enhancements in a 0.5 kWeSOFC system Evaluate thin wall anode cell with enhanced electrode (infiltration)
for low temperature and high efficiency (low O/C)
5kW System Development Integrate and evaluate low temperature, sub-stoichiometric O/C
operation
Finalize 5KW system packaging
Demonstration
Manufacturing Automation Fuel processing tube fabrication automation
Stack assembly
Acknowledgement DOE Project management: Steven Markovich, Shailesh Vora
Collaborators
University of South Carolina: Prof. Kevin Huang and his team
NETL Team: Dr. Hackett, Dr. Shiwoo Funding Support from SECA through contract number DE-
FE0028063 2.5kW/5kW product dev.
Durable, Efficient SOFC
Increased presence of SOFCs in the US Natural Gas and Telecom markets