Solid State Ammonia Synthesis
NHThree LLC
Jason C. Ganley John H. Holbrook Doug E. McKinley
Ammonia - A Sustainable, Emission-Free Fuel October 15, 2007
Inside the Black Box: Steam Reforming + Haber-Bosch
3 CH4 + 6 H2O + 4 N2 3 CO2 + 8 NH3
O2 Nat Gas H2O Electricity N2 AIR ASU CO2
SMR
H2 NH3
H-B
Energy consumption ~33 MBtu (9500 kWh) per ton NH3
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Inside the Black Box: Steam Reforming + Haber-Bosch
3 CH4 + 6 H2O + 4 N2 3 CO2 + 8 NH3
O2 Nat Gas H2O Electricity N2 AIR ASU CO2
SMR
H2 NH3
H-B
Energy consumption ~33 MBtu (9500 kWh) per ton NH3
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Inside the Black Box: HB Plus Electrolysis
3 H2O 3 H2 + 3/2 O2 3 H2 + N2 2 NH3
O2 Electricity H2O H2 NH3
Electrolyzer
H-B N2 AIR ASU
Energy consumption ~12,000 kWh per ton NH3
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Inside the Black Box: Solid State Ammonia Synthesis
6 H2O + 2 N2 3 O2 + 4 NH3
O2 O2
Electricity H2O SSAS N2 AIR ASU NH3
Energy consumption 7000 - 8000 kWh per ton NH3
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SSAS in a Nutshell
Solid-state electrochemical process Water (steam) decomposed at anode Hydrogen atoms adsorb, stripped of electrons Hydrogen conducts (as proton) through proton-conducting ceramic electrolyte Protons emerge at cathode, regain electrons, and react with adsorbed, dissociated nitrogen atoms to form NH3 Patent application February 2007
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SSAS Features and Advantages
Does not require expensive, energyintensive electrolyzers High pressures (e.g. for Haber-Bosch synthesis) are not required Co-production of oxygen gas Synthesis reactors in the form of multiple tube bundles in geometric arrangement Straightforward NH3 capacity expansion by adding synthesis tube bundle modules
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SSAS Primary Components
H2O, liquid 1 bar Pump H2O, liquid 15 bar Heat Recovery Boiler Superheated Steam
Recycled H2O Flash Tank O2 to Storage/Sales
O2/H2O Mix Furnace SSAS Tube Module 550C
Heat Recovery N2, 15 bar Compressor N2 from ASU 1 bar NH3/N2 Mix Recycled N2 Flash Tank Liquid NH3 to Storage/Sales
Current Work: Protonic Ceramic
Preferred compositions identified
Good thermal stability, capable of thermal cycling High ionic conductivity Stability in humid or dry atmospheres Stable in reducing, neutral, or oxidizing conditions
Refinement of processing techniques
Ceramic synthesis routes -Solid state chemical reaction vs. autoingintion -Sintering and densification, catalyst support Ceramic forming -Bulk powder pressing -Tape casting, spin coating
Current Work: Catalysis
Maximize: ionic and electronic conductivity, surface area, catalytic action Oxidizing atmosphere present
Co-generation of oxygen gas Intermediate temperatures: less severe conditions
Reducing atmosphere present
Ammonia product is a strong reducing agent -Protects stability of many catalyst types -Converts metal oxides to high surface area metallic catalysts Intermediate temperatures: helps prevent sintering of catalyst particles
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Mass Production: Tubular Geometry
Tubular SOFC
SSAS reactor module will have similar tube and manifold arrangement
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PCC Tubes in R&D Labs
LANL
PCC tube fabricated for LANL by TYK Corporation (Japan) by extrusion, used for tritium recovery.
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Economic Comparison
Production Method Measure Natural Gas Energy required per ton of NH3 Capital cost per ton/day NH3 capacity Fuel cost to produce 1 ton of NH3 at large scale [1] Cost of 1 ton NH3 at moderate to large scale [2] Tons of CO2 emitted per ton of NH3 produced 33 MBtu = 9700 kWh Electrolyzer + H-B ~12,000 kWh (H2 production only) ~$750,000 (Cost dominated by electrolyzer) $420 (3.5 /kWh) $240 (2 /kWh) SSAS 7000-8000 kWh
~$500,000
<$200,000
Depends on location and NG cost
$245 (3.5 /kWh) $140 (2 /kWh)
Depends on location and NG cost
>$600 (3.5 /kWh) >$400 (2 /kWh)
~$315 (3.5 /kWh) ~$210 (2 /kWh)
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[1] For NHThrees planned demonstration project, Douglas Co. WA will supply standard 2 /kWh power from hydroelectric [2] Using a capital recovery factor of 12% and purchased nitrogen at $30 per ton of N2 13
Green Ammonia a Renewable Cycle
Renewable Energy Input (Electricity or Heat & Electricity)
NH3 Synthesis 3 H2 + N2 N2 & H2O Return to Environment 2 NH3
NH3 Storage
(Combustion or Fuel Cell)
4 NH3 + 3 O2
2 N2 + 6 H2O
Power Generation
Energy Recovery
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The Sweet Spot for SSAS
Inexpensive electric power
Stranded wind or geothermal Hydroelectric Nuclear Off-peak fossil energy in Midwest OTEC Reliable water supply, need not be pure 420 gallons H2O/ton NH3
Inexpensive heat source to improve efficiency
Concentrated solar thermal Nuclear
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