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Delivering clean hydrogen fuel from ammonia using metal membranes
ENERGY
Michael Dolan | Principal Research Scientist1 November 2017
Power generation: Direct conversion (High-temperature fuel cell)
H2 production: Decomposition and H2purification
Power generation: Combustion (internal combustion engine or turbine)
Renewable Ammonia Export
Solar PV Wind
Electrolysis
Air separation
NH3 synthesis
Transport to AsiaH2
N2
Hybrid H2 and power systems
Ammonia decomposition
ISO14687-3 (stationary):50% non-H2 species, 100 ppbv NH3
ISO14687-2 (mobile):300 ppmv non-H2 species, 100 ppbv NH3
100 ppbv NH3 = 99.99998% conversion
* Use a scrubber or membrane or bothTemperature (°C)
300 400 500 600 700 800
% c
onve
rsio
n
70
75
80
85
90
95
100
1 bar5 bar10 bar
V or V-alloy core
Feed-side catalyst
Permeate-side catalyst
High pressure
Low pressure
Our design philosophy:• Minimise materials costs
(minimise use of palladium)• Use scalable manufacturing
techniques (metal tube extrusion and electroplating)
• Prioritise purity over flux (to meet ISO14687 for PEM fuel cells)
Vanadium-based membranes for H2 purification
CSIRO’s membrane technology10 mm diameter0.2 mm thick500mm longSelf-supporting (no porous support structure which minimises cost)
Catalytic coating
Multi-tube module
Cracking system configuration
cata
lyst
mem
bran
e
NH3
Cracked NH3
H2
N2 + NH3 + H2
450-500°C 300-350°C
500 mm membrane1.5mm diam. granular catalyst: 0.5 wt% Ru layer on Al2O3 support
NH3 flow (slpm)
2 3 4 5 6 7
NH
3 con
vers
ion
(%)
0
20
40
60
80
100
Single-tube prototypeNH3 conversion (150g catalyst loading, 450°C, 5 bar(a) with downstream membrane)
Near-equilibrium NH3 conversion at 450˚C
NH3 decomposition rate is inhibited by H2 (PH2
-0.42)
Equilibrium 97.9%
NH3 feed rate (slpm)
2 3 4 5 6 7
H2 f
lux
(slp
m)
0
2
4
6
8
10
Tota
l H2 r
ecov
ery
(%)
50
60
70
80
90
100
FluxRecovery
Single-tube prototypeH2 flux and recovery (150g catalyst loading, 450°C, 5 bar(a) with downstream membrane)
H2 production rate is inversely proportional to H2 recovery
Can vary yield/flux for specific applications:• Stand-alone with waste heat
Stand-alone with self-heating• Hybrid cracker/combustion
Hours
0 20 40 60 80
H2 f
lux
(SLP
M)
0
2
4
6
8
10
H2 r
ecov
ered
(%)
0
20
40
60
80
100
FluxRecovery
Single-tube prototypeH2 flux and recovery (5.0 slpm NH3, 150g catalyst loading at 450°C with membrane)
• Stable performance over 80 hours at 80% total H recovery
• energy content of retentate ≅enthalpy requirement for cracking
Single-tube prototypeMass spectrum of permeate stream with different feed gas compositions
No enrichment of N2 or NH3 in H2permeate during NH3 cracking:ISO14687 met
Atomic Mass Unit
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
Inte
nsity
(Am
p.)
e-29
e-28
e-27
e-26
e-25
e-24
e-23
e-22
e-21
e-20
e-19
e-18
e-17
e-16
e-15
e-14
H2 permeate during NH3 crackingH2 Permeate during 99.999% H2 feed
H2ONH3
O
N
N2
O2
H2
Multi-tube pilot plant• Membrane area 0.3 m2 (19 x 50 cm
tubes ≈ 120 slpm ≈ 15 kg/day at 80% yield)
• H2 to be compressed and dispensed into FCEVs in Australia
Summary• Australia is at the forefront of renewable ammonia export • CSIRO’s technology can deliver FCEV-grade H2 from ammonia• We’re rapidly scaling this technology towards to 15 kg H2 per day
and beyond, with demonstrations planned in Australia and Asia
• Acknowledgement: Science and Industry Endowment Fund
EnergyMichael DolanPrincipal Research Scientistt +61 7 3327 4126e [email protected] www.csiro.au/energy
ENERGY