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 michael.dolan@csiro.auw www.csiro.au/energy

ENERGY