In ammonia-based solar thermochemical energy storage systems, the stored energy is released when the hydrogen (H2) and nitrogen (N2) react exothermically to synthesize ammonia (NH3), providing thermal energy to a power block for electricity generation. However, ammonia synthesis has not yet been shown to reach temperatures consistent with the highest performance modern power blocks. Two similar ammonia synthesis reactors with different lengths have been used to study the ammonia synthesis reaction at high temperature and pressure and to begin the process of model improvement and validation. With the longer reactor, supercritical steam with flow rate up to 0.09 g/s has been heated from less than 350°C to ∼650°C. This result shows the technical feasibility of using ammonia-based thermochemical energy storage in a CSP plant with a supercritical steam Rankine cycle power block.

1.
M.
Felderhoff
and
B.
Bogdanovic
, “
High Temperature Metal Hydrides as Heat Storage Materials for Solar and Related Applications
,”
International Journal of Molecular Sciences
, vol.
10
, pp.
325
344
(
2009
).
2.
K.
Kyaw
,
H.
Matsuda
, and
M.
Hasatani
, “
Applicability of carbonation decarbonation reactions to high-temperature thermal energy storage and temperature upgrading
,”
Journal of Chemical Engineering of Japan
, vol.
29
, pp.
119
125
(
1996
).
3.
A.
Worner
and
R.
Tamme
, “
CO2 reforming of methane in a solar driven volumetric receiver-reactor
,”
Catalysis Today
, vol.
46
, pp.
165
174
(
1998
).
4.
P.
Pardo
,
A.
Deydier
,
Z.
Anxionnaz-Minyielle
,
S.
Rouge
,
M.
Cabassud
, and
P.
Cognet
, “
A review on high temperature thermochemical heat energy storage
,”
Renewable & Sustainable Energy Reviews
, vol.
32
, pp.
591
610
(
2014
).
5.
A.
Lavine
,
K.
Lovegrove
,
J.
Jordan
,
G. B.
Anleu
,
C.
Chen
,
H.
Aryafar
, and
A.
Sepulveda
, “
Thermochemical Energy Storage with Ammonia: Aiming for the SunShot Cost Target
,” in
SolarPACES 2015 Conference
,
Cape Town, South Africa
,
Oct. 13-16, 2015
.
6.
J. T.
Richardson
,
S. A.
Paripatyadar
, and
J. C.
Shen
, “
Dynamics of a Sodium Heat Pipe Reforming Reactor
,”
Aiche Journal
, vol.
34
, pp.
743
752
(
1988
).
7.
K. M.
Lovegrove
, “
High pressure ammonia dissociation experiments for solar energy transport and storage
,”
International Journal of Energy Research
, vol.
20
, pp.
965
978
(
1996
).
8.
H.
Kreetz
and
K.
Lovegrove
, “
Theoretical analysis and experimental results of a 1 kW(chem) ammonia synthesis reactor for a solar thermochemical energy storage system
,”
Solar Energy
, vol.
67
, pp.
287
296
(
1999
).
9.
J. R.
Jennings
,
Catalytic Ammonia Synthesis Fundamentals and Practice
.
New York
:
Plenum Press
,
1991
.
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