Nitrate based salts have application as a heat transfer fluid and thermal energy storage media in solar field installations and are normally used from 200 °C up to maximum temperatures of ∼550 °C. Molten K2CO3-Na2CO3-Li2CO3 could potentially be used as heat transfer fluid and thermal energy storage media to replace nitrate salts due to its wider temperature operating window (400–900 °C), which improves the heat transfer efficiency. There will be improved operability and the process will be more economical viable if the lower temperature at which carbonate salts can operate could be decreased. This paper explores the melting point and high temperature stability of K2CO3-Na2CO3-Li2CO3 based salt mixtures, the effect of atmosphere and the effect of additives to the melt using experimental investigation and thermodynamic modeling.

References

References
1.
Gil
,
A.
,
Medrano
,
M.
,
Martorell
,
I.
,
Lazaro
,
A.
,
Dolado
,
P.
,
Zalba
,
B.
, and
Cabeza
,
L. F.
,
2010
, “
State of the Art on High Temperature Thermal Energy Storage for Power Generation. Part 1—Concepts, Materials and Modellization
,”
Renewable Sustainable Energy Rev.
,
14
, pp.
31
55
.10.1016/j.rser.2009.07.035
2.
Medrano
,
M.
,
Gil
,
A.
,
Martorell
,
I.
,
Potau
,
X.
, and
Cabeza
,
L. F.
,
2010
, “
State of the Art on High Temperature Thermal Energy Storage for Power Generation. Part 2—Case Studies
,”
Renewable Sustainable Energy Rev.
,
14
, pp.
56
72
.10.1016/j.rser.2009.07.036
3.
Kenisarin
,
M
.,
2010
, “
High-Temperature Phase Change Materials for Thermal Energy Storage
,”
Renewable Sustainable Energy Rev.
,
14
, pp.
955
970
.10.1016/j.rser.2009.11.011
4.
Ren
,
N.
,
Wu
,
Y.-t.
,
Wang
,
T.
, and
Ma
,
C.-f
.,
2011
, “
Experimental Study on Optimized Composition of Mixed Carbonate for Phase Change Thermal Storage in Solar Thermal Power Plant
,”
J. Therm. Anal. Calorim.
,
104
, pp.
1201
1208
.10.1007/s10973-011-1364-5
5.
Bradshaw
,
R. W.
, and
Tyner
,
C. E.
,
1988
, “
Chemical and Engineering Factors Affecting Solar Central Receiver Applications of Ternary Molten Salts
,”
1988 Summer National Meeting, American Institute of Chemical Engineering (AIChE)
,
Denver
, Colorado, USA.
6.
Bradshaw
,
R. W.
, and
Meeker
,
D. E.
,
1990
, “
High-Temperature Stability of Ternary Nitrate Molten Salts for Solar Thermal Energy Systems
,”
Sol. Energy Mater.
,
21
, pp.
51
60
.10.1016/0165-1633(90)90042-Y
7.
Bradshaw
,
R. W.
, and
Siegel
,
N. P.
,
2008
, “
Molten Nitrate Salt Development for Thermal Energy Storage in Parabolic Trough Solar Power Systems
,” Energy Sustainability ES2008, Jacksonville, Florida, 4 p.
8.
Olivares
,
R
.,
2012
, “
The Thermal Stability of Molten Nitrite/Nitrates Salt for Solar Thermal Energy Storage in Different Atmospheres
,”
Sol. Energy
,
86
, pp.
2576
2583
.10.1016/j.solener.2012.05.025
9.
Wu
,
Y.
,
Ren
,
N.
,
Wang
,
T.
, and
Ma
,
C.
,
2011
, “
Experimental Study on Optimized Composition of Mixed Carbonate Salt for Sensible Heat Storage in Solar Thermal Power Plant
,”
Sol. Energy
,
85
, pp.
1957
1966
.10.1016/j.solener.2011.05.004
10.
Olivares
,
R.
,
Chen
,
C.
, and
Wright
,
S.
,
2012
, “
The Thermal Stability of Molten Lithium–Sodium–Potassium Carbonate and the Influence of Additives on the Melting Point
,”
ASME J. Sol. Energy Eng.
,
134
, p.
041002
.10.1115/1.4006895
11.
Zhang
,
L.
,
Jahanshahi
,
S.
,
Sun
,
S.
,
Chen
,
C.
,
Bourke
,
B.
,
Wright
,
S.
, and
Somerville
,
M.
,
2002
, “
CSIRO's Multi-Phase Reaction Model and Its Applications in Industry
,”
JOM
,
54
, pp.
51
56
.10.1007/BF02709751
12.
Wright
,
S.
,
Tran
,
T.
,
Chen
,
C.
,
Olivares
,
R. I.
, and
Sun
,
S.
,
2012
, “
Thermal Stability of Potassium and Sodium Nitrate Molten Salt Mixtures Above 500 °C
,”
Ninth International Conference on Molten Slags
,
Fluxes and Salts (Molten12)
, Beijing.
13.
Pelton
,
A. D.
,
Bale
,
C. W.
, and
Lin
,
P. L.
,
1983
, “
Calculation of Phase Diagrams and Thermodynamic Properties of 14 Additive and Reciprocal Ternary Systems Containing Li2CO3, Na2CO3, K2CO3, Li2SO4, Na2SO4, K2SO4, LiOH, NaOH and KOH
,”
Can. J. Chem.
,
62
, pp.
457
474
.10.1139/v84-078
14.
Kapoor
,
M. L.
, and
Frohberg
,
M. G.
,
1971
, “
Theoretical Treatment of Activities in Silicate Melts
,”
Chemical Metallurgy of Iron and Steel
,
The Iron and Steel Institute
,
London
, pp.
17
22
.
15.
Gaye
,
H.
, and
Welfringer
,
J.
,
1984
, “
Modelling of the Thermodynamic Properties of Complex Metallurgical Slags
,”
The Second International Symposium on Metallurgical Slags and Fluxes
,
TMMS
, Warrendale, pp.
357
366
.
16.
Yaokawa
,
J.
,
Oikawa
,
K.
, and
Anzai
,
K.
,
2007
, “
Thermodynamic Assessment of the KCl-K2CO3-NaCl-Na2CO3 System
,”
CALPHAD
,
31
, pp.
155
163
.10.1016/j.calphad.2007.01.004
17.
Sundman
,
B.
,
Jansson
,
B.
, and
Andersson
,
J. O.
,
1985
, “
The Thermo-Calc Databank System
,”
CALPHAD
,
9
, pp.
153
190
.10.1016/0364-5916(85)90021-5
18.
SGTE Substance Database, version 3, 2008,
Scientific Group Thermodata Europe (SGTE)
, Grenoble, France.
19.
Dessureault
,
Y.
,
Sangster
,
J.
, and
Pelton
,
A. D.
,
1990
, “Coupled Phase Diagram/Thermodynamic Analysis of the Nine Common-Ion Binary Systems Involving the Carbonates and Sulfates of Lithium, Sodium, and Potassium,”
J. Electrochem. Soc
,
137
(
9
), pp.
2941
2950
.10.1149/1.2087103
20.
Rolin
,
M.
, and
Recapet
,
J.
,
1964
, “
Contribution Letude Des Proprietes Thermodynamiques Des Carbonates Alcalins. 1. Le Diagramme Ternaire CO3NA2-CO3K2-CO3LI2
,”
Bull. Soc. Chim. Min. France
,
9
, pp.
2104
2112
.
21.
Reisman
,
A
.,
1961
, “
Heterogeneous Equilibria in the System K2CO3-Na2CO3
,”
J. Am. Chem. Soc.
,
81
, pp.
807
813
.10.1021/ja01513a014
22.
Janz
,
G. J.
, and
Lorenz
,
M. R.
, “
Solid-Liquid Phase Equilibria for Mixtures of Lithium, Sodium, and Potassium Carbonates
,”
J. Chem. Eng. Data
,
6
, pp.
321
323
.10.1021/je00103a001
23.
Volkova
,
L. F.
,
1958
, “
Phase Diagram of K2CO3-Na2CO3-Li2CO3
,”
Izvest. Sibirsk. Oldel. Akad. Nauk. S.S.S.R
,
7
, pp.
33
35
.
24.
Zakhvalinskii
M. N.
, and
Belykh
,
P. D.
,
1970
, “
Ternary Systems of Nitrate, Sodium Nitrite and Cesium Carbonates
,”
Zh. Neorg. Khim.
,
15
(
3
), pp.
856
865
.
You do not currently have access to this content.