High Themal Energy Storage Density Molten Salts for Parabolic

HIGH THEMAL ENERGY STORAGE DENSITY MOLTEN SALTS FOR PARABOLIC

TROUGH SOLAR POWER GENERATION

TAO WANG

RAMANA G. REDDY, COMMITTEE CHAIR NITIN CHOPRA YANG-KI HONG

A THESIS

Submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Metallurgical and Materials Engineering in the Graduate School of The University of Alabama

TUSCALOOSA, ALABAMA

2011

ABSTRACT

New alkali nitrate-nitrite systems were developed by using thermodynamic modeling and the eutectic points were predicted based on the change of Gibbs energy of fusion. Those systems with melting point lower than 130oC were selected for further analysis. The new compounds were synthesized and the melting point and heat capacity were determined using Differential

Scanning Calorimetry (DSC). The experimentally determined melting points agree well with the predicted results of modeling. It was found that the lithium nitrate amount and heating rate have significant effects on the melting point value and the endothermic peaks. Heat capacity data as a function of temperature are fit to polynomial equation and thermodynamic properties like enthalpies, entropies and Gibbs energies of the systems as function of temperature are subsequently induced. The densities for the selected systems were experimentally determined and found in a very close range due to the similar composition. In liquid state, the density values decrease linearly as temperature increases with small slope. Moreover, addition of lithium nitrate generally decreases the density. On the basis of density, heat capacity and the melting point, thermal energy storage was calculated. Among all the new molten salt systems, LiNO3-NaNO3-

KNO3-Mg(NO3)2-MgKN quinary system presents the largest thermal energy storage density as well as the gravimetric density values. Compared to the KNO3-NaNO3 binary solar salt, all the new molten salts present larger thermal energy storage as well as the gravimetric storage density values, which indicate the better thermal energy storage capacity for solar power generation systems.

DEDICATION

This thesis is dedicated to everyone who helped me and guided me through the trials and tribulations of creating this manuscript. In particular, my family and close friends who stood by me throughout the time taken to complete this masterpiece.

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ACKNOWLEDGEMENTS

I am pleased to express my gratitude and appreciation to my advisor, Professor Ramana

G. Reddy, for his patience and guidance during my graduate study and the entire research work. I am greatly benefited from his experience, knowledge and enthusiasm for scientific research.

I would like to express my sincere thanks to Dr. Nitin Chopra and Dr. Yang-Ki Hong for serving on my committee. Their valuable suggestions and comments are very insightful for my research work.

I would like to thank all the research colleagues of Dr. Reddy‟s research group, special thanks to Dr. Divakar Mantha for his valuable suggestions and comments. I would like to extend my gratitude to U.S Department of Energy for the financial support.

Finally, I would like to thank my parents and my fiancée, whose invaluable understanding and loving support helped me through the difficult times.

TABLE OF CONTENTS

ABSTRACT ii

DEDICATION iii

ACKNOWLEDGEMENTS iv

LIST OF TABLES viii

LIST OF FIGURES x

CHAPTER 1. INTRODUCTION 1

CHAPTER 2. LITERATURE REVIEW 11

2.1 Melting point 11

2.2 Density 15

2.3 Heat capacity 18

CHAPTER 3. OBJECTIVES 22

CHAPTER 4. THERMODYNAMIC MODELING OF SALT SYSTEMS 24

4.1 Thermodynamic modeling 24

4.2 Calculations 27

CHAPTER 5. EXPERIMENTAL PROCEDURE 30

5.1 Melting point determination of molten salt mixtures 30

5.1.1 Materials 30

5.1.2 Apparatus and Procedure 30

5.2 Heat Capacity determination of molten salt mixtures 32

5.3 Density determination of molten salt mixtures 33

CHAPTER 6. RESULT AND DISCUSSION 34

6.1 Melting point determination 34

6.1.1 DSC equipment calibration 34

6.1.2 Results 35

6.1.3. Discussion 41

6.2 Heat capacity determination 51

6.2.1 Heat capacity calibration 51

6.2.2 Results 52

6.2.3 Thermodynamic properties 55

6.2.4 Discussion of Gibbs energy change for molten salts 84

6.3 Density determination 86

6.3.1 Density calibration 86

6.3.2 Results and discussions 82

6.4 Thermal energy storage density of molten salts 90

CHAPTER 7. CONCLUSION 94

REFERENCES 96

APPENDIX 104

APPENDIX A 104

APPENDIX B 109

APPENDIX C 114

APPENDIX D 118

APPENDIX E 123

APPENDIX F 128

APPENDIX G 133

APPENDIX H 138

APPENDIX I 143

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LIST OF TABLES

2.1. Melting point of various nitrate salt systems 12

2.2. Melting point of various carbonate salt systems 13

2.3 Melting point of various fluoride/chloride salt systems 14

2.4 Melting point of various hydroixde salt systems 15

2.5 Density coefficients A and B of nitrate salts 16

2.6 Density coefficients A and B of carbonate salts 17

2.7 Density coefficients A and B of chloride/fluoride salts 17

2.8 Density coefficients A and B of molten salt mixture with hydroxide salts 18

2.9 Heat capacity of alkali nitrate salt at 500oC 19

2.10 Heat capacity of alkali carbonate salt at 500oC 19

2.11 Heat capacity of fluoride/chloride salt at 500oC 20

2.12 Heat capacity of hydroxide salt at 500oC 21

4.1 Calculated composition and melting point for multi-component systems 29

6.1 Calibration data of melting points with different samples 35

6.2 DSC results of melting point, transition point and change of enthalpy 41

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6.3 Fusion and solid phase transition temperature for individual salts 42

6.4. Melting points of candidate systems as function of temperatures 51

6.5 Calibration data of heat capacities with different samples 52

6.6 Heat capacity of selected new TES molten salt mixtures 54

6.7 Change of Gibbs energy values at 623.15K for molten salt systems 85

6.8 Calibration of density measurements with different pure nitrate salts 86

6.9 Coefficient of A and B for density determination of salt #1 to salt # 9 87

6.10 Extrapolated value of density and heat capacity at 500oC of salt #1 to salt #9 91

6.11 Energy density of salt #1 to salt #9 compare to solar salt 92

6.12 Gravimetric storage densities for solar salt and new molten salts 93

LIST OF FIGURES

1.1 Theoretical and engineering energy conversion efficiency as function of temperature 6

1.2 Gravimetric storage density for different energy storage systems as function of temperature 8

5.1 Photography of set-up for DSC equipment 31

6.1 Melting point calibration with indium sample 34

6.2 Melting point calibration with KNO3 sample 35

6.3 DSC endothermic peaks of LiNO3-NaNO3-KNO3 salt. 36

6.4 DSC endothermic peaks of NaNO3-NaNO2-KNO3 salt. 37

6.5 DSC endothermic peaks of LiNO3-NaNO3-KNO3-MgK salt. 37

6.6 DSC endothermic peaks of LiNO3-NaNO3-KNO3-NaNO2 salt. 38

6.7 DSC endothermic peaks of LiNO3-NaNO3-NaNO2-KNO3-KNO2 salt. 38

6.8 DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt. 39

6.9 DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt. 39

6.10 DSC endothermic peaks of LiNO3-KNO3-NaNO2-Mg(NO3)2 salt. 40

6.11 DSC endothermic peaks of LiNO3-NaNO3-KNO3-Mg(NO3)2-MgKN Salt. 40

6.12 DSC plot of 69.8wt% KNO3 -30.2wt% NaNO2 binary system 43

6.13 DSC plot of 27.0wt% NaNO3-73.0wt% KNO3 binary system 45

6.14 DSC plot of 45.8wt%LiNO3-54.2wt%KNO3 binary system 45

6.15 DSC plot of 46.0wt% NaNO3-54.0wt% KNO3 binary system 46

6.16(a) DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt for 20oC/min heating rate. 47

6.16(b) DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt for 5oC/min heating rate. 48

6.17(a) DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt for 5oC/min heating rate. 49

6.17(b) DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt for 20oC/min heating rate. 49

6.18 Heat capacity data plot of LiNO3-NaNO3-KNO3 ternary system as function of temperature 53

6.19 Heat capacity of LiNO3-NaNO3-KNO3 in liquid state from 403.15-623.15K 54

6.20 Change of Gibbs energy as function of temperature for molten salt systems 85

6.21 The densities of the salt #1 to salt #5 as function of temperature 87

6.22 The densities of the salt #6 to salt #9 as function of temperature 89

6.23 Densities of the salt #1, salt #2 as function of temperature compared to

the equimolar NaNO3-KNO3 binary system and pure KNO3. 90

6.24 Gravimetric storage density comparison of different energy storage

systems as function of temperature 93

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CHAPTER 1

INTRODUCTION

Renewable energy sources such as wind, solar, water power, geothermal and biomass are playing more and more significant role in our energy supply. Because the cheap cost and infinite amount of energy storage inside the resource, solar energy is emphasized since 20th century and viewed as promising alternative method to satisfy the large energy consumption every day in the world, reduce the emission of carbon and strengthen the economy.

The wind energy was used as a clean energy to generate electricity back to late 19th century.

However, this renewable energy source was not emphasized due to the cheap price of fossil fuel.

The re-emergence happened in mid 1950s when the amount of traditional energy source was found apparently decrease. The development of wind energy usage continued and in 1990 the first mega-watt wind turbine was launched, which was viewed as a symbol of shift to large scale wind energy utilization [1-2]. The modern application of wind energy mainly relies on wind turbine. On the basis of aerodynamic, wind turbine generates certain net positive torque on rotating shaft and then converts the mechanical power to electrical power. As an electrical power generator, wind turbine is connected to some electrical network to transport the electricity to battery charging utilities, residential power systems and large scale energy consuming systems.

In general, most of wind turbines are small scale and can only generate 10KW electrical power.

Only few of the wind turbine systems operate with capacity as large as 5MW. Although the usage of wind energy can reduce the emission of carbon oxide, the noise pollution and high cost

limit its large scale application. Since the wind is not transportable, the electrical energy can only be generated where the wind blows, which also decrease the flexibility of wind energy.

Water power is another term of alternative power supply and it was used for irrigation, operating machines like watermill even before the development of electrical power. The modern application of water power is to generate electricity by using the gravitational force of falling or flowing water. These days, there are various ways for the water power application. The most traditional method is to store the water in dam and generate electricity by converting the potential energy; pump storage is a different way to utilize water power and can change its output depending on the energy demand by moving water between reservoirs at different elevations. In the low energy demand period, excess energy is used to lift water to the higher level, while in the peak period of energy demand, the water is released back to the lower elevation through water turbine. Water power can also be converted by taking advantage of naturally raise and fall of tide to satisfy the demand of electrical energy consumption [3].

Although the usage of water power can reduce the emission of carbon dioxide and cost, it will destroy the ecosystem because of the large land required for construction. There will be methane emission from the reservoir; the potential failure hazard of dam is also a fatal issue and flow shortage caused by drought may also create serious problem. As result of that, water power technique is not a long-term alternative choice.

Geothermal energy is the energy form generated inside the earth. At the very beginning of the planet formation, a large amount of thermal energy was stored from the radioactive decay of minerals, volcanic activity and solar energy absorption. Because of the temperature difference

between the core and the surface of planet, the thermal energy stored inside the earth is driven to the outer surface in the form of heat. This form of renewable energy source can be applied to generate electrical power and heat for industrial, space and agricultural applications.

Theoretically, the deposited amount of geothermal energy is adequate to supply the energy consumption in the world. However, most of the geothermal energy is stored deeply near the core of the earth, the deep drilling and exploration of geothermal energy is very expensive and limits the large-scale use of this renewable energy source [4].

Biomass is a renewable energy source used to generate heat or electricity with living or recently living organism such as wood, waste, (hydrogen) gas and alcohol fuels. The biomass energy can be converted to electrical energy by thermal method such as combustion, pyrolysis, and gasification. Several specific chemical processes may also be able to convert the biomass energy to other forms. The main problem arise from application of biomass is air pollution which contains carbon monoxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants. And the level of air pollution, to some extent, is even above that of traditional fuel resource. Some other possible issue like transportation and sink of carbon also limit the wide usage of this type of alternative energy [5].

Among all the renewable energy sources, solar energy is the most suitable alternative energy for our future life. It is clean, cheap, abundant, without any noise, air pollution, no transportation issue and easy to be obtained anywhere in the earth. Inside the core of the Sun, hydrogen fuses into helium with a rate of 7×1011 kg/s and generates very powerful nucleation power. This type of nucleation explosion creates ultra high temperature in the core of the Sun,

which reaches approximately 16 million K degrees. Although the Sun is not perfectly black body, it still radiates abundant power with the energy density as 1.6×107 watts/m2 [6-7]. Because of the enough amount of hydrogen underneath the surface of the Sun, the radiation given arise of from the nucleation explosion can continue at least 5 million years with the same rate and strength.

The energy reaching the earth is vastly reduced mainly caused by the absorption and spreading of the radiation. It is easily to understand that there are numerous amorphous objects all around the entire universe which can absorb certain portion of the radiation for the Sun. Moreover, the light generated from the spherical object such as the Sun fills all the available space between the origin to the destination. Even though the energy will not be lost in the travelling process, due to the long distance between the Sun to the earth, the surface area of the sphere which is formed with the Sun as center and the distance as radius is much larger than that of the earth. As the result of that, only 1340W/m2 finally reaches the upmost surface of the earth. Even though the final amount of the received solar energy is very small compared to that is initially radiated from the Sun, the average daily solar radiation falling on one area in the continental United States is equivalent in total energy content to 11 barrels of oil. In summary, the solar energy itself is relatively unlimited, useful, clean and almost unexploited energy and definitely can behave as the promising mean for the future energy supply [8].

There are several different methods to take advantage of the solar energy and all the methods can be distinguished into three group: solar parabolic trough, solar tower and solar dish.

Parabolic trough is constructed by silver coated parabolic mirror and there is a Dewar tube going through the length of the mirror and set on the focal point, all the radiation is concentrated on the tube and transfer by heat transfer fluid to the thermal energy storage unit. Solar tower are used to

capture solar energy with thousands of mirrors and focus the concentrated sunlight to the top of the tower which is located in the middle of the heliostats. The thermal energy storage medium within the tower was heated to high temperature and transferred to thermal energy storage tank and eventually sent to steam pump. The solar dish is built with a large, reflective parabolic dish which concentrates all the received sunlight to one spot. There is normally a receiver located on the focal point and transform the solar energy to other forms of useful energy. The working upper limit temperature of solar parabolic trough system is the lowest among these three systems, normally its maximum working temperature is within the range from 400-500oC; the solar tower has higher maximum working temperature which ranges from 500-1000oC; the solar dish has the highest working upper limit temperature which reaches 700-1200oC [9].

The energy conversion efficiency is the most concerned parameter in the solar energy storage application and the theoretical and real engineering efficiency are given in fig 1.1 as function of temperature. The theoretical conversion efficiency can be up to 80% while in real application, the value is always less than 70% regardless of collectors. The actual efficiency increases with temperature in the whole working temperature. As a result of that, the thermal energy storage materials in solar parabolic trough, for instance, should be able to work stably at the upper limit temperature of this type of collection system which is 500oC to ensure the highest efficiency [9, 10].

Fig 1.1 Theoretical and engineering energy conversion efficiency as function of

temperature

Solar energy can be stored in three major forms: sensible heat, latent heat and thermochemical heat. Sensible heat storage was utilized based on the heat capacity and the change as function of temperature of storage materials in the charging and discharging process which correspond to the absorbing and withdrawing energy processes, respectively. The sensible heat stored from the melting point to the maximum working temperature can be expressed by equation 1 [9].

[1]

Where m is the mass of storage material, Tmp and TH are melting point temperature and high temperature in the same phase, respectively, Cp(T) is the heat capacity at different temperature.

Because the sensible heat storage materials remain in a single phase in the working temperature range, the charging and discharging processes are completely reversible for unlimited cycles.

Latent heat storage is operated by absorbing and withdrawing energy in the charging and discharging processes accompanied with fusion of materials [9]. The latent heat collected throughout the working temperature range can be expressed by equation 2 as following:

[2]

Where T is temperature in solid state, Tmp is melting point temperature of storage material, TH is the high temperature in liquid state and is enthalpy of fusion.

Thermochemical heat storage is based on the heat capacity and its change as function of temperature accompanied with chemical reaction. The thermochemical heat collected throughout the working temperature range can be expressed by equation 3.

[3]

Where TL is the low temperature before the reaction, TR is the reaction temperature and

is the enthalpy of chemical reaction. Because of the destruction of the chemical bonds in the reaction process, the charging and discharging process cannot be completely reversible, which reduces the stability and recyclability of storage operation [10].

Sensible energy storage method is chosen to ensure the efficient usage of solar energy for parabolic trough system of which the maximum working temperature ranges from 400-500oC.

Different from thermochemical heat storage, the sensible heat storage can achieve completely reversible working condition under unlimited cycles. Also, fig 1.2 illustrates that the sensible heat storage materials mainly work in the working temperature range for parabolic trough system,

and the gravimetric energy storage densities of sensible heat is higher than that of latent heat materials [9 -11].

Fig 1.2 Gravimetric storage density for different energy storage systems as function of

temperature

Various materials are chosen to serve as thermal energy storage fluid for sensible heat such as water, thermal oil, ionic liquid and molten salt [12]. The properties of different heat transfer fluid determine the performance of solar energy heating system. In these days, the efficiency and cost of output of electrical power mainly relies on the parabolic trough solar power plant and the thermal storage fluid [12]. A large investment cost is needed to dispatch

100MW to 200MW energy by consuming the energy transfer fluids. Given by this situation, the development of new thermal storage fluid with higher thermal energy storage density is paramount to lower the expense for generating energy and a lot of effect has been put on design of new systems [13-16].

Water is commonly used as heat transfer and thermal energy storage fluid in industry because of its low cost, high heat capacity and high thermal conductivity. However, the limitation for using this medium is also obvious that the temperature range within which the liquid state can be assured is too small. It is well know that, water can only serve as thermal energy storage liquid above the freezing point 0oC and below the boiling temperature 100oC. In practical experiment, the actual temperature range is even less than 100oC because of the large amount of weight loss near the boiling temperature due to the high vapor pressure. Water is possible to work above 100oC only if high pressure is also applied to avoid the phase transformation, but the cost will be highly increased. Accordingly, water is only suitable to work in low temperature below 100oC.

Thermal oils are also being used in the parabolic trough solar power plant and have very low melting point as low as 12oC [17, 18]. However, the application of the oil for the thermal energy storage liquid is limited by some disadvantages from the physic-chemical properties. The upper limit for this oil is only 300oC and above that the liquid state cannot be maintained.

Moreover, the low thermal decomposition temperature, low density and low heat capacity result in limited thermal energy storage capacity. Since the working temperature range is so narrow, the rankie cycle efficiency is reduced when using the synthetic oil and the cost for generating power is considered to be very expensive [19, 20].

Ionic liquid is another medium served as thermal energy storage fluid. The liquid temperature range of ionic liquid is large, which is one of the main advantages of this type of material. The high heat capacity and density ensure the efficiency of thermal energy storage of

ionic liquid. What‟s more, the excellent chemical stability and little vapor pressure increase the lifetime [21-24]. However, as a result of the very serve corrosion problem to the liquid container and the high cost, the usage of ionic liquid is still limited.

Considering various relative physic-chemical properties of thermal energy storage system, molten salts have been proposed as a suitable group for a wide temperature range application.

They are being emphasized in the solar energy applications because of their low melting point and high upper limit which can increase the stable working range. The high heat capacity increases the thermal energy storage density of the heat storage system; excellent thermal stability and negligible vapor pressure ensure the steadiness of cyclic repeating in the lifetime

[25]; low viscosity strengths the mobility and efficiency of the thermal storage liquid; low utilization cost reduce the investment and protect the economy. The liquidus temperature range of the molten salt varies from 150-600oC, combination of various salts can bring the melting down and further increase the working temperature range. Due to these properties, molten salts can be excellent thermal energy storage fluid in the solar power generation system.

CHAPTER 2

LITERATURE REVIEW

Several physical and thermodynamic properties of thermal energy storage fluid play significant role in determining the efficiency and performance of solar energy storage systems. In order to evaluate the feasibility of systems, the physic-chemical properties of several molten salts should be reviewed. The three determining parameter which directly affect the thermal energy storage capacity in systems are melting point, heat capacity and density.

There are large amount of melting point data available in the literature for various molten salt system in previous literatures while those with melting point less than 120oC is very limited.

All the previous study on molten salt system revealed that five group of molten salts are emphasized and commonly used: alkai or alkaline nitrates, carbonates, sulphates, chloride and hydroxides. Although most of the systems have the same group of cation, the melting point varies a lot from one to anther due to the different effect of anions.

2.1 Melting point

The melting points of individual and multi-component nitrate/nitrite systems are listed in

Table 2.1[26-31]. Among those systems, solar salt (NaNO3/KNO3: 60/40) is the thermal energy storage medium which is currently being used with the freezing point of 221oC [27]. Although the melting point for this system is highest in all the candidate mixtures in this group, the lowest

combined compound cost makes it widely used in solar energy storage field. Another ternary

o system HITEC which contains NaNO3, KNO3 and NaNO2 has freezing point of 141 C [28].

This combination brings the melting point down but the lack of combination of optimum features limits its further application [29]. Some mixtures such as LiNO3-Ca(NO3)2-KNO3 are not often utilized because they increase the compound cost at the same time of lowering the melting point to around 120oC [30], moreover , the decreased melting point is still high compared to the organic oil. There are also several systems have the melting points less than 100oC or even 60oC, they are not used in the parabolic trough solar power plant due to the decomposition of some components during high temperature [31].

Table 2.1. Melting point of various nitrate salt systems

Compound Melting Point (ºC)

LiNO3 253

NaNO3 307

KNO3 334

Ca(NO3)2 561

Sr(NO3)2 570

Ba(NO3)2 590

NaNO3-NaNO2 221

NaNO3-NaNO2-KNO3 141

NaNO3-KNO3-CaNO3 133

LiNO3-KNO3-NaNO3 120

KNO3-CaNO3-LiNO3 117

LiNO3-KNO3-NHNO3 92

KNO3-NHNO3-AgNO3 52

The melting points of individual and multi-component carbonate systems are listed in

Table 2.2 [26, 32, 33]. Different from the nitrate salts, the melting points for both the individual

and multi-component carbonate systems are on the higher side. The lowest melting point is achieved with lithium, sodium and potassium carbonate ternary system whose melting point is still 277oC higher than that of the nitrate ternary system with the same cations [32]. Besides, because of the thermal decomposition issue, the choice of component involved in the multi- component carbonate systems is limited. Some salt like CaCO3 doesn‟t have stable form at high temperature and the lack of multi-component system reduces the chance of the synthesis of low melting point salt mixtures. Even though this group of salt is not thermally stable and the working temperature range is relatively small, it is still viewed as possible candidate working at high temperature due to its low price.

Table 2.2 Melting point of various carbonate salt systems

Compound Melting Point (ºC)

Li2CO3 732 Na2CO3 858

K2CO3 900

MgCO3 990 Na2CO3-K2CO3 710 Li2CO3-Na2CO3 496 Li2CO3-K2CO3 488 Li2CO3-K2CO3-Na2CO3 397

Alkali and Alkaline fluoride/chloride salts are also selected as one possible choice as the thermal energy storage fluid and the melting point examined from previous literatures are given in table 2.3 [34-38]. A lot of study has been done for this group of salt and the melting points were found in the same range as the carbonate group. And for the pure salt, metal chloride salts have lower melting point than metal fluoride ones.

Table 2.3 Melting point of various fluoride/chloride salt systems

Compound Melting Point (ºC) LiF 849 NaF 996 KF 858 LiCl 610 NaCl 801 KCl 771 LiF-KF 493 LiF-NaF 652 LiCl-KF 487 LiF-NaF-KF 454 LiF-NaF-KF-MgF2 449 LiF-KF-BaF2 320 LiF-KF-CsF-RbF 256

Several studies were also conducted to determine the melting point of molten hydroxide salts and the results are shown in Table.2.4. The data of pure salts and multi-component mixtures merely in this group were not much determined in the literatures. Generally, they are mixed with other groups of anion and form some low melting point salt mixtures [39-42]. On the basis of the previous literature data, alkali hydroxide salts and their mixture with salts in other groups have relatively lower melting point compared with pure carbonate and fluoride/ chloride group salt mixtures. Most of the melting points given in Table 4 are lower than 300oC; sodium potassium hydroxide binary mixture even reaches the melting point below 200oC. Accordingly, relatively large temperature range can be obtained by using hydroxide salt mixtures or adding them as additive.

Table 2.4 Melting point of various hydroixde salt systems

Compound Melting Point (ºC) LiOH-LiF 427 NaOH-KOH 170 LiOH-NaOH 213

NaOH-NaNO2 232

NaOH-NaNO3 237

NaOH-NaCl-NaNO3 242

NaOH-NaCl-Na2CO3 282

2.2 Density

For the solar energy storage system, density for the thermal energy storage fluid is also essential parameter. The density is needed for the size calculation as function of temperature and assessing for the thermal stability of thermoclines. Besides, density as function of temperature is used to evaluate the volume change in the process of freezing which contributes to potential stress.

Alkali/alkaline nitrate salts were studied very much about their density as function of temperature. All the results indicate that the density was decreased linearly as temperature increases and any specific density value in the molten state can be expressed by equation as equation 4:

 = A-BT [4]

Where  (g/cm3) is the density of salt, A (g/cm3) is the initial density value at 0oC and B

(mg/cm3·°C) is the density change slope as function of temperature. The coefficients are shown in

Table 2.5 for the nitrate group molten salts. Among these systems, pure sodium nitrate has the largest value which reveals the high initial density value at low temperature [43]. Conversely, lithium nitrate has the lowest value while it presents the smallest decrease trend as temperature increases [44]. The densities and A, B values of multi-component nitrate salts were included in the range of those two salts discussed above.

Table 2.5 Density coefficients A and B of nitrate salts

Compound A(g/cm3) B×103(g/cm3·°C)

LiNO3 1.922 0.556

NaNO3 2.334 0.767

KNO3 2.127 0.760

NaNO3-KNO3 2.134 0.773

KNO3-CaNO3-LiNO3 2.172 0.735

LiNO3-KNO3-NaNO3 2.083 0.715

Several experiments were also conducted to measure the density as function of temperature for the individual and multi-component carbonate salt systems. The density of the carbonate salt also follow the same trend as that of nitrate salt and the temperature dependence of density followed the linear equation as discussed above. It is observed that all the carbonate salts have higher initial density coefficient A than the nitrate salt. The largest value is reached to 2.511 and even the lowest value in this group is greater than the maximum A of nitrate group [45-49].

What‟s more, the regression slope coefficient B of carbonate salt is lower compared to that of the nitrate salt group. Accordingly, the salts in this group present larger density in the molten state and the density coefficient A and B are given in Table 2.6.

Table 2.6 Density coefficients A and B of carbonate salts

Compound A(g/cm3) B×103(g/cm3·°C)

Li2CO3 2.303 0.532

Na2CO3 2.350 0.448

Na2CO3-K2CO3 2.473 0.483

Li2CO3-K2CO3 2.511 0.599

Li2CO3-Na2CO3 2.456 0.519

Li2CO3-Na2CO3-K2CO3 2.364 0.544

Density of metal fluoride and chloride molten salt were also examined and present similar regression trend as temperature increases. The linear temperature dependence is also expressed by the same equation. On the basis of previous literature data, the pure chloride salt shows lower density than the fluoride salt with the same cation in the molten state [49]. What‟s more, the sodium halide salt has the largest density value while the lithium halide salt has the lowest value, which is very similar to the nitrate group salt. The density determination coefficient A and B are given in Table.2.7.

Table 2.7 Density coefficients A and B of chloride/fluoride salts

Compound A(g/cm3) B×103(g/cm3·°C) LiCl 1.766 0.432 NaCl 1.991 0.543 KCl 1.976 0.583 LiF 2.226 0.490 NaF 2.581 0.636 KF 2.469 0.651 LiF-NaF 2.520 0.818 LiCl-NaF-KCl 2.436 0.742 LiF-NaF-MgF 2.240 0.701

The density measurement of hydroxide was not conducted as much as those three anion groups discussed above. Only few data of density is available for the alkali hydroxide salt when added into other salt systems and temperature dependence also follows the linear regression trend [32, 41]. The density determination coefficient A and B are given in Table 2.8.

Table. 2.8 Density coefficients A and B of molten salt mixture with hydroxide salts

Compound A(g/cm3) B×103(g/cm3·°C) LiCl-LiOH 1.6 0.443 LiF-LiOH 1.65 0.471

2.3 Heat capacity

In the heating process, the temperature of solar energy storage molten salt is increase by absorbing energy from the solar radiation. Conversely, the same amount of heat is released and applied to heating system in the process of cooling. Heat capacity is the amount of heat required to increase the temperature of certain material by 1 oC and can be viewed as the directly relevant parameter to the energy storage ability. To some extent, the large heat capacity assures the efficiency of the application of solar energy storage materials

The heat capacity of alkali/alkaline nitrate salt was investigated for both individual and multi-component system in the previous literature. To simplify the comparison, only the heat capacity value at 500oC is shown in all the following tables. In the liquid state, the heat capacity increases with temperature following linear equation and the increasing slope is as small as 10-5 to 10-4 [50, 51]. Among those alkali nitrate salt systems, lithium nitrate has the largest heat

capacity at 500oC while potassium nitrate presents the lowest value at that temperature. In table

2.9, the heat capacity results at the selected temperature in literature are given.

Table 2.9 Heat capacity of alkali nitrate salt at 500oC

Compound Heat capacity(J/g·K)

LiNO3 2.175

NaNO3 1.686

KNO3 1.400 NaNO3-KNO3 1.533 LiNO3-KNO3 1.642 LiNO3-KNO3-NaNO3 1.681

For the carbonate salt systems, in the molten state, the heat capacity is almost constant and almost independent with temperature [32, 33]. Same as the nitrate group salts, the heat capacity for pure carbonate salt decreases as the atomic number of the alkali element increases, which means the value for lithium carbonate is the largest and that of potassium carbonate is the smallest. Generally, the heat capacity value for carbonate in molten state is larger than that in solid state. However, the sodium-potassium carbonate binary system is an exception, for which the heat capacity in solid state is larger than liquid state. In table 2.10, the heat capacity results of carbonate salts at the selected temperature in literature are given.

Table 2.10 Heat capacity of alkali carbonate salt at 500oC

Compound Heat Capacity(J/g·K)

Li2CO3 2.50

Na2CO3 1.78

K2CO3 1.51

Na2CO3-K2CO3 1.57

Li2CO3-K2CO3 1.60

Li2CO3-Na2CO3 2.09

Li2CO3-K2CO3-Na2CO3 1.63

The heat capacity of fluoride/chloride salt was measured in several literature and found that for the pure salt, the lithium halide has the biggest heat capacity data in the molten state while the potassium halides shows the lowest heat capacity value. Similar to the carbonate group, the heat capacity value of fluoride/chloride salt varies little with temperature in the liquid state

[32, 33]. The values at 500oC for the alkali/alkaline halides are shown in Table 2.11.

Table 2.11 Heat capacity of fluoride/chloride salt at 500oC

Compound Heat Capacity (J/g·K) LiCl 1.48 NaCl 1.15 KCl 0.90 LiF-KF 1.63

NaCl-MgCl2 1.00 LiF-NaF-KF 1.55

KCl-MgCl2-CaCl2 0.92

The heat capacity of pure and multi-component hydroxide salt systems is limited in the previous literature and the values in the liquid state follow linear equation which is observed for all the molten salt discussed above [52]. The values at 500oC for the alkali/alkaline halides are shown in Table 2.12.

Table 2.12 Heat capacity of hydroxide salt at 500oC

Compound Heat Capacity(J/g·K) NaOH 1.88 LiOH-NaOH 2.21 NaOH-KOH 1.82

In summary, on the basis of comparison of various physic-chemical properties, molten nitrate slats have relatively low melting point, excellent working temperature range, reasonable density and high heat capacity. As the result of that, molten nitrate salt is suitable to be applied as the thermal energy storage fluid in the solar energy storage system.

CHAPTER 3

OBJECTIVES

Based on review of previous literature data, it is found that there are several disadvantages such as the high melting point, relatively low density value or poor heat capacity in liquid state which limit the application of molten salt in certain groups in solar thermal energy storage system. Conversely, alkali/alkaline nitrate salt is considered as the suitable choice and proposed as the thermal energy storage liquid for high temperature.

Currently, the used thermal energy storage liquid is NaNO3 (60mol%)-KNO3 (40mol%) binary system (solar salt) which has the melting point at 221oC [30]. Although the melting point for this salt mixture is not the lowest, it is still emphasized because of its low investment cost.

However, there are some drawbacks for this binary nitrate mixture. The main disadvantage is the high melting point. In evenings or in winter, the molten salt can easily freeze and block the pipeline. As a result of that, some auxiliary cost should be added to overcome this problem and the total investment will be increased.

Development and synthesis of newer molten salt mixtures with freezing point lower than those currently used for thermal energy storage applications is necessary for higher efficiency of utilization of solar energy and getting rid of any unnecessary cost. The approach to develop lower freezing point molten salt mixtures is by the prediction of new eutectic mixtures and also

by the development of new nitrate compounds. Besides these two most well known systems, several other mixtures were also studied. Preliminary evaluation of several new molten salt flux systems based on requirements for thermal energy storage systems, mainly including freezing point, density, heat capacity, viscosity, and thermal energy storage density. The promising candidate low melting point molten salt system should satisfy the requirements that eutectic melting temperatures are lower than 220oC and the thermal energy storage densities are higher than binary solar salt. It is known that the melting point can be lowered by the addition of one or more ABNO3 nitrate compounds where A and B are cations. Consequently, several multi- component systems which have more constituent salts than solar salt were came up with and studied with little fundamental data on the physic-chemical properties at the required operating conditions available at present.

In this thesis, the new systems with simulated eutectic compositions were tested for their experimental melting points, heat capacities using the Differential Scanning Calorimetry (DSC) technique which is considered to be the accurate instrument for thermodynamic data analysis

[53-59]. Some significant thermodynamic properties such as heat capacity, enthalpy, and entropy and Gibbs energy were calculated in the thesis to evaluate the energy change of the system in the phase change process and the potential of being applied in the parabolic trough solar power plant.

The energy density was obtained by using the experimental measured density and heat capacity of the mixtures in molten state. Finally, 9 down-selected systems were present and discussed.

CHAPTER 4

THERMODYNAMIC MODELING OF SALT SYSTEMS

4.1 Thermodynamic modeling

To lower the melting point of solar energy storage system, multi-component system is applicable. Thermodynamic model was introduced to predict the eutectic temperature of salt systems based on the Gibbs energies of fusion of individual salt and that of mixing of constituent binary systems. At the eutectic temperature, the Gibbs energies in the liquid state and solid state of salt are equal. In thermodynamics, Gibbs energy of fusion can be expressed by the equation given as follows:

G = H-TS [5]

Where H is the change of enthalpy of fusion and S is the change of entropy of fusion. Equally, the entropy change of fusion can be expressed by differentiating G and the equation is given:

 [6]

It is known that the change in entropy can be expressed in terms of change in heat capacity in the melting process as:

 [7]

If the change of heat capacity is assume to be independent of temperature, the integral of from Tm to T can be shown as:

[8]

where Sm is the entropy of fusion at the melting point which is equal to . Accordingly,

Eq.8 can be rewritten as:

[9]

Substituting Eq. 9 in Eq. 6 and integrating the equation from Tm to T we get,

[10]

Eq. 10 illustrates that by using the change of heat capacity, melting point and enthalpy of fusion, the Gibbs energy change at any temperature can be obtained.

The standard Gibbs energy of fusion of a salt „1‟ can be expressed in terms of the activity of the salt as:

[11]

where is the molar excess Gibbs energy and X1 is the molefraction of the salt „1‟. Gibbs energy of fusion at any give temperature T is expressed by Eq 7 in terms of its molefraction and partial molar excess Gibbs energy.

Take LiNO3-NaNO3-KNO3 as an example in which the integral molar excess Gibbs energy is composed of the summation of the Gibbs energies of three constituent binary system and one ternary. The expression of the integral excess Gibbs energy is given by Eq.12.

[12]

Gibbs energies of the three constituent binary systems, LiNO3-NaNO3, LiNO3-KNO3, and

NaNO3-KNO3 of the LiNO3-NaNO3-KNO3 ternary system are taken from the literature [48, 49].

The Gibbs energies of mixing or the integral excess Gibbs energies of the three constituent binary systems of the LiNO3-NaNO3-KNO3 ternary system are given below:

LiNO3-NaNO3 Binary System

J/mol [13]

LiNO3-KNO3 Binary System

J/mol [14]

NaNO3-KNO3 Binary System

J/mol [15]

When assume the intergral excess Gibbs energy of to be zero, the excess Gibbs energy in the ternary system can be expressed by the summation of three constituent binary systems:

[16]

Generally, the partial molar excess Gibbs energies are reduced from the integral molar excess Gibbs energy and can be expressed by the generalized equation for certain “m” component salt as:

[17]

In the ternary system, the i value equals to 1,2 and 3, and the partial molar excess Gibbs energy of mixing for each component can be expressed as follows:

[18]

[19]

[20]

Based on Eq. 7 and the partial molar excess Gibbs energy of individual component, the

Gibbs energy in the fusion can be expressed as Eq.21- 23.

[21]

[22]

[23]

4.2 Calculations

The fusion of the ternary salt system is defined by solutions of Eq. 21-Eq. 23. Newton-

Raphson method can be used to solve these three non-linear equations by linearizing the non- linear equations using the Taylor series and truncating the series to first order derivatives.

Consider the three non-linear functions F, G, and H in three variables, x, y, and z. The three equations that are solved for the three variables are written as:

F(x, y, z) = 0;

G(x, y, z) = 0;

H(x, y, z) = 0; [24]

The partial derivatives of the function F with respect to x, y and z are given as:

; ; ; [25]

Similarly, the partials derivatives can be expressed for the other two functions G and H.

Newton-Raphson iterative method of solving the three equations in three variables essentially deals with the solution of the incremental vector in the matrix equation given below.

[26]

For the initial values of x, y, and z, (say xi, yi, and zi) the right hand side vector contains the values of the functions at the initial values (xi, yi, and zi). The 3×3 matrix on the left hand side contains the partial derivatives of the functions with respect to the three variables at the initial values. Solutions of the matrix equation (Eq. 26) result in the increments of the variables x, y, and z. The variables for the next iteration will then be xi + x, yi + y, and zi + z. The process of solving the matrix equation (Eq. 26) is continued until the increments in the variables

x, y, and z is less than a very small quantity. The iteration process is then said to be

converged and the values of the variables at convergence of the solution are the roots of the system of the three fusion equations.

The composition of LiNO3, NaNO3 and KNO3 and the eutectic temperature is solved by using the Newton-Raphson iterative method. Different from the data in previous literature, the eutectic temperature for the ternary is 116oC. Besides, the composition for each component is also different from those published in literatures. The new molten ternary system is composed of

25.92 wt% LiNO3, 20.01 wt% NaNO3, and 54.07 wt% KNO3. The similar method is also applied to other multi-component systems to determine the composition and eutectic temperature. The predicted melting points for new solar energy storage system are given Table.4.1.

Table 4.1 Calculated composition and melting point of multi-component molten salts systems

Composition (wt%) Calc. T System mp LiNO3 NaNO3 KNO3 NaNO2 KNO2 Mg(NO3)2 MgKN (°C) Salt #1 25.9 20 54.1 - - - - 116 Salt #2 - 16.1 54.7 29.2 - - - 123.8 Salt #3 17.5 14.2 50.5 17.8 - - - 98.6 Salt #4 11.5 10.4 27.4 - - - 50.7 98.6 Salt #5 17.2 13.9 47.6 17.2 4.1 - - 95.7 Salt #6 9 42.3 33.6 - 15.1 - - 100.0 Salt #7 19.3 - 54.6 23.7 2.4 - - 108.1 Salt #8 19.3 - 55.9 23.9 - 0.9 - 100.8 Salt #9 15.4 17.2 32.4 - - 8.3 26.7 103.6

CHAPTER 5

EXPERIMENTAL PROCEDURE

5.1 Melting point determination of molten salt mixtures

5.1.1 Materials

Ternary, quaternary and quinary nirate and nitrite mixtures were tested in the thesis. Most components in the mixtures don‟t require any pre-preparation and can be used as received. The only exception is new developed MgKN which was composed of 66.67 mol% KNO3 and 33.33 mol% Mg(NO3)2. This unique compound is synthesized from magnesium nitrate hexahydrate

(98%, Alfa Aesar) and potassium nitrate (ACS, 99.0% min, Alfa Aesar) and added into the mixture as one single component. As received magnesium nitrate hexahydrate is dehydrated before synthesizing MgKN compound. Weighted amount of magnesium nitrate taken in a stainless steel crucible and placed on a hot plate in an argon atmosphere. Temperature of the salt is measured with a thermocouple immersed in the salt. The temperature was held at 523.15 K for

2 hours. The salt solidifies to a white mass. The temperature of the salt is then raised to 573.15 K slowly to remove any traces of moisture and to ensure complete dehydration. The complete removal of water is ascertained by weight loss.

5.1.2 Apparatus and Procedure

Differential scanning calorimetry (DSC) analysis was performed using Perkin Elmer

Diamond DSC instrument and the setup is shown in fig. 5.1. Heat flow and temperature can be recorded in the instrument with an accuracy of 0.0001 mW and 0.01 K respectively. The measurements were made under purified nitrogen atmosphere with a flow rate of 20cc/min and at a heating rate of 5 K/min.

Fig 5.1 Photography of set-up for DSC equipment

After dehydration if necessary, each component was weighed to an accuracy of 0.1mg with the electrical balance and mixed thoroughly in a stainless steel crucible. Later, the mixture is heated up to certain temperature at which the entire salt melts. At this temperature the salt mixture was held for about 30 minutes. The salt mixture is allowed to air cool to ambient temperature. This procedure is repeated 3 to 4 times to get the well-mixed compound. Standard aluminum pan with lid used for DSC measurements are weighed before the experiment. Small amount of the synthesized compound is placed carefully in the aluminum pan and closed with the lid. The lid is crimped by a sample press and the pan is weighed. The weight of the sample is

determined by removing the weight of the pan and lid. For the determination of melting point and heat capacity (20-25) mg of the sample was used.

Perkin-Elmer Diamond Differential Scanning Calorimeter (DSC) is used to measure the melting point and heat capacity of compound. The crimped ample pan was immediately put inside the sample chamber of DSC after preparation and held at 523.15 K for 10 hours to remove the trace amount of moisture possibly caught in the process of loading sample and also to ensure a homogeneous mixture. In the experimental procedure, a temperature range from 298.15 K to

523.15 K was set with a heating rate of 5 K min1 followed by a cooling cycle at the same rate.

This cycle is repeated for at least 6 times to ensure good mixture of the sample and reproducibility of the results.

5.2 Heat Capacity determination of molten salt mixtures

To start Cp measurement, the same procedure as that of melting point determination is followed with an addition of „iso-scan-iso‟ steps to the program after 5-cycle temperature scan.

Starting from 298.15 K, the temperature was held for 5 minutes before and after each scan step.

Small temperature scan range is chosen to avoid thermal resistance between device and testing sample except when the temperature is approaching the melting temperature. The upper limit for the Cp measurement was set to 623.15 K in our experiments. Since the change in the molar heat capacity of the salt in the liquid state is very small, the Cp data in the liquid state can be easily fit to an equation and extrapolated to higher temperatures. To get the value of molar heat capacity of the sample, heat flow curve for the baseline of the empty sample pan also needs to be obtained immediately following the identical “iso-scan-iso” steps which were used for the actual sample

run. The difference of heat flow between the actual crimpled sample and the empty sample pan is the absolute heat absorbed by the test sample.

5.3 Density determination of molten salt mixtures

Density measurement was carried out with standard densitometer which has fixed volume.

Initial weight of the densitometer is measured and noted. Salt composition, of which the density is measured, is placed in a beaker on a hot place. The densitometer is also placed on the same hot plate. The temperature is set to a fixed value above the melting point of the salt and is measured by a thermocouple. After the salt is melted and when the temperature shows stable reading, the molten salt is poured in to the densitometer up to the set mark on the sensitometer bottle. The weight of the densitometer with the molten salt is measured. The weight difference between this weight and the weight of empty densitometer gives the weight of the molten salt at the fixed set temperature. By knowing the fixed volume in the densitometer, the density of the salt at that temperature can be calculated. This procedure is repeated at least three times to accurately determine the density of the salt.

CHAPTER 6

RESULT AND DISCUSSION

6.1 Melting point determination

6.1.1 DSC equipment calibration

Before the actual melting point measurement, pure indium, zinc metal and several individual salts were used to calibrate the DSC equipment. For metals, only one sharp peak was observed for each and the heat flow curve for indium metal is shown in fig 6.1. However, larger and boarder peaks are found for salts, just like the condition illustrated in fig 6.2 for pure potassium nitrate. Based on the results shown in Table 6.1, the experimental data for melting points and enthalpies of fusion have excellent agreement with the literature values [60-63]. The variation of point is within 0.7% and the variation of change of enthalpy is less than 3%.

Figure 6.1 Melting point calibration with indium sample

Figure 6.2 Melting point calibration with KNO3 sample

Table 6.1 Calibration data of melting points with different samples

Lit. Expt. Lit. Expt. Lit. Expt. Lit. Expt. Sample Tmp Tmp Ttrans Ttrans ΔHfusion ΔHfusion ΔHtrans ΔHtrans °C °C °C °C J/g J/g J/g J/g Indium 156.6 156.3 - - 28.6 27.8 - - Zinc 419.5 418.8 - - 108.6 106.8 - - LiNO3 256.7 255.0 - - 361.7 363.3 - - NaNO3 310.0 308.1 277.0 275.3 177.7 175.6 14.7 15.2 KNO3 337.0 337.2 133.0 133.2 99.3 100.5 53.8 52.9

6.1.2 Results

Differential scanning calorimetry (DSC) was used to determine the melting point and any solid state phase transitions of the salt mixture. A low scanning rate was chosen to record the heat flow curve as function of temperature in order to improve the sensitivity of detection [64]. It helps to pick up any small endothermic peaks and also avoids the thermal resistance between the

internal furnace and sample. Nine systems were chosen to test and the eutectic composition is already listed in Table 4.1.

All the selected systems are composed of alkaline nitrate and nitrite and most of them have three basic components which are lithium, sodium, potassium nitrate or nitrite. All the quaternary and quinary systems were developed on the basis of the LiNO3-NaNO3-KNO3 baseline ternary.

Figure 6.3-6.11 shows the DSC plot of all the salt systems. DSC plots for each system were collected for at least five runs (each run with fresh salt preparation) to ensure the reproducibility.

All the onset temperatures, peak temperatures, predicted temperatures, enthalpy of fusion for melting peaks and the solid phase transformation temperatures are given in Table.6.2.

Figure 6.3 DSC endothermic peaks of LiNO3-NaNO3-KNO3 salt.

Figure 6.4 DSC endothermic peaks of NaNO3-NaNO2-KNO3 salt.

Figure 6.5 DSC endothermic peaks of LiNO3-NaNO3-KNO3-MgK salt.

Figure 6.6 DSC endothermic peaks of LiNO3-NaNO3-KNO3-NaNO2 salt.

Figure 6.7 DSC endothermic peaks of LiNO3-NaNO3-NaNO2-KNO3-KNO2 salt.

Figure 6.8 DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt.

Figure 6.9 DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt.

Figure 6.10 DSC endothermic peaks of LiNO3-KNO3-NaNO2-Mg(NO3)2 salt.

Figure 6.11 DSC endothermic peaks of LiNO3-NaNO3-KNO3-Mg(NO3)2-MgKN salt

Table 6.2 illustrates that the predicted melting point is close to the experimental determined value and most deviation is within 10% except for system #9. The great agreement

between experimental and calculated data verifies the accuracy and feasibility of the thermodynamic modeling.

Table 6.2 DSC results of melting point, transition point and predicted melting point

T T ΔH System mp trans fusion Calculated, °C Onset, °C Peak, °C Peak, °C J/g Salt #1 116.0 99.4 119.1 104.3 60.0 Salt #2 123.8 115.0 124.0 NA 9.7 Salt #3 98.6 94.0 99.9 NA 24.4 Salt #4 98.6 94.0 101.0 NA 6.0 Salt #5 95.7 91.0 95.0 NA 6.2 Salt #6 100.0 93.0 96.0 NA 8.6 Salt #7 108.1 99.2 100.3 79.3 6.0 Salt #8 100.8 101.0 101.9 85.3 5.9 Salt #9 103.6 83.4 89.2 NA 9.3

6.1.3. Discussion

It is observed that the first curve is different from last ones shown in the DSC plots and this phenomenon is common for all the melting point measurement with DSC technique. This happened because in the first cycle, the moisture caught by salt mixture, especially the lithium nitrate, was removed in the process of heating. Moreover, the partially solidified sample in the sample loading process can be re-homogenized in the first heating cycle [65-67]. In figure 6.3,

6.9 and 6.10, more than one endothermic peak was found. The first smaller endothermic peak refers to solid state phase transition of the salt mixture. The second larger endothermic peak refers to the melting of the salt. Normally, the onset temperature of transition is taken as the experimental transition point for any metallic sample. However, in case of molten salts mixtures, since the thermal conductivity is low [68-74], the complete transition is ensured only at the peak

transition temperature. The thermal gradient which exists due to the low thermal conductivity of the salt results in internal heat flow which enhances the mixing in the salt. Thus, the transition temperature is defined as the peak temperature of phase transition. For salt No.1, the small endothermic peak happened before and was connected to the main peak which occurred at

390.27K. The first endothermic peaks for salt No. 7 and 8 occurred at almost the same temperature because of the similar composition for these two compounds. Since the small amount of magnesium nitrate and potassium nitrite contained in these two compounds, the small endothermic peak can hardly be related to these two components. Obviously, the rest three major components must have something to do with the first peaks happened before the melting peaks for both cases. Each component among the major three ones were tested to find out any possible solid phase transition peaks of them and the results shown in Table. 6.3, which reveals that lithium nitrate doesn't have any phase transition peak in solid state while potassium nitrate and sodium nitrite both own the solid phase transformation peaks before their melting peaks.

Table 6.3 Fusion and solid phase transition temperature for individual salts

System Tmp, °C Ttrans, °C ΔHfusion, J/g ΔHtrans, J/g LiNO3 255.0 - 363.3 - KNO3 337.2 133.2 100.5 52.9 NaNO2 431.1 41.70 111.9 8.80

The further investigation was carried out by running the KNO3-NaNO2 (55.0 wt% and 23.8 wt %) binary compound with the very similar weight percentage as that in salt No. 7 (54.6 wt% and

23.7 wt%) and salt No. 8 (55.9wt% and 23.9wt%). By converting the weight percentage of the studied binary system into 100% scale, the weight fraction for sodium nitrate and potassium nitrate can be rewritten as 69.8wt% and 30.2wt%. The DSC plot for this binary system was

shown in fig 6.12. Although the solid transition and melting temperature were brought down by adding lithium nitrate, the shape of the plots in fig. 6.9 and 6.10 are identical to that shown in fig.

6.12. The enthalpy of solid state transformation of the binary salt was also converted to that in both quaternary systems by using the weight fraction occupied by the binary system and the comparable change of converted enthalpy between the binary system and two quaternary systems indicates the relevance of the solid transition peaks in salt #7 and #8 to the combined effect of potassium nitrate and sodium nitrite.

Figure 6.12 DSC plot of 69.8wt% KNO3- 30.2wt% NaNO2 binary system

The similar analysis was applied to No.1 salt to find out the reason for the presence of a small peak adherent to the main melting peak before the melting point. Sodium nitrate and potassium nitrate binary system was synthesized based on the weight fraction of these two constituent salts in No. 1 salt. DSC plot for the sodium nitrate-potassium nitrate binary system in

Fig. 6.13 with the converted composition which is essentially same as that in the No.1 ternary system shows smooth heat flow curve before the melting peak, which means the solid transition peak in ternary is not simply relative to the binary system. Assumption was made that the solid

phase transformation peak in the ternary salt is resulted from a multiple effect, i.e. the combination of one of the eutectic binary system involved in the ternary salt mixture and the other binary system which is composed of the rest components. The statement is verified that the small peak in salt #1 is mainly caused by the solid phase transformation peak in lithium nitrate- potassium nitrate eutectic binary system given the similar shape of the DSC plots in Fig. 6.14.

Since in salt No.1 there is excess amount of sodium nitrate to form the lithium nitrate-sodium nitrate binary system, the rest sodium nitrate can interact with potassium nitrate and form new sodium-potassium nitrate system which is shown in fig.6.15. Besides, a solid phase transformation peak is observed in fig.6.15 which has a very small area and won‟t change the shape of phase transformation peak in fig.6.14 when these two binary systems are combined and form salt #1. The enthalpies of solid state transformation in two binary salts were also converted to that in salt #1 by using the weight fractions occupied by both binary systems. The difference of the change of converted enthalpies between the lithium-potassium nitrate eutectic binary and ternary system is filled by the binary mixture which is composed of the rest components: sodium nitrate-potassium nitrate. The comparable converted values of enthalpy change between salt #1 and its two constituent binary systems further verify the assumption that the solid phase transformation happened in salt #1 is mainly due to the combined effect of LiNO3-KNO3 eutectic binary system and NaNO3-KNO3 binary system.

Figure.6.13 DSC plot of 27.0wt% NaNO3-73.0wt% KNO3 binary system

Figure.6.14 DSC plot of 45.8wt%LiNO3-54.2wt%KNO3 binary system

Figure.6.15 DSC plot of 46.0wt% NaNO3-54.0wt% KNO3 binary system

Unlike those discussed mixtures above, salt No.2, Salt No.4, Salt No.5 and Salt No.6 have only one relatively board melting peak and the heat flow curve before and after are very stable.

Similarly, there is no solid transformation peaks observed in salt No.3, salt No.7 and salt No.8.

However, the heat flow after the melting peak in these cases are not stable and the main endothermic peak is followed by a small hump which is considered to be the recrystallization process once the compound entered into the liquid state. When the process is finished, the heat flow curve returns to steady state.

Heating rate is a significant parameter when collect the heat flow curves by using DSC technique. Fig 6.16(a) and Fig 6.16(b) illustrate the difference of melting point for salt No.6 due to the change of heating rate. If the heating rate is 20oC/min, the peak temperature and onset temperature for the melting peak is 96.69oC and 92.21oC, respectively. Once the heating rate is decreased to 5oC/min, these two temperatures will also be lowered to 96.14oC and 91.90oC. The difference is resulted from the diverse amount of thermal resistance between the testing sample and the furnace inside the DSC instrument [75]. Under higher heating rate, the decisive thermal

resistance is raised due to the low thermal conductivity medium between the furnace and the actual sample. The insensitivity of gas heat conduction medium in DSC results each unit of temperature increase on one side cannot have an immediate response on the other side of the gas.

Consequently, the sample holder which is connected the furnace has a higher temperature than that inside the sample. In this condition, the value of temperature profile collected as the sample holder temperature is larger than the actual temperature. The deviation will be much smaller when the heating rate is reduced. In the case, the thermal resistance will be decreased because of the lower temperature gradient of the gas medium in the heating process. As a result of that, the collected temperature from the sensor attached to the sample holder will be very close to the actual temperature inside the testing sample.

o Figure 6.16(a) DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt for 20 C/min

heating rate.

o Figure 6.16(b) DSC endothermic peaks of LiNO3-NaNO3-KNO3-KNO2 salt for 5 C/min

heating rate.

Besides the difference of temperature while using higher and lower heat rate, the solution of DSC will also be affected by different heating rate. Fig. 6.17(a) shows the DSC plot for salt

No. 7 using the heating rate as 5oC/min and the DSC plot in Fig. 6.17(b) is collected under the heating rate as 20oC/min. It can be observed that in the lower heating rate, two small separated peaks can be viewed as two parts of the solid phase transformation process, while in Fig. 6.17(b) two small peaks before the melting peak merge and present as a board hump. The qualification of resolution can be executed by the term named resolution factor RMKE which is calculated as the ratio of the peak heat flow value of the separated peaks to that of the concave point between two peaks. The equation for determining RMIKE is given in Eq. 27 [76, 77].

RMIKE =hpeak/hmin [27]

o Figure 6.17(a). DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt for 5 C/min

heating rate.

o Figure 6.17(b). DSC endothermic peaks of LiNO3-KNO3-NaNO2-KNO2 salt for 20 C/min

heating rate.

In the case of lower heating rate, the RMKE is determined to be 1.5 and the value for higher heating rate is not available because the concave point of heat flow doesn‟t exist from

Fig.6.17(b). Since the higher RMKE value indicates better resolution, it can be stated that the

lower heating rate also results in greater sensitivity of the equipment to pick up any small endothermic peaks.

Besides the down-selected 9 compounds, some more salt mixtures were also tested. Most of them were not selected to the final candidate for the thermal energy storage application because of their higher melting point. Table 6.4 gives some of the trial systems measured with

DSC technique. It is illustrated that the melting points of mixtures with lower or even no content of lithium nitrate turn out to be higher than those with sufficient amount of lithium nitrate. For most of the mixtures with melting point lower than 120oC, the amount of lithium nitrate should be larger than 8.1wt%. Also, all of the systems in table 6.4 with lithium nitrate less than 1.5wt% have melting point higher than 140oC. Based on the observation above, it is concluded that the lithium nitrate can be used as an additive to bring the melting point down for thermal energy storage systems.

Table 6.4 Melting points of candidate systems as function of temperatures

Onset Peak System Composition (wt%) Temp Temp (oC) (oC)

LiNO3 – NaNO3 – KNO2 10.7 45.9 43.4 89.0 91.0 LiNO - KNO - NaNO 19.6 56.4 24.1 102.4 104.6 3 3 2 LiNO - NaNO - KNO - KNO 9.0 42.3 33.7 15.1 93.0 96.0 3 3 3 2 LiNO - NaNO - NaNO - KNO 8.1 45.4 6.5 40.1 90.0 91.0 3 3 2 2 LiNO - KNO - NaNO - KNO 19.3 54.6 23.7 2.4 99.2 100.3 3 3 2 2 LiNO - KNO - NaNO – Mg(NO ) 19.3 55.9 23.8 0.9 101.0 102.0 3 3 2 3 2 LiNO - NaNO - KNO - Mg(NO ) 3 3 3 3 2 15.4 17.2 32.4 8.3 26.7 83.4 89.2 - MgK LiNO - NaNO - KNO – Ca(NO ) 1.4 39.0 33.3 26.3 125.0 147.0 3 3 2 3 2 NaNO - KNO - NaNO - KNO 42.5 16.3 7.1 34.1 140.7 144.7 3 3 2 2 NaNO - KNO - KNO – Mg(NO ) 43.2 14.6 38.0 4.2 138.6 142.1 3 3 2 3 2 NaNO - NaNO - KNO - Ca(NO ) 45.1 9.2 41.0 4.8 115.0 139.0 3 2 2 3 2 LiNO - NaNO - NaNO - KNO - 3 3 2 2 1.5 39.3 3.7 32.3 23.2 138.0 148.0 Ca(NO3)2 LiNO - NaNO - KNO - Ca(NO ) - 3 3 2 3 2 1.4 37.9 31.3 27.5 2.0 133.9 153.4 Mg(NO3)2

6.2 Heat capacity determination

6.2.1 Heat capacity calibration

DSC was also calibrated for the heat capacity measurement. Lithium nitrate, sodium

nitrate and potassium nitrate were examined for the heat capacities from room temperature to

upper limit temperature for the instrument. In liquid state, the heat capacity values for each salt

can be fit to straight line with trace amount of increasing trend. Since the temperature range from

the onset temperature of liquid state to the upper limit of DSC is relatively small, the heat

capacity values for pure individual salts can be viewed as constants. The comparison between the

theoretical and experimental heat capacity data is given in Table 6.5. Except lithium nitrate, the

experimental heat capacities data for the rest two systems are almost same as the literature. Even for lithium nitrate which demonstrates the biggest difference from the literature data, the 2.8% vibration is still within a reasonable range

Table 6.5 Calibration data of heat capacities with different samples

Lit. Cp Expt. Cp Sample J/g.K J/g.K

LiNO3 2.18 2.12 NaNO3 1.69 1.67 KNO3 1.40 1.39

6.2.2 Results

The materials used in the heat capacity measurements are the same as those in the melting point experiments. Molar heat capacities of the all compound were measured by the DSC equipment from room temperature to 623.15 K. The heat flow is recorded as a function of temperature in “iso-scan-iso” steps at intervals of 20 K. The „iso stage‟ refers to isothermal holding at a particular temperature, „scan stage‟ refers to the heat flow recording at a heating rate of 5 K min1 up to a an increment of 25 K, followed by another isothermal holding stage. This is a standard procedure followed in the measurement of heat capacity of materials using the DSC equipment [63, 64]. This procedure of heat capacity measurement has two advantages; (i) any heat fluctuations during the recording are avoided by the isothermal steps and (ii) any phase transition can be highlighted by the choice of temperature range. The absolute heat flow to the sample is determined by subtracting the heat flow collected by running a baseline curve with an empty pan. Because the heat capacity measurement in the heating process corresponds to

collecting the value of required heat flow at each temperature, all the heat capacity plots have the same shape with that of heat flow in the melting point measurements. Take the heat capacity plot of LiNO3-NaNO3-KNO3 ternary system as an instance which is shown in fig 6.18, the heat capacity curve also has two different peaks. The first little peaks corresponds to one occurs at

390.27K which was observed in fig 6.3, the second large and sharp peak happened right after the small one is prevalent to the endothermic peak with the peak temperature as 390.27 K. Similarly, after the phase transformation, the heat capacity in liquid state becomes very stable and increase with temperature linearly with little slope.

Fig 6.18 Heat capacity data plot of LiNO3-NaNO3-KNO3 ternary system as function of

temperature

The heat capacity change as function of temperature for salt No.1 was illustrated in fig

6.19. Based on the trend of heat capacity in the liquid state, any value for the system in the liquid can be extrapolated. The expressions for heat capacity in liquid state for the new molten salt systems were discussed and given in the next section.Table.6.6 shows the specific heat capacity

of the all the selective compounds measured at 623.15 K and extrapolated at 773.15K. Besides, the molar heat capacities at 773.15K are given in Table 6.6 of all the salts.

Fig 6.19 Heat capacity of LiNO3-NaNO3-KNO3 in liquid state from 403.15-623.15K

Table 6.6 Heat capacity of selected new TES molten salt mixtures

Expt. (623.15K) Extrapolated(773.15K) Extrapolated(773.15K) System Cp, J/g.K Cp, J/g.K Molar Cp, J/mol.K Salt #1 1.53 1.70 152.1 Salt #2 1.43 1.68 151.5 Salt #3 1.48 1.55 218.3 Salt #4 1.53 1.66 141.1 Salt #5 1.53 1.70 144.0 Salt #6 1.51 1.63 143.5 Salt #7 1.56 1.67 144.3 Salt #8 1.55 1.68 141.0 Salt #9 1.61 1.70 193.7

6.2.3 Thermodynamic properties

The standard thermodynamic properties such as entropy, enthalpy, and Gibbs energy for salt mixtures are determined from the experimental data of melting point and heat capacity in the temperature range of the present study and expression for determining these properties are given in equation 28-30. In thermodynamics, all these three properties are related to heat capacity and its variances with temperature. In the studied temperature range (298.15K-623.15K), they can be described as expression includes heat capacity:

[28]

[29]

[30]

Where Tt is the solid transformation temperature, Tmp is the melting point, ΔHt is enthalpy of solid phase transformation and ΔHfusion is enthalpy of fusion. The standard thermodynamic properties, entropy, enthalpy and Gibbs energies as function of temperature for each compound are expressed in the following section.

6.2.3.1 LiNO3-NaNO3-KNO3 (Salt #1)

The heat capacity data can be divided into two sections for LiNO3-NaNO3-KNO3 compound; (i) solid state 1 (323.15-384.15) K (ii) liquid state (403.15-623.15) K. Accordingly,

the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound.

6.2.3.1.1 Heat capacity of solid state 1: (298.15-384.15) K

The heat capacity data for LiNO3-NaNO3-KNO3 compound in the solid state 1 in the temperature range of 298.15 to 384.15 K is fit to a second order polynomial equation. Eqn. (31) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

[31]

( ) K

R2 = 0.982

6.2.3.1.2 Heat capacity of liquid state: (403.15-623.15) K

The heat capacity data for LiNO3-NaNO3-KNO3 compound in the liquid state in the temperature range of 403.15 to 623.15 K is fit to a linear equation. Eqn. (32) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

J/K.mol [32]

R2 = 0.947

Heat capacity data of the LiNO3-NaNO3-KNO3 compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.1.3 Thermodynamic properties of solid state 1(298.15-384.15) K:

J/K.mol [33]

J/mol [34]

[35]

J/mol

6.2.3.1.4 Thermodynamic properties of liquid state 2(403.15-623.15) K:

[36]

J/K·mol

J/mol [37]

[38]

J/mol

Among the equations above, equation (33)-(35) refer to the thermodynamic properties for solid state; equations (36)-(38) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values in the studied temperature ranges for solid and liquid state are given in Table A.1 and A.2 in appendix A, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.2 NaNO3-NaNO2-KNO3 (Salt #2)

The heat capacity data can be divided into two sections for NaNO3-NaNO2-KNO3 compound; (i) solid state 1 (323.15-392.15) K (ii) liquid state (413.15-623.15) K. Accordingly, the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound.

6.2.3.2.1 Heat capacity of solid state 1: (298.15-392.15) K

The heat capacity data for NaNO3-NaNO2-KNO3 compound in the solid state in the temperature range of 298.15 to 392.15 K is fit to a second order polynomial equation. Eqn. (39) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

· [39]

( ) K

R2 = 0.978

6.2.3.2.2 Heat capacity of liquid state: (403.15-623.15) K

The heat capacity data for NaNO3-NaNO2-KNO3 compound in the liquid state in the temperature range of 403.15 to 623.15 K is fit to a second order polynomial equation. Eqn. (40) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

· [40]

R2 = 0.941

Heat capacity data of the NaNO3-NaNO2-KNO3 compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.2.3 Thermodynamic properties of solid state 1(298.15-392.15) K:

J/K.mol [41]

J/mol [42]

[43]

J/mol

6.2.3.2.4 Thermodynamic properties of liquid state 2(403.15-623.15) K:

J/K·mol [44]

J/mol [45]

[46]

J/mol

Among the equations above, equation (41)-(43) refer to the thermodynamic properties for solid state; equations (44)-(46) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are given in Table B.1 and B.2 in appendix B, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.3 LiNO3-NaNO3 -KNO3-MgK (Salt #3)

The heat capacity data can be divided into two sections for LiNO3-NaNO3 -KNO3-MgK compound; (i) solid state 1 (298.15-364.15) K (ii) liquid state (421.15-623.15) K. Accordingly, the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound.

6.2.3.3.1 Heat capacity of solid state 1: (298.15-364.15) K

The heat capacity data for LiNO3-NaNO3 -KNO3-MgK compound in the solid state in the temperature range of 298.15 to 364.15 K is fit to a second order polynomial equation. Eqn. (47) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

· [47]

( ) K

R2 = 0.995

6.2.3.3.2 Heat capacity of liquid state: (421.15-623.15) K

The heat capacity data for LiNO3-NaNO3 -KNO3-MgK compound in the liquid state in the temperature range of 421.15 to 623.15 K is fit to a second order polynomial equation. Eqn. (48) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

· [48]

R2 = 0.963

Heat capacity data of the LiNO3-NaNO3 -KNO3-MgK compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.3.3 Thermodynamic properties of solid state 1(298.15-364.15) K:

J/K.mol [49]

J/mol [50]

[51]

J/mol

6.2.3.3.4 Thermodynamic properties of liquid state 2(421.15-623.15) K:

J/K·mol [52]

J/mol [53]

[54] [29]

J/mol

Among the equations above, equation (49)-(51) refer to the thermodynamic properties for

solid state; equations (52)-(54) refer to thermodynamic properties of the liquid. The entropy,

enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are

given in Table C.1and C.2 in appendix C, respectively, with the corresponding heat capacity as

function of temperature.

6.2.3.4 LiNO3-NaNO3-KNO3-NaNO2 (Salt #4)

The heat capacity data can be divided into two sections for LiNO3-NaNO3-KNO3-NaNO2 compound; (i) solid state 1 (298.15-363.15) K (ii) liquid state (381.15-623.15) K. Accordingly, the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound. 6.2.3.4.1 Heat capacity of solid state 1: (298.15-363.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-NaNO2 compound in the solid state in the temperature range of 298.15 to 363.15 K is fit to a second order polynomial equation. Eqn. (55) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

· [55]

( ) K

R2 = 0.995

6.2.3.4.2 Heat capacity of liquid state: (381.15-623.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-NaNO2 compound in the liquid state in the temperature range of 381.15 to 623.15 K is fit to a second order polynomial equation. Eqn. (56) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

· [56]

R2 = 0.972

Heat capacity data of the LiNO3-NaNO3 -KNO3-MgK compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.4.3 Thermodynamic properties of solid state 1(298.15-363.15) K:

J/K.mol [57]

J/mol [58]

[59]

J/mol

6.2.3.4.4 Thermodynamic properties of liquid state 2(381.15-623.15) K:

J/K·mol [60]

J/mol [61]

[37]

J/mol [62]

Among the equations above, equation (57)-(59) refer to the thermodynamic properties for solid state; equations (60)-(62) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are given in Table D.1 and D.2 in appendix D, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.5 LiNO3-NaNO3-NaNO2-KNO3-KNO2 (Salt #5)

The heat capacity data can be divided into two sections for LiNO3-NaNO3-NaNO2-KNO3-

KNO2 compound; (i) solid state 1 (298.15-359.15) K (ii) liquid state (375.15-623.15) K.

Accordingly, the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound.

6.2.3.5.1 Heat capacity of solid state 1: (298.15-359.15) K

The heat capacity data for LiNO3-NaNO3-NaNO2-KNO3-KNO2 compound in the solid state in the temperature range of 298.15 to 359.15 K is fit to a second order polynomial equation. Eqn.

(63) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

· [63]

( ) K

R2 = 0.996

6.2.3.5.2 Heat capacity of liquid state: (375.15-623.15) K

The heat capacity data for LiNO3-NaNO3-NaNO2-KNO3-KNO2 compound in the liquid state in the temperature range of 375.15 to 623.15 K is fit to a second order polynomial equation.

Eqn. (64) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

· [64]

R2 = 0.969

Heat capacity data of the LiNO3-NaNO3-NaNO2-KNO3-KNO2 compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.5.3 Thermodynamic properties of Solid state 1(298.15-359.15) K:

J/K.mol [65]

J/mol [66]

[67]

J/mol

6.2.3.5.4 Thermodynamic properties of liquid state 2(375.15-623.15) K:

J/K·mol [68]

J/mol [69]

[45]

J/mol [70]

Among the equations above, equation (65)-(67) refer to the thermodynamic properties for

solid state; equations (68)-(70) refer to thermodynamic properties of the liquid. The entropy,

enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are

given in Table E.1 and E.2 in appendix E, respectively, with the corresponding heat capacity as

function of temperature.

6.2.3.6 LiNO3-NaNO3-KNO3-KNO2 (Salt #6)

The heat capacity data can be divided into two sections for LiNO3-NaNO3-KNO3-KNO2

compound; (i) solid state 1 (298.15-359.15) K (ii) liquid state (375.15-623.15) K. Accordingly,

the heat capacity data are fit to two separate polynomial equations corresponding to the three

phases of the compound.

6.2.3.6.1 Heat capacity of solid state 1: (298.15-365.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-KNO2 compound in the solid state in the

temperature range of 298.15 to 365.15 K is fit to a second order polynomial equation. Eqn. (71)

gives the polynomial equation along with the least square fit parameter (R2) in the temperature

range for the solid state 1 of the compound.

· [71]

( ) K

R2 = 0.998

6.2.3.6.2 Heat capacity of liquid state: (375.15-623.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-KNO2 compound in the liquid state in the temperature range of 375.15 to 623.15 K is given in Table 20. The data is fit to a second order polynomial equation. Eqn. (72) gives the linear equation along with the least square fit parameter

(R2) in the temperature range for the liquid state of the compound.

· [72]

R2 = 0.953

Heat capacity data of the LiNO3-NaNO3-KNO3-KNO2 compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.6.3 Thermodynamic properties of solid state 1(298.15-359.15) K:

J/K.mol [73]

J/mol [74]

[75]

J/mol

6.2.3.6.4 Thermodynamic properties of liquid state 2(375.15-623.15) K:

J/K·mol [76]

J/mol [77]

J/mol [78]

Among the equations above, equation (73)-(75) refer to the thermodynamic properties for solid state; equations (76)-(78) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are

given in Table F.1 and F.2 in appendix F, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.7 LiNO3-KNO3-NaNO2-KNO2 (Salt #7)

The heat capacity data can be divided into three sections; (i) solid state 1 (298.15-354.15)

K (ii) solid state 2 (362.15-373.15) K (iii) liquid state (379.15-623.15) K. Accordingly, the heat capacity data are fit to three separate polynomial equations corresponding to the three phases of the compound.

6.2.3.7.1 Heat capacity of solid state 1: (298.15-354.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-KNO2 compound in the solid state 1 in the temperature range of 298.15 to 354.15 K is fit to a second order polynomial equation. Eqn.

(79) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

· [79]

(298.15-354.15) K

R2 = 0.993

6.2.3.7.2 Heat capacity of solid state 2: (362.15-373.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-KNO2 compound in the solid state 2 in the temperature range of 362.15 to 373.15 K is fit to a second order polynomial equation. Eqn.

(80) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 2 of the compound.

· [80]

R2 = 0.977

6.2.3.7.3 Heat capacity of liquid state: (379.15-623.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-KNO2 compound in the liquid state in the temperature range of 379.15 to 623.15 K is fit to a linear equation. Eqn. (81) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

· [81]

R2 = 0.961

Heat capacity data of the LiNO3-KNO3-NaNO2-KNO2 compound in the two solid states follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.7.4 Thermodynamic properties of solid state 1(298.15-354.15) K:

J/K.mol [82]

J/mol [83]

[84]

J/mol

6.2.3.7.5 Thermodynamic properties of solid state 2(362.15-373.15) K:

J/K·mol [85]

J/mol [86]

[87] [62]

J/mol

6.2.3.7.6 Thermodynamic properties of liquid state (379.15-623.15) K:

J/K.mol [88]

J/mol [89]

J/mol [90]

Among the equations above, equation (82)-(84) refer to the thermodynamic properties for solid 1; equation (85)-(87) refer to the thermodynamic properties for solid 2; equations (88)-(90) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values

in the studied temperature range for solid 1, solid 2 and liquid state are given in Table G.1-G.3 in

appendix G, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.8 LiNO3-KNO3-NaNO2-Mg(NO3)2 (salt #8)

The heat capacity data can be divided into three sections; (i) solid state 1 (298.15-354.15)

K (ii) solid state 2 (362.15-373.15) K (iii) liquid state (379.15-623.15) K. Accordingly, the heat

capacity data are fit to three separate polynomial equations corresponding to the three phases of

the compound.

6.2.3.8.1 Heat capacity of solid state 1: (298.15-337.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in the solid

state 1 in the temperature range of 298.15 to 337.15 K is fit to a second order polynomial

equation. Eqn. (91) gives the polynomial equation along with the least square fit parameter (R2)

in the temperature range for the solid state 1 of the compound.

[91]

(298.15-337.15) K

R2 = 0.994

6.2.3.8.2 Heat capacity of solid state 2: (361.15-364.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in the solid state 2

in the temperature range of 361.15 to 364.15 K is given in Table 4. The data is fit to a second

order polynomial equation. Eqn. (92) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 2 of the compound.

[92]

R2 = 0.992

6.2.3.8.3 Heat capacity of liquid state: (411.15-623.15) K

The heat capacity data for LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in the liquid state in the temperature range of 411.15 to 623.15 K is given in Table 5. The data is fit to a linear equation. Eqn. (93) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

[93]

R2 = 0.934

Heat capacity data of the LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in the two solid states follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.8.4 Solid state 1(298.15-354.15) K:

J/K.mol [94]

J/mol [95]

[96]

J/mol

6.2.3.8.5 Solid state 2(361.15-364.15) K:

J/K.mol [97]

J/mol [98]

[99] [74]

J/mol

6.2.3.8.6 Liquid state (411.15-623.15) K:

J/K.mol [100]

J/mol [101]

J/mol [102]

Among the equations above, equation (94)-(96) refer to the thermodynamic properties for solid 1; equation (97)-(99) refer to the thermodynamic properties for solid 2; equations (100)-

(102) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy

values in the studied temperature range for solid 1, solid 2 and liquid state are given in Table H.1 and H.2 in appendix H, respectively, with the corresponding heat capacity as function of temperature.

6.2.3.9 LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK(Salt #9)

The heat capacity data can be divided into two sections for LiNO3-NaNO3-KNO3-

Mg(NO3)2-MgK compound; (i) solid state 1 (298.15-353.15) K (ii) liquid state (391.15-623.15) K.

Accordingly, the heat capacity data are fit to two separate polynomial equations corresponding to the three phases of the compound.

6.2.3.9.1 Heat capacity of solid state 1: (298.15-353.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK compound in the solid state in the temperature range of 298.15 to 353.15 K is fit to a second order polynomial equation.

Eqn. (103) gives the polynomial equation along with the least square fit parameter (R2) in the temperature range for the solid state 1 of the compound.

[103]

( ) K

R2 = 0.996

6.2.3.9.2 Heat capacity of liquid state: (391.15-623.15) K

The heat capacity data for LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK compound in the liquid state in the temperature range of 391.15 to 623.15 K is fit to a second order polynomial equation.

Eqn. (104) gives the linear equation along with the least square fit parameter (R2) in the temperature range for the liquid state of the compound.

[104]

R2 = 0.951

Heat capacity data of the LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK compound in the solid state follows a second order polynomial curve whereas the heat capacity is linear in the liquid state.

6.2.3.9.3 Solid state 1(298.15-353.15) K:

J/K.mol [105]

J/mol [106]

[107]

J/mol

6.2.3.9.4 Liquid state 2(391.15-623.15) K:

J/K·mol [108]

J/mol [109]

[110]

J/mol

Among the equations above, equation (105)-(107) refer to the thermodynamic properties for solid state; equations (108)-(110) refer to thermodynamic properties of the liquid. The entropy, enthalpy and Gibbs energy values in the studied temperature range for solid and liquid state are given in Table I.1 and I.2 in appendix I, respectively, with the corresponding heat capacity as function of temperature.

6.2.4 Discussion of Gibbs energy change for molten salts

The Gibbs energy change data as function of temperature for 9 systems are given in fig

6.20 and the values at 623.15K are shown in Table 6.7. Every system demonstrates continuous

curve throughout the whole studied temperature range. Most of systems have similar Gibbs

energy change values for each temperature spot due to the comparable compositions and

properties of constituent salts. However, salt #3 and salt #9. Both of these salts have certain

amount of MgKN compound which presents large absolute amount of change of Gibbs energy in

the same studied temperature range [66]. Since the change of Gibbs energy for multi-component

mixture is relevant to that of each constituent salt, the large absolute value of ΔG of MgKN

mainly contributes to the largely negative value of salt #3 and salt #9 shown in fig. 6.20. Besides,

it is observed that most systems contain nitrite salts present lower absolute value of Gibbs energy

change. For example, salt #1 doesn‟t include any nitrite salt and has a relatively high absolute

value of Gibbs energy change as 17.04kJ/mol while other systems having nitrite salts show lower

value varies from 13.72kJ/mol to 15.92kJ/mol.

Fig 6.20 Change of Gibbs energy as function of temperature for molten salt systems

Table 6.7 Change of Gibbs energy values at 623.15K for molten salt systems

S.No. System ΔG/(kJ/mol)

1 LiNO3-NaNO3-KNO3 17.04

2 NaNO3- NaNO2- KNO3 13.72

3 LiNO3- NaNO3- KNO3- MgKN 28.07

4 LiNO3- NaNO3- KNO3- NaNO2 14.43

5 LiNO3- NaNO3- NaNO2-KNO3- KNO2 14.41

6 LiNO3-NaNO3-KNO3-KNO2 15.70

7 LiNO3-KNO3-NaNO2-KNO2 15.92

8 LiNO3-KNO3-NaNO2-Mg(NO3)2 15.83

9 LiNO3-NaNO3-KNO3-Mg(NO3)2 -MgKN 22.17

6.3 Density determination

6.3.1 Density calibration

Several pure molten salts are used to calibrate the density measurement set-up before the actual density measurement. All the density values decrease as function of temperature in the liquid state and follow the same linear equations as described in eq. 4. The experimental values

o at 350 C for KNO3, NaNO3 and LiNO3 are selected to compare with the literature data at the same temperature. The results are shown in Table 6.8. Based on the comparison of the literature data and the experimental data, the variation of density for molten nitrate salt is within in 4%.

Table 6.8 Calibration of density measurements with different pure nitrate salts

Literature density Experimental density Sample g/cm3 g/cm3

LiNO3 1.727 1.701 NaNO3 2.066 2.144 KNO3 1.860 1.855 6.3.2 Results and discussions

The density result of the salt as function of temperature is plotted for all the salts in Figure

6.21 and Figure 6.22. It is observed that the temperature dependence of density above the melting point is different from that in solid state. As known, in solid state, the density of salt has an exponential relation with temperature, while in these liquid cases the density values have linearly dependence with temperature. The stable variation as function of temperature allows the extrapolation of density at even higher temperature. The regression analysis is performed to get the coefficient used for describing eq. 4 and the results for the coefficients are shown in

Table.6.9 [78-80]. It is observed that the change of composition is implied on the coefficient A which indicates the initial point at 150oC. The temperature dependence coefficient B doesn‟t change much with composition, which may be mainly affected by the group of anion and cation.

Table 6.9 Coefficient A and B for density determination of salt #1-salt # 9

A B×103 Salt No. System (g/cm3) (g/cm3·°C)

1 LiNO3-NaNO3-KNO3 2.032 0.493 2 NaNO3- NaNO2- KNO3 2.081 0.570

3 LiNO3- NaNO3- KNO3-MgKN 2.055 0.526 4 LiNO3- NaNO3- KNO3- NaNO2 2.033 0.520 5 LiNO3- NaNO3- NaNO2-KNO3- KNO2 2.018 0.485 6 LiNO3-NaNO3-KNO3-KNO2 2.060 0.554 7 LiNO3-KNO3-NaNO2-KNO2 2.048 0.554 8 LiNO3-KNO3-NaNO2-Mg(NO3)2 2.044 0.524 9 LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK 2.060 0.566

Figure 6.21 The densities of the salt #1-salt #5 as function of temperature

In figure 6.21, all the density values are clustered around 1.98g/cm3 at 150oC to

1.86g/cm3 at high temperature end and the deviation of density between all the mixtures is within

3 in 0.047g/ cm . Among all the salt mixtures, the NaNO3-NaNO2-KNO3 ternary system demonstrates the highest density value throughout the studied temperature range and LiNO3-

NaNO3-KNO3 ternary system, LiNO3- NaNO3-KNO3-NaNO2 quaternary system and LiNO3-

NaNO3-KNO3-NaNO2-KNO2 quinary system show densities at the bottom side of Fig 6.21. For salt #2, which doesn‟t contain any lithium nitrate, the density at every selected temperature spot is obviously higher than that of salt #1, #4 and #5 which have large amount of lithium nitrate.

Moreover, the salt #3 which contains the relatively small amount of lithium nitrate stays in between of salt #1 and salt #2. This comparison illustrates that the addition of lithium nitrate has an offsetting effect on density for molten salt and it is consistent with previous literature reports

[81]. The four systems presented in figure 6.22 also show even closer density values in the studied temperature range. Similarly, salt #6 which contains the least lithium nitrate has the largest density. Salt #7 and salt #8 have almost same composition for the three dominating components, as a result of that, the density curves for both mixtures are determined by the same regression coefficient A and B. Moreover, the larger amount of lithium nitrate involved in these two salt mixtures contributes to the lower density given in figure.6.22, which further verifies the significantly offsetting effect of lithium nitrate on density.

Figure 6.22 The densities of the salt #6-salt #9 as function of temperature

The salt mixtures with maximum and minimum amount of lithium nitrate were plotted and compared with equimolar NaNO3-KNO3 binary system and pure KNO3 salt in Fig.6.23 [82, 83].

It is observed that the NaNO3-KNO3 binary system has very similar density value to that of salt

#2 because of the analogous type and composition of component in both salts. The density of pure KNO3 is slightly lower than the binary salt mixture which indicates the density of NaNO3 is close to but higher than KNO3 in the studied temperature range. Salt #1 shows the lowest density in Fig.6.23 due to the offsetting effect on density caused by lithium nitrate which has been discussed above.

Figure 6.23 Density of the salt #1, salt #2 as function of temperature compared to the

equimolar NaNO3-KNO3 binary system and pure KNO3.

6.4 Thermal energy storage density of molten salts

The energy density which is considered as one of the most significant parameters of TES application can be evaluated by calculation based on the measured density, heat capacity and working temperature range. The equation of the thermal energy storage density (E) at working temperature of 500oC is expressed in equation. 111:

E = Cp·· (500-Tm) [111]

o Where Cp and  are extrapolated heat capacity and density at 500 C, respectively, Tm is melting point for salt mixture. The extrapolation of density and heat capacity is based on the linear temperature dependence for both parameters in molten state and the values are shown in

Table 6.10.

Table 6.10 Extrapolated value of density and heat capacity at 500oC of salt #1-salt #9

Salt Density Heat Capacity System No. (g/mL) (J/g.K)

1 LiNO3-NaNO3-KNO3 1.785 1.70

2 NaNO3- NaNO2- KNO3 1.796 1.68

3 LiNO3-NaNO3-KNO3-MgK 1.773 1.55 4 LiNO3- NaNO3- KNO3- NaNO2 1.792 1.66

5 LiNO3- NaNO3- NaNO2-KNO3- KNO2 1.796 1.70

6 LiNO3-NaNO3-KNO3-KNO2 1.783 1.63

7 LiNO3-KNO3-NaNO2-KNO2 1.771 1.67

8 LiNO3-KNO3-NaNO2-Mg(NO3)2 1.782 1.68

9 LiNO3-NaNO3-KNO3-Mg(NO3)2-MgK 1.777 1.70

The calculated energy density for each salt is given in Table 6.11 compared with that of solar salt (NaNO3-KNO3). All the new synthesized salt mixtures have significantly higher energy density than solar salt and salt #3 shows the highest energy density among the new salts.

Although salt #1 has higher heat capacity and good melting point, the energy density is still the lowest among new salt mixtures given by the effect of low density. The conclusion can be drawn from these observations that the energy density is a property affected by multiple parameters and every part plays an important role in determining the efficiency of energy storage of salt mixtures.

Table 6.11 Energy density of salt #1-salt #9 compare to solar salt

Energy Density Salt No. System 500°C (MJ/m3)

0 NaNO3- KNO3 756 1 LiNO3-NaNO3-KNO3 1162 2 NaNO3- NaNO2- KNO3 1135

3 LiNO3-NaNO3-KNO3-MgKN 1099

4 LiNO3- NaNO3- KNO3- NaNO2 1189 5 LiNO3- NaNO3- NaNO2-KNO3- KNO2 1232 6 LiNO3-NaNO3-KNO3-KNO2 1174 7 LiNO3-KNO3-NaNO2-KNO2 1183 8 LiNO3-KNO3-NaNO2-Mg(NO3)2 1192 9 LiNO3-NaNO3-KNO3-Mg(NO3)2-MgKN 1242

The gravimetric storage density of new molten salts are listed in Table 6.12 and compared with those different storage systems in fig 6.24. It is found that in the parabolic trough working temperature range, the gravimetric storage densities of new molten salts are located on the higher side. Even though some reported sensible energy storage liquids have larger gravimetric density values than the new salts, the maximum working temperatures reveal the instable working condition at 500oC. Taking conversion efficiency, thermal stability and gravimetric storage density into considerations, the new molten salts are the most suitable choices of the sensible heat storage for parabolic trough application.

Fig 6.24 Gravimetric storage density comparison of different energy storage systems as

function of temperature

Table 6.12 Gravimetric storage densities for solar salt and new molten salts

Salt Gravimetric Storage Density System No. 500°C (kJ/kg)

0 NaNO3- KNO3 404

1 LiNO3-NaNO3-KNO3 560

2 NaNO3- NaNO2- KNO3 533

3 LiNO3-NaNO3-KNO3-MgKN 575

4 LiNO3- NaNO3- KNO3- NaNO2 612 5 LiNO3- NaNO3- NaNO2-KNO3- KNO2 595 6 LiNO3-NaNO3-KNO3-KNO2 594

7 LiNO3-KNO3-NaNO2-KNO2 604

8 LiNO3-KNO3-NaNO2-Mg(NO3)2 610

9 LiNO3-NaNO3-KNO3-Mg(NO3)2-MgKN 649

CHAPTER 7

CONCLUSION

The melting points of new molten salts were experimentally determined using DSC.

Different from metals, the melting point was chosen as the peak temperature rather than onset temperature of the endothermic peak due to the low thermal conductivity and broad phase transition range of the molten nitride salt mixture. All of the nine new molten salts have melting points from 89oC to 124oC which are much lower than current sodium-potassium binary solar salt. Some systems such as salt No.1, No.7 and No.8 have solid phase transformation observed from the DSC plots. It is found that the phase transformations of salt No. 7 and No. 8 are mainly contributed to the KNO3-NaNO2 binary system, while the small solid transformation peak of salt

No.1 is resulted from the combined effect of the KNO3-LiNO3 eutectic binary system involved in the ternary salt and another binary system which is composed of the rest components. The heating rate of DSC was revealed as a significant parameter for the any endothermic peak determination. When using lower heating rate, the thermal resistance between the studied sample and the furnace will be minimal and the resolution of peak detection will be enhanced.

The heat capacities of all the multi-component salts (#1 to #9) were determined using DSC and found varying from 1.43 to 1.61 J/g.K at 350oC. The heat capacity in the liquid state demonstrates linear increase trend as function of temperature. On the basis of that, the heat capacity was extrapolated to parabolic trough operating temperature of 500oC. Besides, heat capacity data as function of temperature are fit to polynomial equation and thermodynamic

properties like enthalpy, entropy and Gibbs energies of the compound as function of temperature are subsequently deduced.

Experimental measurements of density of multi-component systems were conducted as

function of temperature in their liquid state. In liquid state, the density values decrease linearly

as temperature increases. The results of those mixtures were compared to the solar salt and

individual constituent salts. The comparison demonstrates that the addition of lithium nitrate

lowers the density, which is consistent with the observation that lithium nitrate has the lowest

density among all the individual salts in the studied temperature range. On the basis of densities,

heat capacities and the melting points, energy storage density for all the new salts were

calculated and compared to the binary solar salt. Among all the new molten salt systems,

LiNO3-NaNO3-KNO3-Mg(NO3)2-MgKN quinary system (salt #9) presents the largest thermal

energy storage density as well as the gravimetric density values. Moreover, the larger thermal

energy storage as well as gravimetric storage densities compared to the solar salt indicate the

better energy storage capacities of new salts for solar power generation systems.

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103

APPENDIX

Appendix A

Table A.1 Thermodynamic properties of LiNO3-KNO3-NaNO3 compound in solid state

(298.15-403.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 342 12.90 4.17 -0.25 299 0.27 0.08 0.00 343 13.17 4.26 -0.26 300 0.59 0.18 0.00 344 13.45 4.36 -0.27 301 0.91 0.28 0.00 345 13.72 4.45 -0.28 302 1.23 0.37 0.00 346 13.99 4.55 -0.29 303 1.54 0.47 0.00 347 14.27 4.64 -0.31 304 1.86 0.56 0.00 348 14.54 4.74 -0.32 305 2.17 0.66 0.00 349 14.81 4.83 -0.33 306 2.48 0.76 0.00 350 15.08 4.93 -0.35 307 2.79 0.85 0.00 351 15.35 5.03 -0.36 308 3.10 0.95 -0.01 352 15.62 5.12 -0.38 309 3.40 1.04 -0.01 353 15.89 5.22 -0.39 310 3.71 1.14 -0.01 354 16.16 5.32 -0.41 311 4.01 1.23 -0.01 355 16.43 5.41 -0.42 312 4.32 1.33 -0.02 356 16.70 5.51 -0.44 313 4.62 1.42 -0.02 357 16.97 5.61 -0.45 314 4.92 1.52 -0.02 358 17.24 5.70 -0.47 315 5.21 1.61 -0.03 359 17.51 5.80 -0.48 316 5.51 1.71 -0.03 360 17.77 5.90 -0.50 317 5.81 1.80 -0.04 361 18.04 6.00 -0.52 318 6.10 1.90 -0.04 362 18.31 6.10 -0.53 319 6.40 1.99 -0.05 363 18.58 6.19 -0.55 320 6.69 2.09 -0.05 364 18.85 6.29 -0.57

104

321 6.98 2.18 -0.06 365 19.11 6.39 -0.59 322 7.27 2.28 -0.07 366 19.38 6.49 -0.60 323 7.56 2.37 -0.07 367 19.65 6.59 -0.62 324 7.85 2.46 -0.08 368 19.92 6.69 -0.64 325 8.14 2.56 -0.09 369 20.18 6.79 -0.66 326 8.42 2.65 -0.09 370 20.45 6.89 -0.68 327 8.71 2.75 -0.10 371 20.72 6.99 -0.70 328 8.99 2.84 -0.11 372 20.98 7.09 -0.72 329 9.28 2.94 -0.12 373 21.25 7.19 -0.74 330 9.56 3.03 -0.12 374 21.52 7.29 -0.76 331 9.84 3.13 -0.13 375 21.79 7.39 -0.78 332 10.12 3.22 -0.14 376 22.05 7.50 -0.80 333 10.41 3.31 -0.15 377 22.32 7.60 -0.82 334 10.69 3.41 -0.16 378 22.59 7.70 -0.84 335 10.96 3.50 -0.17 379 22.86 7.80 -0.86 336 11.24 3.60 -0.18 380 23.12 7.91 -0.88 337 11.52 3.69 -0.19 381 23.39 8.01 -0.90 338 11.80 3.79 -0.20 382 23.66 8.11 -0.93 339 12.07 3.88 -0.21 383 23.93 8.22 -0.95 340 12.35 3.98 -0.22 384 24.20 8.32 -0.97 341 12.63 4.07 -0.23 384.15 24.24 8.34 -0.97

Table A.2 Thermodynamic properties of LiNO3-KNO3-NaNO3 compound in liquid state

(403.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 403.15 42.87 15.65 -1.63 514 70.70 28.38 -7.96 404 43.10 15.75 -1.67 515 70.94 28.50 -8.03 405 43.37 15.85 -1.71 516 71.17 28.63 -8.10 406 43.63 15.96 -1.75 517 71.41 28.75 -8.17 407 43.90 16.07 -1.80 518 71.65 28.87 -8.24 408 44.17 16.18 -1.84 519 71.88 28.99 -8.31 409 44.43 16.29 -1.89 520 72.12 29.11 -8.39 410 44.70 16.40 -1.93 521 72.35 29.24 -8.46 411 44.96 16.51 -1.97 522 72.59 29.36 -8.53 412 45.23 16.62 -2.02 523 72.82 29.48 -8.60

105

413 45.49 16.72 -2.06 524 73.06 29.60 -8.68 414 45.76 16.83 -2.11 525 73.29 29.73 -8.75 415 46.02 16.94 -2.16 526 73.52 29.85 -8.82 416 46.29 17.05 -2.20 527 73.76 29.97 -8.90 417 46.55 17.16 -2.25 528 73.99 30.10 -8.97 418 46.81 17.27 -2.30 529 74.22 30.22 -9.04 419 47.08 17.38 -2.34 530 74.46 30.34 -9.12 420 47.34 17.49 -2.39 531 74.69 30.47 -9.19 421 47.60 17.60 -2.44 532 74.92 30.59 -9.27 422 47.86 17.71 -2.49 533 75.16 30.71 -9.34 423 48.13 17.82 -2.53 534 75.39 30.84 -9.42 424 48.39 17.93 -2.58 535 75.62 30.96 -9.49 425 48.65 18.04 -2.63 536 75.85 31.09 -9.57 426 48.91 18.16 -2.68 537 76.08 31.21 -9.65 427 49.17 18.27 -2.73 538 76.32 31.34 -9.72 428 49.43 18.38 -2.78 539 76.55 31.46 -9.80 429 49.69 18.49 -2.83 540 76.78 31.58 -9.88 430 49.95 18.60 -2.88 541 77.01 31.71 -9.95 431 50.21 18.71 -2.93 542 77.24 31.83 -10.03 432 50.46 18.82 -2.98 543 77.47 31.96 -10.11 433 50.72 18.94 -3.03 544 77.70 32.08 -10.18 434 50.98 19.05 -3.08 545 77.93 32.21 -10.26 435 51.24 19.16 -3.13 546 78.16 32.33 -10.34 436 51.49 19.27 -3.18 547 78.39 32.46 -10.42 437 51.75 19.38 -3.23 548 78.62 32.59 -10.50 438 52.01 19.50 -3.28 549 78.85 32.71 -10.58 439 52.26 19.61 -3.34 550 79.08 32.84 -10.66 440 52.52 19.72 -3.39 551 79.31 32.96 -10.73 441 52.78 19.83 -3.44 552 79.53 33.09 -10.81 442 53.03 19.95 -3.49 553 79.76 33.22 -10.89 443 53.29 20.06 -3.55 554 79.99 33.34 -10.97 444 53.54 20.17 -3.60 555 80.22 33.47 -11.05 445 53.80 20.28 -3.65 556 80.45 33.59 -11.13 446 54.05 20.40 -3.71 557 80.67 33.72 -11.21 447 54.30 20.51 -3.76 558 80.90 33.85 -11.30 448 54.56 20.62 -3.82 559 81.13 33.98 -11.38 449 54.81 20.74 -3.87 560 81.36 34.10 -11.46 450 55.06 20.85 -3.93 561 81.58 34.23 -11.54 451 55.32 20.97 -3.98 562 81.81 34.36 -11.62 452 55.57 21.08 -4.04 563 82.04 34.48 -11.70

106

453 55.82 21.19 -4.09 564 82.26 34.61 -11.78 454 56.07 21.31 -4.15 565 82.49 34.74 -11.87 455 56.33 21.42 -4.21 566 82.71 34.87 -11.95 456 56.58 21.54 -4.26 567 82.94 34.99 -12.03 457 56.83 21.65 -4.32 568 83.17 35.12 -12.12 458 57.08 21.77 -4.38 569 83.39 35.25 -12.20 459 57.33 21.88 -4.43 570 83.62 35.38 -12.28 460 57.58 22.00 -4.49 571 83.84 35.51 -12.37 461 57.83 22.11 -4.55 572 84.07 35.64 -12.45 462 58.08 22.23 -4.61 573 84.29 35.76 -12.53 463 58.33 22.34 -4.66 574 84.52 35.89 -12.62 464 58.58 22.46 -4.72 575 84.74 36.02 -12.70 465 58.83 22.57 -4.78 576 84.96 36.15 -12.79 466 59.07 22.69 -4.84 577 85.19 36.28 -12.87 467 59.32 22.80 -4.90 578 85.41 36.41 -12.96 468 59.57 22.92 -4.96 579 85.64 36.54 -13.04 469 59.82 23.04 -5.02 580 85.86 36.67 -13.13 470 60.07 23.15 -5.08 581 86.08 36.80 -13.22 471 60.31 23.27 -5.14 582 86.31 36.93 -13.30 472 60.56 23.39 -5.20 583 86.53 37.06 -13.39 473 60.81 23.50 -5.26 584 86.75 37.19 -13.48 474 61.05 23.62 -5.32 585 86.97 37.32 -13.56 475 61.30 23.73 -5.38 586 87.20 37.45 -13.65 476 61.55 23.85 -5.44 587 87.42 37.58 -13.74 477 61.79 23.97 -5.51 588 87.64 37.71 -13.82 478 62.04 24.09 -5.57 589 87.86 37.84 -13.91 479 62.28 24.20 -5.63 590 88.08 37.97 -14.00 480 62.53 24.32 -5.69 591 88.31 38.10 -14.09 481 62.77 24.44 -5.75 592 88.53 38.23 -14.18 482 63.01 24.56 -5.82 593 88.75 38.36 -14.26 483 63.26 24.67 -5.88 594 88.97 38.49 -14.35 484 63.50 24.79 -5.94 595 89.19 38.63 -14.44 485 63.75 24.91 -6.01 596 89.41 38.76 -14.53 486 63.99 25.03 -6.07 597 89.63 38.89 -14.62 487 64.23 25.15 -6.14 598 89.85 39.02 -14.71 488 64.48 25.26 -6.20 599 90.07 39.15 -14.80 489 64.72 25.38 -6.26 600 90.29 39.28 -14.89 490 64.96 25.50 -6.33 601 90.51 39.42 -14.98 491 65.20 25.62 -6.39 602 90.73 39.55 -15.07 492 65.44 25.74 -6.46 603 90.95 39.68 -15.16

107

493 65.69 25.86 -6.53 604 91.17 39.81 -15.25 494 65.93 25.98 -6.59 605 91.39 39.94 -15.35 495 66.17 26.10 -6.66 606 91.61 40.08 -15.44 496 66.41 26.21 -6.72 607 91.83 40.21 -15.53 497 66.65 26.33 -6.79 608 92.05 40.34 -15.62 498 66.89 26.45 -6.86 609 92.26 40.48 -15.71 499 67.13 26.57 -6.92 610 92.48 40.61 -15.81 500 67.37 26.69 -6.99 611 92.70 40.74 -15.90 501 67.61 26.81 -7.06 612 92.92 40.88 -15.99 502 67.85 26.93 -7.13 613 93.14 41.01 -16.08 503 68.09 27.05 -7.19 614 93.35 41.14 -16.18 504 68.33 27.17 -7.26 615 93.57 41.28 -16.27 505 68.56 27.29 -7.33 616 93.79 41.41 -16.36 506 68.80 27.41 -7.40 617 94.01 41.54 -16.46 507 69.04 27.54 -7.47 618 94.22 41.68 -16.55 508 69.28 27.66 -7.54 619 94.44 41.81 -16.65 509 69.52 27.78 -7.61 620 94.66 41.95 -16.74 510 69.75 27.90 -7.68 621 94.87 42.08 -16.84 511 69.99 28.02 -7.75 622 95.09 42.22 -16.93 512 70.23 28.14 -7.82 623 95.31 42.35 -17.03 513 70.47 28.26 -7.89 623.15 95.34 42.37 -17.04

108

Appendix B

Table B.1 Thermodynamic properties of NaNO3-NaNO2-NaNO3 compound in liquid state

(298.15-392.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 347 12.33 3.82 -0.46 299 0.22 0.06 0.00 348 12.58 3.90 -0.48 300 0.49 0.14 -0.01 349 12.83 3.98 -0.49 301 0.75 0.22 -0.01 350 13.07 4.06 -0.51 302 1.01 0.29 -0.01 351 13.32 4.15 -0.53 303 1.27 0.37 -0.02 352 13.56 4.23 -0.54 304 1.53 0.44 -0.02 353 13.81 4.31 -0.56 305 1.79 0.52 -0.03 354 14.05 4.40 -0.58 306 2.05 0.59 -0.03 355 14.30 4.48 -0.60 307 2.30 0.67 -0.04 356 14.55 4.56 -0.61 308 2.56 0.75 -0.04 357 14.79 4.65 -0.63 309 2.82 0.82 -0.05 358 15.04 4.73 -0.65 310 3.08 0.90 -0.05 359 15.28 4.82 -0.67 311 3.33 0.98 -0.06 360 15.53 4.90 -0.69 312 3.59 1.05 -0.07 361 15.77 4.98 -0.71 313 3.84 1.13 -0.07 362 16.02 5.07 -0.73 314 4.10 1.21 -0.08 363 16.26 5.15 -0.75 315 4.35 1.28 -0.09 364 16.51 5.24 -0.77 316 4.61 1.36 -0.10 365 16.75 5.33 -0.79 317 4.86 1.44 -0.10 366 17.00 5.41 -0.81 318 5.11 1.51 -0.11 367 17.24 5.50 -0.83 319 5.37 1.59 -0.12 368 17.49 5.58 -0.85 320 5.62 1.67 -0.13 369 17.73 5.67 -0.87 321 5.87 1.75 -0.14 370 17.98 5.76 -0.89 322 6.12 1.82 -0.15 371 18.22 5.84 -0.92 323 6.37 1.90 -0.16 372 18.47 5.93 -0.94 324 6.63 1.98 -0.17 373 18.71 6.02 -0.96 325 6.88 2.06 -0.18 374 18.96 6.11 -0.98 326 7.13 2.14 -0.19 375 19.20 6.20 -1.00 327 7.38 2.22 -0.20 376 19.45 6.28 -1.03 328 7.63 2.29 -0.21 377 19.69 6.37 -1.05 329 7.88 2.37 -0.22 378 19.94 6.46 -1.07

109

330 8.13 2.45 -0.23 379 20.18 6.55 -1.10 331 8.38 2.53 -0.24 380 20.43 6.64 -1.12 332 8.63 2.61 -0.25 381 20.68 6.73 -1.15 333 8.87 2.69 -0.27 382 20.92 6.82 -1.17 334 9.12 2.77 -0.28 383 21.17 6.91 -1.20 335 9.37 2.85 -0.29 384 21.41 7.00 -1.22 336 9.62 2.93 -0.30 385 21.66 7.09 -1.25 337 9.87 3.01 -0.32 386 21.91 7.18 -1.27 338 10.11 3.09 -0.33 387 22.15 7.27 -1.30 339 10.36 3.17 -0.34 388 22.40 7.37 -1.32 340 10.61 3.25 -0.36 389 22.65 7.46 -1.35 341 10.86 3.33 -0.37 390 22.89 7.55 -1.38 342 11.10 3.41 -0.39 391 23.14 7.64 -1.40 343 11.35 3.49 -0.40 392 23.39 7.74 -1.43 344 11.60 3.57 -0.42 392.15 23.42 7.75 -1.44 345 11.84 3.65 -0.43

Table B.2 Thermodynamic properties of NaNO3-NaNO2-NaNO3 compound in liquid state

(413.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 414 32.80 11.49 -2.09 520 56.08 22.35 -6.82 415 33.02 11.58 -2.12 521 56.30 22.46 -6.87 416 33.25 11.67 -2.16 522 56.51 22.57 -6.93 417 33.48 11.77 -2.19 523 56.72 22.68 -6.98 418 33.70 11.86 -2.23 524 56.94 22.79 -7.04 419 33.93 11.96 -2.26 525 57.15 22.90 -7.10 420 34.16 12.05 -2.29 526 57.36 23.02 -7.16 421 34.38 12.15 -2.33 527 57.57 23.13 -7.21 422 34.61 12.24 -2.36 528 57.79 23.24 -7.27 423 34.83 12.34 -2.40 529 58.00 23.35 -7.33 424 35.06 12.43 -2.43 530 58.21 23.47 -7.39 425 35.29 12.53 -2.47 531 58.42 23.58 -7.45 426 35.51 12.63 -2.50 532 58.64 23.69 -7.50 427 35.74 12.72 -2.54 533 58.85 23.80 -7.56 428 35.96 12.82 -2.57 534 59.06 23.92 -7.62 429 36.19 12.91 -2.61 535 59.27 24.03 -7.68

110

430 36.41 13.01 -2.65 536 59.48 24.14 -7.74 431 36.63 13.11 -2.68 537 59.70 24.26 -7.80 432 36.86 13.20 -2.72 538 59.91 24.37 -7.86 433 37.08 13.30 -2.76 539 60.12 24.49 -7.92 434 37.31 13.40 -2.79 540 60.33 24.60 -7.98 435 37.53 13.50 -2.83 541 60.54 24.71 -8.04 436 37.75 13.59 -2.87 542 60.75 24.83 -8.10 437 37.98 13.69 -2.91 543 60.96 24.94 -8.16 438 38.20 13.79 -2.94 544 61.18 25.06 -8.22 439 38.42 13.89 -2.98 545 61.39 25.17 -8.28 440 38.65 13.98 -3.02 546 61.60 25.29 -8.35 441 38.87 14.08 -3.06 547 61.81 25.40 -8.41 442 39.09 14.18 -3.10 548 62.02 25.52 -8.47 443 39.32 14.28 -3.14 549 62.23 25.63 -8.53 444 39.54 14.38 -3.18 550 62.44 25.75 -8.59 445 39.76 14.48 -3.22 551 62.65 25.86 -8.66 446 39.98 14.58 -3.26 552 62.86 25.98 -8.72 447 40.21 14.68 -3.30 553 63.07 26.10 -8.78 448 40.43 14.77 -3.34 554 63.28 26.21 -8.84 449 40.65 14.87 -3.38 555 63.49 26.33 -8.91 450 40.87 14.97 -3.42 556 63.70 26.45 -8.97 451 41.09 15.07 -3.46 557 63.91 26.56 -9.04 452 41.31 15.17 -3.50 558 64.12 26.68 -9.10 453 41.54 15.27 -3.54 559 64.33 26.80 -9.16 454 41.76 15.37 -3.58 560 64.54 26.91 -9.23 455 41.98 15.47 -3.63 561 64.75 27.03 -9.29 456 42.20 15.57 -3.67 562 64.96 27.15 -9.36 457 42.42 15.68 -3.71 563 65.17 27.27 -9.42 458 42.64 15.78 -3.75 564 65.38 27.38 -9.49 459 42.86 15.88 -3.80 565 65.59 27.50 -9.55 460 43.08 15.98 -3.84 566 65.80 27.62 -9.62 461 43.30 16.08 -3.88 567 66.00 27.74 -9.69 462 43.52 16.18 -3.93 568 66.21 27.86 -9.75 463 43.74 16.28 -3.97 569 66.42 27.98 -9.82 464 43.96 16.39 -4.01 570 66.63 28.10 -9.88 465 44.18 16.49 -4.06 571 66.84 28.21 -9.95 466 44.40 16.59 -4.10 572 67.05 28.33 -10.02 467 44.62 16.69 -4.15 573 67.26 28.45 -10.09 468 44.84 16.80 -4.19 574 67.47 28.57 -10.15 469 45.06 16.90 -4.24 575 67.67 28.69 -10.22

111

470 45.28 17.00 -4.28 576 67.88 28.81 -10.29 471 45.50 17.10 -4.33 577 68.09 28.93 -10.36 472 45.72 17.21 -4.37 578 68.30 29.05 -10.42 473 45.93 17.31 -4.42 579 68.51 29.17 -10.49 474 46.15 17.41 -4.46 580 68.71 29.29 -10.56 475 46.37 17.52 -4.51 581 68.92 29.41 -10.63 476 46.59 17.62 -4.56 582 69.13 29.53 -10.70 477 46.81 17.73 -4.60 583 69.34 29.66 -10.77 478 47.03 17.83 -4.65 584 69.54 29.78 -10.84 479 47.24 17.93 -4.70 585 69.75 29.90 -10.91 480 47.46 18.04 -4.74 586 69.96 30.02 -10.98 481 47.68 18.14 -4.79 587 70.17 30.14 -11.05 482 47.90 18.25 -4.84 588 70.37 30.26 -11.12 483 48.12 18.35 -4.89 589 70.58 30.38 -11.19 484 48.33 18.46 -4.94 590 70.79 30.51 -11.26 485 48.55 18.56 -4.98 591 71.00 30.63 -11.33 486 48.77 18.67 -5.03 592 71.20 30.75 -11.40 487 48.98 18.77 -5.08 593 71.41 30.87 -11.47 488 49.20 18.88 -5.13 594 71.62 31.00 -11.54 489 49.42 18.99 -5.18 595 71.82 31.12 -11.62 490 49.63 19.09 -5.23 596 72.03 31.24 -11.69 491 49.85 19.20 -5.28 597 72.24 31.37 -11.76 492 50.07 19.30 -5.33 598 72.44 31.49 -11.83 493 50.28 19.41 -5.38 599 72.65 31.61 -11.90 494 50.50 19.52 -5.43 600 72.85 31.74 -11.98 495 50.72 19.62 -5.48 601 73.06 31.86 -12.05 496 50.93 19.73 -5.53 602 73.27 31.98 -12.12 497 51.15 19.84 -5.58 603 73.47 32.11 -12.20 498 51.36 19.95 -5.63 604 73.68 32.23 -12.27 499 51.58 20.05 -5.68 605 73.89 32.36 -12.34 500 51.80 20.16 -5.74 606 74.09 32.48 -12.42 501 52.01 20.27 -5.79 607 74.30 32.61 -12.49 502 52.23 20.38 -5.84 608 74.50 32.73 -12.57 503 52.44 20.49 -5.89 609 74.71 32.86 -12.64 504 52.66 20.59 -5.95 610 74.91 32.98 -12.72 505 52.87 20.70 -6.00 611 75.12 33.11 -12.79 506 53.09 20.81 -6.05 612 75.32 33.23 -12.87 507 53.30 20.92 -6.10 613 75.53 33.36 -12.94 508 53.52 21.03 -6.16 614 75.73 33.48 -13.02 509 53.73 21.14 -6.21 615 75.94 33.61 -13.09

112

510 53.94 21.25 -6.27 616 76.15 33.74 -13.17 511 54.16 21.36 -6.32 617 76.35 33.86 -13.25 512 54.37 21.47 -6.37 618 76.56 33.99 -13.32 513 54.59 21.58 -6.43 619 76.76 34.12 -13.40 514 54.80 21.69 -6.48 620 76.96 34.24 -13.48 515 55.02 21.80 -6.54 621 77.17 34.37 -13.55 516 55.23 21.91 -6.59 622 77.37 34.50 -13.63 517 55.44 22.02 -6.65 623 77.58 34.62 -13.71 518 55.66 22.13 -6.70 623.15 77.61 34.64 -13.72

113

Appendix C

Table C.1. Thermodynamic properties of LiNO3-NaNO3-KNO3-MgK compound in solid

state (298.15-364.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 333 19.37 6.11 -0.34 299 0.48 0.14 0.00 334 19.92 6.29 -0.36 300 1.04 0.31 0.00 335 20.47 6.47 -0.38 301 1.60 0.48 0.00 336 21.02 6.66 -0.40 302 2.16 0.65 0.00 337 21.56 6.84 -0.42 303 2.72 0.82 -0.01 338 22.11 7.03 -0.45 304 3.29 0.99 -0.01 339 22.66 7.21 -0.47 305 3.85 1.16 -0.01 340 23.21 7.40 -0.49 306 4.41 1.33 -0.02 341 23.75 7.58 -0.52 307 4.96 1.50 -0.02 342 24.30 7.77 -0.54 308 5.52 1.67 -0.03 343 24.85 7.96 -0.56 309 6.08 1.85 -0.03 344 25.39 8.15 -0.59 310 6.64 2.02 -0.04 345 25.94 8.33 -0.62 311 7.20 2.19 -0.05 346 26.48 8.52 -0.64 312 7.76 2.36 -0.06 347 27.03 8.71 -0.67 313 8.31 2.54 -0.06 348 27.57 8.90 -0.70 314 8.87 2.71 -0.07 349 28.12 9.09 -0.72 315 9.42 2.89 -0.08 350 28.66 9.28 -0.75 316 9.98 3.06 -0.09 351 29.21 9.47 -0.78 317 10.54 3.24 -0.10 352 29.75 9.66 -0.81 318 11.09 3.41 -0.11 353 30.29 9.85 -0.84 319 11.64 3.59 -0.12 354 30.84 10.04 -0.87 320 12.20 3.77 -0.14 355 31.38 10.24 -0.90 321 12.75 3.95 -0.15 356 31.92 10.43 -0.94 322 13.31 4.12 -0.16 357 32.46 10.62 -0.97 323 13.86 4.30 -0.18 358 33.00 10.82 -1.00 324 14.41 4.48 -0.19 359 33.55 11.01 -1.03 325 14.96 4.66 -0.20 360 34.09 11.20 -1.07 326 15.52 4.84 -0.22 361 34.63 11.40 -1.10 327 16.07 5.02 -0.24 362 35.17 11.59 -1.14 328 16.62 5.20 -0.25 363 35.71 11.79 -1.17 329 17.17 5.38 -0.27 364 36.25 11.99 -1.21

114

330 17.72 5.56 -0.29 364.15 36.33 12.02 -1.21 331 18.27 5.74 -0.30 332 18.82 5.93 -0.32

Table C.2 Thermodynamic properties of LiNO3-NaNO3-KNO3-MgK compound in liquid

state (421.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 421.15 74.28 26.73 -4.55 523 117.88 47.25 -14.40 422 74.68 26.90 -4.61 524 118.27 47.45 -14.52 423 75.15 27.10 -4.68 525 118.66 47.66 -14.64 424 75.62 27.30 -4.76 526 119.04 47.86 -14.76 425 76.08 27.50 -4.84 527 119.43 48.07 -14.88 426 76.55 27.70 -4.91 528 119.82 48.27 -15.00 427 77.02 27.90 -4.99 529 120.21 48.47 -15.12 428 77.48 28.10 -5.07 530 120.59 48.68 -15.24 429 77.95 28.30 -5.14 531 120.98 48.88 -15.36 430 78.41 28.49 -5.22 532 121.37 49.09 -15.48 431 78.87 28.69 -5.30 533 121.75 49.29 -15.60 432 79.33 28.89 -5.38 534 122.13 49.50 -15.72 433 79.79 29.09 -5.46 535 122.52 49.70 -15.84 434 80.25 29.29 -5.54 536 122.90 49.91 -15.97 435 80.71 29.49 -5.62 537 123.28 50.11 -16.09 436 81.17 29.69 -5.70 538 123.66 50.32 -16.21 437 81.63 29.89 -5.78 539 124.04 50.52 -16.34 438 82.08 30.09 -5.86 540 124.42 50.73 -16.46 439 82.54 30.29 -5.95 541 124.80 50.93 -16.59 440 82.99 30.49 -6.03 542 125.18 51.14 -16.71 441 83.45 30.69 -6.11 543 125.56 51.34 -16.84 442 83.90 30.89 -6.20 544 125.94 51.55 -16.96 443 84.35 31.09 -6.28 545 126.32 51.75 -17.09 444 84.80 31.29 -6.36 546 126.69 51.96 -17.21 445 85.25 31.49 -6.45 547 127.07 52.17 -17.34 446 85.70 31.69 -6.54 548 127.45 52.37 -17.47

115

447 86.15 31.89 -6.62 549 127.82 52.58 -17.60 448 86.59 32.09 -6.71 550 128.20 52.78 -17.72 449 87.04 32.29 -6.79 551 128.57 52.99 -17.85 450 87.48 32.49 -6.88 552 128.94 53.19 -17.98 451 87.93 32.69 -6.97 553 129.32 53.40 -18.11 452 88.37 32.89 -7.06 554 129.69 53.61 -18.24 453 88.81 33.09 -7.15 555 130.06 53.81 -18.37 454 89.26 33.29 -7.24 556 130.43 54.02 -18.50 455 89.70 33.49 -7.32 557 130.80 54.22 -18.63 456 90.14 33.69 -7.41 558 131.17 54.43 -18.76 457 90.58 33.89 -7.50 559 131.54 54.64 -18.89 458 91.02 34.09 -7.60 560 131.91 54.84 -19.02 459 91.45 34.29 -7.69 561 132.28 55.05 -19.16 460 91.89 34.49 -7.78 562 132.64 55.26 -19.29 461 92.33 34.69 -7.87 563 133.01 55.46 -19.42 462 92.76 34.89 -7.96 564 133.38 55.67 -19.56 463 93.19 35.09 -8.06 565 133.74 55.88 -19.69 464 93.63 35.29 -8.15 566 134.11 56.08 -19.82 465 94.06 35.49 -8.24 567 134.47 56.29 -19.96 466 94.49 35.70 -8.34 568 134.84 56.50 -20.09 467 94.92 35.90 -8.43 569 135.20 56.70 -20.23 468 95.35 36.10 -8.53 570 135.57 56.91 -20.36 469 95.78 36.30 -8.62 571 135.93 57.12 -20.50 470 96.21 36.50 -8.72 572 136.29 57.32 -20.63 471 96.64 36.70 -8.82 573 136.65 57.53 -20.77 472 97.07 36.90 -8.91 574 137.01 57.74 -20.91 473 97.49 37.10 -9.01 575 137.37 57.95 -21.04 474 97.92 37.31 -9.11 576 137.73 58.15 -21.18 475 98.34 37.51 -9.21 577 138.09 58.36 -21.32 476 98.77 37.71 -9.30 578 138.45 58.57 -21.46 477 99.19 37.91 -9.40 579 138.81 58.77 -21.60 478 99.61 38.11 -9.50 580 139.17 58.98 -21.74 479 100.04 38.31 -9.60 581 139.53 59.19 -21.88 480 100.46 38.52 -9.70 582 139.88 59.40 -22.02 481 100.88 38.72 -9.80 583 140.24 59.60 -22.16 482 101.30 38.92 -9.90 584 140.60 59.81 -22.30 483 101.71 39.12 -10.01 585 140.95 60.02 -22.44 484 102.13 39.32 -10.11 586 141.31 60.23 -22.58 485 102.55 39.53 -10.21 587 141.66 60.44 -22.72 486 102.97 39.73 -10.31 588 142.01 60.64 -22.86

116

487 103.38 39.93 -10.42 589 142.37 60.85 -23.00 488 103.80 40.13 -10.52 590 142.72 61.06 -23.15 489 104.21 40.34 -10.62 591 143.07 61.27 -23.29 490 104.62 40.54 -10.73 592 143.42 61.48 -23.43 491 105.04 40.74 -10.83 593 143.78 61.68 -23.58 492 105.45 40.94 -10.94 594 144.13 61.89 -23.72 493 105.86 41.14 -11.04 595 144.48 62.10 -23.86 494 106.27 41.35 -11.15 596 144.83 62.31 -24.01 495 106.68 41.55 -11.26 597 145.18 62.52 -24.15 496 107.09 41.75 -11.36 598 145.52 62.73 -24.30 497 107.50 41.96 -11.47 599 145.87 62.93 -24.44 498 107.91 42.16 -11.58 600 146.22 63.14 -24.59 499 108.31 42.36 -11.69 601 146.57 63.35 -24.74 500 108.72 42.56 -11.79 602 146.92 63.56 -24.88 501 109.12 42.77 -11.90 603 147.26 63.77 -25.03 502 109.53 42.97 -12.01 604 147.61 63.98 -25.18 503 109.93 43.17 -12.12 605 147.95 64.19 -25.33 504 110.34 43.38 -12.23 606 148.30 64.39 -25.47 505 110.74 43.58 -12.34 607 148.64 64.60 -25.62 506 111.14 43.78 -12.45 608 148.99 64.81 -25.77 507 111.54 43.99 -12.57 609 149.33 65.02 -25.92 508 111.94 44.19 -12.68 610 149.67 65.23 -26.07 509 112.34 44.39 -12.79 611 150.02 65.44 -26.22 510 112.74 44.60 -12.90 612 150.36 65.65 -26.37 511 113.14 44.80 -13.02 613 150.70 65.86 -26.52 512 113.54 45.00 -13.13 614 151.04 66.07 -26.67 513 113.94 45.21 -13.24 615 151.38 66.28 -26.82 514 114.33 45.41 -13.36 616 151.72 66.49 -26.97 515 114.73 45.62 -13.47 617 152.06 66.70 -27.13 516 115.13 45.82 -13.59 618 152.40 66.91 -27.28 517 115.52 46.02 -13.70 619 152.74 67.12 -27.43 518 115.91 46.23 -13.82 620 153.08 67.33 -27.58 519 116.31 46.43 -13.93 621 153.42 67.54 -27.74 520 116.70 46.64 -14.05 622 153.75 67.74 -27.89 521 117.09 46.84 -14.17 623 154.09 67.95 -28.04 522 117.48 47.04 -14.28 623.15 154.14 67.99 -28.07

117

Appendix D

Table D.1 Thermodynamic properties of LiNO3-NaNO3-KNO3-NaNO2 compound in solid state

(298.15-363.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 299 0.21 0.06 0.00 333 8.67 2.77 -0.12 300 0.47 0.14 0.00 334 8.91 2.85 -0.12 301 0.72 0.22 0.00 335 9.16 2.93 -0.13 302 0.97 0.29 0.00 336 9.40 3.02 -0.14 303 1.22 0.37 0.00 337 9.64 3.10 -0.15 304 1.47 0.45 0.00 338 9.89 3.18 -0.16 305 1.72 0.53 0.00 339 10.13 3.27 -0.17 306 1.97 0.60 0.00 340 10.37 3.35 -0.18 307 2.23 0.68 0.00 341 10.61 3.43 -0.19 308 2.48 0.76 0.00 342 10.85 3.52 -0.19 309 2.73 0.84 0.00 343 11.09 3.60 -0.20 310 2.98 0.92 -0.01 344 11.34 3.69 -0.21 311 3.23 0.99 -0.01 345 11.58 3.77 -0.22 312 3.48 1.07 -0.01 346 11.82 3.85 -0.24 313 3.73 1.15 -0.01 347 12.06 3.94 -0.25 314 3.98 1.23 -0.02 348 12.30 4.02 -0.26 315 4.23 1.31 -0.02 349 12.54 4.11 -0.27 316 4.47 1.39 -0.02 350 12.77 4.19 -0.28 317 4.72 1.47 -0.03 351 13.01 4.28 -0.29 318 4.97 1.55 -0.03 352 13.25 4.36 -0.30 319 5.22 1.63 -0.03 353 13.49 4.45 -0.32 320 5.47 1.71 -0.04 354 13.73 4.53 -0.33 321 5.72 1.79 -0.04 355 13.96 4.62 -0.34 322 5.96 1.87 -0.05 356 14.20 4.70 -0.35 323 6.21 1.95 -0.05 357 14.44 4.79 -0.37 324 6.46 2.03 -0.06 358 14.67 4.87 -0.38 325 6.70 2.11 -0.06 359 14.91 4.96 -0.39 326 6.95 2.20 -0.07 360 15.14 5.04 -0.41 327 7.20 2.28 -0.08 361 15.38 5.13 -0.42 328 7.44 2.36 -0.08 362 15.61 5.22 -0.43 329 7.69 2.44 -0.09 363 15.84 5.30 -0.45 330 7.93 2.52 -0.10 363.15 15.88 5.32 -0.45

118

331 8.18 2.60 -0.10

Table D.2 Thermodynamic properties of LiNO3-NaNO3-KNO3-NaNO2 compound in liquid

state (381.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 381.15 22.81 7.65 -1.04 503 56.39 22.42 -5.94 382 23.07 7.75 -1.06 504 56.64 22.55 -6.00 383 23.38 7.87 -1.09 505 56.89 22.67 -6.06 384 23.69 7.98 -1.11 506 57.13 22.80 -6.11 385 23.99 8.10 -1.13 507 57.38 22.92 -6.17 386 24.30 8.22 -1.16 508 57.63 23.05 -6.23 387 24.60 8.34 -1.18 509 57.87 23.17 -6.29 388 24.91 8.46 -1.21 510 58.12 23.30 -6.34 389 25.21 8.57 -1.23 511 58.36 23.42 -6.40 390 25.51 8.69 -1.26 512 58.61 23.55 -6.46 391 25.82 8.81 -1.28 513 58.85 23.67 -6.52 392 26.12 8.93 -1.31 514 59.10 23.80 -6.58 393 26.42 9.05 -1.34 515 59.34 23.92 -6.64 394 26.72 9.17 -1.36 516 59.59 24.05 -6.70 395 27.02 9.28 -1.39 517 59.83 24.17 -6.76 396 27.32 9.40 -1.42 518 60.07 24.30 -6.82 397 27.62 9.52 -1.44 519 60.32 24.43 -6.88 398 27.92 9.64 -1.47 520 60.56 24.55 -6.94 399 28.21 9.76 -1.50 521 60.80 24.68 -7.00 400 28.51 9.88 -1.53 522 61.04 24.80 -7.06 401 28.81 9.99 -1.56 523 61.28 24.93 -7.12 402 29.10 10.11 -1.59 524 61.52 25.06 -7.18 403 29.40 10.23 -1.62 525 61.76 25.18 -7.24 404 29.69 10.35 -1.64 526 62.00 25.31 -7.31 405 29.99 10.47 -1.67 527 62.24 25.44 -7.37 406 30.28 10.59 -1.70 528 62.48 25.56 -7.43 407 30.57 10.71 -1.74 529 62.72 25.69 -7.49 408 30.87 10.83 -1.77 530 62.96 25.81 -7.56

119

409 31.16 10.95 -1.80 531 63.20 25.94 -7.62 410 31.45 11.07 -1.83 532 63.44 26.07 -7.68 411 31.74 11.19 -1.86 533 63.68 26.19 -7.75 412 32.03 11.30 -1.89 534 63.91 26.32 -7.81 413 32.32 11.42 -1.92 535 64.15 26.45 -7.87 414 32.61 11.54 -1.96 536 64.39 26.57 -7.94 415 32.90 11.66 -1.99 537 64.62 26.70 -8.00 416 33.19 11.78 -2.02 538 64.86 26.83 -8.07 417 33.47 11.90 -2.06 539 65.10 26.96 -8.13 418 33.76 12.02 -2.09 540 65.33 27.08 -8.20 419 34.05 12.14 -2.12 541 65.57 27.21 -8.26 420 34.33 12.26 -2.16 542 65.80 27.34 -8.33 421 34.62 12.38 -2.19 543 66.04 27.46 -8.39 422 34.90 12.50 -2.23 544 66.27 27.59 -8.46 423 35.19 12.62 -2.26 545 66.50 27.72 -8.53 424 35.47 12.74 -2.30 546 66.74 27.85 -8.59 425 35.75 12.86 -2.33 547 66.97 27.97 -8.66 426 36.04 12.98 -2.37 548 67.20 28.10 -8.73 427 36.32 13.10 -2.40 549 67.44 28.23 -8.79 428 36.60 13.22 -2.44 550 67.67 28.36 -8.86 429 36.88 13.34 -2.48 551 67.90 28.48 -8.93 430 37.16 13.46 -2.51 552 68.13 28.61 -9.00 431 37.44 13.58 -2.55 553 68.36 28.74 -9.07 432 37.72 13.71 -2.59 554 68.60 28.87 -9.13 433 38.00 13.83 -2.63 555 68.83 29.00 -9.20 434 38.28 13.95 -2.67 556 69.06 29.12 -9.27 435 38.56 14.07 -2.70 557 69.29 29.25 -9.34 436 38.83 14.19 -2.74 558 69.52 29.38 -9.41 437 39.11 14.31 -2.78 559 69.75 29.51 -9.48 438 39.39 14.43 -2.82 560 69.98 29.64 -9.55 439 39.66 14.55 -2.86 561 70.20 29.76 -9.62 440 39.94 14.67 -2.90 562 70.43 29.89 -9.69 441 40.21 14.79 -2.94 563 70.66 30.02 -9.76 442 40.49 14.91 -2.98 564 70.89 30.15 -9.83 443 40.76 15.04 -3.02 565 71.12 30.28 -9.90 444 41.03 15.16 -3.06 566 71.34 30.41 -9.97 445 41.31 15.28 -3.10 567 71.57 30.54 -10.05 446 41.58 15.40 -3.14 568 71.80 30.66 -10.12 447 41.85 15.52 -3.19 569 72.03 30.79 -10.19 448 42.12 15.64 -3.23 570 72.25 30.92 -10.26

120

449 42.40 15.76 -3.27 571 72.48 31.05 -10.33 450 42.67 15.89 -3.31 572 72.70 31.18 -10.41 451 42.94 16.01 -3.36 573 72.93 31.31 -10.48 452 43.21 16.13 -3.40 574 73.15 31.44 -10.55 453 43.47 16.25 -3.44 575 73.38 31.57 -10.63 454 43.74 16.37 -3.49 576 73.60 31.70 -10.70 455 44.01 16.50 -3.53 577 73.83 31.83 -10.77 456 44.28 16.62 -3.57 578 74.05 31.96 -10.85 457 44.55 16.74 -3.62 579 74.28 32.08 -10.92 458 44.81 16.86 -3.66 580 74.50 32.21 -11.00 459 45.08 16.98 -3.71 581 74.72 32.34 -11.07 460 45.35 17.11 -3.75 582 74.94 32.47 -11.14 461 45.61 17.23 -3.80 583 75.17 32.60 -11.22 462 45.88 17.35 -3.84 584 75.39 32.73 -11.29 463 46.14 17.47 -3.89 585 75.61 32.86 -11.37 464 46.41 17.60 -3.94 586 75.83 32.99 -11.45 465 46.67 17.72 -3.98 587 76.05 33.12 -11.52 466 46.93 17.84 -4.03 588 76.28 33.25 -11.60 467 47.20 17.96 -4.08 589 76.50 33.38 -11.67 468 47.46 18.09 -4.12 590 76.72 33.51 -11.75 469 47.72 18.21 -4.17 591 76.94 33.64 -11.83 470 47.98 18.33 -4.22 592 77.16 33.77 -11.91 471 48.25 18.46 -4.27 593 77.38 33.90 -11.98 472 48.51 18.58 -4.32 594 77.60 34.03 -12.06 473 48.77 18.70 -4.37 595 77.82 34.16 -12.14 474 49.03 18.82 -4.41 596 78.04 34.29 -12.22 475 49.29 18.95 -4.46 597 78.25 34.42 -12.29 476 49.55 19.07 -4.51 598 78.47 34.55 -12.37 477 49.80 19.19 -4.56 599 78.69 34.69 -12.45 478 50.06 19.32 -4.61 600 78.91 34.82 -12.53 479 50.32 19.44 -4.66 601 79.13 34.95 -12.61 480 50.58 19.56 -4.71 602 79.34 35.08 -12.69 481 50.83 19.69 -4.76 603 79.56 35.21 -12.77 482 51.09 19.81 -4.81 604 79.78 35.34 -12.85 483 51.35 19.94 -4.87 605 80.00 35.47 -12.93 484 51.60 20.06 -4.92 606 80.21 35.60 -13.01 485 51.86 20.18 -4.97 607 80.43 35.73 -13.09 486 52.11 20.31 -5.02 608 80.64 35.86 -13.17 487 52.37 20.43 -5.07 609 80.86 35.99 -13.25 488 52.62 20.55 -5.13 610 81.07 36.13 -13.33

121

489 52.88 20.68 -5.18 611 81.29 36.26 -13.41 490 53.13 20.80 -5.23 612 81.50 36.39 -13.49 491 53.38 20.93 -5.28 613 81.72 36.52 -13.57 492 53.64 21.05 -5.34 614 81.93 36.65 -13.66 493 53.89 21.17 -5.39 615 82.15 36.78 -13.74 494 54.14 21.30 -5.45 616 82.36 36.92 -13.82 495 54.39 21.42 -5.50 617 82.58 37.05 -13.90 496 54.64 21.55 -5.55 618 82.79 37.18 -13.98 497 54.89 21.67 -5.61 619 83.00 37.31 -14.07 498 55.14 21.80 -5.66 620 83.21 37.44 -14.15 499 55.39 21.92 -5.72 621 83.43 37.57 -14.23 500 55.64 22.05 -5.78 622 83.64 37.71 -14.32 501 55.89 22.17 -5.83 623 83.85 37.84 -14.41 502 56.14 22.30 -5.89 623.15 83.88 37.86 -14.43

122

Appendix E

Table E.1 Thermodynamic properties of LiNO3-NaNO3-NaNO2-KNO3-KNO2 compound

in solid state (298.15-359.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 330 9.13 2.87 -0.14 299 0.25 0.07 0.00 331 9.41 2.96 -0.15 300 0.54 0.16 0.00 332 9.70 3.06 -0.16 301 0.83 0.25 0.00 333 9.98 3.15 -0.17 302 1.12 0.34 0.00 334 10.26 3.24 -0.18 303 1.41 0.42 0.00 335 10.54 3.34 -0.19 304 1.70 0.51 0.00 336 10.81 3.43 -0.20 305 1.99 0.60 -0.01 337 11.09 3.53 -0.21 306 2.28 0.69 -0.01 338 11.37 3.62 -0.22 307 2.57 0.78 -0.01 339 11.65 3.71 -0.24 308 2.86 0.87 -0.01 340 11.93 3.81 -0.25 309 3.15 0.96 -0.02 341 12.21 3.90 -0.26 310 3.43 1.05 -0.02 342 12.48 4.00 -0.27 311 3.72 1.13 -0.02 343 12.76 4.09 -0.28 312 4.01 1.22 -0.03 344 13.04 4.19 -0.30 313 4.30 1.31 -0.03 345 13.31 4.28 -0.31 314 4.58 1.40 -0.03 346 13.59 4.38 -0.32 315 4.87 1.49 -0.04 347 13.86 4.47 -0.34 316 5.16 1.59 -0.04 348 14.14 4.57 -0.35 317 5.44 1.68 -0.05 349 14.41 4.66 -0.36 318 5.73 1.77 -0.06 350 14.68 4.76 -0.38 319 6.02 1.86 -0.06 351 14.96 4.86 -0.39 320 6.30 1.95 -0.07 352 15.23 4.95 -0.41 321 6.59 2.04 -0.07 353 15.50 5.05 -0.42 322 6.87 2.13 -0.08 354 15.77 5.14 -0.44 323 7.15 2.22 -0.09 355 16.05 5.24 -0.46 324 7.44 2.32 -0.09 356 16.32 5.34 -0.47 325 7.72 2.41 -0.10 357 16.59 5.43 -0.49 326 8.00 2.50 -0.11 358 16.86 5.53 -0.50 327 8.29 2.59 -0.12 359 17.13 5.63 -0.52 328 8.57 2.69 -0.13 359.15 17.17 5.64 -0.52 329 8.85 2.78 -0.13

123

Table E.2 Thermodynamic properties of LiNO3-NaNO3-NaNO2-KNO3-KNO2 compound

in liquid state (376-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 375.15 23.23 7.77 -0.94 500 55.25 21.73 -5.90 376 23.47 7.86 -0.96 501 55.48 21.84 -5.95 377 23.75 7.97 -0.98 502 55.72 21.96 -6.01 378 24.03 8.08 -1.01 503 55.95 22.08 -6.06 379 24.31 8.18 -1.03 504 56.19 22.20 -6.12 380 24.59 8.29 -1.06 505 56.42 22.32 -6.18 381 24.87 8.39 -1.08 506 56.65 22.43 -6.23 382 25.15 8.50 -1.11 507 56.89 22.55 -6.29 383 25.42 8.61 -1.13 508 57.12 22.67 -6.35 384 25.70 8.71 -1.16 509 57.35 22.79 -6.40 385 25.98 8.82 -1.18 510 57.59 22.91 -6.46 386 26.26 8.93 -1.21 511 57.82 23.03 -6.52 387 26.53 9.03 -1.23 512 58.05 23.15 -6.58 388 26.81 9.14 -1.26 513 58.28 23.26 -6.64 389 27.08 9.25 -1.29 514 58.52 23.38 -6.69 390 27.36 9.35 -1.32 515 58.75 23.50 -6.75 391 27.63 9.46 -1.34 516 58.98 23.62 -6.81 392 27.91 9.57 -1.37 517 59.21 23.74 -6.87 393 28.18 9.68 -1.40 518 59.44 23.86 -6.93 394 28.45 9.78 -1.43 519 59.67 23.98 -6.99 395 28.73 9.89 -1.46 520 59.90 24.10 -7.05 396 29.00 10.00 -1.48 521 60.13 24.22 -7.11 397 29.27 10.11 -1.51 522 60.36 24.34 -7.17 398 29.54 10.22 -1.54 523 60.59 24.46 -7.23 399 29.81 10.32 -1.57 524 60.82 24.58 -7.29 400 30.08 10.43 -1.60 525 61.05 24.70 -7.35 401 30.35 10.54 -1.63 526 61.28 24.82 -7.41 402 30.62 10.65 -1.66 527 61.51 24.94 -7.47 403 30.89 10.76 -1.69 528 61.73 25.06 -7.54 404 31.16 10.86 -1.72 529 61.96 25.18 -7.60 405 31.43 10.97 -1.76 530 62.19 25.30 -7.66

124

406 31.70 11.08 -1.79 531 62.42 25.42 -7.72 407 31.97 11.19 -1.82 532 62.65 25.54 -7.78 408 32.23 11.30 -1.85 533 62.87 25.66 -7.85 409 32.50 11.41 -1.88 534 63.10 25.78 -7.91 410 32.77 11.52 -1.92 535 63.33 25.91 -7.97 411 33.03 11.63 -1.95 536 63.55 26.03 -8.04 412 33.30 11.74 -1.98 537 63.78 26.15 -8.10 413 33.56 11.85 -2.02 538 64.00 26.27 -8.16 414 33.83 11.95 -2.05 539 64.23 26.39 -8.23 415 34.09 12.06 -2.08 540 64.45 26.51 -8.29 416 34.36 12.17 -2.12 541 64.68 26.63 -8.36 417 34.62 12.28 -2.15 542 64.90 26.76 -8.42 418 34.88 12.39 -2.19 543 65.13 26.88 -8.49 419 35.15 12.50 -2.22 544 65.35 27.00 -8.55 420 35.41 12.61 -2.26 545 65.58 27.12 -8.62 421 35.67 12.72 -2.29 546 65.80 27.24 -8.68 422 35.93 12.83 -2.33 547 66.02 27.37 -8.75 423 36.19 12.94 -2.36 548 66.25 27.49 -8.82 424 36.45 13.05 -2.40 549 66.47 27.61 -8.88 425 36.71 13.17 -2.44 550 66.69 27.73 -8.95 426 36.97 13.28 -2.47 551 66.92 27.86 -9.02 427 37.23 13.39 -2.51 552 67.14 27.98 -9.08 428 37.49 13.50 -2.55 553 67.36 28.10 -9.15 429 37.75 13.61 -2.59 554 67.58 28.22 -9.22 430 38.01 13.72 -2.62 555 67.80 28.35 -9.29 431 38.27 13.83 -2.66 556 68.03 28.47 -9.35 432 38.52 13.94 -2.70 557 68.25 28.59 -9.42 433 38.78 14.05 -2.74 558 68.47 28.72 -9.49 434 39.04 14.16 -2.78 559 68.69 28.84 -9.56 435 39.29 14.28 -2.82 560 68.91 28.96 -9.63 436 39.55 14.39 -2.86 561 69.13 29.09 -9.70 437 39.81 14.50 -2.90 562 69.35 29.21 -9.77 438 40.06 14.61 -2.94 563 69.57 29.33 -9.83 439 40.32 14.72 -2.98 564 69.79 29.46 -9.90 440 40.57 14.83 -3.02 565 70.01 29.58 -9.97 441 40.83 14.95 -3.06 566 70.23 29.71 -10.04 442 41.08 15.06 -3.10 567 70.45 29.83 -10.11 443 41.33 15.17 -3.14 568 70.67 29.95 -10.19 444 41.59 15.28 -3.18 569 70.89 30.08 -10.26 445 41.84 15.40 -3.22 570 71.10 30.20 -10.33

125

446 42.09 15.51 -3.27 571 71.32 30.33 -10.40 447 42.34 15.62 -3.31 572 71.54 30.45 -10.47 448 42.60 15.73 -3.35 573 71.76 30.58 -10.54 449 42.85 15.85 -3.39 574 71.98 30.70 -10.61 450 43.10 15.96 -3.44 575 72.19 30.83 -10.69 451 43.35 16.07 -3.48 576 72.41 30.95 -10.76 452 43.60 16.18 -3.52 577 72.63 31.08 -10.83 453 43.85 16.30 -3.57 578 72.84 31.20 -10.90 454 44.10 16.41 -3.61 579 73.06 31.33 -10.98 455 44.35 16.52 -3.65 580 73.28 31.45 -11.05 456 44.60 16.64 -3.70 581 73.49 31.58 -11.12 457 44.85 16.75 -3.74 582 73.71 31.70 -11.20 458 45.10 16.87 -3.79 583 73.93 31.83 -11.27 459 45.34 16.98 -3.83 584 74.14 31.95 -11.34 460 45.59 17.09 -3.88 585 74.36 32.08 -11.42 461 45.84 17.21 -3.93 586 74.57 32.21 -11.49 462 46.09 17.32 -3.97 587 74.79 32.33 -11.57 463 46.33 17.43 -4.02 588 75.00 32.46 -11.64 464 46.58 17.55 -4.06 589 75.22 32.58 -11.72 465 46.83 17.66 -4.11 590 75.43 32.71 -11.79 466 47.07 17.78 -4.16 591 75.64 32.84 -11.87 467 47.32 17.89 -4.20 592 75.86 32.96 -11.94 468 47.56 18.01 -4.25 593 76.07 33.09 -12.02 469 47.81 18.12 -4.30 594 76.28 33.22 -12.10 470 48.05 18.24 -4.35 595 76.50 33.34 -12.17 471 48.30 18.35 -4.40 596 76.71 33.47 -12.25 472 48.54 18.47 -4.44 597 76.92 33.60 -12.33 473 48.78 18.58 -4.49 598 77.14 33.73 -12.40 474 49.03 18.70 -4.54 599 77.35 33.85 -12.48 475 49.27 18.81 -4.59 600 77.56 33.98 -12.56 476 49.51 18.93 -4.64 601 77.77 34.11 -12.64 477 49.75 19.04 -4.69 602 77.99 34.23 -12.71 478 50.00 19.16 -4.74 603 78.20 34.36 -12.79 479 50.24 19.27 -4.79 604 78.41 34.49 -12.87 480 50.48 19.39 -4.84 605 78.62 34.62 -12.95 481 50.72 19.51 -4.89 606 78.83 34.75 -13.03 482 50.96 19.62 -4.94 607 79.04 34.87 -13.11 483 51.20 19.74 -4.99 608 79.25 35.00 -13.18 484 51.44 19.85 -5.04 609 79.46 35.13 -13.26 485 51.68 19.97 -5.10 610 79.67 35.26 -13.34

126

486 51.92 20.09 -5.15 611 79.88 35.39 -13.42 487 52.16 20.20 -5.20 612 80.09 35.51 -13.50 488 52.40 20.32 -5.25 613 80.30 35.64 -13.58 489 52.64 20.44 -5.30 614 80.51 35.77 -13.66 490 52.88 20.55 -5.36 615 80.72 35.90 -13.74 491 53.12 20.67 -5.41 616 80.93 36.03 -13.83 492 53.35 20.79 -5.46 617 81.14 36.16 -13.91 493 53.59 20.90 -5.52 618 81.35 36.29 -13.99 494 53.83 21.02 -5.57 619 81.56 36.42 -14.07 495 54.07 21.14 -5.62 620 81.77 36.55 -14.15 496 54.30 21.26 -5.68 621 81.98 36.67 -14.23 497 54.54 21.37 -5.73 622 82.19 36.80 -14.31 498 54.78 21.49 -5.79 623 82.39 36.93 -14.40 499 55.01 21.61 -5.84 623.15 82.42 36.95 -14.41

127

Appendix F

Table F.1 Thermodynamic properties of LiNO3-NaNO3 -KNO3-KNO2 compound in solid

state (298.15-359.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 330 10.63 3.34 -0.17 299 0.29 0.09 0.00 331 10.96 3.45 -0.18 300 0.63 0.19 0.00 332 11.28 3.56 -0.19 301 0.97 0.29 0.00 333 11.61 3.66 -0.20 302 1.31 0.39 0.00 334 11.93 3.77 -0.21 303 1.65 0.50 0.00 335 12.25 3.88 -0.22 304 1.99 0.60 -0.01 336 12.58 3.99 -0.24 305 2.33 0.70 -0.01 337 12.90 4.10 -0.25 306 2.67 0.81 -0.01 338 13.22 4.21 -0.26 307 3.00 0.91 -0.01 339 13.55 4.32 -0.28 308 3.34 1.01 -0.02 340 13.87 4.43 -0.29 309 3.68 1.12 -0.02 341 14.19 4.54 -0.30 310 4.01 1.22 -0.02 342 14.51 4.64 -0.32 311 4.35 1.33 -0.03 343 14.83 4.75 -0.33 312 4.68 1.43 -0.03 344 15.15 4.86 -0.35 313 5.02 1.53 -0.04 345 15.47 4.97 -0.36 314 5.35 1.64 -0.04 346 15.78 5.08 -0.38 315 5.69 1.74 -0.05 347 16.10 5.19 -0.39 316 6.02 1.85 -0.05 348 16.42 5.31 -0.41 317 6.35 1.96 -0.06 349 16.74 5.42 -0.43 318 6.68 2.06 -0.06 350 17.05 5.53 -0.44 319 7.02 2.17 -0.07 351 17.37 5.64 -0.46 320 7.35 2.27 -0.08 352 17.69 5.75 -0.48 321 7.68 2.38 -0.09 353 18.00 5.86 -0.49 322 8.01 2.48 -0.09 354 18.32 5.97 -0.51 323 8.34 2.59 -0.10 355 18.63 6.08 -0.53 324 8.67 2.70 -0.11 356 18.94 6.19 -0.55 325 9.00 2.80 -0.12 357 19.26 6.31 -0.57 326 9.32 2.91 -0.13 358 19.57 6.42 -0.59 327 9.65 3.02 -0.14 359 19.88 6.53 -0.61 328 9.98 3.13 -0.15 359.15 19.93 6.55 -0.61 329 10.30 3.23 -0.16

128

Table F.2 Thermodynamic properties of LiNO3-NaNO3 -KNO3-KNO2 compound in liquid

state (375.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 375.15 26.91 9.26 -0.83 500 61.11 24.16 -6.40 376 27.17 9.36 -0.85 501 61.36 24.28 -6.46 377 27.47 9.48 -0.88 502 61.61 24.40 -6.52 378 27.78 9.59 -0.91 503 61.85 24.53 -6.58 379 28.08 9.71 -0.94 504 62.10 24.65 -6.65 380 28.38 9.82 -0.96 505 62.35 24.78 -6.71 381 28.69 9.94 -0.99 506 62.59 24.90 -6.77 382 28.99 10.05 -1.02 507 62.84 25.02 -6.83 383 29.29 10.17 -1.05 508 63.08 25.15 -6.90 384 29.59 10.28 -1.08 509 63.33 25.27 -6.96 385 29.89 10.40 -1.11 510 63.57 25.40 -7.02 386 30.19 10.51 -1.14 511 63.81 25.52 -7.09 387 30.49 10.63 -1.17 512 64.06 25.65 -7.15 388 30.79 10.75 -1.20 513 64.30 25.77 -7.21 389 31.09 10.86 -1.23 514 64.54 25.90 -7.28 390 31.38 10.98 -1.26 515 64.79 26.02 -7.34 391 31.68 11.09 -1.29 516 65.03 26.15 -7.41 392 31.98 11.21 -1.33 517 65.27 26.27 -7.47 393 32.27 11.32 -1.36 518 65.51 26.40 -7.54 394 32.57 11.44 -1.39 519 65.75 26.52 -7.60 395 32.86 11.56 -1.42 520 65.99 26.65 -7.67 396 33.16 11.67 -1.46 521 66.24 26.77 -7.74 397 33.45 11.79 -1.49 522 66.48 26.90 -7.80 398 33.74 11.91 -1.52 523 66.72 27.02 -7.87 399 34.03 12.02 -1.56 524 66.96 27.15 -7.94 400 34.33 12.14 -1.59 525 67.19 27.27 -8.00 401 34.62 12.26 -1.63 526 67.43 27.40 -8.07 402 34.91 12.37 -1.66 527 67.67 27.53 -8.14 403 35.20 12.49 -1.70 528 67.91 27.65 -8.21 404 35.49 12.61 -1.73 529 68.15 27.78 -8.27 405 35.78 12.72 -1.77 530 68.39 27.90 -8.34

129

406 36.06 12.84 -1.80 531 68.62 28.03 -8.41 407 36.35 12.96 -1.84 532 68.86 28.15 -8.48 408 36.64 13.07 -1.87 533 69.10 28.28 -8.55 409 36.93 13.19 -1.91 534 69.33 28.41 -8.62 410 37.21 13.31 -1.95 535 69.57 28.53 -8.69 411 37.50 13.43 -1.99 536 69.81 28.66 -8.76 412 37.78 13.54 -2.02 537 70.04 28.79 -8.83 413 38.07 13.66 -2.06 538 70.28 28.91 -8.90 414 38.35 13.78 -2.10 539 70.51 29.04 -8.97 415 38.64 13.90 -2.14 540 70.75 29.17 -9.04 416 38.92 14.01 -2.18 541 70.98 29.29 -9.11 417 39.20 14.13 -2.22 542 71.22 29.42 -9.18 418 39.48 14.25 -2.26 543 71.45 29.55 -9.25 419 39.77 14.37 -2.30 544 71.68 29.67 -9.32 420 40.05 14.49 -2.34 545 71.92 29.80 -9.39 421 40.33 14.60 -2.38 546 72.15 29.93 -9.47 422 40.61 14.72 -2.42 547 72.38 30.05 -9.54 423 40.89 14.84 -2.46 548 72.61 30.18 -9.61 424 41.17 14.96 -2.50 549 72.85 30.31 -9.68 425 41.45 15.08 -2.54 550 73.08 30.44 -9.76 426 41.72 15.19 -2.58 551 73.31 30.56 -9.83 427 42.00 15.31 -2.62 552 73.54 30.69 -9.90 428 42.28 15.43 -2.66 553 73.77 30.82 -9.98 429 42.56 15.55 -2.71 554 74.00 30.95 -10.05 430 42.83 15.67 -2.75 555 74.23 31.07 -10.13 431 43.11 15.79 -2.79 556 74.46 31.20 -10.20 432 43.38 15.91 -2.84 557 74.69 31.33 -10.27 433 43.66 16.03 -2.88 558 74.92 31.46 -10.35 434 43.93 16.14 -2.92 559 75.15 31.59 -10.42 435 44.21 16.26 -2.97 560 75.38 31.71 -10.50 436 44.48 16.38 -3.01 561 75.61 31.84 -10.58 437 44.75 16.50 -3.06 562 75.84 31.97 -10.65 438 45.03 16.62 -3.10 563 76.07 32.10 -10.73 439 45.30 16.74 -3.15 564 76.29 32.23 -10.80 440 45.57 16.86 -3.19 565 76.52 32.35 -10.88 441 45.84 16.98 -3.24 566 76.75 32.48 -10.96 442 46.11 17.10 -3.28 567 76.97 32.61 -11.03 443 46.38 17.22 -3.33 568 77.20 32.74 -11.11 444 46.65 17.34 -3.38 569 77.43 32.87 -11.19 445 46.92 17.46 -3.42 570 77.65 33.00 -11.26

130

446 47.19 17.58 -3.47 571 77.88 33.13 -11.34 447 47.46 17.70 -3.52 572 78.11 33.26 -11.42 448 47.73 17.82 -3.56 573 78.33 33.38 -11.50 449 48.00 17.94 -3.61 574 78.56 33.51 -11.58 450 48.26 18.06 -3.66 575 78.78 33.64 -11.66 451 48.53 18.18 -3.71 576 79.01 33.77 -11.73 452 48.80 18.30 -3.76 577 79.23 33.90 -11.81 453 49.06 18.42 -3.81 578 79.45 34.03 -11.89 454 49.33 18.54 -3.86 579 79.68 34.16 -11.97 455 49.59 18.66 -3.91 580 79.90 34.29 -12.05 456 49.86 18.78 -3.96 581 80.12 34.42 -12.13 457 50.12 18.90 -4.01 582 80.35 34.55 -12.21 458 50.39 19.02 -4.06 583 80.57 34.68 -12.29 459 50.65 19.14 -4.11 584 80.79 34.81 -12.37 460 50.91 19.26 -4.16 585 81.01 34.94 -12.45 461 51.18 19.38 -4.21 586 81.24 35.07 -12.54 462 51.44 19.51 -4.26 587 81.46 35.20 -12.62 463 51.70 19.63 -4.31 588 81.68 35.33 -12.70 464 51.96 19.75 -4.36 589 81.90 35.46 -12.78 465 52.22 19.87 -4.41 590 82.12 35.59 -12.86 466 52.48 19.99 -4.47 591 82.34 35.72 -12.94 467 52.74 20.11 -4.52 592 82.56 35.85 -13.03 468 53.00 20.23 -4.57 593 82.78 35.98 -13.11 469 53.26 20.35 -4.63 594 83.00 36.11 -13.19 470 53.52 20.48 -4.68 595 83.22 36.24 -13.28 471 53.78 20.60 -4.73 596 83.44 36.37 -13.36 472 54.04 20.72 -4.79 597 83.66 36.50 -13.44 473 54.30 20.84 -4.84 598 83.88 36.63 -13.53 474 54.55 20.96 -4.90 599 84.10 36.76 -13.61 475 54.81 21.08 -4.95 600 84.32 36.90 -13.69 476 55.07 21.21 -5.00 601 84.54 37.03 -13.78 477 55.32 21.33 -5.06 602 84.75 37.16 -13.86 478 55.58 21.45 -5.12 603 84.97 37.29 -13.95 479 55.83 21.57 -5.17 604 85.19 37.42 -14.03 480 56.09 21.70 -5.23 605 85.41 37.55 -14.12 481 56.34 21.82 -5.28 606 85.62 37.68 -14.20 482 56.60 21.94 -5.34 607 85.84 37.81 -14.29 483 56.85 22.06 -5.40 608 86.06 37.95 -14.38 484 57.10 22.19 -5.45 609 86.27 38.08 -14.46 485 57.36 22.31 -5.51 610 86.49 38.21 -14.55

131

486 57.61 22.43 -5.57 611 86.70 38.34 -14.64 487 57.86 22.55 -5.63 612 86.92 38.47 -14.72 488 58.12 22.68 -5.68 613 87.13 38.60 -14.81 489 58.37 22.80 -5.74 614 87.35 38.74 -14.90 490 58.62 22.92 -5.80 615 87.56 38.87 -14.98 491 58.87 23.05 -5.86 616 87.78 39.00 -15.07 492 59.12 23.17 -5.92 617 87.99 39.13 -15.16 493 59.37 23.29 -5.98 618 88.21 39.26 -15.25 494 59.62 23.42 -6.04 619 88.42 39.40 -15.34 495 59.87 23.54 -6.10 620 88.64 39.53 -15.42 496 60.12 23.66 -6.16 621 88.85 39.66 -15.51 497 60.37 23.79 -6.22 622 89.06 39.79 -15.60 498 60.62 23.91 -6.28 623 89.28 39.93 -15.69 499 60.86 24.03 -6.34 623.15 89.31 39.95 -15.70

132

Appendix G

Table G.1 Thermodynamic properties of LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in

solid I state (298.15-337.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 319 5.78 1.62 -0.04 299 0.24 0.00 0.00 320 6.06 1.70 -0.05 300 0.52 0.00 0.00 321 6.33 1.79 -0.05 301 0.80 0.07 0.00 322 6.60 1.88 -0.06 302 1.08 0.16 0.00 323 6.88 1.97 -0.07 303 1.36 0.24 0.00 324 7.15 2.05 -0.07 304 1.64 0.32 0.00 325 7.42 2.14 -0.08 305 1.92 0.41 0.00 326 7.69 2.23 -0.09 306 2.19 0.49 0.00 327 7.96 2.32 -0.09 307 2.47 0.58 0.00 328 8.23 2.41 -0.10 308 2.75 0.67 -0.01 329 8.51 2.50 -0.11 309 3.03 0.75 -0.01 330 8.78 2.59 -0.11 310 3.30 0.84 -0.01 331 9.05 2.68 -0.12 311 3.58 0.92 -0.01 332 9.32 2.77 -0.13 312 3.86 1.01 -0.02 333 9.59 2.85 -0.14 313 4.13 1.09 -0.02 334 9.85 2.94 -0.15 314 4.41 1.18 -0.02 335 10.12 3.03 -0.16 315 4.68 1.27 -0.03 336 10.39 3.12 -0.17 316 4.96 1.35 -0.03 337 10.66 3.21 -0.18 317 5.23 1.44 -0.03 337.15 10.70 3.31 -0.19 318 5.51 1.53 -0.04

Table G.2 Thermodynamic properties of LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in

solid II state (361.15-364.15K)

ΔS ΔH ΔG T/(K) (J/mol.K) (kJ/mol) (kJ/mol) 361.15 24.33 8.25 -0.54

133

362 24.54 8.32 -0.56 363 24.78 8.41 -0.59 364 25.03 8.50 -0.61 364.15 25.06 8.51 -0.62

Table G.3 Thermodynamic properties of LiNO3-KNO3-NaNO2-Mg(NO3)2 compound in

liquid state (411.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 411.15 38.33 13.66 -2.10 518 66.04 26.49 -7.72 412 38.57 13.76 -2.13 519 66.28 26.61 -7.78 413 38.85 13.87 -2.17 520 66.52 26.74 -7.85 414 39.13 13.99 -2.21 521 66.75 26.86 -7.92 415 39.41 14.11 -2.25 522 66.99 26.99 -7.98 416 39.69 14.22 -2.29 523 67.23 27.11 -8.05 417 39.97 14.34 -2.33 524 67.47 27.23 -8.12 418 40.25 14.46 -2.37 525 67.70 27.36 -8.19 419 40.53 14.57 -2.41 526 67.94 27.48 -8.25 420 40.81 14.69 -2.45 527 68.18 27.61 -8.32 421 41.09 14.81 -2.49 528 68.41 27.73 -8.39 422 41.37 14.93 -2.53 529 68.65 27.86 -8.46 423 41.65 15.04 -2.57 530 68.88 27.98 -8.53 424 41.92 15.16 -2.62 531 69.12 28.10 -8.60 425 42.20 15.28 -2.66 532 69.35 28.23 -8.67 426 42.48 15.39 -2.70 533 69.59 28.35 -8.73 427 42.75 15.51 -2.74 534 69.82 28.48 -8.80 428 43.03 15.63 -2.79 535 70.05 28.60 -8.87 429 43.30 15.75 -2.83 536 70.29 28.73 -8.94 430 43.58 15.87 -2.87 537 70.52 28.85 -9.02 431 43.85 15.98 -2.92 538 70.75 28.98 -9.09 432 44.12 16.10 -2.96 539 70.98 29.10 -9.16 433 44.39 16.22 -3.00 540 71.22 29.23 -9.23 434 44.67 16.34 -3.05 541 71.45 29.35 -9.30

134

435 44.94 16.46 -3.09 542 71.68 29.48 -9.37 436 45.21 16.57 -3.14 543 71.91 29.60 -9.44 437 45.48 16.69 -3.18 544 72.14 29.73 -9.51 438 45.75 16.81 -3.23 545 72.37 29.86 -9.59 439 46.02 16.93 -3.28 546 72.60 29.98 -9.66 440 46.29 17.05 -3.32 547 72.83 30.11 -9.73 441 46.56 17.16 -3.37 548 73.06 30.23 -9.80 442 46.83 17.28 -3.41 549 73.29 30.36 -9.88 443 47.10 17.40 -3.46 550 73.52 30.48 -9.95 444 47.36 17.52 -3.51 551 73.75 30.61 -10.03 445 47.63 17.64 -3.56 552 73.98 30.74 -10.10 446 47.90 17.76 -3.60 553 74.20 30.86 -10.17 447 48.16 17.88 -3.65 554 74.43 30.99 -10.25 448 48.43 18.00 -3.70 555 74.66 31.11 -10.32 449 48.69 18.12 -3.75 556 74.89 31.24 -10.40 450 48.96 18.23 -3.80 557 75.11 31.37 -10.47 451 49.22 18.35 -3.85 558 75.34 31.49 -10.55 452 49.49 18.47 -3.90 559 75.57 31.62 -10.62 453 49.75 18.59 -3.95 560 75.79 31.75 -10.70 454 50.02 18.71 -4.00 561 76.02 31.87 -10.77 455 50.28 18.83 -4.05 562 76.25 32.00 -10.85 456 50.54 18.95 -4.10 563 76.47 32.13 -10.93 457 50.80 19.07 -4.15 564 76.70 32.25 -11.00 458 51.06 19.19 -4.20 565 76.92 32.38 -11.08 459 51.32 19.31 -4.25 566 77.14 32.51 -11.16 460 51.59 19.43 -4.30 567 77.37 32.63 -11.23 461 51.85 19.55 -4.35 568 77.59 32.76 -11.31 462 52.11 19.67 -4.40 569 77.82 32.89 -11.39 463 52.36 19.79 -4.46 570 78.04 33.02 -11.47 464 52.62 19.91 -4.51 571 78.26 33.14 -11.55 465 52.88 20.03 -4.56 572 78.49 33.27 -11.62 466 53.14 20.15 -4.61 573 78.71 33.40 -11.70 467 53.40 20.27 -4.67 574 78.93 33.52 -11.78 468 53.66 20.39 -4.72 575 79.15 33.65 -11.86 469 53.91 20.51 -4.78 576 79.37 33.78 -11.94 470 54.17 20.63 -4.83 577 79.60 33.91 -12.02 471 54.42 20.75 -4.88 578 79.82 34.04 -12.10 472 54.68 20.87 -4.94 579 80.04 34.16 -12.18 473 54.94 20.99 -4.99 580 80.26 34.29 -12.26 474 55.19 21.11 -5.05 581 80.48 34.42 -12.34

135

475 55.45 21.23 -5.10 582 80.70 34.55 -12.42 476 55.70 21.35 -5.16 583 80.92 34.68 -12.50 477 55.95 21.47 -5.21 584 81.14 34.80 -12.58 478 56.21 21.60 -5.27 585 81.36 34.93 -12.66 479 56.46 21.72 -5.33 586 81.58 35.06 -12.74 480 56.71 21.84 -5.38 587 81.80 35.19 -12.83 481 56.96 21.96 -5.44 588 82.01 35.32 -12.91 482 57.22 22.08 -5.50 589 82.23 35.45 -12.99 483 57.47 22.20 -5.55 590 82.45 35.57 -13.07 484 57.72 22.32 -5.61 591 82.67 35.70 -13.15 485 57.97 22.44 -5.67 592 82.89 35.83 -13.24 486 58.22 22.57 -5.73 593 83.10 35.96 -13.32 487 58.47 22.69 -5.79 594 83.32 36.09 -13.40 488 58.72 22.81 -5.85 595 83.54 36.22 -13.49 489 58.97 22.93 -5.90 596 83.75 36.35 -13.57 490 59.22 23.05 -5.96 597 83.97 36.48 -13.65 491 59.47 23.17 -6.02 598 84.19 36.60 -13.74 492 59.71 23.30 -6.08 599 84.40 36.73 -13.82 493 59.96 23.42 -6.14 600 84.62 36.86 -13.91 494 60.21 23.54 -6.20 601 84.83 36.99 -13.99 495 60.46 23.66 -6.26 602 85.05 37.12 -14.08 496 60.70 23.79 -6.32 603 85.26 37.25 -14.16 497 60.95 23.91 -6.38 604 85.48 37.38 -14.25 498 61.19 24.03 -6.45 605 85.69 37.51 -14.33 499 61.44 24.15 -6.51 606 85.91 37.64 -14.42 500 61.69 24.27 -6.57 607 86.12 37.77 -14.51 501 61.93 24.40 -6.63 608 86.33 37.90 -14.59 502 62.17 24.52 -6.69 609 86.55 38.03 -14.68 503 62.42 24.64 -6.75 610 86.76 38.16 -14.76 504 62.66 24.77 -6.82 611 86.97 38.29 -14.85 505 62.91 24.89 -6.88 612 87.19 38.42 -14.94 506 63.15 25.01 -6.94 613 87.40 38.55 -15.03 507 63.39 25.13 -7.01 614 87.61 38.68 -15.11 508 63.63 25.26 -7.07 615 87.82 38.81 -15.20 509 63.88 25.38 -7.13 616 88.03 38.94 -15.29 510 64.12 25.50 -7.20 617 88.25 39.07 -15.38 511 64.36 25.63 -7.26 618 88.46 39.20 -15.47 512 64.60 25.75 -7.33 619 88.67 39.33 -15.55 513 64.84 25.87 -7.39 620 88.88 39.46 -15.64 514 65.08 26.00 -7.46 621 89.09 39.59 -15.73

136

515 65.32 26.12 -7.52 622 89.30 39.72 -15.82 516 65.56 26.24 -7.59 623 89.51 39.85 -15.91 517 65.80 26.37 -7.65 623.15 89.54 39.87 -15.92

137

Appendix H

Table H.1 Thermodynamic properties of LiNO3-KNO3-NaNO2-KNO2 compound in solid I

state (298.15-354.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 327 7.68 2.41 -0.11 299 0.23 0.07 0.00 328 7.94 2.49 -0.11 300 0.50 0.15 0.00 329 8.20 2.58 -0.12 301 0.77 0.23 0.00 330 8.46 2.66 -0.13 302 1.04 0.31 0.00 331 8.72 2.75 -0.14 303 1.31 0.39 0.00 332 8.98 2.84 -0.15 304 1.58 0.48 0.00 333 9.24 2.92 -0.16 305 1.85 0.56 -0.01 334 9.50 3.01 -0.16 306 2.12 0.64 -0.01 335 9.76 3.10 -0.17 307 2.39 0.72 -0.01 336 10.02 3.18 -0.18 308 2.65 0.81 -0.01 337 10.28 3.27 -0.19 309 2.92 0.89 -0.01 338 10.53 3.36 -0.20 310 3.19 0.97 -0.02 339 10.79 3.44 -0.21 311 3.45 1.05 -0.02 340 11.05 3.53 -0.22 312 3.72 1.14 -0.02 341 11.30 3.62 -0.24 313 3.99 1.22 -0.03 342 11.56 3.71 -0.25 314 4.25 1.30 -0.03 343 11.82 3.79 -0.26 315 4.52 1.39 -0.04 344 12.07 3.88 -0.27 316 4.78 1.47 -0.04 345 12.33 3.97 -0.28 317 5.05 1.56 -0.04 346 12.58 4.06 -0.29 318 5.31 1.64 -0.05 347 12.84 4.15 -0.31 319 5.58 1.72 -0.05 348 13.09 4.24 -0.32 320 5.84 1.81 -0.06 349 13.35 4.33 -0.33 321 6.11 1.89 -0.07 350 13.60 4.41 -0.35 322 6.37 1.98 -0.07 351 13.85 4.50 -0.36 323 6.63 2.06 -0.08 352 14.11 4.59 -0.37 324 6.89 2.15 -0.08 353 14.36 4.68 -0.39 325 7.16 2.23 -0.09 354 14.61 4.77 -0.40 326 7.42 2.32 -0.10 354.15 14.65 4.78 -0.40

138

Table H.2 Thermodynamic properties of LiNO3-KNO3-NaNO2-KNO2 compound in solid 2

state (362.15-373.15K)

ΔS ΔH ΔG T/(K) (J/mol.K) (kJ/mol) (kJ/mol) 362.15 23.87 7.77 -0.46 363 24.08 8.09 -0.55 364 24.32 8.17 -0.57 365 24.57 8.26 -0.60 366 24.81 8.35 -0.62 367 25.06 8.43 -0.65 368 25.30 8.52 -0.67 369 25.55 8.61 -0.70 370 25.79 8.70 -0.72 371 26.04 8.79 -0.75 372 26.28 8.88 -0.77 373 26.53 8.98 -0.80 373.15 26.57 9.07 -0.83

Table H.3 Thermodynamic properties of LiNO3-KNO3-NaNO2-KNO2 compound in liquid

state (379.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 379.15 29.66 10.25 -1.00 502 61.74 24.32 -6.67 380 29.91 10.34 -1.02 503 61.98 24.44 -6.74 381 30.20 10.45 -1.05 504 62.22 24.56 -6.80 382 30.48 10.56 -1.08 505 62.46 24.68 -6.86 383 30.77 10.67 -1.12 506 62.70 24.80 -6.92 384 31.05 10.78 -1.15 507 62.94 24.92 -6.99 385 31.34 10.89 -1.18 508 63.17 25.04 -7.05 386 31.62 11.00 -1.21 509 63.41 25.16 -7.11 387 31.91 11.11 -1.24 510 63.65 25.28 -7.18

139

388 32.19 11.22 -1.27 511 63.88 25.41 -7.24 389 32.47 11.33 -1.30 512 64.12 25.53 -7.30 390 32.75 11.44 -1.34 513 64.36 25.65 -7.37 391 33.04 11.55 -1.37 514 64.59 25.77 -7.43 392 33.32 11.66 -1.40 515 64.83 25.89 -7.50 393 33.60 11.77 -1.44 516 65.06 26.01 -7.56 394 33.88 11.88 -1.47 517 65.30 26.13 -7.63 395 34.16 11.99 -1.50 518 65.53 26.25 -7.69 396 34.44 12.10 -1.54 519 65.77 26.38 -7.76 397 34.72 12.21 -1.57 520 66.00 26.50 -7.82 398 35.00 12.32 -1.61 521 66.24 26.62 -7.89 399 35.27 12.43 -1.64 522 66.47 26.74 -7.96 400 35.55 12.54 -1.68 523 66.70 26.86 -8.02 401 35.83 12.65 -1.71 524 66.94 26.98 -8.09 402 36.11 12.76 -1.75 525 67.17 27.11 -8.16 403 36.38 12.87 -1.79 526 67.40 27.23 -8.22 404 36.66 12.99 -1.82 527 67.63 27.35 -8.29 405 36.93 13.10 -1.86 528 67.86 27.47 -8.36 406 37.21 13.21 -1.90 529 68.10 27.60 -8.43 407 37.48 13.32 -1.93 530 68.33 27.72 -8.50 408 37.76 13.43 -1.97 531 68.56 27.84 -8.56 409 38.03 13.54 -2.01 532 68.79 27.96 -8.63 410 38.30 13.66 -2.05 533 69.02 28.09 -8.70 411 38.57 13.77 -2.09 534 69.25 28.21 -8.77 412 38.85 13.88 -2.13 535 69.48 28.33 -8.84 413 39.12 13.99 -2.16 536 69.71 28.45 -8.91 414 39.39 14.10 -2.20 537 69.94 28.58 -8.98 415 39.66 14.22 -2.24 538 70.17 28.70 -9.05 416 39.93 14.33 -2.28 539 70.40 28.82 -9.12 417 40.20 14.44 -2.32 540 70.63 28.95 -9.19 418 40.47 14.55 -2.36 541 70.86 29.07 -9.26 419 40.74 14.67 -2.40 542 71.08 29.19 -9.33 420 41.01 14.78 -2.45 543 71.31 29.32 -9.40 421 41.28 14.89 -2.49 544 71.54 29.44 -9.47 422 41.54 15.00 -2.53 545 71.77 29.57 -9.55 423 41.81 15.12 -2.57 546 71.99 29.69 -9.62 424 42.08 15.23 -2.61 547 72.22 29.81 -9.69 425 42.34 15.34 -2.65 548 72.45 29.94 -9.76 426 42.61 15.46 -2.70 549 72.67 30.06 -9.84 427 42.88 15.57 -2.74 550 72.90 30.19 -9.91

140

428 43.14 15.68 -2.78 551 73.13 30.31 -9.98 429 43.41 15.80 -2.82 552 73.35 30.44 -10.05 430 43.67 15.91 -2.87 553 73.58 30.56 -10.13 431 43.93 16.02 -2.91 554 73.80 30.68 -10.20 432 44.20 16.14 -2.96 555 74.03 30.81 -10.28 433 44.46 16.25 -3.00 556 74.25 30.93 -10.35 434 44.72 16.36 -3.05 557 74.48 31.06 -10.42 435 44.99 16.48 -3.09 558 74.70 31.18 -10.50 436 45.25 16.59 -3.14 559 74.92 31.31 -10.57 437 45.51 16.71 -3.18 560 75.15 31.43 -10.65 438 45.77 16.82 -3.23 561 75.37 31.56 -10.72 439 46.03 16.94 -3.27 562 75.60 31.69 -10.80 440 46.29 17.05 -3.32 563 75.82 31.81 -10.87 441 46.55 17.16 -3.36 564 76.04 31.94 -10.95 442 46.81 17.28 -3.41 565 76.26 32.06 -11.03 443 47.07 17.39 -3.46 566 76.49 32.19 -11.10 444 47.33 17.51 -3.51 567 76.71 32.31 -11.18 445 47.59 17.62 -3.55 568 76.93 32.44 -11.26 446 47.85 17.74 -3.60 569 77.15 32.57 -11.33 447 48.10 17.85 -3.65 570 77.37 32.69 -11.41 448 48.36 17.97 -3.70 571 77.59 32.82 -11.49 449 48.62 18.08 -3.75 572 77.82 32.94 -11.57 450 48.88 18.20 -3.79 573 78.04 33.07 -11.64 451 49.13 18.32 -3.84 574 78.26 33.20 -11.72 452 49.39 18.43 -3.89 575 78.48 33.32 -11.80 453 49.64 18.55 -3.94 576 78.70 33.45 -11.88 454 49.90 18.66 -3.99 577 78.92 33.58 -11.96 455 50.15 18.78 -4.04 578 79.14 33.70 -12.04 456 50.41 18.89 -4.09 579 79.36 33.83 -12.12 457 50.66 19.01 -4.14 580 79.57 33.96 -12.20 458 50.92 19.13 -4.19 581 79.79 34.08 -12.28 459 51.17 19.24 -4.24 582 80.01 34.21 -12.36 460 51.42 19.36 -4.30 583 80.23 34.34 -12.44 461 51.67 19.47 -4.35 584 80.45 34.47 -12.52 462 51.93 19.59 -4.40 585 80.67 34.59 -12.60 463 52.18 19.71 -4.45 586 80.88 34.72 -12.68 464 52.43 19.82 -4.50 587 81.10 34.85 -12.76 465 52.68 19.94 -4.56 588 81.32 34.98 -12.84 466 52.93 20.06 -4.61 589 81.54 35.10 -12.92 467 53.18 20.17 -4.66 590 81.75 35.23 -13.00

141

468 53.43 20.29 -4.72 591 81.97 35.36 -13.08 469 53.68 20.41 -4.77 592 82.19 35.49 -13.17 470 53.93 20.53 -4.82 593 82.40 35.62 -13.25 471 54.18 20.64 -4.88 594 82.62 35.74 -13.33 472 54.43 20.76 -4.93 595 82.83 35.87 -13.41 473 54.68 20.88 -4.99 596 83.05 36.00 -13.50 474 54.93 21.00 -5.04 597 83.27 36.13 -13.58 475 55.17 21.11 -5.10 598 83.48 36.26 -13.66 476 55.42 21.23 -5.15 599 83.70 36.39 -13.75 477 55.67 21.35 -5.21 600 83.91 36.52 -13.83 478 55.92 21.47 -5.26 601 84.13 36.64 -13.91 479 56.16 21.58 -5.32 602 84.34 36.77 -14.00 480 56.41 21.70 -5.37 603 84.55 36.90 -14.08 481 56.65 21.82 -5.43 604 84.77 37.03 -14.17 482 56.90 21.94 -5.49 605 84.98 37.16 -14.25 483 57.15 22.06 -5.54 606 85.20 37.29 -14.34 484 57.39 22.18 -5.60 607 85.41 37.42 -14.42 485 57.63 22.29 -5.66 608 85.62 37.55 -14.51 486 57.88 22.41 -5.72 609 85.83 37.68 -14.59 487 58.12 22.53 -5.78 610 86.05 37.81 -14.68 488 58.37 22.65 -5.83 611 86.26 37.94 -14.77 489 58.61 22.77 -5.89 612 86.47 38.07 -14.85 490 58.85 22.89 -5.95 613 86.68 38.20 -14.94 491 59.10 23.01 -6.01 614 86.90 38.33 -15.03 492 59.34 23.13 -6.07 615 87.11 38.46 -15.11 493 59.58 23.24 -6.13 616 87.32 38.59 -15.20 494 59.82 23.36 -6.19 617 87.53 38.72 -15.29 495 60.06 23.48 -6.25 618 87.74 38.85 -15.38 496 60.30 23.60 -6.31 619 87.95 38.98 -15.46 497 60.55 23.72 -6.37 620 88.16 39.11 -15.55 498 60.79 23.84 -6.43 621 88.37 39.24 -15.64 499 61.03 23.96 -6.49 622 88.58 39.37 -15.73 500 61.27 24.08 -6.55 623 88.79 39.50 -15.82 501 61.51 24.20 -6.61 623.15 88.83 39.52 -15.83

142

Appendix I

Table I.1 Thermodynamic properties of LiNO3-NaNO3 -KNO3-Mg(NO3)2-MgK compound

in solid state (298.15-353.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 298.15 0.00 0.00 0.00 327 11.71 3.66 -0.17 299 0.35 0.10 0.00 328 12.11 3.79 -0.18 300 0.76 0.23 0.00 329 12.50 3.92 -0.19 301 1.17 0.35 0.00 330 12.90 4.05 -0.21 302 1.58 0.48 0.00 331 13.30 4.18 -0.22 303 1.99 0.60 0.00 332 13.69 4.31 -0.23 304 2.40 0.72 -0.01 333 14.09 4.44 -0.25 305 2.81 0.85 -0.01 334 14.48 4.58 -0.26 306 3.22 0.97 -0.01 335 14.88 4.71 -0.28 307 3.63 1.10 -0.02 336 15.27 4.84 -0.29 308 4.04 1.22 -0.02 337 15.66 4.97 -0.31 309 4.45 1.35 -0.02 338 16.05 5.10 -0.32 310 4.86 1.48 -0.03 339 16.44 5.24 -0.34 311 5.26 1.60 -0.03 340 16.83 5.37 -0.36 312 5.67 1.73 -0.04 341 17.22 5.50 -0.37 313 6.08 1.86 -0.05 342 17.61 5.63 -0.39 314 6.48 1.98 -0.05 343 18.00 5.77 -0.41 315 6.89 2.11 -0.06 344 18.39 5.90 -0.43 316 7.29 2.24 -0.07 345 18.77 6.03 -0.44 317 7.70 2.37 -0.07 346 19.16 6.17 -0.46 318 8.10 2.50 -0.08 347 19.55 6.30 -0.48 319 8.50 2.62 -0.09 348 19.93 6.43 -0.50 320 8.91 2.75 -0.10 349 20.31 6.57 -0.52 321 9.31 2.88 -0.11 350 20.70 6.70 -0.54 322 9.71 3.01 -0.12 351 21.08 6.83 -0.56 323 10.11 3.14 -0.13 352 21.46 6.97 -0.59 324 10.51 3.27 -0.14 353 21.84 7.10 -0.61 325 10.91 3.40 -0.15 353.15 21.90 7.12 -0.61 326 11.31 3.53 -0.16

143

Table I.2 Thermodynamic properties of LiNO3-NaNO3 -KNO3-Mg(NO3)2-MgK compound

in liquid state (391.15-623.15K)

ΔS ΔH ΔG ΔS ΔH ΔG T/(K) T/(K) (J/mol.K) (kJ/mol) (kJ/mol) (J/mol.K) (kJ/mol) (kJ/mol) 391.15 44.13 10.56 -1.91 508 88.90 35.21 -9.78 392 44.50 15.35 -1.95 509 89.24 35.38 -9.86 393 44.92 15.49 -2.00 510 89.59 35.56 -9.95 394 45.35 15.66 -2.04 511 89.93 35.74 -10.04 395 45.77 15.83 -2.09 512 90.27 35.91 -10.13 396 46.20 15.99 -2.13 513 90.62 36.09 -10.22 397 46.62 16.16 -2.18 514 90.96 36.26 -10.31 398 47.04 16.33 -2.23 515 91.30 36.44 -10.41 399 47.46 16.50 -2.27 516 91.64 36.61 -10.50 400 47.89 16.66 -2.32 517 91.98 36.79 -10.59 401 48.31 16.83 -2.37 518 92.32 36.97 -10.68 402 48.72 17.00 -2.42 519 92.66 37.14 -10.77 403 49.14 17.17 -2.47 520 93.00 37.32 -10.87 404 49.56 17.34 -2.52 521 93.34 37.50 -10.96 405 49.97 17.51 -2.57 522 93.68 37.67 -11.05 406 50.39 17.67 -2.62 523 94.02 37.85 -11.15 407 50.80 17.84 -2.67 524 94.35 38.02 -11.24 408 51.22 18.01 -2.72 525 94.69 38.20 -11.34 409 51.63 18.18 -2.77 526 95.03 38.38 -11.43 410 52.04 18.35 -2.82 527 95.36 38.55 -11.52 411 52.45 18.52 -2.87 528 95.70 38.73 -11.62 412 52.86 18.69 -2.93 529 96.03 38.91 -11.72 413 53.27 18.85 -2.98 530 96.37 39.08 -11.81 414 53.68 19.02 -3.03 531 96.70 39.26 -11.91 415 54.09 19.19 -3.09 532 97.03 39.44 -12.01 416 54.50 19.36 -3.14 533 97.37 39.62 -12.10 417 54.90 19.53 -3.20 534 97.70 39.79 -12.20 418 55.31 19.70 -3.25 535 98.03 39.97 -12.30 419 55.71 19.87 -3.31 536 98.36 40.15 -12.40 420 56.12 20.04 -3.36 537 98.69 40.32 -12.49 421 56.52 20.21 -3.42 538 99.02 40.50 -12.59

144

422 56.92 20.38 -3.47 539 99.35 40.68 -12.69 423 57.32 20.55 -3.53 540 99.68 40.86 -12.79 424 57.72 20.72 -3.59 541 100.01 41.04 -12.89 425 58.12 20.89 -3.65 542 100.34 41.21 -12.99 426 58.52 21.06 -3.71 543 100.66 41.39 -13.09 427 58.92 21.23 -3.76 544 100.99 41.57 -13.19 428 59.32 21.40 -3.82 545 101.32 41.75 -13.29 429 59.71 21.57 -3.88 546 101.65 41.92 -13.40 430 60.11 21.74 -3.94 547 101.97 42.10 -13.50 431 60.51 21.91 -4.00 548 102.30 42.28 -13.60 432 60.90 22.08 -4.06 549 102.62 42.46 -13.70 433 61.29 22.25 -4.12 550 102.95 42.64 -13.80 434 61.69 22.42 -4.19 551 103.27 42.82 -13.91 435 62.08 22.59 -4.25 552 103.59 42.99 -14.01 436 62.47 22.76 -4.31 553 103.92 43.17 -14.11 437 62.86 22.93 -4.37 554 104.24 43.35 -14.22 438 63.25 23.10 -4.44 555 104.56 43.53 -14.32 439 63.64 23.27 -4.50 556 104.88 43.71 -14.43 440 64.03 23.44 -4.56 557 105.20 43.89 -14.53 441 64.42 23.61 -4.63 558 105.53 44.07 -14.64 442 64.80 23.78 -4.69 559 105.85 44.24 -14.74 443 65.19 23.95 -4.76 560 106.17 44.42 -14.85 444 65.57 24.12 -4.82 561 106.48 44.60 -14.96 445 65.96 24.29 -4.89 562 106.80 44.78 -15.06 446 66.34 24.46 -4.95 563 107.12 44.96 -15.17 447 66.73 24.64 -5.02 564 107.44 45.14 -15.28 448 67.11 24.81 -5.09 565 107.76 45.32 -15.38 449 67.49 24.98 -5.15 566 108.08 45.50 -15.49 450 67.87 25.15 -5.22 567 108.39 45.68 -15.60 451 68.25 25.32 -5.29 568 108.71 45.86 -15.71 452 68.63 25.49 -5.36 569 109.02 46.04 -15.82 453 69.01 25.66 -5.43 570 109.34 46.22 -15.93 454 69.39 25.84 -5.50 571 109.65 46.40 -16.04 455 69.77 26.01 -5.57 572 109.97 46.58 -16.15 456 70.15 26.18 -5.64 573 110.28 46.76 -16.26 457 70.52 26.35 -5.71 574 110.60 46.94 -16.37 458 70.90 26.52 -5.78 575 110.91 47.12 -16.48 459 71.28 26.70 -5.85 576 111.22 47.30 -16.59 460 71.65 26.87 -5.92 577 111.54 47.48 -16.70 461 72.02 27.04 -5.99 578 111.85 47.66 -16.81

145

462 72.40 27.21 -6.06 579 112.16 47.84 -16.92 463 72.77 27.38 -6.14 580 112.47 48.02 -17.04 464 73.14 27.56 -6.21 581 112.78 48.20 -17.15 465 73.51 27.73 -6.28 582 113.09 48.38 -17.26 466 73.88 27.90 -6.36 583 113.40 48.56 -17.37 467 74.25 28.07 -6.43 584 113.71 48.74 -17.49 468 74.62 28.25 -6.50 585 114.02 48.92 -17.60 469 74.99 28.42 -6.58 586 114.33 49.10 -17.72 470 75.36 28.59 -6.65 587 114.64 49.28 -17.83 471 75.73 28.77 -6.73 588 114.95 49.46 -17.94 472 76.09 28.94 -6.80 589 115.25 49.64 -18.06 473 76.46 29.11 -6.88 590 115.56 49.82 -18.17 474 76.82 29.28 -6.96 591 115.87 50.01 -18.29 475 77.19 29.46 -7.03 592 116.17 50.19 -18.41 476 77.55 29.63 -7.11 593 116.48 50.37 -18.52 477 77.92 29.80 -7.19 594 116.78 50.55 -18.64 478 78.28 29.98 -7.27 595 117.09 50.73 -18.76 479 78.64 30.15 -7.35 596 117.39 50.91 -18.87 480 79.00 30.32 -7.42 597 117.70 51.09 -18.99 481 79.37 30.50 -7.50 598 118.00 51.28 -19.11 482 79.73 30.67 -7.58 599 118.31 51.46 -19.23 483 80.09 30.84 -7.66 600 118.61 51.64 -19.35 484 80.45 31.02 -7.74 601 118.91 51.82 -19.46 485 80.80 31.19 -7.82 602 119.21 52.00 -19.58 486 81.16 31.37 -7.91 603 119.52 52.18 -19.70 487 81.52 31.54 -7.99 604 119.82 52.37 -19.82 488 81.88 31.71 -8.07 605 120.12 52.55 -19.94 489 82.23 31.89 -8.15 606 120.42 52.73 -20.06 490 82.59 32.06 -8.23 607 120.72 52.91 -20.18 491 82.94 32.24 -8.32 608 121.02 53.09 -20.30 492 83.30 32.41 -8.40 609 121.32 53.28 -20.42 493 83.65 32.59 -8.48 610 121.62 53.46 -20.55 494 84.01 32.76 -8.57 611 121.92 53.64 -20.67 495 84.36 32.93 -8.65 612 122.22 53.82 -20.79 496 84.71 33.11 -8.73 613 122.52 54.01 -20.91 497 85.06 33.28 -8.82 614 122.81 54.19 -21.03 498 85.42 33.46 -8.90 615 123.11 54.37 -21.16 499 85.77 33.63 -8.99 616 123.41 54.56 -21.28 500 86.12 33.81 -9.08 617 123.70 54.74 -21.40 501 86.47 33.98 -9.16 618 124.00 54.92 -21.53

146

502 86.81 34.16 -9.25 619 124.30 55.10 -21.65 503 87.16 34.33 -9.34 620 124.59 55.29 -21.78 504 87.51 34.51 -9.42 621 124.89 55.47 -21.90 505 87.86 34.68 -9.51 622 125.18 55.65 -22.03 506 88.20 34.86 -9.60 623 125.48 55.84 -22.15 507 88.55 35.03 -9.69 623.15 125.52 56.02 -22.17

147