A simple instrument for ultraviolet-visible absorption spectrophotometry in high temperature molten salt media

2000 ◽  
Vol 71 (6) ◽  
pp. 2283-2287 ◽  
Author(s):  
Jianzhong Li ◽  
Purnendu K. Dasgupta
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Visible Absorption ◽  
Absorption Spectrophotometry ◽  
Simple Instrument

Absorption and Stripping of CO2 with a Molten Salt Slurry in a Bubble Column at High Temperature

2006 ◽  
Vol 29 (9) ◽  
pp. 1118-1121 ◽  
Author(s):  
K. Terasaka ◽  
Y. Suyama ◽  
K. Nakagawa ◽  
M. Kato ◽  
K. Essaki
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Bubble Column

Octahedral–tetrahedral equilibria in aqueous cobalt(II) solutions at high temperatures

1980 ◽  
Vol 58 (14) ◽  
pp. 1418-1426 ◽  
Author(s):  
Thomas Wilson Swaddle ◽  
Leonard Fabes
Keyword(s):  
Sulfuric Acid ◽  
High Temperature ◽  
Absorption Band ◽  
High Temperatures ◽  
Intensity Ratio ◽  
Hydrogen Sulfate ◽  
Sulfate Ion ◽  
Acidic Media ◽  
Visible Absorption ◽  
Upper Limits

Evidence is presented to indicate that aqueous Co2+ exists as the hexaaquo-ion in equilibrium with minor amounts (upper limits 0.08% at 298 K, 7% at 625 K, at 16–25 MPa) of tetraaquocobalt(II), with ΔH ~ +17 kJ mol−1. The single visible absorption band of the supposed Co(H2O)42+ has maxima at 552 nm and 486 nm in the intensity ratio 2:1. Hydrogen sulfate ion (up to 0.5 M at least) does not complex Co2+(aq) detectably in acidic media, 290–625 K, and sulfuric acid therefore holds promise as a non-complexing strong monobasic acid for high-temperature aqueous studies. In water containing 2.0 M or more Cl−, the tetrahedral form of cobalt(II) is CoCl42−, ΔH for the octahedral → tetrahedral equilibrium being +62 kJ mol−1; forCoBr42−, the corresponding ΔH is +70 kJ mol−1, the greater endothermicity accounting entirely for the lower stability relative to CoCl42−.

Electrochemical Studies on High-Temperature Corrosion of Silicon-Iron Coatings and Iron Aluminide Intermetallic Alloys by Molten Salts

CORROSION ◽  
2001 ◽  
Vol 57 (6) ◽  
pp. 489-496 ◽  
Author(s):  
M. Amaya ◽  
J. Porcayo-Calderon ◽  
L. Martinez
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Electric Power ◽  
Molten Salts ◽  
Corrosion Current ◽  
High Temperature Corrosion ◽  
Iron Aluminide ◽  
Fuel Oil ◽  
Silicon Iron ◽  
Salt Corrosion

Abstract The performance of Fe-Si coatings and an iron aluminide (FeAl) intermetallic alloy (FeAl40at%+0.1at%B+10vol%Al2O3) in molten salts containing vanadium pentoxide (V2O5) and sodium sulfate (Na2SO4) is reported. Corrosion and fouling by ash deposits containing V2O5 and Na2SO4 are typical corrosion problems in fuel oil-fired electric power units. High-temperature corrosion tests were performed using both electrochemical polarization and immersion techniques. The temperature interval of this study was 600°C to 900°C, and the molten salts were 80wt%V2O5-20wt%Na2SO4. Curves of corrosion current density vs temperature obtained by the potentiodynamic studies are reported, as well as the weight loss vs temperature curves from molten salt immersion tests. Both Fe-Si coatings and FeAl40at%+0.1at%B+10vol%Al2O3 showed good behavior against molten salt corrosion. The final results show the potential of these coatings and alloys to solve the high-temperature corrosion in fuel oil-fired electric power units.

Molten salt electrolytes for high-temperature lithium cells

1989 ◽  
Vol 26 (1-2) ◽  
pp. 37-48 ◽  
Author(s):  
D.R. Vissers ◽  
L. Redey ◽  
T.D. Kaun
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Molten Salt Electrolytes ◽  
Lithium Cells

Electrolytic synthesis of ZrSi/ZrC nanocomposites from ZrSiO4 and carbon black powder in molten salt

2020 ◽  
Vol 111 (7) ◽  
pp. 581-586
Author(s):  
Li Ming ◽  
Wu Xiufeng
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Carbon Black ◽  
Molten Salt ◽  
Cell Voltage ◽  
Black Powder ◽  
X Ray ◽  
Carbon Black Powder ◽  
Transmission Electron ◽  
A Cell

Abstract ZrSi/ZrC nanocomposites have stable high-temperature properties, where conventional materials cannot meet increasingly demanding high-temperature environments. In this paper, the microstructure and electrochemical reduction mechanism of ZrSi/ZrC nanocomposites have been studied. A mixture of ZrSiO4 and carbon black powder was processed using ball grinding, sheet pressing, and sintering, and cylindrically-sintered sheet was prepared as the cathode for the electrolytic work. A high purity graphite rod was utilized as the anode.The microstructure of the electrolytic product was characterized and analyzed using X-ray diffraction, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and transmission electron microscopy. The experimental results showed that the diameter of the as-synthesized ZrSi/ ZrC fibers typically range between 100-400 nm when produced by the electrolysis of sintered pellets in equimolar CaCl2-NaCl molten salt at 850°C with a cell voltage of 2.8 V for 20 h under an argon atmosphere. The nanofibers were formed in core-shell microstructures that overlap and grow.

Development of High Temperature, Corrosion Resistant Sensors for Concentrating Solar Power Systems

2014 ◽  
Author(s):  
Michael W. Usrey ◽  
Yiping Liu ◽  
Mark Anderson ◽  
Jon Lubbers ◽  
Brady Knowles ◽  
...  
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Solar Power ◽  
Thermal Flux ◽  
Temperature Cycling ◽  
Chloride Salt ◽  
Concentrating Solar Power ◽  
Salt Corrosion ◽  
Chloride Salts ◽  
Functional Ceramics

Solar power is a sustainable resource which can reduce the power generated by fossil fuels, lowering greenhouse gas emissions and increasing energy independence. The U.S. Department of Energy’s SunShot Initiative has set goals to increase the efficiency of concentrating solar power (CSP) systems. One SunShot effort to help CSP systems exceed 50% efficiency is to make use of high-temperature heat transfer fluids (HTFs) and thermal energy storage (TES) fluids that can increase the temperature of the power cycle up to 1300°C. Sporian has successfully developed high-temperature operable pressure, temperature, thermal flux, strain, and flow sensors for gas path measurements in high-temperature turbine engines. These sensors are based on a combination of polymer derived ceramic (PDC) sensors, advanced high-temperature packaging, and integrated electronics. The overall objective is the beneficial application of these sensors to CSP systems. Through collaboration with CSP industry stakeholders, Sporian has established a full picture of operational, interface, and usage requirements for trough, tower, and dish CSP architectures. In general, sensors should have accurate measurement, good reliability, reasonable cost, and ease of replacement or repair. Sensors in contact with hot salt HTF and TES fluids will experience temperature cycling on a daily basis, and parts of the system may be drained routinely. Some of the major challenges to high-temperature CSP implementation include molten salt corrosion and flow erosion of the sensors. Potential high-temperature sensor types that have been identified as of interest for CSP HTF/TES applications include temperature, pressure, flow, and level sensors. Candidate solar salts include nitrate, carbonate, and chloride, with different application temperatures ranging from 550°C-900°C. Functional ceramics were soaked for 500 hours in molten nitrate, carbonate, and chloride salts, showing excellent corrosion resistance in chloride salts and good resistance in nitrate salts. The demonstration of functional ceramics in relevant HTFs laid the foundation for full prototype sensor and packaging demonstration. Sporian has developed a packaging approach for ceramic-based sensors in various harsh gaseous environments at temperatures up to 1400°C, but several aspects of that packaging are not compatible with corrosive and electrically conductive HTFs. In addition to consulting published literature, a 300 hour soak test in molten chloride salt allowed the authors to identify suitable structural metals and ceramics. Based on discussions with stakeholders, molten salt corrosion testing and room-temperature water flow testing, suitable for CSP sensor/packaging concepts were identified for future development, and initial prototypes have been built and tested.

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