High-Temperature Sorbents for CO2Made of Alkali Metals Doped on CaO Supports

2004 ◽  
Vol 108 (23) ◽  
pp. 7794-7800 ◽  
Author(s):  
Ettireddy P. Reddy ◽  
Panagiotis G. Smirniotis
Keyword(s):  
High Temperature ◽  
Alkali Metals

Miscibility Gaps in Fused Salts Note VIII. Mixtures Formed by LiF and two Alkali Bromides

1975 ◽  
Vol 30 (6-7) ◽  
pp. 821-824
Author(s):  
G. Flor ◽  
Ch. Margheritis ◽  
C. Sinistri
Keyword(s):  
Temperature Field ◽  
High Temperature ◽  
Critical Temperature ◽  
Large Deviations ◽  
Alkali Metals ◽  
Ternary Systems ◽  
Fused Salts ◽  
Miscibility Gaps

Abstract Demixing phenomena were studied in 12 mixtures type LiF + (MeI, MeII)Br, MeI and MeII being alkali metals. Previous measurements of the LL equilibria in the system LiF + CsBr were extended to the high temperature field to evaluate the position of the point of maximum. Moreover, the data obtained on the system LiF + NaBr were analyzed in order to calculate the critical temperature of the "submerged" gap. The results allowed to test the thermodynamic theories concerning the reciprocal ternary systems in the case of large deviations from ideality.

scholarly journals Problems of sodium using in pulsating heat pipe made from fused silica

2018 ◽  
Vol 207 ◽  
pp. 04004
Author(s):  
Radovan Nosek ◽  
Tatiana Liptáková ◽  
Libor Trško ◽  
Zuzana Kolková ◽  
Milan Malcho ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Pipe ◽  
Alkali Metals ◽  
High Efficiency ◽  
Fused Silica ◽  
Operating Conditions ◽  
Liquid Sodium ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
High Temperature Reaction

You Heat pipe is a high efficiency heat transfer element, depends on the evaporation, condensation and circulation of inside working fluid. The working fluid of a high temperature pulsating heat pipe is generally alkali metals, and sodium heat pipe can operate in range of 500-1100°C. In order to investigate terminal velocity of working fluid, the glass pulsating heat pipe was produced for experimental purposes. The experiment was carried out, in order to simulate real operating conditions in range of 500-1100°C. Sudden boiling of liquid sodium (b.p. = 883°C at 1 atm) inside the all quartz-made heat pipe results in high-temperature reaction of sodium vapour with the inner wall surface. The reaction became more aggressive with increasing vapour temperature and resulted in heat pipe explosion. The evaluation of damage character is analysed in this paper.

High-temperature testing of metals for erosion strength in molten alkali metals

1980 ◽  
Vol 16 (2) ◽  
pp. 179-181
Author(s):  
V. K. Alekseev ◽  
R. G. Perel'man ◽  
Yu. D. Denisov
Keyword(s):  
High Temperature ◽  
Alkali Metals ◽  
High Temperature Testing

High temperature—high pressure neutron scattering experiments on expanded liquid alkali metals

1990 ◽  
Vol 4 (1-6) ◽  
pp. 549-551
Author(s):  
R. Winter ◽  
W.-C. Pilgrim ◽  
F. Hensel ◽  
T. Bodensteiner ◽  
W. Gläser
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Neutron Scattering ◽  
Alkali Metals ◽  
Liquid Alkali Metals ◽  
High Temperature High Pressure

Hastelloy G 35 сorrosion tests for intergranular corrosion resistance

2021 ◽  
Vol 26 (2) ◽  
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
High Temperature ◽  
Normal State ◽  
Intergranular Corrosion ◽  
Alkali Metals ◽  
Iron Sulfate ◽  
Average Depth ◽  
Rate Of Penetration

The article is devoted to the analysis of corrosion behavior and assessment of the resistance of Hastelloy G 35. Nickel-based alloys (steels) containing chromium, molybdenum, tungsten, possibly iron are widely used as materials for the manufacture of equipment in high-temperature technological processes using solutions of highly hygroscopic halides (chlorides) in molten halides (chlorides) of alkali metals. During the operation of the equipment, the instability of the surface of apparatus and pipelines to corrosion is determined. In this test, 4 samples of 80×20×3 mm were used, of which 2 samples were subjected to provoking heating, and 2 samples were examined in their normal state. Our tests were carried out in a boiling aqueous solution of iron sulfate and sulfuric acid for 48 ± 0.25 h. Further, the bent samples were examined using an MBS-9 microscope with a magnification of х8. The results of corrosion tests are also presented. As a result of the study, the rate of penetration of corrosion of the alloy was calculated. Hastelloy microstructure is presented. The average depth of destruction was determined from the six maximum values detected in six fields of view. According to the research results, the corresponding conclusions were made.

scholarly journals High-T, High-P Hydrothermal Synthesis of Uranium Silicates and Germanates

2014 ◽  
Vol 70 (a1) ◽  
pp. C759-C759
Author(s):  
Kwang-Hwa Lii
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Hydrothermal Synthesis ◽  
Alkali Metals ◽  
Spent Nuclear Fuel ◽  
Mixed Valence ◽  
Oxidation States ◽  
Uranyl Silicates ◽  
High Pressure Reaction ◽  
High Temperature High Pressure

Most uranium minerals can be classified as oxidized species in which U is fully oxidized to U(VI), and reduced species, in which U occurs primarily as U(IV). Uranyl silicates are an important group of uranium(VI) minerals in the altered zones of many uranium deposits [1]. Uranyl silicates have also received attention because they form when spent nuclear fuel interacts with water containing silicon under oxidizing conditions. One naturally occurring uranium(IV) silicate exists, namely coffinite (USiO4), which is the most important ore mineral for uranium after uraninite. Numerous synthetic uranium(VI) silicates and germanates containing organic amines or alkali metals as countercations have also been reported [2]. In contrast to the uranium(VI) compounds, the chemistry of materials containing uranium(V) is considerably less developed owing to the tendency of U(V) to either oxidize to U(VI) or disproportionate to U(IV) and U(VI). We have synthesized a pentavalent-uranium silicate and a germanate by a high-temperature, high-pressure hydrothermal method in gold ampoules contained in a high-pressure reaction vessel at ca. 600 °C and 170 MPa [3a,b]. Following the synthesis of the U(V) compounds, a number of mixed-valence uranium silicates and germanates have been synthesized, for example, a mixed-valence uranium(IV,V) silicate, Cs2K(UO)2Si4O12 [3c], a uranium(IV,VI) germanate, Cs8U(UO2)3(Ge3O9)3·3H2O [3d], uranium(V,VI) silicates and germanates, A3(U2O4)Ge2O7 (A = Rb, Cs) and [Na9F2][(UO2)3(Si2O7)2] [3e,f], and a uranium(IV,V,VI) silicate, Na7UO2(UO)2(UO2)2Si4O16 [3g] in which three oxidation states of uranium co-exist in one compound. In addition, tetravalent-uranium compounds, Cs2USi6O15 and Cs4UGe8O20 [3h,i], were also synthesized. All members in the family of uranium silicates and germanates with the oxidation states of uranium from +4 to +6 have been observed. In this presentation the high-temperature, high-pressure hydrothermal synthesis, crystal structures, and XPS spectroscopy of these interesting compounds will be reported.

Development of High-Strength-Fabricable Tantalum-Base Alloys

1993 ◽  
Vol 322 ◽  
Author(s):  
R. W. Buckman
Keyword(s):  
High Temperature ◽  
Refractory Metal ◽  
Alkali Metals ◽  
Acid Corrosion ◽  
The United States ◽  
Development Effort ◽  
Alloy Development ◽  
Temperature Oxidation ◽  
High Temperature Short Time ◽  
Oxidation Resistant

AbstractIn the 1950s, Ta-7.5%W and the Ta-2.5%W were the only tantalum alloys of commercial significance. An intensive alloy development effort occurred between 1958 and 1968 in response to Air Force and Navy aerospace needs for high-temperature, oxidation-resistant alloys for rocket and air-breathing engines and airframe applications. Compatibility with oxidation-resistant coatings, high-temperature short-time strength, fabricability and weldability were of prime importance. These programs led to the development of Ta-10w%W, Ta-30w%Nb-7.5w%V, T-111(Ta-8w%W-2w%Hf), and T-222(Ta-10w%W-2.5w%Hf-O.Olw%C). T-111, with its demonstrated compatibility with liquid alkali metals, and combination of strength, fabricability and weldability, was selected by NASA as the baseline reference alloy for space nuclear power systems studies. Significant quantities of T- 111 and T-222 were produced in the 1960s. Today, however, production is limited to unalloyed tantalum and the tantalum-tungsten binaries because of the demand of the chemical industry for materials with outstanding acid corrosion resistance. To again produce T-11 and T-222 on a commercial basis will require relearning by the refractory metal alloy producers. The current lack of experience in the refractory metal industry with these high temperature alloys will necessitate recovery of the expertise needed for the United States to effectively compete in this technology arena.

The Release Behavior of Potassium and Sodium in the Biomass High-Temperature Entrained-Flow Gasification

2011 ◽  
Vol 71-78 ◽  
pp. 2434-2441 ◽  
Author(s):  
Qing Chen ◽  
Jin Song Zhou ◽  
Qin Feng Mei ◽  
Zhong Yang Luo
Keyword(s):  
High Temperature ◽  
Alkali Metals ◽  
Sodium Content ◽  
Water Soluble ◽  
Release Behavior ◽  
Basic Oxide ◽  
Entrained Flow ◽  
Ash Melting ◽  
Entrained Flow Gasification ◽  
Physical And Chemical

Experiments were performed to investigate the release behavior of potassium and sodium in the biomass high-temperature entrained-flow gasification with the addition of acid oxide SiO2, basic oxide MgO, amphoteric oxide Al2O3. The results showed that the volatilization of alkali was found to strongly depend on temperature. High gasification temperature strengthened the alkali release. When the reactor temperature was 1200°C, the volatilization of alkali species were about 37.87% for K and 71.14% for Na. Three additives all favored the retention of potassium and sodium and the content of water-soluble potassium and sodium in the ash. Among the three additives, MgO had the best retention effect. The potassium and sodium content in the gas phase was as low as 46.6% and 67.3% compared with raw straw, respectively. In the entrained-flow gasification with short residence time, the additives retained more alkali metals by the physical and chemical adsorption. Part of the additive utilized as physical adsorbent during the gasification enhanced the ash melting point of the residue carbon.

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