Effect of Potassium Carbonate Additive on CO2 Absorption in Lithium Zirconate Powder

1998 ◽  
Vol 547 ◽  
Author(s):  
T. Ohashi ◽  
K. Nakagawa
Keyword(s):  
Potassium Carbonate ◽  
Room Temperature ◽  
Absorption Rate ◽  
Co2 Absorption ◽  
The Past ◽  
Lithium Zirconate ◽  
Kinetics Of

AbstractLithium zirconate, which reacts with CO2 reversibly at temperatures over 500°C, is expected to find wider application than conventional CO2 absorbents, as the latter can be used only at room temperature. We examined the effect of potassium carbonate, which had usually been added to facilitate the formation of lithium zirconate in the past, on the kinetics of CO2 absorption reaction. The result shows that the CO2 absorption rate of lithium zirconate powder is extremely accelerated by the potassium carbonate additive. We conclude that this acceleration results from the formation of a eutectic carbonate composed of Li2CO3 and K2CO3.

scholarly journals Experimental Study of CO2 Absorption in Potassium Carbonate Solution Promoted by Triethylenetetramine

2018 ◽  
Vol 12 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Rouzbeh Ramezani ◽  
Saeed Mazinani ◽  
Renzo Di Felice
Keyword(s):  
Partial Pressure ◽  
Potassium Carbonate ◽  
Absorption Rate ◽  
Low Cost ◽  
Total Concentration ◽  
Absorption Capacity ◽  
Correlated Data ◽  
Co2 Absorption ◽  
Cell Reactor ◽  
Stirred Cell

Background: Separation of CO 2 as the major cause of global warming is essential. In this work, potassium carbonate (K 2 CO 3 ) solution was selected as a base solvent for CO 2 absorption due to its ease of regeneration energy, low cost and low environmental impact. However, the absorption rate of CO 2 with K 2 CO 3 needs to be improved by adding a suitable promoter. Therefore, the performance of CO 2 in K 2 CO 3 solution promoted by triethylenetetramine (TETA) in terms of absorption capacity and absorption rate of CO2 was studied. Method: Experiments were conducted at a total concentration of 2.5 (M) with different TETA mole fractions at temperatures of 303, 313 and 323 K, and CO2 partial pressure up to 30 kPa using a stirred cell reactor. The effect of CO2 partial pressure, temperature and concentration of TETA on absorption capacity and absorption rate of CO2 in K2CO3+TETA solution was discussed in detail. Results: The CO2 loading capacity obtained in this work was compared with monoethanolamine (MEA) and a better performance was observed for K2CO3+TETA solution. In addition, experimental results revealed that the addition of TETA to K2CO3 improved the CO2 reaction rate. Finally, the response surface methodology was employed to correlate the CO2 solubility. It was found that the correlated data are in good agreement with the experiment results. Conclusion: As an overall conclusion, the solution of K2CO3+TETA can be used as a promising absorbent in post combustion CO2 capture processes.

scholarly journals Acceleration Effect of Ternary Carbonate on CO2 Absorption Rate in Lithium Zirconate Powder.

2001 ◽  
Vol 109 (1274) ◽  
pp. 829-833 ◽  
Author(s):  
Kenji ESSAKI ◽  
Kazuaki NAKAGAWA ◽  
Masahiro KATO
Keyword(s):  
Absorption Rate ◽  
Co2 Absorption ◽  
Lithium Zirconate

Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel

1991 ◽  
Vol 49 ◽  
pp. 584-585
Author(s):  
R. Varughese ◽  
S. W. Thompson ◽  
P. R. Howell
Keyword(s):  
Room Temperature ◽  
Transformation Products ◽  
Accurate Description ◽  
Granular Bainite ◽  
Preliminary Results ◽  
The Past ◽  
Light Micrograph ◽  
Multiphase Reaction ◽  
Detailed Nature

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

Kinetics of the Thermal Disappearance of Radicals Formed During the Radiolysis of Aspartic Acid

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihai Contineanu ◽  
iulia Contineanu ◽  
Ana Neacsu ◽  
Stefan Perisanu
Keyword(s):  
Thermal Resistance ◽  
Aspartic Acid ◽  
Room Temperature ◽  
Esr Spectra ◽  
Complex Mechanism ◽  
Radical Species ◽  
Mechanisms Of Formation ◽  
Kinetics Of

The radiolysis of the isomers L-, D- and DL- of the aspartic acid, in solid polycrystalline state, was investigated at room temperature. The analysis of their ESR spectra indicated the formation of at least two radicalic entities. The radical, identified as R3, resulting from the deamination of the acid, exhibits the highest concentration and thermal resistance. Possible mechanisms of formation of three radical species are suggested, based also on literature data. The kinetics of the disappearance of radical R3 indicated a complex mechanism. Three possible variants were suggested for this mechanism.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

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