scholarly journals Use of a phenomenological chemical scale for the identification of high distribution coefficient impurities within the ITS-90

2016 ◽  
Vol 117 ◽  
pp. 012026
Author(s):  
D H Lowe
Keyword(s):  
Distribution Coefficient ◽  
High Distribution Coefficient

Consideration on modeling of Nb sorption onto clay minerals

2020 ◽  
Vol 108 (11) ◽  
pp. 873-877
Author(s):  
Tetsuji Yamaguchi ◽  
Saki Ohira ◽  
Ko Hemmi ◽  
Logan Barr ◽  
Asako Shimada ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
Clay Minerals ◽  
Safety Assessment ◽  
Distribution Coefficients ◽  
Surface Species ◽  
Complex Species ◽  
Intermediate Depth ◽  
Speciation Model ◽  
Surface Phases ◽  
High Distribution Coefficient

AbstractSorption distribution coefficient (Kd) of niobium-94 on minerals are an important parameter in safety assessment of intermediate-depth disposal of waste from core internals etc. The Kd of Nb on clay minerals in Ca(ClO4)2 solutions were, however, not successfully modeled in a previous study. The high distribution coefficients of Nb on illite in Ca(ClO4)2 solutions were successfully reproduced by taking Ca–Nb–OH surface species into account. Solubility of Nb was studied in Ca(ClO4)2 solutions and the results were reproduced by taking an aqueous Ca–Nb–OH complex species, CaNb(OH)6+, into account in addition to previously reported Nb(OH)6− and Nb(OH)72−. Based on this aqueous speciation model, the Ca–Nb–OH surface species responsible for the sorption of Nb on illite in Ca(ClO4)2 solutions was presumed to be X_OCaNb(OH)6. Although uncertainties exist in the speciation of aqueous Ca–Nb–OH species, the result of this study proposed a possible mechanism for high distribution coefficient of Nb on illite in Ca(ClO4)2 solutions. The mechanism includes Ca–Nb–OH complex formation in aqueous, solid and surface phases.

Ethylsulphate-Based Ionic Liquids in the Liquid–Liquid Extraction of Pyrrole and Pyridine from Isododecane at 298.15 K

2015 ◽  
Vol 10 (3) ◽  
pp. 161-171 ◽  
Author(s):  
Nurshakirin Hazim Chan ◽  
Hanee Farzana Hizaddin ◽  
Ramalingam Anantharaj ◽  
Tamal Banerjee
Keyword(s):  
Experimental Data ◽  
Ionic Liquids ◽  
Distribution Coefficient ◽  
Significant Role ◽  
Entire Range ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Lle Data ◽  
Denitrification Process ◽  
High Distribution Coefficient

Abstract Ternary liquid-liquid equilibria for four systems containing ionic liquids {1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) and 1-ethyl-3-methylpyridinium ethylsulphate ([EMPY][EtSO4])}(1)+pyrrole/pyridine(2)+isododecane (3) have been determined at 298.15 K. The solute distribution coefficient and selectivity were calculated from experimental LLE data. All systems showed high distribution coefficient and selectivity values at the entire range of pyrrole or pyridine in feed. The consistency of experimental data was ascertained by applying the Othmer-Tobias and hand equations. Furthermore, the experimental LLE data have been compared and correlated using COSMO-RS, NRTL and UNIQUAC models. The influence of aromatic structure without inside ring of cation has a significant role on denitrification process at 298.15 K.

Imidazolium-based dicationic ionic liquids: highly efficient extractants for separating aromatics from aliphatics

2018 ◽  
Vol 20 (13) ◽  
pp. 3101-3111 ◽  
Author(s):  
Congfei Yao ◽  
Yucui Hou ◽  
Weize Wu ◽  
Shuhang Ren ◽  
Hui Liu
Keyword(s):  
Ionic Liquids ◽  
Distribution Coefficient ◽  
High Selectivity ◽  
Highly Efficient ◽  
Alternative Solvents ◽  
Potential Alternative ◽  
Dicationic Ionic Liquids ◽  
High Distribution Coefficient

Imidazolium-based dicationic ionic liquids (DILs) are potential alternative solvents for the extraction of aromatics from aliphatics with both high selectivity and high distribution coefficient.

Mathematical modelling of salt purification by recrystallization. Countercurrent arrangement

1986 ◽  
Vol 51 (11) ◽  
pp. 2481-2488
Author(s):  
Benitto Mayrhofer ◽  
Jana Mayrhoferová ◽  
Lubomír Neužil ◽  
Jaroslav Nývlt
Keyword(s):  
Steady State ◽  
Simple Model ◽  
Mathematical Modelling ◽  
Distribution Coefficient ◽  
Mother Liquor ◽  
Equilibrium Temperature ◽  
Operating Conditions ◽  
Limiting Case

The paper presents a simple model of recrystallization with countercurrent flows of the solution and the crystals being purified. The model assumes steady-state operating conditions, an equilibrium between the outlet streams of each stage, and the same equilibrium temperature and distribution coefficient for all stages. With these assumptions, the model provides the basis for analyzing the variation in the degree of purity as a function of the number of recrystallization stages. The analysis is facilitated by the use of a diagram constructed for the limiting case of perfect removal of the mother liquor from the crystals between the stages.

Computational Parameters in Correlation Analysis: Gas-Water Distribution Coefficient

1999 ◽  
Vol 64 (11) ◽  
pp. 1727-1747 ◽  
Author(s):  
George R. Famini ◽  
Dalia Benyamin ◽  
Christina Kim ◽  
Rattiporn Veerawat ◽  
Leland Y. Wilson
Keyword(s):  
Correlation Analysis ◽  
Distribution Coefficient ◽  
Water Distribution ◽  
Solvation Energy ◽  
Linear Solvation Energy Relationships ◽  
Linear Solvation Energy Relationship ◽  
Energy Relationships ◽  
Linear Solvation Energy ◽  
Water Equilibrium ◽  
Linear Solvation

Theoretical linear solvation energy relationships (TLSER) combine computational molecular parameters with the linear solvation energy relationship (LSER) of Kamlet and Taft to characterize and predict properties of compounds. This paper examines the correlation of the gas-water equilibrium constant for 423 compounds with the TLSER parameters. Also, it describes new parameters designed to improve the TLSER information content.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

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