The Experts below are selected from a list of 90 Experts worldwide ranked by ideXlab platform
Xingliang Li - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on the Protonation of N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid in aqueous solutions: Potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.
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effect of temperature on the Protonation of n 2 hydroxyethyl ethylenediamine n n n triacetic acid in aqueous solutions potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.
Leigh R. Martin - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on the Protonation of N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid in aqueous solutions: Potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.
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effect of temperature on the Protonation of n 2 hydroxyethyl ethylenediamine n n n triacetic acid in aqueous solutions potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.
D. F. Parra - One of the best experts on this subject based on the ideXlab platform.
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A VERSATILE AND HIGH-PRECISION SOLUTION-REACTION ISOPERIBOL CALORIMETER
Journal of Thermal Analysis and Calorimetry, 2008Co-Authors: E. F. Vargas, J. C. Moreno, J. Forero, D. F. ParraAbstract:A new solution-reaction isoperibol calorimeter was developed to measure enthalpies of solution and reaction. A new system of sample cell was developed to avoid the breaking of glass ampoules, hence making the sample cell reusable. The system is suitable for measuring molar enthalpies of solid-liquid and liquid-liquid interactions at different temperatures. The reproducibility and accuracy of the apparatus were tested by measuring the Enthalpy of solution of KCl in water at 298.15 K and the Enthalpy of Protonation of THAM in HCl (0.1 M) at 298.15 K. The results showed the uncertainty taken as the reproducibility was ±0.3% and the difference with the literature values was within ±0.5%.
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A versatile and high-precision solution—reaction isoperibol calorimeter
Journal of Thermal Analysis and Calorimetry, 2008Co-Authors: E. F. Vargas, J. C. Moreno, J. Forero, D. F. ParraAbstract:A new solution-reaction isoperibol calorimeter was developed to measure enthalpies of solution and reaction. A new system of sample cell was developed to avoid the breaking of glass ampoules, hence making the sample cell reusable. The system is suitable for measuring molar enthalpies of solid-liquid and liquid-liquid interactions at different temperatures. The reproducibility and accuracy of the apparatus were tested by measuring the Enthalpy of solution of KCl in water at 298.15 K and the Enthalpy of Protonation of THAM in HCl (0.1 M) at 298.15 K. The results showed the uncertainty taken as the reproducibility was ±0.3% and the difference with the literature values was within ±0.5%.
Gilles Richner - One of the best experts on this subject based on the ideXlab platform.
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thermokinetic properties and performance evaluation of benzylamine based solvents for co2 capture
Chemical Engineering Journal, 2015Co-Authors: Gilles Richner, Marcel Maeder, Graeme Puxty, Amanda Carnal, William Conway, Pauline PearsonAbstract:Abstract Carbon dioxide (CO 2 ) post combustion capture and storage is the most mature technology option for the mitigation of CO 2 emissions from fossil fuel electricity generation. Typically CO 2 separation at low pressure is achieved by reactive chemical absorption using aqueous amines. In this work benzylamine (BZA) has been assessed in terms of the chemical and physical properties relevant for its application as an aqueous amine CO 2 absorbent. BZA was found to have similar reaction kinetics with CO 2 to monoethanolamine (MEA) ( k carb = 7600 M −1 s −1 at 35 °C and E a = 38 kJ mol −1 ) and similar carbamate stability but with a ∼40% larger Enthalpy of Protonation. It was also found to be less corrosive and have lower viscosity and heat capacity. Significant performance gains relative to MEA 30 wt% were predicted by using BZA in a formulation with either MEA or 2-amino-2-methyl-1-proponal (AMP) with predicted reductions in reboiler duty up to 13%, improvements in mass transfer up to 20% and low corrosion potential.
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Promoting CO2 absorption in aqueous amines with benzylamine
Energy Procedia, 2013Co-Authors: Gilles RichnerAbstract:Abstract Post-combustion capture of CO 2 is the most mature technique for reducing greenhouse gas emissions from coal fired power stations. In this study, aqueous benzylamine (BA) was investigated as a potential solvent for CO 2 capture. First, CO 2 loading capacities in 30% wt/wt aqueous benzylamine were determined by vapour liquid equilibrium (VLE) experiment in a stirred vessel between 40 °C and 80 °C, over a pressure range up to 900 kPa. At 15 kPa and 40 °C, 0.45 mol CO 2 /mol BA was absorbed. Protonation and carbamate thermodynamic equilibrium constants as well as the standard Enthalpy of Protonation were determined. Benzylamine showed a similar pKa (8.89 at 40 °C) but a larger pKa variation with temperature than MEA. The carbamate stability constant changed little with temperature. Benzylamine was then investigated as a CO 2 absorption rate promoter in aqueous MDEA in a stirred vessel with a plane horizontal gas-liquid interface. Benzylamine performed better than MEA and DEA as a rate promoting agent, a larger amount of benzylamine in aqueous MDEA resulting in a higher enhancement of CO 2 absorption rate.
Francesco Endrizzi - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on the Protonation of N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid in aqueous solutions: Potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.
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effect of temperature on the Protonation of n 2 hydroxyethyl ethylenediamine n n n triacetic acid in aqueous solutions potentiometric and calorimetric studies
The Journal of Chemical Thermodynamics, 2015Co-Authors: Xingliang Li, Zhicheng Zhang, Francesco Endrizzi, Leigh R. MartinAbstract:Abstract The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An 3+ ) from trivalent lanthanides (Ln 3+ ). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na + , lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA ( N -(2-hydroxyethyl)ethylenediamine- N , N ′, N ′-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln 3+ and An 3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process ( e.g. , higher temperatures). Thermodynamics of the Protonation and complexation of HEDTA with Ln 3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the Protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two Protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the Enthalpy of Protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two Protonation reactions occur on the diamine nitrogen atoms, while the third Protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln 3+ /An 3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln 3+ /An 3+ in the modified TALSPEAK process.