Predicting Vapor-Liquid-Solid Equilibria in Multicomponent Aqueous Solutions of Electrolytes

Zemaitis, Joseph F.

doi:10.1021/bk-1980-0133.ch010

Cited by 25 publications

(21 citation statements)

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“…(3) and (4)). The Bromley-Zemaitis activity coefficient model [8,9] developed by Bromley [11] and empirically modified by Zemaitis [10] is used in the OLI software to calculate the ion activity coefficients. This model has been successfully used for electrolytes of 0-30 M at 0-473 K [8]; hence, it is appropriate for the present system, which is less than 1 M at 288.15-308.15 K. The Bromley-Zemaitis activity coefficient model for the case of cation i in a multicomponent electrolyte solution is expressed by…”

Section: Ion Activity Coefficient and Water Activity Relationshipsmentioning

confidence: 99%

“…The supersaturation (S) of MgCO3 Á 3H 2 O was exactly calculated by aqueous (H + ion) model in OLI StreamAnalyzer software package (version 2.0) [8]. Activity coefficient estimation in this model was done by the Bromley-Zemaitis [9][10][11] equation and thermodynamic equilibrium constant was estimated by the HKF equation [12][13][14]. The effect of temperature, supersaturation and the addition of NaCl on the nucleation of MgCO 3 Á 3H 2 O was investigated systematically.…”

Section: Introductionmentioning

confidence: 99%

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Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

Cheng

2010

Journal of Crystal Growth

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Section: Ion Activity Coefficient and Water Activity Relationshipsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

Cheng

2010

Journal of Crystal Growth

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“…The Bromley‐Zemaitis activity coefficient equation, which represents only ion–ion interactions, was developed by Bromley and empirically modified by Zemaitis . This model has been widely adopted for electrolytes with concentrations of 0–30 M at 0–473.15 K. The Bromley‐Zemaitis activity coefficient equation for the case of cation i in a multicomponent electrolyte solution can be described as follows:

\begin{matrix} \log γ_{i} = \frac{- {AZ}_{i}^{2} \sqrt{I}}{1 + \sqrt{I}} + \sum_{j} true[\frac{false(0.06 + 0.6 B_{ij} false) | Z_{i} Z_{j} |}{{true(1 + \frac{1.5 I}{| Z_{i} Z_{j} |} true)}^{2}} + B_{ij} + C_{ij} I + D_{ij} I^{2} true] \times {(\frac{| Z_{i} | + | Z_{j} |}{2})}^{2} m_{j} \end{matrix}

where j indicates all anions in solution, A is the Debye‐Hückel parameter, I is the ionic strength of the solution, B , C , and D are temperature‐dependent empirical coefficients, Z i and Z j are the cation and anion charges, respectively.…”

Section: Methodsmentioning

confidence: 99%

A practical approach to produce Mg‐Al spinel based on the modeling of phase equilibria for NH₄Cl‐MgCl₂‐AlCl₃‐H₂O system

Gao

2012

AIChE Journal

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Based on chemical modeling of phase equilibria for the NH4Cl‐MgCl2‐AlCl3‐H2O system, a practical approach to produce Mg‐Al spinel (MgAl2O4) (widely used as refractory brick, supports in catalysts, and inert material for oxygen carriers) is proposed and proven feasible. This novel process includes coprecipitation of Mg4Al2(OH)14·3H2O from the NH3‐MgCl2‐AlCl3‐H2O system; calcination of Mg4Al2(OH)14·3H2O to obtain Mg‐Al spinel and recovery of NH4Cl from NH4Cl‐rich solutions by feeding MgCl2‐AlCl3. A MSMPR reactor was applied to investigate the effect of temperature, feed concentration, and NH4Cl addition on coprecipitation of precursor Mg4Al2(OH)14·3H2O from MgCl2‐AlCl3 solutions with Mg/Al ratio = 2 through gradual addition of NH4OH. The phase equilibria of the NH4Cl‐MgCl2‐AlCl3‐H2O system were determined over the temperature range 283.2 to 363.2 K using dynamic method. The experimental solubilities were regressed to obtain new Bromley‐Zemaitis model parameters. These newly obtained parameters were verified by predicting the quaternary system. A chemical model for the NH4Cl‐MgCl2‐AlCl3‐H2O system has been established with the OLI platform. All the results generated from this study will provide the theoretical basis for Mg‐Al spinel production. The high quality Mg‐Al spinel was prepared by calcination of precursor from 773.2 to 1273.2 K, and the NH4Cl was successfully recovered through the common ion effect of MgCl2‐AlCl3 addition. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1855–1867, 2013

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“…There are several types of coefficient models that may be used in this context. 41,42 However, the Bromley-Zemaitis activity coefficient model 42 developed by Bromley 43 and empirically modified by Zemaitis 41 is one of the models used by the OLI software. This model has been successfully used for electrolytes with concentrations of 0-30 M at 0-200 C; hence, it is appropriate for calculating the OH À ion activity coefficient in the NaOH-NaAl(OH) 4 -H 2 O systems after validation.…”

Section: Chemistry Of Aqueous Aluminum and Silica In Naoh Solutionmentioning

confidence: 99%

A new process for Al₂O₃ production from low‐grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH‐NaAl(OH)₄ media

Xiao

2011

AIChE Journal

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A new process of Al 2 O 3 production from low-grade diasporic bauxite based on the reactive silica dissolution and stabilization in concentrated NaOH-NaAl(OH) 4 solutions is proposed and proved feasible. NaOH and Al 2 O 3 concentrations and leaching temperature were found to be the main factors affecting the leaching process of reactive silica. The A/S (mass ratio of Al 2 O 3 /SiO 2 ) of diasporic bauxite was enhanced from 5.4 to 15 by reactive silica removal under the optimum operation conditions. Two obvious steps control the whole leaching process of reactive silica in NaOH-NaAl(OH) 4 media: reactive silica dissolution and desilication products (DSPs) precipitation. The kinetics data of two controlling steps fit a shrinking core model based on the calculation of OH À activity with the aid of OLI platform and an empirical kinetic model well, respectively. Apparent activation energies of reactive silica leaching in the temperature range from 80 to 110 C are 101.91 and 58.65 kJ mol À1 for the two steps, respectively. The stabilization mechanism of reactive silica in concentrated NaOH-NaAl(OH) 4 solution was also elucidated based on the complexation of aluminum-bearing species and the calculation of supersaturation to DSP. It was found that the concentration of OH À sharply decreases due to the formation of Al(OH) 4 À species with increasing aluminum concentration, suppressing greatly DSP precipitation. This proposed process paves the way for Al 2 O 3 production from low-grade diasporic bauxite with high-reactive silica content.A/S ¼ mass ratio of Al 2 O 3 /SiO 2 DSP ¼ desilication products S ¼ supersaturation K sp ¼ the solubility product constant of DSP k ¼ the kinetic rate constant (refer to Eq. 10) k 1 ¼ the dissolution kinetic rate constant of reactive silica, kg L À1 min À1 Figure 16. SEM morphologies of Al 2 O 3 obtained in this study.

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Predicting Vapor-Liquid-Solid Equilibria in Multicomponent Aqueous Solutions of Electrolytes

Cited by 25 publications

References 0 publications

Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

A practical approach to produce Mg‐Al spinel based on the modeling of phase equilibria for NH₄Cl‐MgCl₂‐AlCl₃‐H₂O system

A new process for Al₂O₃ production from low‐grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH‐NaAl(OH)₄ media

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Predicting Vapor-Liquid-Solid Equilibria in Multicomponent Aqueous Solutions of Electrolytes

Cited by 25 publications

References 0 publications

Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

Nucleation kinetics of nesquehonite (MgCO3·3H2O) in the MgCl2−Na2CO3 system

A practical approach to produce Mg‐Al spinel based on the modeling of phase equilibria for NH4Cl‐MgCl2‐AlCl3‐H2O system

A new process for Al2O3 production from low‐grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH‐NaAl(OH)4 media

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A practical approach to produce Mg‐Al spinel based on the modeling of phase equilibria for NH₄Cl‐MgCl₂‐AlCl₃‐H₂O system

A new process for Al₂O₃ production from low‐grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH‐NaAl(OH)₄ media