scholarly journals Modelling of the Phase-Partitioning Behaviors for CO2-Brine System at Geological Conditions

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Xiaohui Sun ◽  
Zhiyuan Wang ◽  
Yingjie Li ◽  
Hangyu Li ◽  
Haikang He ◽  
...  
Keyword(s):  
Activity Coefficient ◽  
Aqueous Phase ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Salting Out ◽  
Model Calculations ◽  
Rich Phase ◽  
Phase Partitioning ◽  
Proposed Model ◽  
Geological Conditions

Abstract An improved phase-partitioning model is proposed for the prediction of the mutual solubility in the CO2-brine system containing Na+, K+, Ca2+, Mg2+, Cl-, and SO42-. The correlations are computationally efficient and reliable, and they are primarily designed for incorporation into a multiphase flow simulator for geology- and energy-related applications including CO2 sequestration, CO2-enhanced geothermal systems, and CO2-enhanced oil recovery. The model relies on the fugacity coefficient in the CO2-rich phase and the activity coefficient in the aqueous phase to estimate the phase-partitioning properties. In the model, (i) the fugacity coefficients are simulated by a modified Peng-Robinson equation of state which incorporates a new alpha function and binary interaction parameter (BIP) correlation; (ii) the activity coefficient is estimated by a unified equilibrium constant model and a modified Margules expression; and (iii) the simultaneous effects of salting-out on the compositions of the CO2-rich phase and the aqueous phase are corrected by a Pizter interaction model. Validation of the model calculations against literature experimental data and traditional models indicates that the proposed model is capable of predicting the phase-partitioning behaviors in the CO2-brine system with a higher accuracy at temperatures of up to 623.15 K and pressures of up to 350 MPa. Using the proposed model, the phase diagram of the CO2+H2O system is generated. An abrupt change in phase compositions is revealed during the transfer of the CO2-rich phase from vapor to liquid or supercritical. Furthermore, the preliminary simulation shows that the salting-out effect can considerably decrease the water content in the CO2-rich phase, which has not been well experimentally studied so far.

scholarly journals Predicting the phase behavior of hydrogen in NaCl brines by molecular simulation for geological applications

2019 ◽  
Vol 190 ◽  
pp. 7 ◽  
Author(s):  
Cristina Lopez-Lazaro ◽  
Pierre Bachaud ◽  
Isabelle Moretti ◽  
Nicolas Ferrando
Keyword(s):  
Force Field ◽  
Molecular Simulation ◽  
Large Scale ◽  
Simulated Data ◽  
Hydrogen Solubility ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Average Deviation ◽  
Salting Out ◽  
Henry Constants

Hydrogen is targeted to have a significant influence on the energy mix in the upcoming years. Its underground injection is an efficient solution for large-scale and long-term storage. Furthermore, natural hydrogen emissions have been proven in several locations of the world, and the potential underground accumulations constitute exciting carbon-free energy sources. In this context, comprehensive models are necessary to better constrain hydrogen behavior in geological formations. In particular, solubility in brines is a key-parameter, as it directly impacts hydrogen reactivity and migration in porous media. In this work, Monte Carlo simulations have been carried out to generate new simulated data of hydrogen solubility in aqueous NaCl solutions in temperature and salinity ranges of interest for geological applications, and for which no experimental data are currently available. For these simulations, molecular models have been selected for hydrogen, water and Na+ and Cl− to reproduce phase properties of pure components and brine densities. To model solvent-solutes and solutes-solutes interactions, it was shown that the Lorentz-Berthelot mixing rules with a constant interaction binary parameter are the most appropriate to reproduce the experimental hydrogen Henry constants in salted water. With this force field, simulation results match measured solubilities with an average deviation of 6%. Additionally, simulation reproduced the expected behaviors of the H2O + H2 + NaCl system, such as the salting-out effect, a minimum hydrogen solubility close to 57 °C, and a decrease of the Henry constant with increasing temperature. The force field was then used in extrapolation to determine hydrogen Henry constants for temperatures up to 300 °C and salinities up to 2 mol/kgH2O. Using the experimental measures and these new simulated data generated by molecular simulation, a binary interaction parameter of the Soreide and Whiston equation of state has been fitted. The obtained model allows fast and reliable phase equilibrium calculations, and it was applied to illustrative cases relevant for hydrogen geological storage or H2 natural emissions.

A method for selective separation of scandium (III) from yttrium and a number of rare-earth elements for its subsequent determination

2018 ◽  
Vol 84 (11) ◽  
pp. 23-27
Author(s):  
M. I. Degtev ◽  
A. A. Yuminova ◽  
A. S. Maksimov ◽  
A. P. Medvedev
Keyword(s):  
Rare Earth ◽  
Aqueous Phase ◽  
Selective Isolation ◽  
Optimum Ratio ◽  
Extraction Condition ◽  
Sulfosalicylic Acid ◽  
Salting Out ◽  
Subsequent Determination ◽  
Toxic Organic Solvents ◽  
Metal Ions Extraction

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.

Extraction of hafnium(IV) with organophosphorus reagents from solutions of mineral acids mixtures

1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Synergic Effect ◽  
Salting Out ◽  
Initial Concentration ◽  
Mixed Complexes ◽  
Synergic Extraction ◽  
Mineral Acids

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.

scholarly journals Modelling Sorption Thermodynamics and Mass Transport of n-Hexane in a Propylene-Ethylene Elastomer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1157
Author(s):  
Daniele Tammaro ◽  
Lorenzo Lombardi ◽  
Giuseppe Scherillo ◽  
Ernesto Di Maio ◽  
Navanshu Ahuja ◽  
...  
Keyword(s):  
Mass Transport ◽  
Interaction Parameter ◽  
Sorption Isotherms ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Theoretical Interpretation ◽  
Sorption Behavior ◽  
Solvent Mixtures ◽  
Random Lattice ◽  
Hexane Vapor

Optimization of post polymerization processes of polyolefin elastomers (POE) involving solvents is of considerable industrial interest. To this aim, experimental determination and theoretical interpretation of the thermodynamics and mass transport properties of POE-solvent mixtures is relevant. Sorption behavior of n-hexane vapor in a commercial propylene-ethylene elastomer (V8880 VistamaxxTM from ExxonMobil, Machelen, Belgium) is addressed here, determining experimentally the sorption isotherms at temperatures ranging from 115 to 140 °C and pressure values of n-hexane vapor up to 1 atm. Sorption isotherms have been interpreted using a Non Random Lattice Fluid (NRLF) Equation of State model retrieving, from data fitting, the value of the binary interaction parameter for the n-hexane/V8880 system. Both the cases of temperature-independent and of temperature-dependent binary interaction parameter have been considered. Sorption kinetics was also investigated at different pressures and has been interpreted using a Fick’s model determining values of the mutual diffusivity as a function of temperature and of n-hexane/V8880 mixture composition. From these values, n-hexane intra-diffusion coefficient has been calculated interpreting its dependence on mixture concentration and temperature by a semi-empiric model based on free volume arguments.

Toluene degradation in a two-phase partitioning bioreactor involving a hydrophobic ionic liquid as a non-aqueous phase liquid

2017 ◽  
Vol 117 ◽  
pp. 31-38 ◽  
Author(s):  
Thi-vi-na Nguyen ◽  
Alfredo Santiago Rodriguez Castillo ◽  
Solène Guihéneuf ◽  
Pierre-François Biard ◽  
Ludovic Paquin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Aqueous Phase ◽  
Toluene Degradation ◽  
Two Phase ◽  
Phase Partitioning ◽  
Partitioning Bioreactor ◽  
Hydrophobic Ionic Liquid ◽  
Phase Liquid ◽  
Two Phase Partitioning Bioreactor

scholarly journals Glycosyl-phosphatidylinositol-anchored membrane proteins can be distinguished from transmembrane polypeptide-anchored proteins by differential solubilization and temperature-induced phase separation in Triton X-114

1991 ◽  
Vol 280 (3) ◽  
pp. 745-751 ◽  
Author(s):  
N M Hooper ◽  
A Bashir
Keyword(s):  
Phase Separation ◽  
Membrane Proteins ◽  
Aqueous Phase ◽  
Hydrophobic Membrane ◽  
Rich Phase ◽  
Glycosyl Phosphatidylinositol ◽  
Ionic Detergent ◽  
Membrane Spanning ◽  
Triton X ◽  
Insoluble Pellet

Treatment of kidney microvillar membranes with the non-ionic detergent Triton X-114 at 0 degrees C, followed by low-speed centrifugation, generated a detergent-insoluble pellet and a detergent-soluble supernatant. The supernatant was further fractionated by phase separation at 30 degrees C into a detergent-rich phase and a detergent-depleted or aqueous phase. Those ectoenzymes with a covalently attached glycosyl-phosphatidylinositol (G-PI) membrane anchor were recovered predominantly (greater than 73%) in the detergent-insoluble pellet. In contrast, those ectoenzymes anchored by a single membrane-spanning polypeptide were recovered predominantly (greater than 62%) in the detergent-rich phase. Removal of the hydrophobic membrane-anchoring domain from either class of ectoenzyme resulted in the proteins being recovered predominantly (greater than 70%) in the aqueous phase. This technique was also applied to other membrane types, including pig and human erythrocyte ghosts, where, in both cases, the G-PI-anchored acetylcholinesterase partitioned predominantly (greater than 69%) into the detergent-insoluble pellet. When the microvillar membranes were subjected only to differential solubilization with Triton X-114 at 0 degrees C, the G-PI-anchored ectoenzymes were recovered predominantly (greater than 63%) in the detergent-insoluble pellet, whereas the transmembrane-polypeptide-anchored ectoenzymes were recovered predominantly (greater than 95%) in the detergent-solubilized supernatant. Thus differential solubilization and temperature-induced phase separation in Triton X-114 distinguished between G-PI-anchored membrane proteins, transmembrane-polypeptide-anchored proteins and soluble, hydrophilic proteins. This technique may be more useful and reliable than susceptibility to release by phospholipases as a means of identifying a G-PI anchor on an unpurified membrane protein.

scholarly journals Constraining condensed-phase formation kinetics of secondary organic aerosol components from isoprene epoxydiols

2016 ◽  
Vol 16 (3) ◽  
pp. 1245-1254 ◽  
Author(s):  
T. P. Riedel ◽  
Y.-H. Lin ◽  
Z. Zhang ◽  
K. Chu ◽  
J. A. Thornton ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Atmospheric Aerosols ◽  
Rate Constants ◽  
Reaction Rate ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Model Calculations ◽  
Reaction Rate Constants ◽  
Aerosol Mass

Abstract. Isomeric epoxydiols from isoprene photooxidation (IEPOX) have been shown to produce substantial amounts of secondary organic aerosol (SOA) mass and are therefore considered a major isoprene-derived SOA precursor. Heterogeneous reactions of IEPOX on atmospheric aerosols form various aerosol-phase components or "tracers" that contribute to the SOA mass burden. A limited number of the reaction rate constants for these acid-catalyzed aqueous-phase tracer formation reactions have been constrained through bulk laboratory measurements. We have designed a chemical box model with multiple experimental constraints to explicitly simulate gas- and aqueous-phase reactions during chamber experiments of SOA growth from IEPOX uptake onto acidic sulfate aerosol. The model is constrained by measurements of the IEPOX reactive uptake coefficient, IEPOX and aerosol chamber wall losses, chamber-measured aerosol mass and surface area concentrations, aerosol thermodynamic model calculations, and offline filter-based measurements of SOA tracers. By requiring the model output to match the SOA growth and offline filter measurements collected during the chamber experiments, we derive estimates of the tracer formation reaction rate constants that have not yet been measured or estimated for bulk solutions.

Selective Transport of Water-Soluble Proteins from Aqueous to Ionic Liquid Phase via a Temperature-Sensitive Phase Change of These Mixtures

2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Change ◽  
Aqueous Phase ◽  
Selective Dissolution ◽  
Selective Extraction ◽  
Soluble Proteins ◽  
Water Soluble ◽  
Temperature Sensitive ◽  
Salting Out ◽  
Key Factor ◽  
The Difference

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.

scholarly journals Constraining condensed-phase formation kinetics of secondary organic aerosol components from isoprene epoxydiols

2015 ◽  
Vol 15 (20) ◽  
pp. 28289-28316 ◽  
Author(s):  
T. P. Riedel ◽  
Y.-H. Lin ◽  
Z. Zhang ◽  
K. Chu ◽  
J. A. Thornton ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Atmospheric Aerosols ◽  
Rate Constants ◽  
Reaction Rate ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Model Calculations ◽  
Reaction Rate Constants ◽  
Aerosol Mass

Abstract. Isomeric epoxydiols from isoprene photooxidation (IEPOX) have been shown to produce substantial amounts of secondary organic aerosol (SOA) mass and are therefore considered a major isoprene-derived SOA precursor. Heterogeneous reactions of IEPOX on atmospheric aerosols form various aerosol-phase components or "tracers" that contribute to the SOA mass burden. A limited number of the reaction rate constants for these acid-catalyzed aqueous-phase tracer formation reactions have been constrained through bulk laboratory measurements. We have designed a chemical box model with multiple experimental constraints to explicitly simulate gas- and aqueous-phase reactions during chamber experiments of SOA growth from IEPOX uptake onto acidic sulfate aerosol. The model is constrained by measurements of the IEPOX reactive uptake coefficient, IEPOX and aerosol chamber wall-losses, chamber-measured aerosol mass and surface area concentrations, aerosol thermodynamic model calculations, and offline filter-based measurements of SOA tracers. By requiring the model output to match the SOA growth and offline filter measurements collected during the chamber experiments, we derive estimates of the tracer formation reaction rate constants that have not yet been measured or estimated for bulk solutions.

Influence of Equation-of-States on Supercritical CO2 Combustion

2020 ◽  
Author(s):  
K. R. V. (Raghu) Manikantachari ◽  
Scott M. Martin ◽  
Ramees K. Rahman ◽  
Carlos Velez ◽  
Subith S. Vasu
Keyword(s):  
Supercritical Co2 ◽  
Carbon Capture ◽  
Flame Structure ◽  
Compressibility Factor ◽  
Operating Conditions ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Combustion Modeling ◽  
Equation Of States ◽  
Supercritical Combustion

Abstract Fossil fuel based direct-fired supercritical CO2 (sCO2) cycles are gaining the attention of industry, academia and government due to their remarkable efficiency and carbon capture at high-source temperatures. Modeling plays an important role in the development of sCO2 combustors because experiments are very expensive at the designed operating conditions of these direct-fired cycles. Inaccurate density estimates are detrimental to the simulation output. Hence, this work focuses on comprehensive evaluation of the influence and applicability various equation-of-states (EOS) which are being used in the supercritical combustion modeling literature. A state-of-the-art supercritical combustion modeling methodology is used to simulate counter-flow supercritical CO2 flames by using various equation-of-states. The results show that, using the corresponding state principle to evaluate compressibility factor is not accurate. Also, van der Waal type EOSs predictions can be as accurate as complex Benedict-Webb-Rubin EOSs; hence van der Waal EOSs are more suitable to simulate sCO2 combustor simulations. Non-ideal effects are significant under the operating conditions considered in this work. The choice of EOS significantly influences the flame structure and heat release rate. Also, assuming the binary interaction parameter as zero is reasonable in sCO2 combustion simulations.

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