Modeling the solubility of carbon dioxide in the MDEA + AEEA aqueous solution using the SAFT-HR equation of state and extended UNIQUAC model

2021 ◽  
pp. 1-17
Author(s):  
Azam Najafloo ◽  
Hossein Sakhaeinia
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Liquid Phase ◽  
Equation Of State ◽  
Chemical Equilibrium ◽  
Extended Uniquac ◽  
Extended Uniquac Model ◽  
Point Calculation ◽  
Interior Loop ◽  
Fugacity Coefficients

In this study, a thermodynamic model has been used to determine the solubility of carbon dioxide in an aqueous solution which is the combination of methyldiethanolamine (MDEA) and aminoethylethanolamine (AEEA). The physical equilibriums have been considered between the liquid and vapor phases and chemical equilibrium in the liquid phase. The SAFT-HR equation of state has been used to specify the fugacity coefficients of the components in the vapor phase. The liquid phase is considered as an electrolyte solution besides; the extended UNIQUAC has been applied to figure out the activity coefficients. The bubble point calculation has been used in this research. This method includes two main loops. Calculations related to chemical equilibrium are performed in the interior loop and the ones associated with phase equilibrium are done in the exterior loop. The solubility of carbon dioxide has been predicted by the optimized parameters of the model in the temperature range of 308.2–368.2 K. It has been calculated that the absolute average relative deviations of the model are 16.65, 19.33, 28.91 and 19.99 in the calculation of partial pressure of carbon dioxide in various loadings at the temperatures of 308.2, 328.2, 343.2 and 368.2 K.

Modeling of Carbon Dioxide Absorption by Aqueous Ammonia Solutions Using the Extended UNIQUAC Model

2010 ◽  
Vol 49 (24) ◽  
pp. 12663-12674 ◽  
Author(s):  
Victor Darde ◽  
Willy J. M. van Well ◽  
Erling H. Stenby ◽  
Kaj Thomsen
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Ammonia ◽  
Carbon Dioxide Absorption ◽  
Uniquac Model ◽  
Extended Uniquac ◽  
Extended Uniquac Model

scholarly journals Una extensión teórica aplicada a los ácidos puros de cadena larga en la fase líquida para analizar su comportamiento en la fase sólida

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Moilton Franco Junior ◽  
Nattacia Rocha ◽  
Warley Pereira
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Liquid Phase ◽  
Equation Of State ◽  
Bulk Modulus ◽  
Phase Behavior ◽  
Solid Phase ◽  
The One

In this work, Peng-Robinson EOS (equation of state) was chosen to represent liquid phase behavior. Then, regarding the three acids, Lauric, Palmitic and Stearic, bulk modulus coefficients were calculated in three values of pressures (0.1, 1.0 and 2.0 GPa) and a range of temperature of 350-450 K. According to the literature, results for carbon dioxide, bulk modulus in the liquid phase is in the same line for the one in the solid phase considering the temperature dimension. Based on it, in this work, the bulk modulus was estimated at three temperatures for three acids in solid-phase by extrapolating the results in the liquid phase. Despite there are no experimental data available in the literature, these results seem to be consistent with the thermodynamic constraints, and useful discussions were provided.

scholarly journals Solubility of CO 2 in [1- n -butylthiolanium][Tf 2 N]+toluene mixtures: liquid–liquid phase split separation and modelling

2015 ◽  
Vol 373 (2057) ◽  
pp. 20150011 ◽  
Author(s):  
Roberto I. Canales ◽  
Michael J. Lubben ◽  
Maria Gonzalez-Miquel ◽  
Joan F. Brennecke
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquids ◽  
Liquid Phase ◽  
Equation Of State ◽  
Ternary Systems ◽  
Separation Process ◽  
Initial Composition ◽  
Screening Model ◽  
Low Viscosity ◽  
Binary And Ternary Systems

Carbon dioxide has been shown to be an effective antisolvent gas for separating organic compounds from ionic liquids (ILs) by inducing a liquid–vapour to liquid–liquid–vapour transition. Using carbon dioxide, toluene can be separated from imidazolium, phosphonium and pyridinum cation-based ILs with the bis(trifluoromethylsulfonyl)imide anion, which is relatively hydrophobic and has a high toluene solubility. A new IL with relatively low viscosity is tested here for the same toluene separation process: 1- n -butylthiolanium bis(trifluoromethylsulfonyl)imide. Carbon dioxide solubility in binary and ternary systems containing toluene and 1- n -butylthiolanium bis(trifluoromethylsulfonyl)imide is measured at 298.15 and 313.15 K up to 7.4 MPa. Solubility behaviour in this IL is similar to imidazolium-based ILs with the same anion. However, phase split pressures are lower when 1- n -butylthiolanium bis (trifluoromethylsulfonyl)imide is used instead of 1- n -hexyl-3-methylimidazolium bis(trifluoromethylsu- lfonyl)imide at the same conditions of temperature and initial composition of toluene in the IL. Solubility data are modelled with the conductor-like screening model for real solvents combined with the Soave–Redlich–Kwong equation of state, which provides good qualitative results.

scholarly journals Density Measurements of Two Liquefied Biomethane-Like Mixtures over the Temperature Range from (100 to 180) K at Pressures up to 9.0 MPa

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Giuseppe Cavuoto ◽  
Nils von Preetzmann ◽  
Philipp Eckmann ◽  
Jianrong Li ◽  
Adriaan M. H. van der Veen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Equation Of State ◽  
Single Phase ◽  
Magnetic Suspension ◽  
Saturated Liquid ◽  
Homogeneous Liquid ◽  
Combined Uncertainty ◽  
Phase Liquid ◽  
Cell Densities

AbstractDensities of two synthetic biomethane-like mixtures were measured in the homogeneous liquid phase and the supercritical region using a low-temperature single-sinker magnetic-suspension densimeter. Both mixtures consist of methane, nitrogen, hydrogen and oxygen, whereas the second mixture additionally contains carbon dioxide. For the first mixture, four isotherms from (100 to 160) K were studied over the pressure range from (1.5 to 6.6) MPa. The second mixture was investigated along three isotherms from (140 to 180) K at pressures of (2.6 to 9.0) MPa, where only the densities at 180 K are usable due to solidification of the carbon dioxide at the lower temperatures. The relative expanded combined uncertainty (k = 2) of the experimental densities was estimated to be in the range of (0.022 to 0.027)  % for the first mixture and (0.046 to 0.054)  % for the second mixture, respectively. Due to a supercritical liquefaction procedure and the integration of a special VLE-cell, densities in the homogeneous liquid phase could be measured without changing the composition of the liquefied mixture. Moreover, saturated-liquid densities were determined by extrapolation of the experimental single-phase liquid densities to the vapor pressure, which was determined experimentally for the mixture without carbon dioxide and calculated with an equation of state (EOS) for the mixture containing carbon dioxide. The relative expanded combined uncertainty (k = 2) of the saturated-liquid densities is less than 0.08 % in most cases. The new experimental results were compared with the GERG-2008 equation of state; the deviations are less than 0.17 %.

Atom Condensed Fukui Function for Condensed Phases and Biological Systems and Its Application to Enzymatic Fixation of Carbon Dioxide

2019 ◽  
Author(s):  
Javier Oller ◽  
David A. Sáez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Molecular System ◽  
Chemical Reactivity ◽  
Nucleophilic Attack ◽  
Stable Conformation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Dynamics Simulations ◽  
Fixation Of Carbon Dioxide

<div><div><div><p>Local reactivity descriptors such as atom condensed Fukui functions are promising computational tools to study chemical reactivity at specific sites within a molecule. Their applications have been mainly focused on isolated molecules in their most stable conformation without considering the effects of the surroundings. Here, we propose to combine QM/MM Born-Oppenheimer molecular dynamics simulations to obtain the microstates (configurations) of a molecular system using different representations of the molecular environment and calculate Boltzmann weighted atom condensed local reac- tivity descriptors based on conceptual DFT. Our approach takes the conformational fluctuations of the molecular system and the polarization of its electron density by the environment into account allowing us to analyze the effect of changes in the molecular environment on reactivity. In this contribution, we apply the method mentioned above to the catalytic fixation of carbon dioxide by crotonyl-CoA carboxylase/reductase and study if the enzyme alters the reactivity of its substrate compared to an aqueous solution. Our main result is that the protein en- vironment activates the substrate by the elimination of solute-solvent hydrogen bonds from aqueous solution in the two elementary steps of the reaction mechanism: the nucleophilic attack of a hydride anion from NADPH on the α, β unsaturated thioester and the electrophilic attack of carbon dioxide on the formed enolate species.</p></div></div></div>

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

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