Equilibrium Solubility Of Carbon Dioxide Research Articles

Modeling CO2 loading capacity of triethanolamine aqueous solutions using advanced white-box approaches: GMDH, GEP, and GP

The equilibrium solubility of carbon dioxide (CO2) in the solvents is a key essential characteristic that has to be evaluated for successful absorption-based CO2 capture procedures. In this study, the CO2 loading capacity of triethanolamine (TEA) aqueous solutions was estimated using three famous white-box algorithms namely gene expression programming (GEP), genetic programming (GP), and group method of data handling (GMDH). For achieving the aim of this study, 258 data in a wide range of pressure, temperature, and amine concentration were collected from literature. Temperature, partial pressure of CO2, and amine concentration were used as input parameters. The results demonstrated that GMDH correlation is more accurate than GEP and GP with a determination coefficient (R2) of 0.9813 and root mean square error of 0.0222. The R2 values of 0.9713 and 0.9664 for the GEP and GP, respectively, demonstrated that the GEP and GP also showed accurate predictions. In addition, GMDH approach accurately predicted the anticipated trends of the CO2 loading in response to changes in the partial pressure of CO2 and temperature. The Pearson and Spearman correlation analyses were also incorporated in this research which showed that temperature and CO2 partial pressure have almost the same relative effect on CO2 loading, while amine concentration has the lowest effect on it.

Measuring and modeling equilibrium solubility of carbon dioxide in aqueous solution of dimethylaminoethanol and 3-methylaminopropylamine

The equilibrium solubility of carbon dioxide in an aqueous mixture comprised of 40 wt.% dimethylaminoethanol (DMAE) and 5 wt.% 3‒(Methylamino)propylamine (MAPA) was measured at temperatures (313.15, 328.15, 343.15, and 358.15) K and in the total pressure range of (7.9–359.7) kPa. The heat of absorption of carbon dioxide in the aqueous solution was measured at 328.15 K. Equilibrium constant of reaction of formation of carbamate by MAPA was measured experimentally in the temperature range of (298.15–333.15) K. The Deshmukh‒Mather thermodynamic model was applied to correlate the equilibrium solubility data. The small value of average absolute percent deviation (AAD% = 2.56) of the correlated values from experimental data implies good correlative accuracy of the Deshmukh–Mather model. The tuned model was also used to calculate the heat of absorption of carbon dioxide into the aqueous solution of DMAE + MAPA. The AAD% of calculated heat of absorption from the measured values was 3.91.

High-pressure experimental and theoretical study of CO2 solubility in aqueous blends of lysine salts with piperazine as new absorbents

Vapour-liquid equilibrium of carbon dioxide loaded potassium and sodium l-lysine salts have been investigated in the region of high-pressure and high loadings. The equilibrium solubility of carbon dioxide was measured in separate aqueous l-lysine alkaline salts for a range of temperature (303.15–363.15 K), solution concentrations (1.0–3.0 M) and pressure (95–4204 kPa). In addition to that, solubility of carbon dioxide in blends of both aforementioned amino acid salts with piperazine were investigated. All the studied solutions exhibited an increase in the carbon dioxide loading values with increase in the pressure and had a negative relationship with increase in the temperature and solvent concentration. Furthermore, the experimental data was correlated by the Kent-Eisenberg model. The correlated values shows a good agreement (AAD% of 5.15%) with experimental values. The regressed parameters of the model allows satisfactory estimation of the loadings of carbon dioxide in all studied solutions, for parametric studies. The study shows that l-lysine salts are potential green solvents for the carbon dioxide capture at high pressure.

Carbon dioxide absorption into aqueous potassium salt solutions of glutamine amino acid

Amino acid salts (AAS) are mentioned as potential solvents for the separation and capture of carbon dioxide (CO2). This study investigates the aqueous solution of Potassium Glutaminate (K-Glu) solvent from different viewpoints including equilibrium solubility of carbon dioxide varying the concentration and absorption temperature at different pressures, reaction kinetics and mechanism between K-Glu and CO2, heat of absorption and cyclic absorption and regeneration efficiency. The reaction rate was calculated using the obtained experimental data and quasi first order overall reaction rate is proposed. The successive absorption-desorption preliminary tests showed a negligible drop in CO2 capture capacity over consecutive cycles through regeneration at 343.15 K. The proposed solvent has the advantages of high absorption rate and capacity (compared with monoethanolamine and N-methyldiethanolamine) with interesting aspects such as lower corrosion rate, environmental biening and high resistance against thermal and oxidative degradation covering the shortcomings of conventional amines, which considers it as a potential new solvent.

Modeling and experiments of equilibrium solubility of carbon dioxide in aqueous N-(2-hydroxyethyl) pyrrolidine solution

Abstract In this work, the equilibrium CO2 solubilities of the aqueous N-(2-hydroxyethyl) pyrrolidine (N-(2-HE) PRLD) at different concentrations (1.0 mol/L–5.0 mol/L) were measured at different temperatures (298 K–333 K) and pressures (8 kPa–101 kPa), using a vapor–liquid equilibrium apparatus. Four semi-empirical thermodynamic models (Cf model, Kent–Eisenberg model, Hu–Chakma model and Li–Shen model) were used to correlate and predict the CO2 solubility data of the N-(2-HE) PRLD-CO2–H2O system. The results showed that the Hu–Chakma model, which is one of the models that incorporates the effect of amine concentration and CO2 loading, and accounted for nonideality caused by higher temperature, species concentrations and CO2 loadings, was best able to predict results that are in agreement with the experimental vapor–liquid equilibrium measurements in this work.

Equilibrium solubility of carbon dioxide in aqueous blend of monoethanolamine (MEA) and 2-1-piperazinyl-ethylamine (PZEA) solutions: Experimental and optimization study

In order to study the influence of 2-(1-piperazinyl)-ethylamine (PZEA) as a promoter on the solubility of CO2 in aqueous monoethanolamine (MEA) solution, the equilibrium solubility of CO2 (mole CO2/mole blend solution) in MEA+PZEA aqueous solutions were measured experimentally using a vapor–liquid equilibrium (VLE) equipment at constant total blend concentration of 2.5moldm−3 in temperatures ranging from 30 to 50°C and initial partial pressures between 30 and 70kPa. The response surface methodology (RSM) based on central composite design (CCD) was used to explore the relationship between three independent parameters (1: molar ratio of PZEA to MEA, 2: initial partial pressure of CO2 (PCO2), 3: temperature) on the CO2 loading capacity. Analysis of variance (ANOVA) showed a good agreement between experimental data and statistical model. The maximum CO2 loading capacity occurred at 0.8 (2M PZEA+0.5M MEA) molar ratio of PZEA to MEA.

High pressure measurement and thermodynamic modelling of the solubility of carbon dioxide in N-methyldiethanolamine and 1-butyl-3-methylimidazolium acetate mixture

In the present work, the equilibrium solubility of carbon dioxide (CO2) in mixtures of N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate ionic liquid ([bmim][acetate]) is measured at temperatures (303.15 to 343.15)K and over a pressure range of (0.1 to 3.9)MPa. The mass fraction compositions of the MDEA and [bmim][acetate] in the mixture are (0.3,0.7) and (0.5,0.5), respectively. The experimental results are presented as the partial pressure of CO2 against its molality (mol CO2 per kg of solvent) and mole fraction of CO2. Moreover, using the measured values, the enthalpy of solution for the CO2 solubility in the mixtures is calculated. Considering the present results at the given conditions, it is observed that replacing the aqueous media of the MDEA solution by [bmim][acetate] can reduce significantly the enthalpy of solution of CO2 in the solvent.For thermodynamic modelling, a new equation of state (PR-TS EoS) is extended by combining the Peng–Robinson (PR) equation of state as a cubic term for non-specific energy contribution and the Two-State Association Model (TSAM) for association energy contribution based on the frame of the cubic plus equation of state. Furthermore, the PR-TS EoS is applied to correlate the new experimental data of this work. To model the ternary (CO2+MDEA+[bmim][acetate]) system, the parameters of the PR-TS EoS are first adjusted for the pure components. Subsequently, the solubility of CO2 in pure [bmim][acetate] is correlated so that the binary molecular interaction parameters for this binary sub system are optimised. Finally, the equilibrium solubility of CO2 in ternary mixture of {MDEA+[bmim][acetate]} correlates with the per cent average absolute deviation (AAD%) of 11.78 between the calculated and experimental partial pressure of CO2.

Equilibrium solubility of carbon dioxide in aqueous 2-((2-aminoethyl)amino)ethanol and N-methyldiethanolamine solution and modeling by electrolyte mPR-CPA EoS

In the present work, the equilibrium solubility of carbon dioxide (CO2) in aqueous amine mixture solutions of 2-((2-aminoethyl)amino)ethanol (AEEA) and N-methyldiethanolamine (MDEA) is measured in the temperature range of 308.2K to 368.2K and the pressure range of 101kPa to 4448kPa. The (vapor+liquid) equilibrium of binary AEEA and water system is measured at constant pressure of 86.6kPa. The dielectric constant of AEEA is also obtained experimentally in the temperature range of 293.2K to 348.2K. For thermodynamic modeling the electrolyte modified Peng-Robinson cubic plus association equation of state (emPR-CPA EoS) [A.T. Zoghi, F. Feyzi, M.R. Dehghani, Ind. Eng. Chem. Res. 51 (2012) 9875–9885] is applied and the solubility of CO2 in the aqueous mixture of AEEA and MDEA is obtained. In order to model the quaternary system, parameters of the emPR-CPA EoS are first adjusted for pure components. Then, the binary molecular interaction parameters for binary sub systems (CO2–Water, CO2–MDEA, CO2–AEEA, MDEA–Water, AEEA–Water) and the ionic interaction parameters for ternary sub systems (MDEA–CO2–Water) and (AEEA–CO2–Water) are optimized. By the emPR-CPA EoS the CO2 solubility is obtained in the ternary sub-systems (MDEA–CO2–Water) and (AEEA–CO2–Water) with average absolute percent deviations (AAD%) equal to 17.32 and 14.63, respectively. Finally, the equilibrium solubility of CO2 in aqueous mixture of AEEA+MDEA is obtained with AAD%=24.3 and root mean square relative deviation percent (RMSD%)=27.67.

Equilibrium solubility of carbon dioxide in N-methyldiethanolamine + piperazine aqueous solution: Experimental measurement and prediction

New experimental data for equilibrium solubility of carbon dioxide in aqueous solutions of N-methyldiethanolamine (MDEA) and piperazine (PZ) are reported for temperature range of 363–423K and pressure range of 26.3–204.3kPa. The measured data in combination with the data collected from literature are used to modify Deshmukh–Mather model for prediction of the solubility of carbon dioxide in MDEA+PZ solutions. In this model, a modified extended Debye–Hückel expression for electrolyte solutions is used for the calculation of activity coefficients. More than 300 data points in a wide range of temperatures, pressures and concentrations are used to optimize the interaction parameters for the studied system. Genetic Algorithm minimization technique is used for this optimization process. The gas-phase fugacity coefficients are also included and are calculated using Peng–Robinson equation of state. The predictions of the proposed model are compared with the experimental data reported by Liu et al. The results show a very good agreement between experimental data and model predictions.

Equilibrium Solubility of Carbon Dioxide in an Aqueous Mixture of N-Methyldiethanolamine and Diisopropanolamine: An Experimental and Modeling Study

In the present work, the equilibrium solubility of carbon dioxide was measured for three different aqueous mixture of N-methyldiethanolamine (MDEA) and diisopropanolamine (DIPA). The sum of the mass fraction of MDEA and DIPA for each aqueous mixture was constant at 100 w = 50. The mass fraction of DIPA was chosen as 100 w = (1, 3, and 5) for the mixture, respectively. The experimental data were measured for the temperature range of (313.2 to 358.2) K and the equilibrium CO2 partial pressure of (85 to 3984) kPa. To predict and correlate the equilibrium solubility behavior of carbon dioxide with an aqueous mixture of MDEA and DIPA, the Deshmukh–Mather model was used. The binary interaction parameters of the model were tuned by regression of experimental data. Having used the tuned parameters, the equilibrium behavior of CO2 with relevant aqueous solution was estimated and compared with the equivalent experimental values. The average absolute deviation (AAD %) was obtained to be 13.2 % for all data points.

Equilibrium solubility of carbon dioxide in aqueous solutions of (diethylenetriamine + piperazine)

In this study, we report new experimental measurements on the solubility of carbon dioxide in aqueous blended amine solutions containing diethylenetriamine (DETA) and piperazine (PZ) (at 30wt% total amine concentration). Solubility data for CO2 in aqueous DETA solutions at several concentrations (20,30,40)wt% are also presented. Measurements were performed in a vapor-liquid equilibrium apparatus at temperatures (313.2,333.2,353.2)K and pressures up to around 900kPa. It was found that the solubility of CO2 in the systems studied were appreciably higher than in typical amine solvents. A modified Kent–Eisenberg model was used to correlate the obtained solubility of CO2 (expressed as mole CO2 per mole amine) in the solvent with CO2 partial pressure, temperature, and amine concentration. The model gave satisfactory representations of the solubility data at reasonable average absolute deviations between the experimental and the calculated values (of CO2 partial pressures) of 16% and 17%, for the binary and ternary systems, respectively.

An Experimental Investigation of the Influence of Vanadium Pentoxide on the Solubility of CO2 in Aqueous Solutions of Potassium Carbonate

The “hot-potash” process is one of the most commonly used processes to remove carbon dioxide from gases in the chemical industry. The solvent of that absorption process is an aqueous solution of potassium carbonate. Dissolving carbon dioxide in an aqueous solution of K2CO3 results in the conversion of carbonate and CO2 to bicarbonate; that is, carbon dioxide is predominantly dissolved chemically. In industrial applications a single substance or a mixture of several substances are added to the solvent to improve the performance of the process. The specific role of such additives is often unknown, but it is well-established that some additives improve the performance of the “hot-potash” process. One of those additives is vanadium pentoxide. The influence of a small amount of vanadium pentoxide on the equilibrium solubility of carbon dioxide in aqueous solutions of potassium hydroxide was investigated at conditions that are typical for a “hot-ash” process. The experimental results reveal that vanadium pentox...

Equilibrium solubility of carbon dioxide in a 30 wt.% aqueous solution of 2-((2-aminoethyl)amino)ethanol at pressures between atmospheric and 4400 kPa: An experimental and modelling study

New experimental equilibrium data were obtained for the solubility of carbon dioxide in an aqueous solution with 30 wt.% of 2-((2-aminoethyl)amino)ethanol (AEEA) at temperatures ranging from (313.2 to 368.2) K and CO 2 partial pressures ranging from above atmospheric to 4400 kPa. A thermodynamic model based on the Deshmukh–Mather method was applied to correlate and predict the CO 2 solubility in aqueous AEEA solutions. The binary interaction parameters and equilibrium constants for the proposed reactions were determined by data regression. Using the adjusted parameters, equilibrium partial pressures of CO 2 were calculated and compared with the corresponding experimental values at the selected temperatures and pressures. Values of carbon dioxide solubility at other temperatures reported in the literature were also calculated. The average absolute deviation for all of the data points was found to be 8.2%. The enthalpy change of the absorption of CO 2 in the 30 wt.% aqueous solution of AEEA was also estimated with our model.

Equilibrium solubility of carbon dioxide in 2(methylamino)ethanol

In this paper the equilibrium solubility of carbon dioxide in 1.0M, 2.0M and 4.0M 2(methylamino)ethanol (MAE) is measured at 303, 313 and 333K, and at CO2 partial pressures ranging from 1 to 100kPa using stirred cell reactor. The Kent–Eisenberg model was used to predict the solubility of carbon dioxide in MAE solutions. The equilibrium constant representing hydrolysis of carbamate ion is correlated with temperature, CO2 partial pressure and amine concentration by non-linear regression, using experimental results of carbamate ion concentrations. The model predicted results showed good agreement with the experimental solubility results. The solubility profile of CO2 in MAE showed better performance when compared with other commercial amines.

Equilibrium solubility of carbon dioxide in the amine solvent system of (triethanolamine+piperazine+water)

In this study, a new set of data for the equilibrium solubility of carbon dioxide in the amine solvent system that consists of triethanolamine (TEA), piperazine (PZ), and water is presented. Equilibrium solubility values were obtained at T = (313.2, 333.2, and 353.2) K and pressures up to 153 kPa using the vapour-recirculation equilibrium cell. The TEA concentrations in the considered ternary (solvent) mixture were (2 and 3) kmol · m −3 and those of PZ’s were (0.5, 1.0, and 1.5) kmol · m −3 . The solubility data (CO 2 loading in the amine solution) obtained were correlated as a function of CO 2 partial pressure, system temperature, and amine composition via the modified Kent–Eisenberg model. Results showed that the model applied is generally satisfactory in representing the CO 2 absorption into mixed aqueous solutions of TEA and PZ.

Solubility of Carbon Dioxide in Aqueous Solutions of 2-Amino-2-methyl-1,3-propanediol

The equilibrium solubility of carbon dioxide in aqueous solutions of 2-amino-2-methyl-1,3-propanediol (AMPD) has been measured at (30, 40, and 60) °C and the partial pressure of carbon dioxide ranging from (0.5 to 3065) kPa. The concentrations of the aqueous solutions were (10 and 30) mass % AMPD. The tendency of the solubility of carbon dioxide in 30 mass % AMPD aqueous solution at 40 °C was found to be similar to that in 30 mass % N-methyldiethanolamine aqueous solution.

Gas solubility of carbon dioxide and hydrogen sulfide in mixtures of sulfolane with monoethanolamine

Murrieta-Guevara, F., Rebolledo-Libreros, E. and Trejo, A., 1993. Gas solubility of carbon dioxide and hydrogen sulfide in mixtures of sulfolane with monoethanolamine. Fluid Phase Equilibria, 86: 225-231

Calculation of equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine with methyldiethanolamine

Li M.H. and Shen K.-P., 1993. Calculation of equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine with methyldiethanolamme. Fluid Phase Equilibria, 85: 129-140. The equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine (MEA) with methyldiethanolamine (MDEA) has been correlated on the basis of the model of Kent and Eisenberg. The chemical equilibrium constants involving alkanolamines are expressed as functions of temperature, amine concentration and carbon dioxide loading. The constants in the model were determined by fitting to the solubility data of carbon dioxide in aqueous MEA/MDEA solutions for temperatures ranging from 40 to 100°C and for partial pressures of carbon dioxide up to 2000 kPa. Satisfactory results were obtained for calculations of the solubility of carbon dioxide in aqueous MEA/MDEA solutions for the systems tested. When performing the solubility calculations for the systems which are not included in the database, the model predicts reasonably well the solubility of carbon dioxide in aqueous MEA/MDEA solutions.

An investigation of absorption‐reaction of carbon dioxide in liquid diethanolamine by the direct chromatographic perturbation method

AbstractPhysical and chemical equilibrium in the carbon dioxide‐diethanolamine system was studied by the direct chromatographic method. The amine was present as a coating on the inside of a capillary tube. Carbon dioxide‐helium mixtures were passed through the capillary until equilibrium was attained, at which time a sample of C14O2 was injected into the carrier stream. The retention volumes (carrier volume flowed at peak appearance) of concentration and radioactive perturbations were measured at four temperatures and five carrier gas compositions. Static equilibrium solubility of carbon dioxide in the amine was also measured to verify the dynamic results.The theory of reactive chromatographic flow was extended to this system. The concentration and isotope retention volumes, which theory predicts to be different functions of carrier composition, were shown to be self‐consistent. The static solubility data was also seen to be consistent with theory and with the direct chromatographic data. The liquid phase of the system appeared to be ideal except at infinite dilution of carbon dioxide. The apparent departure from ideality could be explained in terms of weak ionization of reaction products. Electrical conductivity measurements tend to confirm this hypothesis.Both physical and chemical equilibrium constants for carbon dioxide were obtained at the four temperatures. Gross heat of reaction and apparent ionization heat were also obtained.