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Ali Haghtalab - One of the best experts on this subject based on the ideXlab platform.
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solubility and thermodynamic modeling of hydrogen sulfide in aqueous diisopropanolamine 2 amino 2 methyl 1 propanol piperazine solution at high pressure
The Journal of Chemical Thermodynamics, 2015Co-Authors: Ali Haghtalab, Amin IzadiAbstract:Abstract Natural gas as a clean source of energy contains several contaminates such as CO2 and H2S that is treated through a natural gas purification unit in gas industry. Moreover, for design and construction of gas contactor equipment, it is necessary to obtain experimental values of solubility for H2S and CO2 in aqueous amine/Alkanolamines. In this work, the solubility of H2S in the blended aqueous diisopropanolamine (DIPA), 2-amino-2-methyl-1-propanol (AMP) and piperazine (Pz) are measured using a static high pressure apparatus through volumetric method. The values are measured at fixed 45 mass per cent of total amine so that the solubility of H2S in the present system is investigated under isothermal conditions at T = (313.15, 328.15 and 343.15) K and in the pressure range of (0.1 to 2.1) MPa. The experimental results are presented as the partial pressure of H2S against acid gas loading (moles H2S per total moles of amine). Also for modeling the solubility of H2S in the blended amine/Alkanolamines, the Electrolyte-NRTL activity coefficient function is applied to the correlation and prediction of the partial pressure of H2S versus the acid gas loading. Considering the present results at the given conditions, it is observed that in the low gas loading region, the effect of enhancing Pz on the solubility of H2S is very low, but at high gas loading the absorption of H2S is intensified by enhancing mass fraction of Pz in alkanolamine.
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simultaneous measurement solubility of carbon dioxide hydrogen sulfide into aqueous blends of Alkanolamines at high pressure
Fluid Phase Equilibria, 2014Co-Authors: Ali Haghtalab, Amin IzadiAbstract:Abstract Treatment of the sour natural gas is a major step in natural gas processing so that the acid gases such as H2S and CO2 are removed from natural gas stream. The acid gases are harmful to environment and destroy the production equipment so that their presence in gas stream leads to corrosion and lowering heating value. On the other hand, for reliable and optimum design of separation equipment, primarily sufficient and accurate equilibrium data of the acid gases solubility in the aqueous Alkanolamines is required. In this work, the simultaneous solubility of the H2S + CO2 in the alkanolamine mixtures is measured at 343 K and total pressure range of 0.1–2.1 MPa. The blends are studied as the aqueous mixtures of N-methyldiethanolamine (MDEA) + 2-amino-2-methyl-1-propanol (AMP) + Piperazine (Pz) and the aqueous mixtures of diisopropanolamine (DIPA), AMP and Pz. For the acid gas solubility measurements, a high pressure static apparatus is used through a volumetric method. The mass fraction of the total alkanolamine is fixed at 0.45 and the results are presented as the partial pressure of each acid gas against its loading (mole acid gas/total mole amine) and mole fraction. The influence of the AMP and Pz on the aqueous DIPA-based and MDEA-based systems are studied so that it is observed that the absorption of the CO2 in the aqueous alkanolamine enhances through separate blending of the AMP and Pz with the aqueous system of MDEA or DIPA and the absorption of the H2S reduces in both of the aqueous DIPA-based and MDEA-based systems.
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solubility and density of carbon dioxide in different aqueous alkanolamine solutions blended with 1 butyl 3 methylimidazolium acetate ionic liquid at high pressure
Journal of Molecular Liquids, 2013Co-Authors: Abolfazl Shojaeian, Ali HaghtalabAbstract:Abstract Using a static high pressure equilibrium cell, the new set of the experimental data is obtained for solubility of carbon dioxide in the aqueous mixtures of different type of Alkanolamines such as N-methyldiethanolamine (MDEA), Diethanolamine (DEA), Diisopropanolamine (DIPA), 2-amino-2-methyl-1-propanol (AMP), and 1-butyl-3-methylimidazolium acetate ionic liquid [bmim] [acetate]. The solubility of CO2 in the aqueous MDEA + [bmim][acetate], DEA + [bmim][acetate], DIPA + [bmim][acetate] and AMP + [bmim][acetate] solutions with 0–10 wt% of ionic liquid and 30–40 wt% alkanolamine are carried out at 1 to 40 bar and 323.15 K. Moreover, the temperature dependency of density for these solutions is measured from 293.15 to 343.15 K with 10 K intervals. The results of the CO2 solubility are represented by partial pressure of CO2 against the loading and mole fraction of CO2. The solubility of the CO2 in all of the aqueous alkanolamine + ionic liquid solutions decreases with increasing weight percent of ionic liquid. Also, the results show that the maximum decrease of CO2 loading belongs to addition of [bmim] [acetate] to the aqueous MDEA solution. Finally, the results of density of the alkanolamine + ionic liquid solutions present that the density enhances with increasing concentration of [bmim][acetate] and reduces linearly with enhancing temperature.
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modeling solubility of acid gases in Alkanolamines using the nonelectrolyte wilson nonrandom factor model
Fluid Phase Equilibria, 2010Co-Authors: Ali Haghtalab, Abolfazl ShojaeianAbstract:Abstract The nonelectrolyte Wilson-nonrandom factor local composition model (N-Wilson-NRF) by Haghtalab and Mazloumi is applied for modeling the vapor–liquid equilibrium of the acid gases (CO2 and H2S)–alkanolamine–water systems. The model is used to calculate the nonideality of species in liquid phase through the activity coefficient equations. In this work, we use the N-Wilson-NRF model for short-range forces in the aqueous electrolyte system of Alkanolamines by using the concept of ion-pair. For the long-range interaction the Pitzer–Debye–Huckel theory is applied. The model is used to correlation of the solubility data of CO2 and H2S in aqueous monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA) and 2-amino-2methyl-1-propanol (AMP) systems over wide range of temperature (0–140 °C), partial pressure (0.001–1000 kPa) and acid gases loading (0.001–1.0 mol gas/mol amine). To show the predictability of the model, the interaction parameters without any additional adjustable parameters are used to predict the solubility of CO2 in aqueous AMP solution at different conditions. The results of the model show a very good agreement with the experimental data.
Geert Versteeg - One of the best experts on this subject based on the ideXlab platform.
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Carbon dioxide removal by Alkanolamines in aqueous organic solvents: A method for enhancing the desorption process
Energy Procedia, 2011Co-Authors: Espen S. Hamborg, Peter W. J. Derks, Edwin P. Van Elk, Geert VersteegAbstract:Abstract Process concepts of using Alkanolamines in aqueous organic solvents have been evaluated by experimental work and process simulations using the Procede Process Simulator. N-methyldiethanolamine (MDEA), methanol, and ethanol were chosen as the respective alkanolamine and organic compounds in the current work. In previous work, the dissociation constants of protonated MDEA at infinite dilution in methanol–water and ethanol–water solvents and the initial mass transfer rates of CO 2 in 3 kmol m −3 MDEA in methanol–water and ethanol–water solvents were determined. In the current work, experimental values of the CO 2 vapor liquid equilibria in 3 kmol m −3 MDEA have been determined in methanol–water and ethanol–water solvents. The experimentally determined results have been implemented into the Procede Process Simulator, which has been used to simulate a CO 2 removal plant with 90% CO 2 removal based on the specification of the flue gas of an 827 MWe pulverized coal fired power plant. A solvent of 3 kmol m −3 MDEA in aqueous methanol solution was considered for conceptual purposes. The results indicatively show a maximum decrease in the reboiler duty of the desorber of about 7.5% at methanol fractions of about 0.06 compared to purely aqueous solutions and a reboiler temperature decrease with increasing methanol fractions. Further experimental results are, however, necessary in order to more precisely simulate CO 2 removal processes by Alkanolamines in aqueous organic solvents.
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the effect of aqueous organic solvents on the dissociation constants and thermodynamic properties of Alkanolamines
Fluid Phase Equilibria, 2010Co-Authors: Espen S. Hamborg, Coen Van Aken, Geert VersteegAbstract:Abstract The dissociation constants of protonated monoethanolamine and N-methyldiethanolamine have been determined in methanol–water, ethanol–water, and t-butanol–water solvents. The alcohol mole fractions were ranging from 0.2 to 0.95 and the temperatures from 283 to 323 K, 283 to 333 K, and at 298.15 K, respective to the different solvents. The experimental results are reported with the standard state thermodynamic properties. The basic strength of the protonated alkanolamine decreases with decreasing dielectric constant and increasing temperature of the solvent. By using the dissociation constants of the Alkanolamines in pure water, it is shown that a Born treatment alone is not able to estimate the dissociation constants when the composition of the solvent is changed to an aqueous organic mixture.
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gas solubility of h2s and co2 in aqueous solutions of n methyldiethanolamine
Journal of Petroleum Science and Engineering, 2007Co-Authors: P J G Huttenhuis, J A Hogendoorn, Neeraj J Agrawal, Geert VersteegAbstract:Alkanolamine processes are used in the industry to remove acid gases, like CO2, H2S and other sulphur components, from natural gas and industrial gas streams. In this process the acid components react with the basic alkanolamine solution via an exothermic, reversible reaction in a gas/liquid absorber. The composition of these amine solutions is continuously changed to optimise the (selective) removal of the several acid components. For the design of gas treating equipment accurate mass transfer, reaction kinetics and solubility data of acid gases in aqueous alkanolamine solutions are required. In this paper new solubility data of H2S and CO2 in aqueous MDEA at different conditions encountered in modern gas treating facilities are presented. The experimental pressure and temperature were varied from 6.9 to 69 bar (methane was used as make-up gas) and from 10 to 25 °C respectively. These new solubility data were evaluated and correlated with an Electrolyte Equation of State Model (EOS) as originally proposed by Furst and Renon [Furst, W., Renon, H., 1993. Representation of Excess Properties of Electrolyte Solutions Using a New Equation of State. AIChE J., 39 (2), pp. 335.]. The application of Equation of State Models for the prediction of VLE data for reactive, ionic systems is a rather new development in this field.
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kinetics of the reaction of co2 with aqueous potassium salt of taurine and glycine
Aiche Journal, 2003Co-Authors: Paramasivam Senthil Kumar, J A Hogendoorn, Geert Versteeg, Paul FeronAbstract:The kinetics of the reaction between CO2 and aqueous potassium salts of taurine and glycine was measured at 295 K in a stirred-cell reactor with a flat gas-liquid interface. For aqueous potassium taurate solutions, the temperature effect on the reaction kinetics was measured at 285 and 305 K. Unlike aqueous primary Alkanolamines, the partial reaction order in amino acid salt changes from one at low salt concentration to approximately 1.5 at salt concentrations as high as 3,000 mol·m-3. At low salt concentrations, the measured apparent rate constant (kapp) for potassium glycinate is comparable to the values in literature. In the absence of reliable information in the literature on the kinetics and mechanism of the reaction, the applicability of the zwitterion and termolecular mechanism (proposed originally for Alkanolamines) was explored. For the zwitterion mechanism, the forward second-order reaction rate constant (k2) of the CO2 reaction with amino acid salt seems to be much higher than for Alkanolamines of similar basicity, indicating that the Bronsted plot for amino acid salts might differ from that of Alkanolamines. The contribution of water to the deprotonation of zwitterion seems to be more significant than reported values for aqueous secondary Alkanolamines.
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new absorption liquids for the removal of co2 from dilute gas streams using membrane contactors
Chemical Engineering Science, 2002Co-Authors: Paramasivam Senthil Kumar, J A Hogendoorn, Paul Feron, Geert VersteegAbstract:A new absorption liquid based on amino acid salts has been studied for CO2 removal in membrane gas–liquid contactors. Unlike conventional gas treating solvents like aqueous Alkanolamines solutions, the new absorption liquid does not wet polyolefin microporous membranes. The wetting characteristics of aqueous Alkanolamines and amino acid salt solutions for a hydrophobic membrane was studied by measuring the surface tension of the liquid and the breakthrough pressure of the liquid into the pores of the membrane. The dependence of the breakthrough pressure on surface tension follows the Laplace–Young equation. The performance of the new absorption liquid in the removal of CO2 was studied in a single fiber membrane contactor over a wide range of partial pressures of CO2 in the gas phase and amino acid salt concentrations in the liquid. A numerical model to describe the mass transfer accompanied by multiple chemical reactions occurring during the absorption of CO2 in the liquid flowing through the hollow fiber was developed. The numerical model gives a good prediction of the CO2 absorption flux across the membrane for the absorption of CO2 in the aqueous amino acid salt solutions flowing through the hollow fiber.
Arturo Trejo - One of the best experts on this subject based on the ideXlab platform.
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corrosion in aqueous solution of two Alkanolamines with co2and h2s n methyldiethanolamine diethanolamine at 393 k
Industrial & Engineering Chemistry Research, 2008Co-Authors: Rafael Eustaquiorincon, Maria Esther Rebolledolibreros, Arturo Trejo, Rene MolnarAbstract:In this work we have used an apparatus constructed in our laboratory to systematically study the corrosion rate on metals and evaluate specialty chemical products for preventing metal corrosion in industrial plants. We performed experimental studies on the effect of specific variables on corrosion rates over carbon steel, such as pressure, concentration of Alkanolamines in aqueous solution, and amount of acid gases (CO2 and H2S). The technique utilized to evaluate the corrosion rate is the well-known weight loss method. With the experimental apparatus and method developed in this work we have determined the corrosion rate of AISI 1010 carbon steel in aqueous solutions of known concentration of N-methyldiethanolamine (MDEA) and diethanolamine (DEA), individually, with and without acid gases, and in different alkanolamine blends with total alkanolamine mass fraction in the range 15−60%, with mass ratios of MDEA/DEA of 3.5/1 and 2/1, with the addition of different amounts of H2S and CO2 at a pressure range o...
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surface tension and foam behaviour of aqueous solutions of blends of three Alkanolamines as a function of temperature
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2007Co-Authors: Jacinto Aguilahernandez, Arturo Trejo, Blanca E GarciafloresAbstract:Abstract We have determined the equilibrium surface tension for aqueous solutions of three Alkanolamines composed of 32.5 mass% N-methyldiethanolamine (MDEA) and 12.5 mass% diethanolamine (DEA) with the addition of 2, 4, 6, 8, and 10 mass% of 2-amino-2-methyl-1-propanol (AMP), at 303.15, 308.15, 313.15, 318.15, 323.15, 328.15, 333.15, 338.15, and 343.15 K. We have also determined experimentally the foaming properties for the same aqueous solutions of three Alkanolamines as in the surface tension study, at 303.15, 313.15, 323.15, 333.15, and 343.15 K. In order to elucidate the effect of the concentration of AMP on the two studied properties we have also determined experimentally the foamability of the aqueous system of two Alkanolamines composed of 32.5 mass% MDEA + 12.5 mass% DEA, at 303.15, 313.15, 323.15, 333.15, and 343.15 K, and for the two binary systems composed of DEA + water and MDEA + water, at concentrations of 10, 20, 30, 40, and 50 mass% of the alkanolamine, at 313.15, 323.15, 333.15, and 343.15 K. In the temperature range studied, the experimental surface tension values of the aqueous blends of three Alkanolamines decrease linearly both as the AMP concentration increases and as the temperature increases. The surface tension results for the aqueous solutions of blends of three Alkanolamines were correlated simultaneously as a function of temperature and AMP concentration. The foamability results for the quaternary systems reveal that the high surface activity of AMP allows it to act favorably as antifoaming agent in the concentration range of 4–10 mass%, at 303.15, 313.15, and 323.15 K. The experimental behaviour of the different studied systems show that the high surface activity of AMP leads to low surface tension, large surface adsorption, large limiting elasticity, and very low foamability for aqueous systems with one, two or three Alkanolamines in which it is present as a component.
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density and viscosity of aqueous blends of three Alkanolamines n methyldiethanolamine diethanolamine and 2 amino 2 methyl 1 propanol in the range of 303 to 343 k
Journal of Chemical & Engineering Data, 2006Co-Authors: Maria Esther Rebolledolibreros, Arturo TrejoAbstract:Experimental values of the density and viscosity for aqueous solutions of three Alkanolamines composed of 32.5 mass % N-methyldiethanolamine (MDEA) and 12.5 mass % diethanolamine (DEA) with 2, 4, 6, 8, and 10 mass % 2-amino-2-methyl-1-propanol (AMP) have been determined in the temperature range of (303.15 to 343.15) K. The experimental results of the density and viscosity are given as a function of both temperature and AMP concentration. In the range of temperature studied, the experimental density values of the aqueous blends of Alkanolamines decrease as the AMP concentration increases while the viscosity values increase as the AMP concentration increases. Correlation equations were obtained to allow the calculation of density and viscosity for aqueous solutions of MDEA and DEA as a function of AMP concentration and temperature.
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gas solubility of co2 in aqueous solutions of n methyldiethanolamine and diethanolamine with 2 amino 2 methyl 1 propanol
Fluid Phase Equilibria, 2004Co-Authors: Maria Esther Rebolledolibreros, Arturo TrejoAbstract:Gas solubility of carbon dioxide in an aqueous solution of 32.5 wt.% N-methyldiethanolamine and 12.5 wt.% diethanolamine with 4, 6, and 10 wt.% 2-amino-2-methyl-1-propanol has been measured, at 313.15, 343.15, and 393.15 K, over a range of pressure from 3 to 2000 kPa, using a chromatographic method for analysis of the liquid phase. The results of the gas solubility are given as the partial pressure of CO 2 against its mole ratio α (mol CO2/mol alkanolamine) and its mole fraction at each temperature studied. The solubility of CO 2 in all the systems studied decreases with an increase in temperature and increases with an increase in the partial pressure of CO 2 at a given temperature and it is a function of the concentration of the mixture of Alkanolamines in solution. The enthalpy of solution of CO 2 has been calculated from the experimental solubility data. © 2004 Elsevier B.V. All rights reserved.
Amin Izadi - One of the best experts on this subject based on the ideXlab platform.
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solubility and thermodynamic modeling of hydrogen sulfide in aqueous diisopropanolamine 2 amino 2 methyl 1 propanol piperazine solution at high pressure
The Journal of Chemical Thermodynamics, 2015Co-Authors: Ali Haghtalab, Amin IzadiAbstract:Abstract Natural gas as a clean source of energy contains several contaminates such as CO2 and H2S that is treated through a natural gas purification unit in gas industry. Moreover, for design and construction of gas contactor equipment, it is necessary to obtain experimental values of solubility for H2S and CO2 in aqueous amine/Alkanolamines. In this work, the solubility of H2S in the blended aqueous diisopropanolamine (DIPA), 2-amino-2-methyl-1-propanol (AMP) and piperazine (Pz) are measured using a static high pressure apparatus through volumetric method. The values are measured at fixed 45 mass per cent of total amine so that the solubility of H2S in the present system is investigated under isothermal conditions at T = (313.15, 328.15 and 343.15) K and in the pressure range of (0.1 to 2.1) MPa. The experimental results are presented as the partial pressure of H2S against acid gas loading (moles H2S per total moles of amine). Also for modeling the solubility of H2S in the blended amine/Alkanolamines, the Electrolyte-NRTL activity coefficient function is applied to the correlation and prediction of the partial pressure of H2S versus the acid gas loading. Considering the present results at the given conditions, it is observed that in the low gas loading region, the effect of enhancing Pz on the solubility of H2S is very low, but at high gas loading the absorption of H2S is intensified by enhancing mass fraction of Pz in alkanolamine.
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simultaneous measurement solubility of carbon dioxide hydrogen sulfide into aqueous blends of Alkanolamines at high pressure
Fluid Phase Equilibria, 2014Co-Authors: Ali Haghtalab, Amin IzadiAbstract:Abstract Treatment of the sour natural gas is a major step in natural gas processing so that the acid gases such as H2S and CO2 are removed from natural gas stream. The acid gases are harmful to environment and destroy the production equipment so that their presence in gas stream leads to corrosion and lowering heating value. On the other hand, for reliable and optimum design of separation equipment, primarily sufficient and accurate equilibrium data of the acid gases solubility in the aqueous Alkanolamines is required. In this work, the simultaneous solubility of the H2S + CO2 in the alkanolamine mixtures is measured at 343 K and total pressure range of 0.1–2.1 MPa. The blends are studied as the aqueous mixtures of N-methyldiethanolamine (MDEA) + 2-amino-2-methyl-1-propanol (AMP) + Piperazine (Pz) and the aqueous mixtures of diisopropanolamine (DIPA), AMP and Pz. For the acid gas solubility measurements, a high pressure static apparatus is used through a volumetric method. The mass fraction of the total alkanolamine is fixed at 0.45 and the results are presented as the partial pressure of each acid gas against its loading (mole acid gas/total mole amine) and mole fraction. The influence of the AMP and Pz on the aqueous DIPA-based and MDEA-based systems are studied so that it is observed that the absorption of the CO2 in the aqueous alkanolamine enhances through separate blending of the AMP and Pz with the aqueous system of MDEA or DIPA and the absorption of the H2S reduces in both of the aqueous DIPA-based and MDEA-based systems.
Yasuro Yamanaka - One of the best experts on this subject based on the ideXlab platform.
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13c nmr study of acid dissociation constant pka effects on the co2 absorption and regeneration of aqueous tertiary Alkanolamines
Energy Procedia, 2014Co-Authors: Kogoro Hayashi, Yukio Furukawa, Hiroshi Sato, Yasuro YamanakaAbstract:Abstract We have studied the formation rates of chemical species such as CO3/HCO3, amine/protonated amine, and carbonate/protonated carbonate in the course of CO 2 absorption at room temperature and concentration changes after CO 2 release upon heating at 93 °C for 30 min for aqueous solutions of 12 kinds of tertiary Alkanolamines using 13C-NMR spectroscopy. A positive linear correlation was found between the CO 2 capture rates of Alkanolamines having a normal hydroxyalkyl group and their p K a values. The CO 2 capture rates of Alkanolamines having a branched hydroxyalkyl group were lower than those in this relationship. The CO 2 release amount of each tertiary amine increased with decreasing p K a, as a general trend. N - ethyldiethanolamine (EDEA) showed the largest CO 2 release amount and a moderately high rate of CO 2 absorption.
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13c nmr study of acid dissociation constant pka effects on the co2 absorption and regeneration of aqueous tertiary alkanolamine piperazine blends
Energy Procedia, 2014Co-Authors: Miho Nitta, Kogoro Hayashi, Yukio Furukawa, Hiroshi Sato, Yasuro YamanakaAbstract:Abstract We have studied the concentration changes of chemical species such as CO32-/HCO3 , amine/protonated species, carbonate/protonated species, carbamates/protonated species, etc. in the course of CO2 absorption and those after CO2 release upon heating at 93 °C for 30 min for aqueous blends of piperazine (PZ) and each of 11 tertiary Alkanolamines using 13C-NMR spectroscopy. The initial rates of CO2 capture of the blends ranged between 0.125 and 0.167 mol/L min, which were contributed by the rapid formation of PZ monocarbamate. A positive linear correlation was found between the CO2 release amounts of the blends upon heating and the pKa values of the tertiary Alkanolamines. The CO2 content captured as PZ mono- and bis-carbamates decreased upon heating in the pKa range smaller than 9.34, whereas it increased upon heating in the pKa range higher than 9.55. A tertiary alkanolamine having the pKa smaller than 9.34 is promising as a blend amine with PZ.