Amine Mass Fraction Research Articles

Densities and isobaric heat capacities at high pressures of aqueous solutions of 2-diethylaminoethanol (DEAE) or 2-ethylaminoethanol (EAE) for CO2 capture

Densities and isobaric heat capacities of DEAE + H2O and EAE + H2O systems are presented in this paper. Density measurements were carried out at high pressure (up to 100 MPa) and temperatures from (293.15 to 393.15) K, with amine mass fractions of 0.1; 0.2; 0.3 and 0.4. These data were gathered using a vibrating tube densimeter (Anton Paar DMA HPM) with a relative expanded uncertainty of ±0.1 % (k = 2). A non-adiabatic quasi-isothermal flow calorimeter was used for isobaric heat capacity measurements with a relative expanded uncertainty better than 1 % (k = 2). Measurements reached pressures up to 25 MPa, and temperatures from (293.15 to 353.15) K, with amine mass fractions of 0.1; 0.2; 0.3 and 0.4. Both amine DEAE + H2O and EAE + H2O systems show a density and isobaric heat capacity decrease with amine mass fraction increase. Density data as a function of temperature, pressure and molality were fitted using a modified Tammann-Tait empirical equation of state. Furthermore, isobaric heat capacity data were correlated using an empirical function of temperature and amine mass fraction, but not pressure due to its lack of sensitivity in the measured data. Both correlations are in good agreement with the uncertainties. Comparison with experimental density data available in literature showed lower deviations than the associated uncertainties. Our isobaric heat capacity experimental data agree well with the scarce literature.

Densities, viscosities and spectroscopic study of partially CO2-loaded nonaqueous blends of 2-butoxyethanol with 2-(ethylamino)ethanol and 2-(butylamino)ethanol at temperatures of (293.15 to 353.15) K

Nonaqueous CO2 absorbents, composed of secondary alkanolamines and 2-alkoxyethanols, have attracted much attention for an energy-efficient CO2 capture process. In this work, densities and viscosities of partially CO2-loaded mixtures of 2-(butylamino)ethanol (BAE) + 2-butoxyethanol (EGBE) and 2-(ethylamino)ethanol (EAE) + EGBE were measured at atmospheric pressure over the temperature range of (293.15 to 353.15) K with amine mass fraction (w1) of (0.10, 0.30 and 0.50) containing various CO2 loading. With increasing CO2 loadings, significant increases in both density and viscosity were observed. Dimensionless ρloaded·ρCO2-free−1 and ηloaded·ηCO2-free−1 from the CO2-free and CO2-loaded systems were fitted by proposed correlations as a function of temperature, amine concentration and CO2 loading. The calculated values of density and viscosity from the correlations are in good agreement with the experimental results, with AADs within 0.15% and 1.60% for density and viscosity respectively. The dramatic increase in viscosity of carbonated solutions was interpreted by the intermolecular interactions and the formation of ionic products in the mixtures based on the FTIR spectral results.

Density, Viscosity, and Excess Properties of MDEA + H2O, DMEA + H2O, and DEEA + H2O Mixtures

This study presents measured density and viscosity of N-methyldiethanolamine (MDEA) + H2O, Dimethylethanolamine (DMEA) + H2O, and Diethylethanolamine (DEEA) + H2O mixtures. The density was measured at amine mass fraction w1 from 0.3 to 1 for the temperature range 293.15–353.15 K. The excess molar volumes VE were determined from density data. Redlich–Kister type polynomials were proposed to fit VE and density deviation ln(ργ) to represent measured densities. The viscosity was measured at amine mass fraction w1 from 0.3 to 1 for the temperature range 293.15–363.15 K. The viscosity deviation ηE and excess free energy of activation for viscous flow ΔGE* were determined from measured viscosities and examined for intermolecular interactions among mixture molecules. Correlations were proposed to fit viscosity data with acceptable accuracies. The McAllister’s three-body model was adopted to fit kinematic viscosities determined from density and dynamic viscosity data. The results showed the importance of examining intermolecular interactions that are discussed in McAllister’s four-body model to improve the accuracies of data fits.

Absorption capacity and CO2 removal efficiency in tray tower by using 2-(ethylamino)ethanol activated 3-(dimethylamino)propan-1-ol aqueous solution

The absorption amount (m) and loading (α) of CO2 in 2-(ethylamino)ethanol (EAE) activated 3-(dimethylamino)propan-1-ol (3DMA1P) aqueous solution were measured. The temperatures ranged from 303.2 K to 323.2 K. The mass fractions of 3DMA1P and EAE respectively ranged from 0.3 to 0.5 and 0.01 to 0.03. The effects of temperature (T) and mass fractions of amines (w) on the absorption performance were illustrated. It’s impressive that the addition of very small amounts of EAE into 3DMA1P aqueous solution significantly enhanced the absorption performance. Moreover, comparison showed that 3DMA1P-EAE aqueous solution appeared much higher CO2 absorption capacity than the widely used MDEA-MEA aqueous solution. Tray towers with different plates (Np = 6, 8 and 10) were used to verify the removal efficiency of CO2 (ηCO2) and the effects of gas flow rate (G), absorbent flow rate (L), w, absorbent feed temperature (T) and Np on ηCO2 were illustrated. Our results showed that when composed of 30% to 50% (mass percent) 3DMA1P and 3% EAE, the absorbents achieved ηCO2 higher than 90%, which met the efficiency requirement specified in a power plant, thus leading to a promising industrial application in the CO2 capture process.

Experiment and model for surface tensions of 2‑diethylaminoethanol‑N‑(2‑aminoethyl)ethanolamine, 2‑diethylaminoethanol‑N‑methyl‑1,3‑propane‑diamine and 2‑diethylaminoethanol‑1,4‑butanediamine aqueous solutions

The surface tensions of 2‑diethylaminoethanol (DEAE)‑N‑(2‑aminoethyl)ethanolamine (AEEA), DEAE‑N‑methyl‑1,3‑propane‑diamine (MAPA) and DEAE‑1,4‑butanediamine (BDA) aqueous solutions have been measured by using the BZY-1 surface tension meter. The mass fractions of DEAE and AEEA/MAPA/BDA respectively ranged from 0.300 to 0.500 and 0.050 to 0.150. The temperature ranged from 303.2 K to 323.2 K. A thermodynamic equation was proposed to model the surface tension and the calculated results agreed well with the experiments. The effects of temperature and mass fraction of amines on the surface tension were demonstrated on the basis of experiments and calculations. The surface thermodynamics including surface enthalpy and surface entropy of blended amine aqueous solutions were also determined, and their temperature and mass fraction dependences were analyzed.

Experiment and model for the viscosity of carbonated 3-(dimethylamino)propan-1-ol and 2-(ethylamino)ethanol blended aqueous solutions

The viscosities (η) of CO2-loaded 3-(dimethylamino)propan-1-ol (3DMA1P) aqueous solutions, CO2-unloaded and CO2-loaded 2-(ethylamino)ethanol (EAE)- 3DMA1P aqueous solutions were measured by using the NDJ-5S rotational viscometer. The temperature ranged from 303.2 K to 323.2 K. The mass fractions of 3DMA1P and EAE ranged from 0.3 to 0.5 and 0.01 to 0.03 respectively. The Weiland equation was used to model the viscosity and the calculated results agreed well with the experimental results. The effects of mass fractions of amines (w), temperature (T) and CO2 loading (α) on viscosity were demonstrated on the basis of experiments and calculations.

Effect of Solvent Concentration on the Energy Demand of an Absorption-Based Natural Gas Sweetening Plant

The removal of CO2 from natural gas will enhance its energy content, decrease the volume to be transported and –if coupled with storage technology- it will also contribute to the control of CO2 emissions. Amine-based chemical absorption is the most advanced CO2 capture system. Yet, high energy requirement is a major hinder to its wide deployment. Among the possible routes of improvement is the use of novel amines that can achieve the trade-off between robustness and low regeneration energy. In this paper, we have studied the use of MDEA/DEA as solvent for the capture of CO2 from natural gas. The presence of BTEX (Benzene, Toluene, Ethyl Benzene and Xylene) in the raw natural gas was taken into account. AspenHysys v9 was used to simulate the chemical absorption system. The impact of solvent composition on key process variables, the required flow rate to achieve transport specification, required reboiler duty, pumping energy, BTEX incineration energy and amine losses, were studied. The optimal operating point corresponding to the lowest energy requirement was identified and the separate contribution of each process parameter was estimated. The study showed that the optimal amine mass fraction is influenced by the presence of BTEX and that it shifts from 0.5 if BTEX are not present in the sour feed gas to 0.45 if their incineration is taken into account.

Density and Viscosity of Partially Carbonated Aqueous Solutions Containing a Tertiary Alkanolamine and Piperazine at Temperatures between 298.15 and 353.15 K

Measurements for the density and viscosity of partially carbonated solutions containing water, piperazine (PZ), and a tertiary amine, which was either dimethylaminoethanol (DMAE) or 2-diethylaminoethanol (DEAE), were conducted with total amine mass fractions of 30% and 40% over a temperature range from 298.15 to 353.15 K. Density and viscosity correlations of these mixtures were developed as functions of amine mass fraction, CO2 loading, and temperature. For both systems investigated, the average absolute relative deviations of the experimental data from these correlation are approximately 0.2% for density and 3% for viscosity. The correlations will be useful for thermodynamic analysis and computer simulations of carbon capture processes utilizing these promising blended amine systems.

Experiments and model for the surface tension of DEAE-PZ and DEAE-MEA aqueous solutions

The surface tension (γ) of 2-diethylaminoethanol (DEAE), DEAE-monoethanolamine (MEA), and DEAE-piperazine (PZ) aqueous solutions was measured by using the BZY-1 surface tension meter. The temperature ranged from 303.2K to 323.2K. The mass fraction of DEAE, MEA and PZ respectively ranged from 0.30 to 0.50, 0.05 to 0.15 and 0.025 to 0.075. An equation was proposed to model the surface tension and the calculated results agreed well with the experiments. The effects of temperature and mass fraction of amines on the surface tension were demonstrated on the basis of experiments and calculations.

Accurate Prediction of the Surface Tensions of Ionic Liquids–Amines–Water Mixtures Regarding CO2 Recovery and Sequestration Processes

A support vector machine (SVM) model is presented concerning accurate prediction of the surface tension of the complex mixtures of ionic liquids (ILs)–amines–water using the most important types of amines employed in the gas sweetening plants, such as monoethanolamine, diethanolamine, and methyldiethanolamine. Different ILs, such as [bmim] [BF4], [bmim] [DCA], [mmim] [dmp], [emim] [dep], [bmim] [BF4], [bmim] [Br], [bmim] [BF4], and [bmim] [Br], are considered in the presented model. The effects of most important influencing parameters, such as temperature and mass fraction of amines and ILs, on the surface tension of the aqueous mixtures of ILs and amines are well represented. A comparison of the presented model and the most important models reveals that the suggested SVM model has better performance in terms of accuracy and generalizability. The percentage average absolute deviation between the predicted and experimental surface tensions is about 0.44% suggesting the superiority of the presented model over wide ranges of temperatures and species concentrations.

Viscosity and density measurements of aqueous amines at high pressures: MDEA-water and MEA-water mixtures for CO2 capture

Viscosity and density are thermophysical properties crucial to characterizing any kind of fluid such as aqueous amines. These blends are becoming more and more relevant for their CO2 capture potential, such that having accurate viscosity and density measurements would prove useful. Densities and viscosities of these mixtures at atmospheric pressure may be found in the literature although it is more difficult to find values at high pressures, these potentially proving interesting when seeking to provide a full description of these fluids.Viscosity and density measurements at high pressures (up to 120MPa) and at temperatures between 293.15K and 353.15K of MDEA+water and MEA+water mixtures (both from 10% to 40% amine mass fraction) are presented in this work. Density measurements were performed with an Anton Paar DMA HPM densimeter with an expanded uncertainty (k=2) less than ±0.7kg·m−3. A falling body technique was used to measure viscosities at high pressures due to its sturdiness in terms of corrosion. Details of this latter equipment are presented, including calibration using n-dodecane and uncertainty calculations, which give a relative expanded uncertainty (k=2) of less than ±2.4% for the highest viscosity and ±2.9% for the lowest.

Experiment and model for the viscosities of MEA-PEG400, DEA-PEG400 and MDEA-PEG400 aqueous solutions

The viscosities (η) of poly(ethylene oxide)400 (PEG400), monoethanolamine (MEA)-PEG400, diethanolamine (DEA)-PEG400 and N-methyldiethanolamine (MDEA)-PEG400 aqueous solutions were measured by using the NDJ-5S digital rotational viscometer. A thermodynamic equation was used to model the viscosities and the calculated results are satisfactory. The effects of temperature, mass fractions of amines and PEG400 on the viscosities were demonstrated on the basis of experiments and calculations.

Experiment and model for the surface tension of amine–ionic liquids aqueous solutions

The surface tension (γ) of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4])–monoethanolamine (MEA), 1-butyl-3-methylimidazolium bromide ([Bmim][Br])–MEA, [Bmim][BF4]–diethanolamine (DEA) and [Bmim][Br]–DEA aqueous solutions was measured by using the BZY-1 surface tension meter. The temperature ranged from (293.2 to 323.2)K. The mass fraction of amines and ionic liquids (ILS) respectively ranged from 0.15 to 0.30 and 0.05 to 0.10. A thermodynamic equation was proposed to model the surface tension of amines–ILS aqueous solutions and the calculated results agreed well with the experiments. The effects of temperature, mass fraction of amines and ILS on the surface tension were demonstrated on the basis of experiments and calculations.

Experiment and model for the surface tension of MEA-PEG400 and DEA-PEG400 aqueous solutions

The surface tension (γ) of monoethanolamine (MEA)-poly(ethylene oxide) 400 (PEG400) and diethanolamine (DEA)-PEG400 aqueous solutions was measured by using the BZY-1 surface tension meter. The temperatures ranged from (298.2 to 323.2)K. The mass fraction of amines and PEG400, respectively, ranged from 0.20 to 0.30 and from 0 to 0.10. A thermodynamic equation was proposed to model the surface tension of the binary and ternary mixtures. The calculated results agreed well with the experiments. The effects of temperature, mass fraction of amines and PEG400 on the surface tension were demonstrated on the basis of experiments and calculations.

Surface Tensions of Carbonated 2‐Amino‐2‐methyl‐1‐propanol and Piperazine Aqueous Solutions

AbstractSurface tensions of carbonated 2‐amino‐2‐methyl‐1‐propanol (AMP) and piperazine (PZ) aqueous solutions were measured by a surface tension meter which employs the Wilhemy plate principle. A thermodynamic model was proposed to correlate the surface tensions of both CO2‐unloaded and CO2‐loaded aqueous solutions by introducing the contribution of CO2 loading into the formulation of surface tension. Based on experiments and calculations, the effects of temperature, mass fractions of amines, and CO2 loading on surface tensions of carbonated aqueous solutions were demonstrated.

Experiment and model for the viscosity of carbonated 2-amino-2-methyl-1-propanol-monoethanolamine and 2-amino-2-methyl-1-propanol-diethanolamine aqueous solution

The viscosities of carbonated 2-amino-2-methyl-1-propanol (AMP)–monoethanolamine (MEA) and AMP–diethanolamine (DEA) aqueous solutions were measured by using a NDJ-1 rotational viscometer. The temperature, total mass fractions of amines and CO2 loading respectively ranged from 303.15K to 323.15K, 0.3 to 0.4 and 0.1 to 0.5. The experiments were satisfactorily modeled by using a modified Grunberg–Nissan equation. The effects of temperature, mass fractions of amines and CO2 loading on the viscosities of carbonated aqueous solutions were demonstrated on the basic of experiments and calculations.

Experiments and model for the viscosity of carbonated 2-amino-2-methyl-1-propanol and piperazine aqueous solution

The viscosities (η) of carbonated 2-amino-2-methyl-1-propanol (AMP)-piperazine (PZ) aqueous solutions were measured by using a NDJ-1 rotational viscometer, with temperatures ranging from 298.15K to 323.15K. The total mass fraction of amines ranged from 0.3 to 0.4. The mass fraction of PZ ranged from 0.05 to 0.10. The Weiland equation was used to correlate the viscosities of both CO2-unloaded and CO2-loaded aqueous solutions and the calculated results agreed well with the experiments. The effects of temperature, mass fractions of amines and CO2 loading (α) on the viscosities of carbonated aqueous solutions were demonstrated on the basis of experiments and calculations.

Experiment and model for the viscosity of carbonated piperazine-N-methyldiethanolamine aqueous solutions

The viscosities of both CO2-unloaded and CO2-loaded piperazine (PZ) promoted N-methyldiethanolamine (MDEA) aqueous solutions were measured by using a NDJ-1 rotational viscometer, with temperatures ranging from 293.15 to 323.15K. The total mass fraction of amines was fixed as 0.5 and the mass fraction of PZ ranged from 0.025 to 0.15. The CO2 loading ranged from 0 to 0.6. The Weiland equation was used to correlate the viscosities and the calculated results agreed well with the experiments. The effects of temperature, mass fraction of amines and CO2 loading on the viscosity were demonstrated.

Solubility of carbon dioxide in aqueous blends of 2-amino-2-methyl-1-propanol and piperazine

In this work, we report new solubility data for carbon dioxide in aqueous blends of 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ). A static-analytical apparatus, validated in previous work, was employed to obtain the results at temperatures of (313.2, 333.2, 373.2, 393.2)K, and at total pressures up to 460kPa. Two different solvent blends were studied, both having a total amine mass fraction of 30%: (25 mass% AMP+5 mass% PZ) and (20 mass% AMP+10 mass% PZ). Comparisons between these PZ activated aqueous AMP systems and 30 mass% aqueous AMP have been made in terms of their cyclic capacities under typical scrubbing conditions of 313K in the absorber and 393K in the stripper. The Kent–Eisenberg model was used to correlate the experimental data.

Experiment and model for the viscosity of carbonated N-methyldiethanolamine–diethanolamine aqueous solutions

The viscosities of carbonated N-methyldiethanolamine (MDEA)–diethanolamine (DEA) aqueous solutions were measured by using a NDJ-1 rotational viscometer, with the temperature, mass fraction of amines and CO2 loading respectively ranging from 293.15K to 343.15K, 0.2 to 0.5 and 0.25 to 0.5. A modified Grunberg–Nissan equation was proposed for the correlation and prediction of the viscosities. The effects of temperature, amine concentration and CO2 loading on the viscosities of carbonated MDEA–DEA aqueous solutions were demonstrated on the basis of experiments and calculations.