Alan E. Mather

The Solubility of Carbon Dioxide in Water at Low Pressure

The system carbon dioxide‐water is of great scientific and technological importance. Thus, it has been studied often. The literature for the solubility of carbon dioxide in water is vast and interdisciplinary. An exhaustive survey was conducted and approximately 100 experimental investigations were found that reported equilibrium data at pressures below 1 MPa. A model based on Henry’s law was used to correlate the low pressure data (those up to 1 MPa). The following correlation of the Henry’s constants (expressed on a mole fraction basis) was developed ln(H21/MPa)=−6.8346+1.2817×104/T−3.7668×106/T2 +2.997×108/T3 The correlation is valid for 273<T<433 K(0<t<160 °C) where T is in K. Any experimental data that deviated significantly from this model were duly noted.

A mathematical model for equilibrium solubility of hydrogen sulfide and carbon dioxide in aqueous alkanolamine solutions

Abstract A thermodynamic model is proposed for the solubility of the acid gases (H 2 S and CO 2 ) in alkanolamine solutions. The model is based on the exten Debye-Huckel theory of electrolyte solutions. Predicted partial pressures of the acid gases over monoethanolamine solutions are in good agreement wit experimental data over the temperature range 25—120°C.

Kinetics of the reaction of carbon dioxide with 2-amino-2-methyl-1-propanol solutions

Abstract Reaction rate constants for the reaction between CO 2 and the sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were determined from measurements of the rate of absorption of CO 2 into both aqueous and nonaqueous (1-propanol) AMP solutions. A stirred-cell reactor having a horizontal liquid-gas interface was used for the absorption studies. The zwitterion mechanism was found to be suitable for modelling the absorption of CO 2 into the aqueous AMP solutions and into the 1-propanol-AMP solvent. The partial order in amine is greater than one for both cases. The kinetic parameters for aqueous AMP solutions were obtained for temperatures from 15 to 45°C and over the concentration range of 0.25–3.5 kmol m −3 of AMP.

Densities, excess molar volumes, and partial molar volumes for binary mixtures of water with monoethanolamine, diethanolamine, and triethanolamine from 25 to 80°C

We have measured densities of binary mixtures of water with monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) over the full range of compositions and over the temperature range from 25 to 80°C. Results of these measurements have been used in calculating excess molar volumes and partial molar volumes. Knowledge of the volumetric properties of these mixtures is useful in connection with industrial treatment of acidic gases; derived excess molar volumes and partial molar volumes can be used as a basis for understanding some of the molecular interactions in water-organic mixtures.

Solubility of N2O in alkanolamines and in mixed solvents

Abstract The solubility of N2O in pure alkanolamines (MEA, DEA, DIPA, TEA, MDEA and AMP) has been measured over the temperature range from 20 to 85 °C at exponential function of temperature. The densities of the pure alkanolamines were determined at temperatures from 20 to 90 °C. A semiempirical model in amine mixtures is presented. The model is based on the work by Prausnitz and Chueh, by Prausnitz and by Boublik and Hala. Correlations of experi out for eight systems (MDEA-H2O, AMP-H2O, DIPA-H2O, DEA-H2O, MEA-H2O, AMP-MDEA-H2O, AMP-TMS-H2O and DEA-EG-H2O) between concentrations. Comparison with the experimental results indicates that the model should be reliable for estimating the solubility of N2O in alkano solvents. The solubility data for pure amines and the correlation for mixed solvents may be applied to estimate the solubility of CO2 gas in pure o 2 analogy.

The solubility of hydrogen sulphide in water from 0 to 90°C and pressures to 1 MPa

Abstract There exists some controversy about the solubility of hydrogen sulphide in water—notably the effect of pressure on the solubility. This paper reviews the experimental data for this system for temperatures between 0 and 90°C and for pressures up to 1 MPa. A simple model is used to correlate all of the data, including data that had previously been rejected as inaccurate. It is demonstrated that observed deviations from the strict Henrys law can be explained by the non-ideality of the vapour phase. Also, non-idealities in the liquid phase are negligible for the stated range of temperature and pressure.

The system carbon dioxide-water and the Krichevsky-Kasarnovsky equation

The system carbon dioxide-water has been studied often. However, there is some controversy about the thermodynamic description of the behavior of this system. Some researchers indicate that the system CO2−H2O is accurately modeled by the Krichevsky-Kasarnovsky equation. Others say that it is not. This paper investigates this controversy. As a part of this study an overview of Henrys law and a discussion of the limitations of the Krichevsky-Kasarnovsky equation are presented. From the analysis presented in this paper, it must be concluded that for temperatures lower than about 100°C, the system CO2-H2O is accurately modeled by the Krichevsky-Kasarnovsky equation. On the other hand, at 100°C and higher, it is not. In order to arrive at this conclusion, four models of the solubility were investigated. Using these models, it is clearly demonstrated that the activity coefficients are not negligible and hence the Krichevsky-Kasarnovsky equation is not applicable at high temperatures.

Viscosities and excess properties of aqueous solutions of ethanolamines from 25 to 80° C

Viscosities of aqueous solutions of monoethanolamine and triethanolamine have been measured from 25 to 80°C over the entire range of concentrations. The excess Gibbs energies for viscous flow have been calculated for aqueous solutions of monoethanolamine, triethanolamine, and also for diethanolamine and methyldiethanolamine from our earlier work [J. Chem. Eng. Data39, 290 (1994)]. The entropy of viscous flow was obtained by using the temperature dependence of the excess Gibbs energy for viscous flow. The structural effects on the viscosity, excess Gibbs energy, and entropy for viscous flow are discussed.

Vaporliquid equilibria for acid gases and lower alkanes in triethylene glycol

Abstract The solubility of carbon dioxide, hydrogen sulfide, methane, ethane and propane in triethylene glycol has been determined at temperatures in the range 25° to 125°C at pressures up to 20 MPa. The experimental results were correlated by a form of the Peng-Robinson equation of state, and interaction parameters have been obtained for these systems. The parameters in the Krichevsky-Ilinskaya equation were obtained from the interaction parameters of the Peng-Robinson equation.

MOLAR HEAT CAPACITIES OF ALKANOLAMINES FROM 299.1 TO 397.8 K: GROUP ADDITIVITY AND MOLECULAR CONNECTIVITY ANALYSES

The molar heat capacities of 14 alkanolamine compounds have been measured at five separate temperatures in the range 299.1 to 397.8 K. These compounds were monoethanolamine (MEA), monomethylethanolamine (MMEA), dimethylethanolamine (DMEA), monoethylethanolamine (MEEA), diethylethanolamine (DEEA), n-propylethanolamine (n-PEA), diisopropylethanolamine (di-PEA), diethanolamine (DEA), methyldiethanolamine (MDEA), ethyldiethanolamine (EDEA), n-butyldiethanolamine(n-BDEA), tert-butyldiethanolamine (tert-BDEA), triethanolamine (TEA) and 2-amino-2-methylpropan-1-ol (AMP). Molar heat capacities of these compounds show a structural dependence, where the molar heat capacity of one molecule may be considered as the sum of various group contributions. Hence, the reported molar heat capacity data have been used as input to a group additivity analysis that yields estimates of CH 2 , OH, NH and N group contributions to molar heat capacities at each investigated temperature. The additivity principle has been explored in more detail by using molecular connectivity indexes to obtain a simple five-term equation that models the molar heat capacities of the investigated alkanolamines over the entire experimental temperature range.