Density, Viscosity and Free Energy of Activation for Viscous Flow of Monoethanol Amine (1) + H2O (2) + CO2 (3) Mixtures

Abstract

Densities and viscosities of aqueous monoethanol amine (MEA) and CO2-loaded aqueous MEA are highly relevant in engineering calculations to perform process design and simulations. Density and viscosity of the aqueous MEA were measured in the temperature range of 293.15 K to 363.15 K with MEA mass fractions ranging from 0.3 to 1.0. Densities of the aqueous MEA were fitted for a density correlation. Eyring’s viscosity model based on absolute rate theory was adopted to determine the excess free energy of activation for viscous flow of aqueous MEA mixtures and was correlated by a Redlich–Kister polynomial. Densities and viscosities of CO2-loaded MEA solutions were measured in the temperature range of 293.15 K to 353.15 K with MEA mass fractions of 0.3, 0.4 and 0.5. The density correlation used to correlate aqueous MEA was modified to fit CO2-loaded density data. The free energy of activation for viscous flow for CO2-loaded aqueous MEA solutions was determined by Eyring’s viscosity model and a correlation was proposed to represent free energy of activation for viscous flow and viscosity. This can be used to evaluate quantitative and qualitative properties in the MEA + H2O + CO2 mixture.

Artificial Neural Networks (ANNs) for Density and Viscosity Predictions of CO2 Loaded Alkanolamine + H2O Mixtures

“…Consequently, the maximum temperature of the density measurements was limited to 323.15 K for some CO2-loaded aqueous amine mixtures to reduce the experimental errors. The uncertainties in density and viscosity measurements are reported in references [23,24]. The study reveals that properly trained feedforward backpropagation ANN models are capable of predicting physical properties of alkanolamine + H 2 O + CO 2 mixtures with good accuracy and models are appropriate for engineering applications of designing process equipment and performing mathematical modelling and simulations of absorption and desorption systems.…”

“…Figure 1 illustrates a schematic of neurons in an ANN consisting of one hidden layer with a single output. The measured data by the authors to perform this study can be found in the sources [23,24]. Table 3 In the developed ANN models, the mole fractions of components and the temperature are considered as the inputs for the network.…”

“…Comparison of these correlations with ANN shows that a properly trained network is capable of predicting density at a high accuracy compared to measured data. A modified Weiland's correlation for amine mixtures with more than one amine is adopted for molar volume of AMP + MEA + H 2 O + CO 2 mixtures [24] to fit density and was compared with ANN predictions. The modified Weiland's correlation was able to fit density with 0.4% AARD and ANN predictions showed better accuracies compared to the modified Weiland's correlation.…”

“…The predicted viscosities are in good agreement with measured data with accuracy as mentioned in Table 5. A modified Weiland's viscosity correlation [24] was adopted to compare the performance of ANN as illustrated in Figure 6a,b. The modified Weiland's viscosity correlation was able to fit the measured viscosities with 2.7% AARD.…”

“…Consequently, the maximum temperature of the density measurements was limited to 323.15 K for some CO 2 -loaded aqueous amine mixtures to reduce the experimental errors. The uncertainties in density and viscosity measurements are reported in references [23,24].…”