English abstract
This study aimed to examine the performance of two new B-alanine based systems as
alternative solvents for CO2 removal process. The first one is Potassium B-alaninate
(K-ala) at three mass concentrations (10, 20, and 30 wt %). In the second system,
Aminoethylpiperazine (APZ) was added as a promoter to enhance the CO2 loading of
the first system. Aminoethylpiperazine was added at 3, 6, and 9 wt%. The CO2
solubility was measured for both systems using a gas solubility unit at three
temperatures (303.15, 313.15, 333.15 K) and four pressures (4, 8, 12, 16 bar). The
number of required experiments was determined using Design Expert software. The
results of this work showed that the solubility strongly depends on the CO2 pressure.
By increasing the pressure, the solubility significantly increases. In contrast, CO2
solubility is inversely proportional to temperature and mass concentration. The results
also obviously showed the improvement of the CO2 loading after promoting with
aminoethylpiperazine. The CO2 loading has improved from about 0.6401 (mol
CO2/mol solvent) before the addition of APZ to 0.8892 (mol CO2/mol solvent) after
promoting with APZ. The average percentage of improvement was about 42 %.
Furthermore, analysis of variance (ANOVA) was performed to study the significance
of the CO2 solubility data.
Physical properties (Density, Viscosity, and Refractive index) of all the solvents at the
studied concentrations were measured for a temperatures range of (298.15 to 333.15
K). The experimental data was regressed as a function of temperature and mass
concentration. The experimental data of all the properties were observed to match the
corresponding correlated lines, therefore the applied correlations are satisfactory to
predict the studied properties at the given temperature and concentration. Along with
these properties, the thermal expansion coefficients were estimated for the studied
solvents using the experimental density results.
Besides, the solution of (K-ala + APZ) at (10 + 6) wt% was further analyzed using
Fourier Transform Infrared (FTIR) Spectroscopy before and after CO2 loading to
explore the changes in the chemical functional groups after the chemical absorption.
From the spectrogram, the characteristic peaks identified for bicarbonate are located
at 1630 and 1360 cm-1.vi
