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Experimental measurements and modelling of CO 2 solubility in aqueous mixtures of benzylamine and N‐(2‐aminoethyl) ethanolamine
Author(s) -
Mukherjee Satyajit,
Bandyopadhyay Syamalendu S.,
Samanta Amar N.
Publication year - 2018
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.2264
Subject(s) - ethanolamine , amine gas treating , solubility , aqueous solution , chemistry , alkanolamine , benzylamine , thermodynamics , absorption (acoustics) , analytical chemistry (journal) , organic chemistry , materials science , physics , composite material
In this work, carbon dioxide solubility in N‐(2‐aminoethyl) ethanolamine (AEEA) activated aqueous benzylamine (BZA) solutions are studied using a stirred‐cell reactor in the temperature and pressure range of 313.15–333.15 K and 0.2–219 kPa, respectively. AEEA is a linear diamine with a primary and secondary amine groups, and BZA is a primary cyclic amine. The concentration of the aqueous blends used are (20mass% BZA + 10mass% AEEA), (24mass% BZA + 6mass% AEEA), and (28mass% BZA + 2mass% AEEA). Density and viscosity of unloaded aqueous amine blends are also measured in experimental temperature and concentration ranges and correlated using Joubian – Acree mathematical model. Model‐predicted density and viscosity data are in good agreement with experimental results showing 0.05% and 3.41% AAD, respectively. To correlate experimental vapor–liquid‐equilibrium data, Kent–Eisenberg (KE), artificial neural network (ANN), and soft models are used. Equilibrium constants of monocarbamate formation reaction of BZA and AEEA are regressed as a function of temperature and CO 2 loading to fit the experimental data with KE model expression. KE model is also utilized to estimate the pH of CO 2 loaded aqueous amine solutions. ANN model is found to predict CO 2 solubility with better accuracy (1.56% AAD) in comparison of KE model (8.27% AAD) and soft model (15.5%). The CO 2 absorption capacity of (20mass% BZA + 10mass% AEEA) solvent (~0.8 mol CO 2 /mol amine) is higher than that of monoethanolamine (~0.5 mol CO 2 /mol amine). Heats of absorption values of (BZA + AEEA) solvents (~25 kJ/mol CO 2 ) predicted from Gibbs–Helmholtz relationship are found to be lower than that of MEA (~87 kJ/mol CO 2 ) and PZ (~66 kJ/mol CO 2 ).