Title:Comparative Study for the Absorption of Carbon Dioxide in
Aqueous Amine Solvents for Enhanced Loading
Volume: 16
Issue: 2
Author(s): Akash Sood*, Avinash Thakur and Sandeep Mohan Ahuja
Affiliation:
- Chemical Engineering Department, Research Lab-III,, Sant Longowal Institute of Engineering and
Technology, Longowal, 148106, Punjab, India
Keywords:
Alkanolamine, polyamines, carbon capture, absorption, heat of absorption, TETA, AMP.
Abstract:
Aims: The current study aimed to investigate the CO2 absorption capacity of the aqueous
alkanolamine, including primary, secondary, tertiary, and sterically hindered amines and polyamines,
i.e., monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA) and 2-amino-2-methyl-1-propanol (AMP), tetraethylenepentamine (TEPA), triethylenetetramine (TETA), 3-(Methylamino)propylamine (MAPA), and diethylenetriamine (DETA) at 40, 60, and 80°C at 1.1 bar.
Methods: An increase in reaction temperature caused a decrement in CO2 loading across the board
for all solvents. The trend of CO2 loading was TEA < MEA < DEA < AMP < MAPA < DETA <
TETA < TEPA at 40 ºC, TEA < DEA < MEA < AMP < MAPA < DETA < TETA < TEPA, at
60ºC and TEA < DEA < AMP < MEA < MAPA < DETA < TETA < TEPA at 80ºC.
Results: The results indicated that TEPA has great potential to be utilized as an energy-efficient
and non-corrosive solvent for CO2 capture since it has outperformed all other aqueous amine solvents
in this present study. Furthermore, the CO2 loading of sterically hindered amine (AMP) at the
same temperature was found to be higher than primary, secondary, and tertiary amines. Heat of
absorption (ΔHabs) was also determined to gauge the energy requirement to regenerate absorbents
for cyclic loading from an economic viewpoint.
Conclusion: DETA has the highest ΔHabs = 84.48 kJ/mol. On the contrary, the long-chain tertiary
amine TEA resulted in the least ΔHabs = 40.21 kJ/mol, among all other solvents. Whereas the sterically
hindered amine (AMP) was observed to possess mid-range ΔHabs, i.e., 58.76 kJ/mol.
Among all selected solvents, polyamines showed higher ΔHabs than other conventional amines
pertaining to the precedence of TEA<AMP<DEA<MEA<TETA<TEPA<MAPA<DETA.