Title:Amine Structure-Foam Behavior Relationship and Its Predictive Foam Model Used for Amine Selection for Design of Amine-based Carbon Dioxide (CO2) Capture Process
Volume: 1
Issue: 1
Author(s): Pailin Muchan, Jessica Narku-Tetteh, Teeradet Supap and Raphael Idem*
Affiliation:
- Clean Energy Technologies Research Institute (CETRI), Faculty of Engineering and Applied Science, University of Regina, Regina, SK, S4S 0A2,Canada
Keywords:
Foam, CO2 absorption, amine structure, prediction model, mine-based CO2 and surface tension.
Abstract:
Background: The use of an amine solution to capture CO2 from flue gases is one of the
methods applied commercially to clean up the exhaust gas stream of a power plant. One of the
issues in this process is foaming which should be known in order to select a suitable amine for
design.
Objectives: In this work, all possible types of amines used for CO2 capture, namely, alkanolamines,
sterically hindered alkanolamines, multi-alkylamines and cyclic amines, were investigated to elucidate
their chemical structure–foaming relationships.
Methods: Foam volume produced by each type of 2M amine solution with its equilibrium CO2
loading was measured at 40°C using 94 mL/min of N2 flow.
Results: Amines with a higher number or a longer chain of the alkyl group exhibited higher foam
volume because of alkyl group’s ability to decrease the surface tension while increasing the viscosity
of the solution. An increase in the number of hydroxyl or amino groups in the amine led to the
reduction of foam formation due to the increase in surface tension and a decrease in viscosity of the
solution. The predictive foam models for non-cyclic and cyclic-amines developed based on the
structural variations, surface tension and viscosity of 29 amines predicted the foam volume very
well with average absolute deviations (AAD) of 12.7 and 0.001%, respectively. The model accurately
predicted the foam volume of BDEA, which was not used in model development with 13.3
%AD.
Conclusion: This foam model is, therefore, indispensable in selecting a suitable amine for an
amine-based CO2 capture plant design and operation.