2-(Methylamino)ethanol for CO₂ Absorption in a Bubble Reactor

Abstract

This paper deals with the study of carbon dioxide capture using 2-(methylamino)ethanol (MAE) aqueous solutions. The reaction was studied in a bubble column reactor (BCR), and the most important aspects of the process, such as the hydrodynamic behavior (bubble size distribution, gas holdup, and interfacial area) and absorption phenomena (load of carbon dioxide and mass-transfer coefficient on the liquid phase), were discussed. The interfacial area was determined using a photographic method. Furthermore, the reaction mechanism was determined using nuclear magnetic resonance ( 1 H and 13 C NMR), thereby the species in the medium were controlled throughout time. These results agreed with carbon dioxide loading values, observing the formation of carbamate at the first part of the experiments and bicarbonate at high carbon dioxide loadings. The carbamate hydrolysis is the bicarbonate production pathway. This wide work has enabled us to perform a global analysis of process and to understand how MAE absorbs the gas phase. MAE aqueous solutions show an attractive behavior with a high carbon dioxide loading and high reaction rate. This information could be used in the near future to select the best conditions to capture carbon dioxide and to improve amine regeneration processes.

Density, Viscosity, and N2O Solubility of Aqueous 2-(Methylamino)ethanol Solution

“…2-(Methylamino)­ethanol (MAE), a secondary amine, has already been proven to be a potential absorbent for CO 2 capture by some researchers. , MAE combines the characteristics of primary and tertiary amines of a high reaction rate with CO 2 and high CO 2 capture capacity, respectively. , Mimura et al studied the reaction kinetics between CO 2 and sterically hindered secondary alkanolamines, such as MAE, ethylaminoethanol (EAE), and butylamino ethanolamine (BAE), the results showed that MAE presents a higher reaction rate with CO 2 than the primary alkanolamine monoethanolamine (MEA) and the secondary alkanolamines EAE and BAE. Folgueira et al have studied the hydrodynamic behavior and the mass-transfer performance of CO 2 with aqueous MAE solution in a bubble column reactor (BCR), as well as the reaction mechanism using analysis by NMR technology. The results showed that the carbamate and bicarbonate are the main products at low and high CO 2 loadings, respectively.…”

Experimental Investigation of the Effect of Nano Heavy Metal Oxide Particles in Piperazine Solution on CO2 Absorption Using a Stirrer Bubble Column

“…In this method, the ratio of the initial height of liquid in the column and the liquid height after injecting gas is measured. The gas holdup with this method is indicated by the following equation: − …”

Experimental Data and Modeling for Viscosity and Refractive Index of Aqueous Mixtures with 2-(Methylamino)ethanol (MAE) and Aminoethylethanolamine (AEEA)

“…MAE has a higher reaction rate than primary amines, but it shows higher absorption capacity than tertiary amines. Some researchers studied MAE and reported it as a potential solvent for CO 2 absorption in terms of CO 2 loading, heat effect, and reaction kinetics. − AEEA is an unhindered diamine that has one primary amine and one secondary amine group. AEEA can absorb 2 mol of CO 2 and shows high CO 2 cyclic capacity, high values of second-order reaction rate, and lower regeneration energy.…”

“…The objective of this paper is to measure the viscosity and refractive index data of pure MAE, pure AEEA, aqueous MAE, aqueous AEEA with different concentrations (5,10,15,20,25, and 30 wt %), and aqueous blend of MAE and AEEA (25 + 5, 20 + 10, 15 + 15, 10 + 20, and 05 + 25 wt % MAE and AEEA) in the temperature range of 293.15−333.15 K. MAE and AEEA weight ratio was selected based on the literature data. Intervals of 5 wt % were selected randomly to measure experimental data and develop empirical correlation.…”