A Comparative Study of the CO2 Absorption in Some Solvent-Free Alkanolamines and in Aqueous Monoethanolamine (MEA).
The neat secondary amines 2-(methylamino)ethanol, 2-(ethylamino)ethanol, 2-(isopropylamino)ethanol, 2-(benzylamino)ethanol and 2-(butylamino)ethanol react with CO2 at 50-60 °C and room pressure yielding liquid carbonated species without their dilution with any additional solvent. These single-component absorbents have the theoretical CO2 capture capacity of 0.50 (mol CO2/mol amine) due to the formation of the corresponding amine carbamates and protonated amines that were identified by the (13)C NMR analysis. These single-component absorbents were used for CO2 capture (15% and 40% v/v in air) in two series of different procedures: (1) batch experiments aimed at investigating the efficiency and the rate of CO2 capture; (2) continuous cycles of absorption-desorption carried out in packed columns with absorption temperatures brought at 50-60 °C and desorption temperatures at 100-120 °C at room pressure. A number of different amines and experimental setups gave CO2 capture efficiency greater than 90%. For comparison purposes, 30 wt % aqueous MEA was used for CO2 capture under the same operational conditions described for the solvent-free amines. The potential advantages of solvent-free alkanolamines over aqueous MEA in the CO2 capture process were discussed.
University of Florence , Department of Chemistry, via della Lastruccia 3, 50019 Sesto Fiorentino, Italy.|ICCOM CNR , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
Francesco
F
Barzagli
ICCOM CNR , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
Fabrizio
F
Mani
ICCOM CNR , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
Maurizio
M
Peruzzini
D000588:Amines / Q000737:chemistry; D002219:Carbamates / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D019856:Ethanolamine / Q000737:chemistry*; D012997:Solvents
D000588:Amines; D002219:Carbamates; D012997:Solvents; D002245:Carbon Dioxide; D019856:Ethanolamine