Zwitterionic "Solutions" for Reversible CO2 Capture.
ChemSusChem
; 16(23): e202300971, 2023 Dec 07.
Article
em En
| MEDLINE
| ID: mdl-37681317
ABSTRACT
The zwitterions resulting from the covalent attachment of 3- or 4-hydroxy benzene to the 1,3-dimethylimidazolium cation represent basic compounds (pKa of 8.68 and 8.99 in aqueous solutions, respectively) that chemisorb in aqueous solutions 0.58â
mol/mol of carbon dioxide at 1.3â
bar (absolute) and 40 °C. Equimolar amounts of chemisorbed CO2 in these solutions are obtained at 10â
bar and 40 °C. Chemisorption takes place through the formation of bicarbonate in the aqueous solution using imidazolium-containing phenolate. CO2 is liberated by simple pressure relief and heating, regenerating the base. The enthalpy of absorption was estimated to be -38â
kJ/mol, which is about 30 % lower than the enthalpy of industrially employed aqueous solutions of MDEA (estimated at -53â
kJ/mol using the same experimental apparatus). The physisorption of CO2 becomes relevant at higher pressures (>10â
bar) in these aqueous solutions. Combined physio- and chemisorption of up to 1.3â
mol/mol at 40â
bar and 40 °C can be attained with these aqueous zwitterionic solutions that are thermally stable and can be recycled at least 20 times.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
ChemSusChem
Assunto da revista:
QUIMICA
/
TOXICOLOGIA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Brasil