Improved solvent formulations for efficient CO₂ absorption and low-temperature desorption.
This experimental study describes efficient CO₂ capture by 2-amino-2-methyl-1-propanol (AMP)/piperazine (PZ) in ethylene glycol monoethyl ether (EGMEE, 2-ethoxyethanol) containing approximately 15 wt % of water. In these experiments, the solvent is continuously circulated between the absorber (packed-bed reactor at 30, 40, or 45 °C) and the desorber (at 80, 85, or 90 °C). The CO₂ -solvent reaction equilibria have been investigated by using ¹³C NMR spectroscopy, which provides confirmatory evidence that the formation of mono- and biscarbamate derivatives of PZ accounts for most of the CO₂ absorbed by the AMP/PZ/EGMEE/H₂O blend. The solid-state structures of AMP carbamate and of the carbonate salt of protonated AMP have been determined by using XRD. Both AMPCO₂(-) and CO(3)(2-) species completely convert to the monoalkyl carbonates on dissolving the respective salts in methanol, ethanol, or ethylene glycol.
ICCOM CNR via Madonna del Piano, 10-50019 Sesto Fiorentino, Firenze, Italy.
Francesco
F
Barzagli
Massimo
M
Di Vaira
Fabrizio
F
Mani
Maurizio
M
Peruzzini
D000042:Absorption; D000588:Amines / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry* / Q000302:isolation & purification; D019855:Ethylene Glycol / Q000737:chemistry; D007700:Kinetics; D000077489:Piperazine; D010879:Piperazines / Q000737:chemistry; D011412:Propanolamines / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013696:Temperature
D000588:Amines; D010879:Piperazines; D011412:Propanolamines; D012997:Solvents; D002245:Carbon Dioxide; D000077489:Piperazine; D019855:Ethylene Glycol; C006551:2-amino-2-methyl-1-propanol