Towards water-insensitive CO2-binding organic liquids for CO2 absorption: Effect of amines as promoter

摘要: Abstract CO2-binding organic liquids (CO2-BOLs) or reversible ionic (RILs), are non-aqueous CO2-triggered switchable polarity solvents which can be used for energy efficient CO2 capture. In this study, the novel three-component CO2-BOLs introduced. They comprised of 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) as an superbase and alkanol in conjunction with amine a promoter. Screening experiments were performed to find best combination CO2-BOL components based on loading absorption rate. The variables were: type alcohol (methanol, n-butanol, sec-butanol, tert-butanol 1-hexanol) (EEA, MEA, AMP, DEA, AEEA, PZ, TETA DETA) using DBU superbase. Statistical mixture design approach Minitab 18 software was implemented experiments, modeling optimization at fixed temperature 35 °C initial pressure 25 bar. It found that DBU/MeOH/MEA system molar ratio 0.3/0.17/0.53 has maximum equilibrium (αeq) uptake within 30 min (αR) 0.444 0.267 mol CO2/mol solvent, respectively. Amine additives promoted efficiency inhibited formation solid precipitates (bicarbonate salt) presence water impurity. Characterization species explaining water-inhibitory effect MEA obtained from FTIR, 1H NMR 13C spectroscopic analysis. Equilibrium solubility data DBU/MeOH (1/2) (0.3/0.6/0.1) also temperatures 308.2 318.2 K range 0–33 bar. results present study effectively utilize wet conditions higher lower regeneration energy.