文摘
The CO2 solubility in N-ethylmonoethanolamine (EMEA) solutions was investigated using the vapor鈥搇iquid equilibrium (VLE) and the absorption鈥揹esorption apparatus. A tertiary amine, N,N-diethylethanolamine (DEEA), was used as a novel solvent, and other nonaqueous solvents, diethylene glycol, triethylene glycol, benzyl alcohol, n-butyl alcohol and polyethylene glycol-200, were used for comparison. The EMEA + DEEA solution displayed a much higher CO2 solubility than other nonaqueous solutions though lower than the EMEA + H2O solution in the VLE experiment. However, the EMEA + DEEA solution exhibited a higher cyclic absorption capacity than EMEA + H2O solution in the cyclic absorption鈥揹esorption experiment. The reaction mechanism of EMEA + DEEA + CO2 was investigated by 13C NMR spectroscopy, which indicated that the nonaqueous solvent of DEEA participated in the chemical absorption of CO2, and thus improved the CO2 solubility. The tertiary amine DEEA used as a nonaqueous solvent shows more excellent performance than alcohols and glycols.