Abstract
The solubility of CO 2 in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) was measured for AHPD mass fractions w = 0.0015,0.005,0.01 and 0.025 at 283.15, 298.15 and 313.15 K and for CO 2 partial pressures within 2–75 kPa. These ranges were compatible with aqueous solutions in use in a CO 2 capture process using human carbonic anhydrase metalloenzyme. The influence of carbonic anhydrase on the solubility of CO 2 in AHPD solution with w = 0.025 at 283.15, 298.15 and 313.15 K was also studied for CO 2 partial pressures below 9 kPa. The modified Kent–Eisenberg model was used to correlate the equilibrium solubility of CO 2 in aqueous AHPD solutions and to determine the deprotonation and carbamate stability constants for AHPD solutions. These equilibrium constants were correlated with temperature, amine concentration and CO 2 loading. To estimate the physical solubility of CO 2 in aqueous AHPD solutions, the solubility of N 2O in aqueous AHPD solutions was also measured for AHPD mass fractions w = 0.0015,0.005,0.01,0.025 and 0.10 at 283.15, 298.15 and 313.15 K. It was found that the enzyme did not influence the solubility of CO 2 in these solutions as the enzyme's function is to catalyze the hydration of CO 2 without affecting the CO 2 thermodynamic equilibrium.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have