Effectof Sarcosinate on the Absorption Kinetics of CO2into AqueousAmmonia Solution.

Promoted aqueous ammonia is a potentialsolvent for CO2separation processes. In this work, weinvestigated the effect of temperature, sarcosinate concentration,and CO2loading on the mass transfer coefficients of CO2absorption in a sarcosinate-promoted aqueous ammonia solutionon a wetted-wall column. We further investigated the kinetics of thereaction between CO2and a blended NH3/sarcosinateabsorbent using stopped-flow spectrophotometric techniques, followingthe pH changes via coupling to pH indicators. Our study revealed thatthe mass transfer coefficient for CO2absorption in a 3M ammonia + 1.5 M sarcosinate blended solution at 288 K is close tothat in 5 M monoethanolamine absorbent at 313 K. We did not observeany synergistic or catalytic effects between NH3and sarcosinatein the blended solution; the mechanism of the reaction of CO2with the NH3/sarcosinate mixture is the simple combinationof the individual reactions of NH3and sarcosinate withCO2. [ABSTRACT FROM AUTHOR]