文摘
In this present work, the absorption kinetics of CO2 into aqueous 1-(2-Hydroxyethyl) piperidine (1-(2-HE)PP) solutions with respect to observed pseudo-first-order rate constant (k0) and second order reaction rate constant (k2), were determined using the stopped-flow apparatus within the 1-(2-HE)PP concentration range of 0.20–1.00 kmol/m3 and a temperature range of 293–313 K. The values of k0 were then represented using the correlation based on the base-catalyzed hydration mechanism. The results show that the correlated values of k0 matched well with the experimental values with an acceptable AAD of 8.3%, which indicates that the base-catalyzed hydration mechanism can satisfactorily describe the experimental kinetics data of the1-(2-HE)PP reaction with CO2. In order to comprehensively understand the kinetics, the ion speciation plots of 1-(2-HE)PP-H2O–CO2 system were developed using the pH method. In addition, the Br?nsted plots between k2 (obtained from stopped-flow apparatus) and pKa (obtained from experimental measurement) for 1-(2-HE)PP were developed, and then used to predict k2 using the values of pKa.