Absorption of Carbon Dioxide into Aqueous Solutions of 2-Piperidineethanol: Kinetics Analysis

This work presents the kinetics of the reaction of CO2 with aqueous 2-piperidineethanol (2-PE) solutions at 303, 313, and 323 K within the amine concentration range of 0.14-1.13 kmol m(-3) using a wetted-wall column absorber. The reaction was described by zwitterionic mechanism to interpret the kinetic data. A qualitative C-13 NMR analysis has been carried out for 2-PE solution in D2O after reaction with CO2, which has indicated the formation of bicarbonate ion. The reaction order was found to be in between 1.10 and 1.12 with respect to amine for the above-mentioned concentration range. The kinetic rate parameters were calculated and presented at each experimental condition. The second-order rate constants, k(2), were obtained as 696, 1147, and 2047 m(3) kmol(-1) s(-1) at 303, 313, and 323 K, respectively, with an activation energy of 45.2 kJ mol(-1).