The kinetics of carbon dioxide capture by solutions of piperazine and N-methyl piperazine

In this paper, kinetics and mechanism of the reaction between CO2 and piperazine (PZ) or n-methyl piperazine (NMP) in aqueous and alcoholic solutions were investigated using direct stopped-flow technique under a range of temperatures (278, 288 and 298 K). The results show that the reactions follow a single termolecular reaction mechanism and the reaction rate between CO2 and aqueous PZ (2669((278K)), 11335((288K)), 18042((298K)) m(3)/kmol.s) is significantly higher than that of commonly employed amines, such as monoethanolamine (MEA). Our results strongly suggest that PZ and PZ derivatives can be used as promoters for CO2 capture by sterically hindered amine solutions.