The effect of functional group position of the piperidine derivatives on the CO2 absorption characteristics in the (H2O-Piperidine-CO2) System

Abstract

Absorption characteristics of 2-methylpiperidine (2MPD), 3-methylpiperidine (3MPD) and 4-methylpiperidine (4MPD) absorbents were studied by a vapor-liquid equilibrium (VLE) apparatus and a differential reaction calorimeter (DRC). Using a VLE apparatus, the CO2 loading capacity of each absorbent was estimated. After reaching the absorption equilibrium, nuclear magnetic resonancespectroscopy (NMR) had been conducted to characterize the species distribution of the (H2O-piperidine-CO2) system. Using a DRC, the reaction of heat was confirmed in accordance with the absorption capacity. The unique characteristics of 2MPD, 3MPD and 4MPD absorbents appeared by the position of methyl group. The 2MPD possessing the methyl group at the ortho position showed its hindrance effect during the absorption process; however, piperidine derivatives possessing the meta position and para position did not show its characteristics in H2O-piperidine-CO2 system.