Experimental methods of CO2 absorption for kinetic analysis

https://doi.org/10.3390/pr9122140

“In an experimental case, the sample of desired CO₂ absorbent was prepared by dissolving pre-weighed amine solvent into deionized water with a certain amount of CA. The pure CO₂ gas was bubbled into DI-water for a certain period of time to obtain the saturated aqueous solution of CO₂. The k0,amine of CO₂ absorption into the aqueous amine solution with or without CA was obtained by the stopped-flow apparatus. The schematic diagram of the stopped-flow apparatus is shown in Figure 2 and its detailed operational description can be found in our previous work [6,9].”

“Figure 2. Schematic diagram of the experimental device.”

“In a typical experimental operation, equal volumes of fresh CO₂ and amine solutions are pushed into the conductance cell by a gas-driven source. A change in the conductivity signal is observed in the cell since the reaction of CO₂ with aqueous amine forms new ionic products. Then the detected signal tends to stabilize before the absorption reaction is complete and reaches equilibrium. The kinetics constant can be obtained by the fitting curve of the conductivity changing with time at different temperatures as listed in our previous work [10]. Each measurement was repeated at least 7 times to ensure the accuracy of the collected data. The effectiveness of the test set-up has been demonstrated in a good consistent with that of Ali et al. [11,12] in our previous work [13].”