Kinetic effect and absorption performance of piperazine activator into aqueous solutions of 2-amino-2-methyl-1-propanol through post-combustion CO2 capture

The current study investigates the absorption kinetics of carbon dioxide (CO2) released from power plant exhaust using activated mixture of 2-amino-2-methyl-1-propanol (AMP) upgraded by piperazine (PZ). An absorption experiment of (AMP+PZ+H2O) was conducted in a wetted wall column absorber with a temperature variation of 298–313 K and CO2 partial pressure of 5–15 kPa. PZ is considered to be a rate promoter by adjustable mass proportion varying from 2 to 10 wt%, while the concentration of entire amine solution remained constant at 30 wt%. Based on the Zwitterions mechanism, an overall reaction pattern of (AMP+PZ+H2O) with CO2 was designed. Considering pseudofirst order reaction criteria, the kinetic rate factors and the overall second order rate constants were calculated. The overall rate constant (kOV) experienced a significant enhancement with a small addition of PZ into aqueous AMP solution. The observed second-order rate constants (k2, PZ) in this experimental study were 60,403, 81,925, 98,591 and 116,521 m3·kmol−1·s−1 at 298, 303, 308 and 313 K correspondingly. The experimental specific rate of absorption into (AMP+PZ+H2O) in connection with the model anticipated rate was determined with deviation of around 4.86% average absolute deviation (AAD).