Solubility of CO₂ in Aqueous Piperazine and its Modeling using the Kent‐Eisenberg Approach

Abstract

A systematic investigation of the equilibrium solubility of CO 2 in aqueous piperazine solutions was conducted in a doublejacketed stirred cell reactor. The solubilities of CO 2 in the solution were measured at 20, 30, 40, and 50 C with CO 2 partial pressures ranging from 0.4±95 kPa. Generally the aqueous piperazine solution exhibits the same characteristics as conventional alkanolamines. Increasing the CO 2 partial pressure increases the gas loading, however increasing the temperature or concentration decreases the CO 2 loading. The values of the CO 2 loading obtained confirm that the piperazine forms stable carbamates. The equilibrium solubility data were analyzed using a Kent-Eisenberg approach. Representation of the model is generally in good agreement with that of the experimental data, especially at high temperature.

Dynamic simulation of MEA absorption process for CO2 capture from power plants

“…The predicted solubility of CO 2 in amine solutions calculated from equilibrium model was in good agreement with the experimental data. Aroua and Salleh (2004) used the KentEisenberg approach to develop the equilibrium constant for CO 2 -H 2 O-PZ system. Three of the equilibrium constants were adjusted to fit the solubility of CO 2 in aqueous piperazine (PZ) at various pressures and temperature with experimental data.…”

Kinetics of absorption of carbon dioxide in aqueous piperazine solutions

“…the literature survey on the kinetics between CO 2 and various alkanolamines by Versteeg et al (1996)-there are only few studies dealing with single aqueous piperazine solutions. Carbon dioxide solubility data have been reported by Aroua and Mohd Salleh (2004), Bishnoi and Rochelle (2000), Derks et al (2005a) and Pérez-Salado Kamps et al (2003), but only two studies on the absorption rate of CO 2 into aqueous piperazine solutions-that can be used to extract kinetic rate data-have been published in literature (Bishnoi and Rochelle, 2000;Sun et al, 2005). This might seem logical due to the fact that, in industry, piperazine is only used in combination with other (alkanol)amines rather than as a stand-alone solvent, but information on the kinetics of the individual components of a solvent with CO 2 is essential for a better understanding of the mechanism and working principle of the absorption process of CO 2 in blends of alkanolamine solutions.…”

Kinetics and modeling of carbon dioxide absorption into aqueous solutions of piperazine

“…But, precise information on the reaction rate constants as well as detail knowledge of the reaction mechanism of the PZ-CO 2 reaction are essential for the process design and simulation of CO 2 absorption in PZ activated aqueous alkanolamine solvents. Although several investigations on the thermodynamic and physicochemical properties of CO 2 -PZ and CO 2 -PZ-activated alkanolamines have been discussed at length in the open literature (Aroua and Mohd Salleh, 2004;Rochelle, 2000, 2002a,b;Derks et al, 2005Derks et al, , 2006Ermatchkov et al, 2003;Liu et al, 1999;Pérez-Salado Kamps et al, 2003;Seo and Hong, 2000;Sun et al, 2005;Xu et al, 1992Xu et al, , 1998Zhang et al, 2001Zhang et al, , 2003, studies on the kinetics of CO 2 -PZ are limited. Furthermore, the agreement between the limited kinetic data, that are available, cannot, in general, be considered satisfactory.…”