Research Of Aqueous Ion-exchange Technology To Optimize X-type Zeolites' CO₂ Capture Capacity

In this paper, in order to find out the optimal ion-exchanged process to promote the X-type zeolites' CO₂ capacity, each ion-exchange time and concentration of ion-exchange solution has been researched through conmen characterization and evaluation, such as, ICP, BET, CO₂- DRIFETS, CO₂- IAE, CO₂- TPD.The results showed that the ion-exchanged degree was proved by increasing the ion-exchanged time at the very beginning. However, when the each exchange time was increased over 6 hours, the ion-exchanged process has arrived the exchanged saturation state, due to the ionization equilibrium between Na+ rested in the zeolites' framework and Na+ in the solution.It is significant to choose a optimal concentration standard of exchanged solution, the ion-exchanged degree would be decreased when the solution concentration was over 0.5mol/L, due to the stereospecific blockade effect and the cation density distribution effects. The results showed that 0.5mol/L is the optimal solution concentration fitting for improving X-type zeolites' CO₂ capture capacity.The CO₂ isothermal adsorption evaluation resulted that the optimal each ion- exchanged time is 6 hours while exchange twice, as well as the concentration is 0.5mol/L, the CO₂ adsorption capacity prepared by the above situation is: KX (6.05mol/kg)> NaX (5.02mol/kg)> LiX (4.93mol/kg)。It can be concluded that KX is more basic than the other zeolites with the results have been achieved by CO₂-TPD, CO₂-DRIFTS and CO₂ desorption active energy. Therefore, the CO₂ capture cyclic utilized ratio of KX is lower compared with LiX and NaX: LiX (98.8%)> NaX (93.9%) >LiX (86.7%).