Chemical Absorption of Carbon Dioxide into Aqueous Piperazine Solutions Using a Stirred Reactor

In this work, the absorption of CO۲ using aqueous piperazine (PZ) solution have been investigated both experimentally and theoretically. The absorption experiments were carried out in a stirred batch contactor with two flat blades. The experimental data are obtained over the temperature range of ۲۹۸–۳۳۸ K and for the PZ concentration, CO۲ partial pressure, and the stirrer speed in the range of ۰.۵–۱.۵ kmol/m۳, ۲.۵-۷.۵ bar, and ۰-۳۰۰ rpm, respectively. The influences of each variable upon the absorption flux, removal efficiency, and loading of CO۲ have been investigated. In addition, a model based on chemical equilibrium in the liquid phase is employed to evaluate the concentration of chemical species in the liquid phase. Evidence suggests that CO۲ absorption flux, removal efficiency, and the loading increase with decreasing the temperature and increasing the stirrer speed. When PZ concentration is increased, the absorption flux and removal efficiency increase and CO۲ loading reduce. Also by increasing PZ concentration from ۰.۵ to ۱.۵ M at a temperature of ۳۸۸ K, absorption efficiency is increased from ۷۰ % to ۹۵ %. CO۲ absorption flux was decreased from about ۰.۰۱۷۵ to ۰.۰۱ mol/m۲ s when CO۲ loading was increased from ۰.۳۲ to ۰.۵۱.

کلیدواژه ها:

Chemical absorption ، Carbon dioxide ، Piperazine solution ، Stirred reactor