The process of removing dilute CO 2 from air by using the mixtures of K 2CO 3 and piperazine (PZ) was conducted in a random packed tower at 25 ℃.The results showed that PZ increased the absorption rate of CO 2 into aqueous K 2CO 3 much more effectively than MEA or DEA. The volumetric overall mass transfer coefficient (K Ga) of dilute CO 2 absorption into K 2CO 3/PZ was measured.The K Ga value was evaluated over the ranges of main operating variables: the concentration of CO 2 in inlet gas, gas flow rate, liquid loading, CO 2 loading in liquid phase,and the concentrations of K 2CO 3 and PZ. The test showed that K Ga could be remarkably improved by increasing liquid loading and the concentration of PZ, and decreasing the concentration of CO 2 in inlet gas, as well as the gas flow rate and CO 2 loading in liquid phase.
