A Novel CO₂ Phase Change Absorbent: MEA/1-Propanol/H₂O

Abstract

Due to the high energy consumption in CO 2 capture by amine absorbents, CO 2 phase change absorbent, CPCA, has attracted a great attention in research institutes recently. Two phases are formed after CO 2 absorption with CPCA as the absorbent, and only the CO 2 -rich phase goes to the stripper, which could potentially reduce the energy consumption. In this work, the CPCAs composed of MEA/1-propanol/H 2 O were developed based on the principles of aqueous two-phase systems. The effects of temperature, amine concentration, and total CO 2 loading on the phase separation of CPCAs were studied. CO 2 loading and 1-propanol distributions in two phases under different experimental conditions were measured. The results indicated that the total CO 2 loading is the key factor affecting the distribution of components in two phases. Moreover, in comparison to traditional 30 wt % MEA, the initial absorption rates of all CPCAs were higher than that of MEA, and its maximum value was 5 times higher. The cyclic capacity of the CPCA with 30% MEA + 30% 1-propanol + 40% H 2 O was 1.70 mol/kg, which was 52% increased comparing to traditional 30 wt % MEA.