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

Due to the high energy consumption in CO2 capture by amine absorbents, CO2 phase change absorbent, CPCA, has attracted a great attention in research institutes recently. Two phases are formed after CO2 absorption with CPCA as the absorbent, and only the CO2-rich phase goes to the stripper, which could potentially reduce the energy consumption. In this work, the CPCAs composed of MEA/1-propanol/H2O were developed based on the principles of aqueous two-phase systems. The effects of temperature, amine concentration, and total CO2 loading on the phase separation of CPCAs were studied. CO2 loading and 1-propanol distributions in two phases under different experimental conditions were measured. The results indicated that the total CO2 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% H2O was 1.70 mol/kg, which was 52% increased comparing to traditional 30 wt % MEA.