CO2 Sorption Properties over Ordered Mesoporous Carbon CMK-3 in the Presence of MDEA Solution

By using the hard template method, CMK-3 can be synthesized. The large Brunauer Emmett Teller surface area and total pore volume of CMK-3 were 1134 m(2)/g and 1.128 cm(3)/g, respectively. The sorption isotherms of CO, on CMK-3 in the presence of MDEA solutions were measured. It was shown that the CO, sorption capacity at low pressure was enhanced by chemical absorption and was higher than that of CMK-3 in the presence of water. However, the formation of the CO2 hydrate was inhibited. When the concentration of the MDEA solution exceeded 1.4 mol/L, no hydrate was formed, and the sorption capacity was only 13 mmol/g at approximately 3.5 MPa, which was significantly lower than that of the water under the same pressure. The inhibitory effect of MDEA on hydrate formation was reduced at a low solution concentration. When the concentration of the MDEA solution was 0.52 mol/L, the gas hydrate was formed at approximately 1.88 MPa; the sorption capacity was approximately 28.7 mmol/g at 3.58 MPa, which was close to the highest CO2 sorption capacity of CMK-3 in pure water. The enthalpy change was -74.82 kJ/mol, which was higher than the enthalpy change of CMK-3 in pure water.