Selective CO2Capture from Flue Gas Using Metal–Organic Frameworks―A Fixed Bed Study

It is important to capture carbon dioxide from flue gas, which is considered one of to be the main cause of global warming. CO2/N2separation by novel adsorbents is a promising method for reducing CO2emission. Meanwhile, water effects on CO2adsorption and CO2/N2selectivity is critical to enable utilization of the adsorbents in practical applications. In this paper, Ni/DOBDC (Ni-MOF-74 or CPO-27-Ni) was synthesized through a solvothermal reaction, and the pellet sample was used in a fixed-bed CO2/N2breakthrough study with and without H2O. The Ni/DOBDC pellet has a high CO2capacity of 3.74 mol/kg at 0.15 bar and a high CO2/N2selectivity of 38, which is much higher than those of reported metal–organic frameworks and zeolites under dry conditions. Trace amounts of water can affect CO2adsorption capacity as well as CO2/N2selectivity for the Ni/DOBDC. However, Ni/DOBDC can retain a significant CO2capacity of 2.2 mol/kg and a CO2/N2selectivity of 22 at 0.15 bar CO2with 3% RH water. These results indicate a promising future for use of the Ni/DOBDC in capturing CO2from flue gas.