Fabrication of Strong Solid Base FeO–MgO for Warm CO2 Capture

A strong solid base, FeO–MgO, is synthesized using magnesium acetate and ferrous acetate in order to meet the requirement of capturing CO 2 in flue gas at a temperature higher than 423 K. After the two salts are ground and carbonized at 823 K, the ferric MgO composite with a surface area exceeding 160 m 2 g −1 is obtained, where ferric oxide species are wrapped by magnesia particles. The influence of ferric salt on the structure and adsorption properties of the strong solid bases is investigated to determine the optimal amount, and the distribution of ferric additive is assessed with X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). With a mass ratio of ferrous oxide of about 3%, the basic sorbent could capture 35 mg g −1 CO 2 at 473 K and the ratio of strong base sites increases to 91%. Both the CO 2 adsorption capacity and the ratio of strong basic sites are higher than those of the other MgO sorbents, which is beneficial for warm CO 2 capture. Additionally, the function of strong basic sites in the ferric MgO sorbent is explored in the instantaneous adsorption of warm CO 2 . The capability in the cycled warm CO 2 adsorption is found to be related to the desorption temperature of CO 2 . Different forms of CO 2 injections are used in adsorption and the influence on the performance of the strong basic sorbent is also studied.