Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under va...Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under various COand water vapor concentrations and the accompanying structural changes of NaCOwere demonstrated by X-ray diffraction（XRD）. Morphological variations were observed during the reaction of COcapture through scanning electron microscope（SEM）. Structural changes and morphological variations, which occurred during the course of the reaction, were then connected to the kinetic and exothermic properties of the COcapture process from the XRD and SEM measurements. The results showed that the bicarbonate formation of NaCOhas two different pathways.For higher COand HO concentrations, the bicarbonate formation proceeded effectively. However, for lower COand HO concentrations, the reactions were more complicated. The formation of NaCO·HO from NaCOas the first step, followed by the subsequent formation of NaH（CO）, and then the bicarbonate formation proceeds. To understand such fundamental properties in COcapture of NaCOis very important for utilization of NaCOas a sorbent for COcapture.展开更多
基金supported by a Grant-in-Aid for Scientific Research(C)(Grant No.15K05583)from the Japan Society for the Promotion of Science
文摘Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under various COand water vapor concentrations and the accompanying structural changes of NaCOwere demonstrated by X-ray diffraction（XRD）. Morphological variations were observed during the reaction of COcapture through scanning electron microscope（SEM）. Structural changes and morphological variations, which occurred during the course of the reaction, were then connected to the kinetic and exothermic properties of the COcapture process from the XRD and SEM measurements. The results showed that the bicarbonate formation of NaCOhas two different pathways.For higher COand HO concentrations, the bicarbonate formation proceeded effectively. However, for lower COand HO concentrations, the reactions were more complicated. The formation of NaCO·HO from NaCOas the first step, followed by the subsequent formation of NaH（CO）, and then the bicarbonate formation proceeds. To understand such fundamental properties in COcapture of NaCOis very important for utilization of NaCOas a sorbent for COcapture.
