| 초록 |
MgO is well known as an intermediate-temperature CO2 absorbent because its carbonate decomposition temperature range is lower than other alkaline metal oxide. Pure MgO absorbs CO2 very slowly with poor absorption capacity. NaNO3 is used as a promoter in order to enhance CO2 absorption capacity and kinetic of MgO dramatically. But the NaNO3-MgO absorbent has several problems for CO2 absorption. The absorbent has a long induction period of about 30 min and the kinetics of CO2 absorption is not fast enough. In attempts find additives that overcome the deficiency of NaNO3 and to achieve better performance in CO2 absorption with NaNO3-MgO absorbent, we found that alkali metal nitrite salts could function as a co-promoter with NaNO3. NaNO3-MgO absorbent showed high performance for CO2 absorption with alkali metal nitrite addition and the absorption kinetics of MgO is greatly increased even when the nitrite content is as low as 10 mol%. Alkali metal nitrites in the molten state have higher concentration of oxide ions (O2-) than do NaNO3. This property can allow fast generation of carbonate and enable fast growth of MgCO3. Also, we find another mechanism of this absorbent that alkali metal nitrites make double carbonate with MgO. Details of the study will be reported on the poster. |
