| The establishment of sorption enhanced water gas shift (SEWGS) reaction was used to control the hydrogen industrial emission of CO2 and the reaction temperature was 200—400℃. Finding a suitable CO2 sorbents for both the system temperature and regenerable high capacity were desirable for SEWGS and became a hot topic in the field of capture CO2. Magnesium oxide was regarded as one of the most potential CO2 solid adsorbent because of its effective CO2 capture capacity within the range 200-400 ℃ and the capacity can reach 24.8 mmol g-1 in theory. But in practicle applications, MgO had a moderate CO2 adsorption capacity(<1mmol g-1). In order to improve the adsorption capacity, several selectively and reversibly MgO-based materials with significantly better CO2 adsorption performance need to fabricate.In this paper, the alkali metal nitrates modified MgO material was synthesized to enhance the CO2 adsorption. By carefully examining the effects of loading amount and the proportion of alkali metal nitrates, we found that when the loading amount was fixed at 10 mol%, and the proportion of LiNO3, NaNO3, KNO3 fixed at 3:6:1, the material had a high CO2 adsorption. This paper also explored the impact of adsorption conditions and the high temperature CO2 adsorption can reach as high as 16.75 mmol g-1 when calcination temperature fixed at 450℃ and adsorption temperature fixed at 300℃ and the adsorption value is the highest value reported so far.The cycling performance of sorbents was also tested by temperature swing adsorption and pressure swing adsorption and in order to investigate the structural change, X-ray diffraction, scanning electron microscope, transmission electron microscope, BET specific surface area test, and fourier transform infrared spectrometer were investigated. Through test the material structure under different temperature, we found that molten alkali metals can promote MgO adsorb CO2. |
PDF Full Text Request