Study of CO2Adsorption Time for Carbonate Species and Linear CO2Formations onto Bimetallic CaO/Fe2O3by Infrared Spectroscopy

Abstract

The CO2adsorption time for carbonate species and linear CO2formation onto bimetallic CaO/Fe2O3was investigated. The total basicity for CaO/Fe2O3was 52.85 cm3g-1 which is located at a medium basic site with maximum CO desorption temperature at 454 °C. The CO2adsorption was conducted by using a fluidized bed reactor at 4, 12, 24 and 36 h. The element distribution on the adsorbent showed carbonate formation through an increment of the C element when the CO2adsorption time was longer. At 4 h of CO2adsorption, the adsorbent is capable of generating bicarbonate, monodentate carbonate and bidentate carbonate species. The vibrational modes of the physisorbed linear CO2for CO2absorbed product at the absorption region of 2240-2402 cm-1 was identified after 36 h of CO2adsorption. The absorption bands were assigned according to the adjacent CO2molecule interactions giving formation of the core layer and second layer linear CO2on the CaO/Fe2O3surfaces. The results of the present work show that the addition of CaO on the Fe2O3surfaces enhanced the basic site of the adsorbent which could generate several carbonate species and CO2adsorbed products at ambient condition.