title: Kinetics and mechanism of direct reaction between CO2 and Ca(OH)2 in micro fluidized bed.
abstract: Even at present it is still difficult to characterize the reaction between CO2 and Ca(OH)2 at high temperature and atmospheric pressure using traditional instruments such as thermogravimetric analyzer and differential scanning calorimeter. This study was devoted to characterizing such a reaction in a newly developed micro fluidized bed reaction analyzer (MFBRA) under isothermal conditions in the temperature range of 773-1023 K. The results indicated that the MFBRA has not only a good adaptability for characterizing the above-mentioned reaction but enables as well a new insight into the mechanism of the reaction. An obvious time delay was identified for the release of the formed steam (H2O) in comparison with the onset of its CO2 absorption, which might be attributed to the formation of an unstable intermediate product Ca(HCO3)2 in the reaction process between CO2 and Ca(OH)2. The activation energy for forming Ca(HCO3)2 was found to be about 40 kJ/mol, which is much lower than that of the reaction between CO2 and CaO.
authors.affiliation: State Key Laboratory of Multi-phase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100080, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
authors.forename: Xi
authors.initials: X
authors.lastname: Zeng
authors.forename: Guangyi
authors.initials: G
authors.lastname: Zhang
authors.forename: Juwei
authors.initials: J
authors.lastname: Zhang
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Guangwen
authors.initials: G
authors.lastname: Xu
mesh_terms: D000327:Adsorption; D002126:Calcium Hydroxide / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D057965:Carbon Sequestration; D007700:Kinetics
chemical_list: D002245:Carbon Dioxide; D002126:Calcium Hydroxide