(598aa) Kinetic Studies of Calcium Oxide Carbonation At Different CO2 Environments

Zhang Lele,  Duan Yonghua, Li Hui, Min Yong

1. Xi'an University of Architecture and Technology; Xi'an Shaanxi 710055; China;

Abstract:

The paper investigates the kinetics analysis pure CaO carbonation by utilizing thermogravimetric analyzer (TGA) at different heating rate (2.5 K/min, 7.5 K/min, 15 K/min, 20 K/min, 30 K/min) and different concentration of CO₂ atmosphere (0%, 30%, 50%, 80%, 100%).  Double extrapolation method (Flynn-Wall-Ozawa) was used to obtain the apparent activation energy  when conversion rate  tends zero;  Then use Coats-Redfern integral equation, push the heating rate to zero to get the activation energy of the sample in the thermal equilibrium state; Finally by comparing E-Bata  with E-Alpha , confirmed the most probable function of the CaO carbonation in different atmosphere , thus get the dynamic reaction model , exponential factor A and reaction rate constant k, and the changing rule of the activation energy E-alpha of CaO carbonation with different atmosphere

Key words: CaO carbonation; thermal analysis kinetics; double extrapolation method；the apparent activation energy E; dynamic reaction model.