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

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.