Kinetic Expression for the Carbonation Reaction of K2CO3/ZrO2 Sorbent for CO2 Capture

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• 作者：Deuk Ki Lee ; Da Young Min ; Hwimin Seo ; Na Young Kang ; Won Choon Choi ; Yong Ki Park
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：July 3, 2013
• 年：2013
• 卷：52
• 期：26
• 页码：9323-9329
• 全文大小：383K
• 年卷期：v.52,no.26(July 3, 2013)
• ISSN：1520-5045

文摘

For the kinetic study of K₂CO₃/ZrO₂ sorbent in the carbonation reaction to capture CO₂ from the flue gas, reaction experiments were carried out at temperatures between 328 and 343 K for CO₂ gas compositions not exceeding 18% at 1 bar, and a phenomenological kinetic model was proposed to fit the carbonation conversion data obtained. Time-dependent carbonation conversions of the sorbent appeared as sigmoid curves. Sigmoid characteristics of the conversion curve were more pronounced for the sorption reaction at lower temperature and lower gas phase concentration of CO₂. Such conversion behavior of fresh-dried K₂CO₃/ZrO₂ sorbent could be closely described with the reaction rate equation in the form: r = kf(X)y_CO2ⁿ . The reaction rate constant k as a temperature dependent term could be represented by Arrhenius鈥?equation with the negative apparent activation energy of 鈭?7.43 kJ/mol and the pre-exponential factor of 3.83 脳 10^鈥? 1/min. The term f(X) was a function introduced to reflect the carbonation rate change with the fractional carbonation conversion X of the sorbent, and its parameters were determined by correlation equations of the reaction temperature and the gas phase concentration of CO₂. The reaction order n with respect to y_CO2, the gas phase mole fraction of CO₂, was determined to be 0.49. And, the characteristics of K₂CO₃/ZrO₂ sorbent in the carbonation reaction for CO₂ capture was discussed in relation to the kinetics obtained.