Adsorptive Separation of Acetic Acid from Dilute Aqueous Solutions: Adsorption Kinetic, Isotherms, and Thermodynamic Studies

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• 作者：Huanhuan Zhang ; Yuming Wang ; Peng Bai ; Xianghai Guo ; Xiuxiu Ni
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2016
• 出版时间：January 14, 2016
• 年：2016
• 卷：61
• 期：1
• 页码：213-219
• 全文大小：370K
• ISSN：1520-5134

文摘

ZSM-5 (Zeolite Scony Moblie-5) (SiO₂/Al₂O₃ = 360, 470), NaY, 13X (pellet, powder) and coconut shell activated carbon (YK-AC) are employed for acetic acid separation from dilute aqueous solutions via adsorption. Zeolite 13X exhibits a much higher adsorption capacity than other zeolites and activated carbon. The effects of adsorption time and different initial acetic acid concentrations were studied. At 71.77 g·kg^–1, the initial acetic acid concentration, 13X in pellet exhibited the highest uptake capacity of 354.03 mg·g^–1 at 318 K. Meanwhile, adsorption equilibrium, kinetics, and thermodynamics of an acetic acid aqueous solution on zeolite 13X in pellet were studied in batch experiments. Kinetic models such as pseudo-first-order, pseudo-second-order, and Elovich have been used to describe the adsorption behavior of zeolite 13X in pellet. Pseudo-second-order was found the most suitable for this system. Langmuir and Freundlich isotherm models were applied to experimental data depending on temperature. The Freundlich isotherm fitted the experimental data better than the Langmuir isotherm for adsorption of acetic acid. Using the thermodynamic equilibrium coefficients obtained at different temperatures, the thermodynamic constants (ΔG, ΔH, and ΔS) of adsorption were also calculated, and the results indicated that the adsorption process of acetic acid on zeolite 13X in pellet was spontaneously endothermic.