Applying Modified Chemical Equilibrium Constants for Improving Equilibrium Species Distribution and Vapor鈥揕iquid Equilibrium (VLE) Prediction of Formaldehyde Aqueous Solutions

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• 作者：Guizhen Li ; Yansheng Liu ; Yufeng Hu ; Jun Wang ; Lehuan Wu ; Chunfeng Shi
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2015
• 出版时间：November 4, 2015
• 年：2015
• 卷：54
• 期：43
• 页码：10901-10909
• 全文大小：653K
• ISSN：1520-5045

文摘

This paper presented a revised model for calculating the chemical and vapor鈥搇iquid equilibria (VLE) of the formaldehyde + water system. Chemical equilibrium constants for the formation of poly(oxymethylene) glycols (HO(CH₂O)_iH, MG_i, i > 1) were reviewed, and selected models were modified to reliably predict the species distribution of formaldehyde aqueous solutions and describe the influence of overall formaldehyde concentration. Besides, the UNIFAC equation for the Gibbs excess energy was combined with the chemical reaction equilibria to represent the experimental VLE data in the literature. In addition, some model parameters were redetermined from the corresponding data fits.