改进的Van der Waals方程推算双组分的吸附平衡

借鉴热力学状态方程在气液平衡中的经验,修改了二维van der Waals状态方程,并在气固吸附平衡中应用。从纯组分的吸附等温线出发,推算气和二氧化碳混和物及二氧化碳和一氧化碳的混和物分别在C_u(I)Y沸石上的吸附平衡。还用另外三个吸附模型的计算和比较。它们是理想吸附溶液模型,Flory—Huggins活度系数方程的吸附空穴溶液模型及二维van der Waals状态方程。结果表明,本文改进的方程推算实验数据的效果比其它模型好,尤其是关于一氧化碳和二氧化碳在C_u(I)Y石上的吸附,络合吸附和物理吸附是同时发生的。

Improved van der Waals Equation for the Prediction of Binary Adsorption Equilibria

By using the experience of the equation of state in gas-liquid equilibria for reference,a modified two-dimensional van der Waals equation was proposed and applied to gas-solid adsorption equilibria.Adsorption equilibrium data of CO-CO2 mixtures and CO2-N2 mixtures on Cu(I)Y zeolite were predicted from single-component adsorption isotherm data.Also,the experimental data were compared with the results calculated according to the other three prediction methods,the ideal adsorbed solution model,the vacancy solution theory of adsorption using Flory-Huggins activity coefficient equation,the two-dimensional van der Waals equation.It showed that the improved van der Waals equation can predict the experimental results better than the other models,especially in the system of adsorption mixed CO and CO2 on Cu(I)Y zeolite,where complex adsorption and physical adsorption occured simultaneously.