Douven Sigrid, Paez Carlos A, Gommes Cedric J
Department of Chemical Engineering, University of Liège, B6A, Allée du 6 août 3, B-4000 Liège, Belgium.
Department of Chemical Engineering, University of Liège, B6A, Allée du 6 août 3, B-4000 Liège, Belgium.
J Colloid Interface Sci. 2015 Jun 15;448:437-50. doi: 10.1016/j.jcis.2015.02.053. Epub 2015 Feb 27.
Several hundred papers are published yearly reporting liquid-phase adsorption kinetics data. In general the data is analyzed using a variety of standard models such as the pseudo first- and second-order models and the Intraparticle-Diffusion model. The validity of these models is often assessed empirically via their ability to fit the data, independently of their physicochemical soundness. The aim of the present paper is to rationalize the analysis of liquid-phase adsorption kinetics data, and to investigate experimental factors that influence the adsorption kinetics, in addition to the characteristics of the adsorbent material itself. For that purpose we use a simple Langmuir adsorption-diffusion model, which enables us to identify three dimensionless numbers that characterize the working regime of any batch adsorption experiment: an adsorption Thiele modulus, a saturation modulus, and a loading modulus. The standard models are found to be particular cases of the general adsorption-diffusion model for specific values of the dimensionless numbers. This provides sound physicochemical criteria for the validity of the models. Based on our modeling, we also propose a general yet simple data analysis procedure to practically estimate the diffusion coefficient in adsorbent pellets starting from adsorption half-times.
每年都会发表数百篇报告液相吸附动力学数据的论文。一般来说，这些数据会使用各种标准模型进行分析，如伪一级和二级模型以及颗粒内扩散模型。这些模型的有效性通常通过它们拟合数据的能力进行实证评估，而不考虑其物理化学合理性。本文的目的是使液相吸附动力学数据的分析合理化，并研究除吸附剂材料本身特性外影响吸附动力学的实验因素。为此，我们使用一个简单的朗缪尔吸附 - 扩散模型，该模型使我们能够确定三个无量纲数，它们表征任何间歇吸附实验的工作状态：吸附西勒模数、饱和模数和负载模数。发现标准模型是一般吸附 - 扩散模型在无量纲数特定值时的特殊情况。这为模型的有效性提供了合理的物理化学标准。基于我们的建模，我们还提出了一个通用且简单的数据分析程序，以便从吸附半衰期实际估计吸附剂颗粒中的扩散系数。
