Development of a thermodynamic model to predict reduced surface excess adsorption isotherms in liquid phase adsorption based on a new method for characterisation of surface groups

基于表面基团表征的新方法，开发热力学模型来预测液相吸附中减少的表面过量吸附等温线

基本信息

批准号：
324528022
负责人：
Professor Dr.-Ing. Dieter Bathen
金额：
--
依托单位：
Lehrstuhl für Thermische Verfahrenstechnik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/324528022?language=en
关键词：
Development thermodynamic model predict reduced

项目摘要

The aim of this project is the prediction of reduced surface excess adsorption isotherms with a validated thermodynamic model. The characterization of the chemical surface groups on the surface of the activated carbons forms the basis for those predictions. In a first step, activated carbons with different surface functionalities will be characterized by different methods. Additionally some of these carbons will be modified by oxidizing chemicals. Then excess isotherms of binary mixtures of probe molecules (toluene, methylcyclohexane and acetone) will be measured on a selection of activated carbons. With the help of these isotherms, the competition of the probe molecules for adsorption to the surface groups can be assessed. Preliminary studies showed that such experiments can qualitatively describe the polar, nonpolar and aromatic character of the activated carbon s surface. A detailed interpretation of the reduced surface excess as well as the size of the region of preferred adsorption of the probe molecules is expected to yield further insights. Additional substance properties like the number of PI-electrons, dipole moments, polarizabilities and Hansen parameters will be used to further the qualitative discussion. Also, a quantitative description of the surface groups is intended. This will lead to a thermodynamic modeling of excess isotherms on activated carbons. A group contribution model will be developed, based on the distribution of surface groups. This model is supposed to take into account functional groups of the adsorptives as well as the activated carbon surface. The model can then be fitted to the experimental excess isotherms. Besides fitting the model to the experimental data, the research is supposed to progress in the direction of a predictive model, opening the possibility of predicting excess isotherms of not experimentally examined probe molecules.

该项目的目的是通过经过验证的热力学模型预测减少的表面过量吸附等温线。活性炭表面化学表面基团的表征构成了这些预测的基础。第一步，具有不同表面功能的活性炭将通过不同的方法进行表征。此外，其中一些碳将通过氧化化学物质进行改性。然后，将在选定的活性炭上测量探针分子二元混合物（甲苯、甲基环己烷和丙酮）的过量等温线。借助这些等温线，可以评估探针分子对表面基团吸附的竞争。初步研究表明，此类实验可以定性描述活性炭表面的极性、非极性和芳香特征。对减少的表面过剩以及探针分子优选吸附区域的大小的详细解释预计将产生进一步的见解。其他物质特性，如 PI 电子数、偶极矩、极化率和汉森参数将用于进一步定性讨论。此外，还旨在对表面基团进行定量描述。这将导致活性炭上过量等温线的热力学模型。将根据表面基团的分布开发基团贡献模型。该模型应该考虑吸附剂的官能团以及活性炭表面。然后可以将该模型拟合到实验的过量等温线。除了将模型与实验数据进行拟合之外，该研究还应该朝着预测模型的方向发展，从而开启预测未经实验检查的探针分子的过量等温线的可能性。