Mayer Fabian, Rehner Philipp, Seiler Jan, Schilling Johannes, Gross Joachim, Bardow André
Energy & Process Systems Engineering, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland.
Institute of Thermodynamics & Thermal Process Engineering, University of Stuttgart, 70569 Stuttgart, Germany.
Ind Eng Chem Res. 2024 Aug 1;63(32):14137-14147. doi: 10.1021/acs.iecr.4c01395. eCollection 2024 Aug 14.
Adsorption is at the heart of many processes from gas separation to cooling. The design of adsorption-based processes requires equilibrium adsorption properties. However, data for adsorption equilibria are limited, and therefore, a model is desirable that uses as little data as possible for its parametrization, while allowing for data interpolation or even extrapolation. This work presents a physics-based model for adsorption isotherms and other equilibrium adsorption properties. The model is based on one-dimensional classical density functional theory (1D-DFT) and the perturbed-chain statistical associating fluid theory (PC-SAFT). The physical processes inside the pores are considered in a thermodynamically consistent approach that is computationally efficient. Once parametrized with a single isotherm, the model is able to extrapolate to other temperatures and outperforms the extrapolation capabilities of state-of-the-art models, such as the empirical isotherm models from Langmuir or Toth. Furthermore, standard combining rules can be used to transfer parameters adjusted to an adsorbent/fluid pair to other fluids. These features are demonstrated for the adsorption of N, CH, and CO in metal-organic frameworks. Thereby, the presented model can calculate temperature-dependent isotherms for various fluids by using data limited to a single isotherm as input.
吸附是从气体分离到冷却等许多过程的核心。基于吸附的过程设计需要平衡吸附特性。然而，吸附平衡的数据有限，因此，需要一个模型，该模型在参数化时使用尽可能少的数据，同时允许数据插值甚至外推。这项工作提出了一种基于物理的吸附等温线和其他平衡吸附特性模型。该模型基于一维经典密度泛函理论（1D-DFT）和扰动链统计缔合流体理论（PC-SAFT）。以热力学一致且计算高效的方式考虑了孔内的物理过程。一旦用单个等温线进行参数化，该模型就能外推到其他温度，并且其外推能力优于诸如朗缪尔或托特的经验等温线模型等现有模型。此外，标准组合规则可用于将针对吸附剂/流体对调整的参数转移到其他流体。这些特性在金属有机框架中对N₂、CH₄和CO₂的吸附中得到了证明。因此，所提出的模型可以通过使用限于单个等温线的数据作为输入来计算各种流体的温度相关等温线。
