Prediction of Multicomponent Adsorption Equilibrium in Industrial Microporous Adsorbents

本研究从理论和实验两个方面研究了 多孔固体上的平衡物理吸附过程， 特别是集中在多分散性的影响， 吸附剂孔隙 从理论上讲，蒙特卡罗模拟在大正则 本文将对吸附过程进行研究， 在分子水平上的多组分流体混合物， 碳的固相内的孔隙。在模拟中， 流体分子之间的相互作用将由 Lennard-Jones势和流体分子间的相互作用 并且吸附剂将使用9-3电势来计算。为 类似流体分子之间的相互作用 参数将通过匹配纯预测获得 液体密度和蒸汽压的组分模拟 实验值。将使用一组组合规则来 从不同的流体相互作用参数中获得不同的流体相互作用参数， 比如互动模拟将建立纯和混合 组分等温线作为温度和压力的函数。在 除了蒙特-卡罗模拟，吸附理论将 将基于理想吸附溶液开发 理论（IAS）。 在实验上，平衡吸附测量将是 使用石墨化碳和小分子， 甲烷、乙烷、乙烯、二氧化碳和丙烯 流动装置在该装置中，将所需的气体混合物 使组合物通过吸附剂，并且使流出气体通过吸附剂。 监测直至其组成与饲料的组成相同。 此时，系统关闭，测量压力， 并且通过加热吸附剂并允许 被解吸的材料流到先前排空的解吸物 坦克解吸罐中的压力和组成为 测量，并从这些测量的材料的量， 已经被吸附到吸附剂上，并且其组合物，可以 计算了除了吸附测量之外，还测量孔径。 分布将通过氮吸附测量。的 吸附结果的解释将利用一个新的 氮气在孔隙中吸附统计力学模型 它基于密度泛函理论， 微孔（20埃和更小）以及中孔（20-5000埃）。 孔径分布将被纳入理论， 理论预测将与实验进行比较。

This research studies, theoretically and experimentally, the process of equilibrium physical adsorption onto porous solids, particularly focusing on the effect of polydispersity of the adsorbent pores. Theoretically, Monte Carlo simulations in the Grand Canonical Ensemble will be undertaken to study the adsorption process of multicomponent fluid mixtures at a molecular level, in slit shaped pores within a solid phase of carbon. In the simulation, interactions among fluid molecules will be represented by a Lennard-Jones potential, and interactions among the fluid molecules and the adsorbent will be accounted for using a 9-3 potential. For the interactions between like fluid molecules, interaction parameters will be obtained by matching the predictions of pure component simulations for the liquid density and vapor pressure with experimental values. A set of combining rules will be used to obtain the unlike fluid interaction parameters from those of the like interactions. The simulations will establish pure and mixed component isotherms as a function of temperature and pressure. In addition to the Monte-Carlo simulations, an adsorption theory will be developed which will be based on the Ideal Adsorbed Solution theory (IAS). Experimentally, equilibrium adsorption measurements will be undertaken using graphitized carbon and small molecules such as methane, ethane, ethylene, carbon dioxide and propylene in an open flow apparatus. In this apparatus, a gas mixture of desired composition is passed over the adsorbent, and the effluent gas is monitored until its composition is identical to that of the feed. At that point, the system is closed, the pressure is measured, and desorption is initiated by heating the adsorbent and allowing the desorbed material to flow to a previously evacuated desorbate tank. The pressure and composition in the desorbate tank is measured, and from these measurements the amount of material which had been adsorbed onto the adsorbent, and its composition, can be calculated. In addition to the adsorption measurements, pore size distributions will be measured by nitrogen adsorption. The interpretation of the adsorption results will utilize a new statistical mechanical model for nitrogen adsorption in a pore which is based on density functional theory and which is valid for micropores (20 A and smaller) as well as mesopores (20-5000 A). The pore size distribution will be factored into the theory, and theoretical predictions will be compared with experiments.