Fast screening of adsorbents: from equilibrium and kinetics to bench scale process tests

在过去的几十年里，新的纳米孔吸附剂和催化剂的开发有了戏剧性的增长。其中最有希望的包括分子筛，从微孔沸石和碳分子筛开始，它们一直主导着该领域，直到上个世纪的最后十年。自20世纪90年代初以来，S开发了一系列新的纳米孔材料，包括周期性介孔分子筛(PMS)、周期性介孔有机硅酸盐(PMO)、层状沸石、金属有机骨架(MOF)以及这些材料的各种杂化和功能化变体。由于这些材料中有大量可能的化学成分和结构，例如，可以制造几乎无限数量的MOF--每种材料都具有不同的性能特征，因此需要开发技术来使用小样本量快速表征材料并允许容易地解释结果。传统上，吸附平衡、动力学和动态测量都是通过重量法、容积法和填充柱流技术进行的。这些技术简单而准确，但它们耗时较长，需要相对大量的吸附样品(通常为颗粒状)，不太适合对准确性要求较低的吸附剂快速筛选研究。

The last several decades have have seen a dramatic increase in the development of new nanoporous adsorbents and catalysts. The most promising among them include molecular sieves, starting with microporous zeolites and carbon molecular sieve, which dominated the field until the last decade of the last century. Since the early 1990's a whole new array of other nanoporous materials have been developed including periodic mesoporous sieves (PMS), periodic mesoporous organosilicates (PMO's), hierarchycal zeolites, metal organic frameworks (MOF's) and a variety of hybrid and functionalized variants of these materials. Due to the large number of possible chemical compositions and structures of some of these materials, e.g., a near infinite number of MOF's can be made- each with different performance characteristics, there is a requirement for developing techniques to characterize materials rapidly using small sample quantities and allowing easy interpretation of the results. Adsorption equilibrium, kinetics and dynamic measurements have traditionally been carried out by gravimetric, volumetric and packed column flow techniques. These techniques are straightforward and accurate, but they are time consuming and require relatively large amounts of adsorbent samples (often in pelleted form) and are not well-suited to adsorbent rapid screening studies, where accuracy is less critical.