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

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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.***The original zero length (ZLC) techique was introduced by Eic and Ruthven in late 1980's to study adsorption kinetics. This technique will be the basis for developing a novel ZLC system designed for the fast screening of adsorbents that would include complete characterization from equilibrium and kinetics to dynamic (breakthrough) characterizations, which is the main objective of this proposal. The results will be used either to select the best performing material from a larger selction of potential adsorbents or it will be used to modify synthesized material in lab in order to produce tailor-made adsorbent for specific application.***The other objectives of the proposed research are:***1) Synthesis and modifications of synthesized adsorbents, in particular, synthesis of novel nanofibrilated cellulose (NFC) adsorbents for gas separations. This development has the potential to create a new market opportunities for the emerging forest bioeconomy. Since a large number of NFC samples will be prepared the synthesized/modified samples will be characterized by the fast screening methods developed in the first part of this proposal.***2) Performance of the selected samples will be tested by bench scale process testing using pressure swing adsorption (PSA) apparatus. These tests will complete a full cycle from the synthesis and rapid screening to the bench scale operation. ***The research proposed here is built on 25 years of our work in the adsorption area. **