Hierarchical Porous Zeolite Structures for Pressure Swing Adsorption Applications

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• 作者：Benjamin Besser ; Henrique Akira Tajiri ; Gerd Mikolajczyk ; Jens M?llmer ; Thomas C. Schumacher ; Stefan Odenbach ; Roger Gl?ser ; Stephen Kroll ; Kurosch Rezwan
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：8
• 期：5
• 页码：3277-3286
• 全文大小：668K
• ISSN：1944-8252

文摘

Porous adsorbents with hierarchical structured macropores ranging from 1 to 100 μm are prepared using a combination of freeze casting and additional sacrificial templating of polyurethane foams, with a zeolite 13X powder serving as adsorbent. The pore system of the prepared monoliths features micropores assigned to the zeolite 13X particle framework, interparticular pores of ～1–2 μm, lamellar pores derived from freeze casting of ～10 μm, and an interconnected pore network obtained from the sacrificial templates ranging from around 100 to 200 μm with a total porosity of 71%. Gas permeation measurements show an increase in intrinsic permeability by a factor of 14 for monoliths prepared with an additional sacrificial templated foam compared to monoliths solely providing freeze casting pores. Cyclic CO₂ adsorption and desorption tests where pressure swings between 8 and 140 kPa reveal constant working capacities over multiple cycles. Furthermore, the monoliths feature a high volumetric working capacity of ～1.34 mmol/cm³ which is competitive to packed beds made of commercially available zeolite 13X beads (～1.28 mmol/cm³). Combined with the faster CO₂ uptake showing an adsorption of 50% within 5–8 s (beads ～10 s), the monoliths show great potential for pressure swing adsorption applications, where high volumetric working capacities, fast uptakes, and low pressure drops are needed for a high system performance.