(716b) Facile and Scalable Fabrication of High-Performance CHA Zeolite Hollow Fiber Membranes and Modules for Gas Separations

Efficient separation of gases such as CO₂ from other molecules such as CH₄, N₂, and hydrocarbons is a key problem in many energy production and greenhouse gas reduction schemes. Zeolite materials have demonstrated attractive gas separation properties, but their industrial application as membranes in gas separations has been elusive because of high cost and low reproducibility of conventional fabrication techniques. We demonstrate a facile, one-step method for fabrication of high-silica CHA zeolite membranes on low-cost alumina hollow fiber substrates along with detailed characterization of the CHA hollow fiber membranes. To demonstrate the scalability of the method, 20 hollow fiber membranes were synthesized in the same batch and assembled into a module. The permeation characteristics of these membranes will be discussed in detail. For example, under dry conditions, the membranes showed high CO₂ permeances up to 3500 GPU (1 Gas Permeation Unit = 3.348×10^-10 mol m^-2 s^-1 Pa^-1) and excellent CO₂ separation performance (e.g., CO₂/CH₄ separation factors up to 210 in the 1-7 bar feed pressure range). Additionally, the membranes exhibited considerable increases in CO₂/N₂ selectivity under humid (saturated water vapor) conditions with moderate permeance drops. This work opens a promising new path for accelerated development of low-cost zeolitic membranes for gas separation technology.