(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.