SSZ-13 membranes on novel silica carbide monoliths for efficient CO2 separation

Abstract

The usage of normal alumina supports brings the uncertain and undesirable aluminum transformation to the high-silica zeolite membranes to reduce Si/Al ratio in framework. In this current study, a novel aluminum-free silica carbide (SiC) monolithic support is used for the synthesis of SSZ-13 membranes with enhanced Si/Al ratio for the first time. Moreover, this high-porosity and monolithic SiC support enables membrane to increase gas permeance and surface-to-volume ratio. High-quality SSZ-13 membranes were prepared after rational modification of synthesis parameters such as synthesis temperature and time and support material. The effects of test temperature, pressure drop, feed flow rate and humidity on separation performance of the monolithic membranes were studied. The formation mechanism of SSZ-13 membrane was also investigated. The Si/Al ratio and CO2 permeance of SSZ-13 membranes on SiC monolith were 100% and 60% higher than that of membrane on alumina monolith, respectively. This monolithic membrane had comparable separation performance but about 2.3 times higher surface-to-volume ratios to the reported tubular zeolite membranes. This solution could be suitable to prepare other high-silica and all-silica zeolite membranes.