Fabrication and Performance Evaluation of Industrial Alumina Based Graded Ceramic Substrate for CO₂ Selective Amino...

The present study mainly focuses on the careful design of an amino-silicate membrane integrated on an asymmetric graded membrane substrate, comprised of a cost-effective macroporous industrial alumina based ceramic support with a systematic graded assemblage of sol-gel derived γ-alumina intermediate and silica-CTAB sublayer-based multilayered interface, specifically dedicated for the separation of CO₂ gas from the binary gas mixture (CO₂/N₂) under nearly identical flue gas atmospheric conditions. The tailor-made industrial α-alumina-based porous ceramic support has been characterized in terms of apparent porosity, bulk density, flexural strength, microstructural feature, pore size, and its distribution to demonstrate its application feasibility toward the evolution of the subsequent membrane structure. The near surface morphology of the subsequent intermediate and submembrane layer has been carefully controlled via precisely scheming the colloidal chemistry and consequently implementing it during the deposition process of the respective γ-alumina and silica-CTAB precursor sols, whereas the potentiality of the quarantined amine groups in the final amino-silicate membrane has been methodically optimized by the appropriate heat treatment process. Finally, the real-time applicability of the hybrid amino-silicate membrane has been evaluated in terms of systematic analysis of the binary gas (CO₂/N₂) separation performance under variable operating conditions. The investigated ceramic membrane exhibited optimum CO₂ permeance of 46.44 GPU with a CO₂/N₂ selectivity of 12.5 at 80 °C under a trans-membrane pressure drop of 0.8 bar having a feed and sweep side water flow rate of 0.03 mL/min, which shows its performance reliability at nearly identical flue gas operating conditions.