Preparation of 13X zeolite powder and membrane: investigation of synthesis parameters impacts using experimental design

Abstract

The Plackett—Burman method was used to identify and rank most affective parameters on hydrothermal synthesis and properties of the 13X zeolite powder with gel composition of Al2O3:aSiO2:bNa2O:cH2O. The affective parameters of SiO2/Al2O3 ratio, synthesis mixture alkalinity, synthesis temperature, and water content were selected for further study of their impacts and gel composition optimization using the Taguchi method. The synthesized powders were characterized by XRD and SEM analysis. Synthesis temperature and mixture alkalinity were found as the most affecting parameters on the 13X zeolite synthesis at the best gel composition of Al2O3:5.4SiO2: 13Na2O: 840H2O. Then 13X zeolite membranes were synthesized on the seeded supports using the optimum gel composition and impacts of synthesis temperature and time and coating layer number on their H2 and CO2 permeances and ideal H2/CO2 selectivity were studied. The optimum 13X zeolite membrane for H2/CO2 separation was obtained by three layer coatings at 80 °C for 16 h with H2 permeance of 2.88 cm3 cm−2.Pa.s and ideal H2/CO2 selectivity of 4.72.