Influences of Acid Post-Treatment on High Silica SSZ-13 Zeolite Membrane

Abstract

Single gas permeance performance of the high silica SSZ-13 zeolite membrane (Si/Al = 79) was greatly improved by acid post-treatment in this work. Effects of post-treatment conditions, such as post-treatment temperature (25, 60, 80, and 100 °C) and time (0–2 h), acid concentration (0–0.6 H+ mol/L), and acid type (HCl, HNO3, H2SO4, and H3PO4), on the single gas permeance performance of the membrane were investigated in this study. Morphology and structure of the acid post-treated membrane is identical with the fresh high silica SSZ-13 zeolites by advance characterization results, only the amorphous on the zeolites surface is removed and filled into the intercrystalline by medium acid post-treatment, which could improve the gas permeance performance of the membranes greatly. When the post-treatment temperature, time, acid type, and H+ concentration are 25 °C, 0.5 h, H2SO4, and 0.4 mol/L, the CO2/CH4, CO2/N2, H2/CH4, and H2/SF6 ideal selectivity of the post-treated high silica SSZ-13 zeolite membrane are increased to 68, 10, 29, and 126 at 0.2 MPa and 25 °C, respectively.

Gas Separation Performance of SSZ-13 Zeolite Membranes on Different Supports

“…SSZ-13 zeolite membranes were prepared on different supports, and the preparation procedure of the membranes was similar to that reported in our previous studies. 20,22 The molar composition of the initial synthesis gel for membranes is 1000SiO 2 : 100Na 2 O: 5Al 2 O 3 : 100TMAdaOH: 80000H 2 O. It is noted that the SSZ-13 zeolite membranes are fabricated on the homemade α-alumina supports (Foshan Ceramics Research Institute, pore size: 2∼3 μm, porosity: 38%, 100 mm length, 12 mm OD, 9 mm ID) and mullite supports (Noritake, pore size: 1.3 μm, porosity: 40%, 100 mm length, 12 mm OD, 9 mm ID).…”

“…It is noted that the SSZ-13 zeolite membranes are fabricated on the homemade α-alumina supports (Foshan Ceramics Research Institute, pore size: 2∼3 μm, porosity: 38%, 100 mm length, 12 mm OD, 9 mm ID) and mullite supports (Noritake, pore size: 1.3 μm, porosity: 40%, 100 mm length, 12 mm OD, 9 mm ID). The assynthesized membranes were post-treated by 0.2 M H 2 SO 4 aqueous solution at room temperature for 0.5 h, and the acid-treated membranes were washed and dried in an oven at 373 K. 20 2.2. Characterization and Gas Separation.…”

Memory Effect on a LDH/zeolite A Composite: An XRD In Situ Study

“…The Al of the network generates a negative charge that is compensated by cations, thus giving the material a cation-exchange property. These materials are used in diverse processes, including adsorption, cation exchange, separation, and catalysis [ 25 , 26 , 27 , 28 , 29 , 30 ].…”

Separation Performance of Si-CHA Zeolite Membrane for a Binary H2/CH4 Mixture and Ternary and Quaternary Mixtures Containing Impurities

“…A zeolite CHA framework has an 8-member-ring, straight, and 3D pore structure with a pore window size of 3.8 Å × 3.8 Å. It is a promising membrane material for distinguishing hydrogen (kinetic diameter of 2.8 Å) from methane (kinetic diameter of 3.8 Å) or higher hydrocarbons by size difference . There were some reports − to develop CHA zeolite membranes such as chabazite, SSZ-13, and Si-CHA for CO 2 separation from N 2 and CH 4.…”

“…It is a promising membrane material for distinguishing hydrogen (kinetic diameter of 2.8 Å) from methane (kinetic diameter of 3.8 Å) or higher hydrocarbons by size difference. 13 There were some reports 14−19 to develop CHA zeolite membranes such as chabazite, SSZ-13, and Si-CHA for CO 2 separation from N 2 and CH 4. But, the literature for H 2 /CH 4 separation using CHA zeolite membranes is very scare.…”