Synthesis and Permeation Properties of a DDR-Type Zeolite Membrane for Separation of CO₂/CH₄ Gaseous Mixtures

Abstract

Using hydrothermal synthesis, a highly hydrophobic DDR-type zeolite membrane was prepared on the outer surface of a porous α-alumina tube. The results of this study show that it is useful for CO2/CH4 separation. Single-gas permeation for CO2, CH4, H2, He, N2, and O2, and CO2/CH4 binary gas permeation, were measured, respectively, at pressures up to 5 and 2 MPa. The respective single-gas permeances of CO2 and CH4 at 298 K at a feed pressure of 0.2 MPa and a permeate pressure of 0.1 MPa were 4.2 × 10-7 and 1.2 × 10-9 mol m-2 s-1 Pa-1; the ideal selectivity for CO2/CH4 was 340. The permeances were in the following order: CO2 > H2 > He > O2 > N2 > CH4. Single-gas permeance was dependent on the relative molecular size of the DDR pore diameter. However, CO2 permeance dominated the adsorption affinity to the pore wall of DDR zeolite. In mixed-gas permeation experiments using the sweep method, the DDR-type zeolite membrane showed high selectivity for CO2/CH4 mixtures of 200 and high CO2 permeance of 3.0 × 10-7 mol m-2 s-1 Pa-1 at 298 K with a feed pressure of 0.2 MPa. Furthermore, the DDR zeolite membranes were compared to other zeolite membranes for evaluation of their CO2/CH4 selectivity and CO2 permeance; the DDR-type zeolite membranes show better CO2/CH4 separation and CO2 permeance.

Synthesis of SAPO-34 membrane using double structure directing agents

“…The seeded support was immersed into the SAPO-34 membranes gel contained in an autoclave and hydrothermal synthesis was carried out at 483 K for 6～8 h. After being washed and centrifugedat 823 K for 6 h, the SAPO-34 zeolite membranes were harvested. TheSAPO-34 membranes gel was prepared by adding Al(i-C 3 H 7 O) 3 to the mixture of DI water and H 3 PO 4 and stirred for 2 h. Ludox AS-40 colloidal silica gel, TEAOH and DPA were added to the gel one by on aging the resulting gel at 323 K, the membranes gel was prepared.…”

“…An energy-efficient approach to separate CO 2 from H 2 is through using zeolite membranes. Zeolites with uniformly sized pores of molecular dimensions used for H 2 /CO 2 separations include zeolite T [1,2], DDR [3], MFI [4] and SAPO-34 [5][6][7][8].…”

Study the Effect of Seeding Suspension Concentration of DD3R Particles on the Modified Surface of Α-Alumina Support for Preparing DD3R Zeolite Membrane with High Quality

“…But, they reported a poor performance with low quality of membrane layer. According to the literature, the most DD3R membranes with good performance were fabricated by Tomita et al, Himeno et al and their co-workers at NGK insulator [5,10].…”

Methods Comparison for the Synthesis of Deca-Dodecasil 3 Rhombohedral (DDR3) Zeolite Crystals

“…Zeolite membranes consist of ultra large, large, medium and small pore framework. DDR3 membrane is a type of zeolite membranes having small pores (0.36 x 0.44nm) framework and exhibited the highest selectivity in CO 2 separation from natural gas [7].…”