Synthesis and Permeation Properties of SAPO-34 Tubular Membranes

Abstract

A SAPO-34 membrane was prepared on an alumina tubular support. This membrane appears to exhibit molecular sieving properties with permeances that decrease as the kinetic diameter increases. The room-temperature permeances of H2 and n-C4H10 were 2.4 × 10-8 and 1.9 × 10-10 mol/(m2 s Pa), respectively, and the permeances were in the order H2 > CO2 > N2 > CH4 > n-C4H10. As the temperature increased, the single gas permeances of H2 and N2 exhibited minima, whereas the permeance of CO2 decreased and that of CH4 increased. As the pressure increased with a constant pressure drop across the membrane, the permeances of H2, CO2, N2, and CH4 decreased. The H2/CH4, CO2/CH4, H2/N2, and CO2/N2 ideal selectivities at 300 K and 270 kPa feed pressure with a 138 kPa pressure drop were 25, 19, 7.4, and 5.7, respectively, and these selectivities decreased with increasing temperature and increased with increasing pressure. The ideal selectivity of N2/CH4 was 3.4 at the same conditions and decreased with increasing temperature and increasing pressure. The H2/CO2 ideal selectivity was 1.3 at the same conditions and increased with increasing temperature and pressure. At 270 kPa feed pressure and 138 kPa pressure drop, the CO2/CH4 mixture selectivity was 30 at 300 K and 3.4 at 470 K.

Synthesis and perfection evaluation of NaA zeolite membrane

“…Compared the NaA zeolite membrane in this study with other small pore size zeolite membrane, e.g. the SAPO-34 zeolite membrane (poresize between 0.43 and 0.50 nm [31]), the latter showed a better H 2 /n-C 4 H 10 permselectivity [23,32], which indicated that methods to improve the perfection of the NaA zeolite membrane will still need to be investigated. …”

“…Although high separation factors have been obtained for these mixtures, the MFI zeolite membrane has not shown good separation performance for permanent gases or permanent gas/organic gas because of the large pore size and the hydrophobic nature of the zeolite [12][13][14][15]. Therefore, the investigation of the zeolite membranes with small pore size has attracted much attention [19][20][21][22][23][24][25].…”

Synthesis of NaA zeolite membranes from clear solution

“…Gas permeation properties of the NaA zeolite membrane with the synthesis time of 2 h after a two-stage synthesis as a function of gas molecular kinetic diameters at 25°C under 0.10 MPa pressure di erence. nm [43]), the latter shows a high permselectivity of H 2 /n-C 4 H 10 [34,44]. In addition, because the pore size of NaA zeolite (0.41 nm) is smaller than the kinetic diameter of n-butane (0.43 nm), the permeation of n-C 4 H 10 indicates that the NaA zeolite membranes have certain defects that have a diameter larger than the pore size of NaA zeolite.…”

A Review of Carbon Dioxide Selective Membranes: A Topical Report

“…These supported zeolite membranes have a thin and continuing zeolite separation layer with the porous support providing mechanical strength to the membrane. Membranes of various zeolites, such as ZSM-5 [30][31][32][33][34][35][36][37], Y type [38][39][40][41][42][43], silicalite [44][45][46][47][48][49][50], A type [42,51,52], P type [53], modernite [33], and silicoaluminophosphate [54][55][56] have been synthesized on porous supports.…”