Synthesis of Ultrathin Zeolite Y Membranes and their Application for Separation of Carbon Dioxide and Nitrogen Gases

Abstract

Synthesis of zeolite Y membranes from submicrometer (>100 nm) and nano seed (<100 nm) crystals on alumina supports was examined and the separation characteristics of these membranes for CO(2) and N(2) were studied. Two secondary growth solutions were examined, one for a rapid growth (hours) and one for a slower growth process (days). Membranes formed from the rapid growth solution resulted in 2-2.5 microm thickness, while for the slower growth solution, a dense membrane of 350-600 nm thickness was formed, covered by a 25 microm porous zeolite layer. With the nano seeds as the seeding layer, no membrane was formed. A mechanism involving seed dissolution to initiate membrane formation is concluded. The separation characteristics of membranes for CO(2)/N(2) separation were similar, with very high selectivities for separation (alpha(CO(2),N(2)) > 500). The thicker membrane had lower permeance. By investigating both single gas and mixed gas permeances, strong evidence for a percolative type separation process is obtained.

Silver nanoparticles embedded in zeolite membranes: release of silver ions and mechanism of antibacterial action

“…13 Briefly, nanometer-sized zeolites are deposited on the alumina support and grown into a continuous membrane by hydrothermal synthesis. The zeolite membranes were then ionexchanged with 0.005 M AgNO 3 solution, washed, and then reduced by hydrazine, as described earlier.…”

“…13 The zeolite membrane is then grown on the seeded side via secondary hydrothermal growth. Figure 1A shows the powder x-ray pattern of a typical membrane.…”

Growth of High‐Quality, Thickness‐Reduced Zeolite Membranes towards N2/CH4 Separation Using High‐Aspect‐Ratio Seeds

“…[4] Zeolites are considered as an excellent membrane material because of their molecular-sized pores and high thermal, mechanical and chemical stabilities.G rowth of thin zeolite membranes with high-quality/negligible defects is highly desirable yet very challenging by hydrothermal synthesis. Up to now,several zeolite membranes with framework type of MFI, [5] Y, [6] T, [7] DDR, [8] SSZ-13, [3] and SAPO-34 [3, 9] have been reported to separate CO 2 from CO 2 /CH 4 mixtures.However, when applied for N 2 /CH 4 separation, they suffer from the low N 2 permeance and/or low N 2 /CH 4 separation selectivity.F or example,S SZ-13 and SAPO-34 membranes were prepared and investigated for N 2 /CH 4 mixture separation in ar ecent study.S SZ-13 membrane displayed superior N 2 /CH 4 separation selectivity of about 13 but with al ow N 2 permeance of 2.2 10 À8 mol m À2 s À1 Pa À1 at 20 8 8C.[3] SAPO-34 membranes, which have the CHA structure and pore entrance size similar to the kinetic diameter of CH 4 ,e xhibited much higher N 2 permeance of about 110 À7 mol m À2 s À1 Pa …”

Membrane Separation Processes for Post-Combustion Carbon Dioxide Capture: State of the Art and Critical Overview

“…A selectivity of 200 and permeance of 200 000 GPU has been obtained based on molecular sieve separation mechanism with a NAY zeolite membrane (Krishna and van Baten, 2011). A higher selectivity of 500 and a CO 2 permeance of 300 GPU have been reported with another type of zeolite membrane (White et al, 2010). It can be seen in Figure 2 that these performances stand far above the trade-off curve of dense polymers.…”