Preparation of high performance ZSM-5 zeolite membranes for CO2/H2 separation

Poly(vinyl alcohol)/ZSM-5 zeolite mixed matrix membranes for pervaporation dehydration of ethanol and n-propanol

“…Figure 4 presents the XRD analysis results obtained for ZSM-5 zeolite, pure PVA, and the MMM samples. As is clearly seen, the XRD spectra of the ZSM-5 zeolite demonstrated sharp peaks at 2θ = 7°–10° and 2θ = 22°, which are consistent with those reported in the literature [ 31 ]. As for PVA, a very broad peak appeared at about 2θ = 20° in its XRD patterns and that broad peak is still maintained after reaction with FA and filling with the ZSM-5 zeolite.…”

Highly Permeable and Well-Oriented SAPO-34 Membranes for CO2 Removal

“…Various methods have been proposed by researchers to increase the permeance of zeolite membranes without compromising their selectivity including self-supporting membranes, reducing the thickness of the zeolite layer, using nanosized seeds, and hierarchical zeolite crystals . Among the studied methods, reducing the thickness of the zeolite layer has shown a high potential not only in increasing the permeance but also in reducing the production cost, which makes it competitive with the commercially available polymer membranes . The efficiency of the secondary growth method in synthesizing a thin, smooth and defect-free zeolite layer with proper attachment to the ceramic support strongly depends on the seeding stage in terms of seed size, support coverage, and seed orientation .…”

“…These seeds then adsorb electrostatically onto the support surface. In our previous works , we have reported a novel method for the preparation of zeolite membranes which consists of a dual-layer procedure for seeding in combination with a varying-temperature synthesis, leading to the production of defect-free and ultrathin membranes. In this method, large seeds are placed on the surface of the substrate as the primary layer, which prevents the penetration of the seeds into the support pores.…”

“…1 In fact, since highly selective membranes exhibit low permeance and vice versa, the trade-off between permeance and selectivity of zeolite membranes is one of the main concerns in their commercialization. 1 Various methods have been proposed by researchers to increase the permeance of zeolite membranes without compromising their selectivity including self-supporting membranes, 4 reducing the thickness of the zeolite layer, 5 using nanosized seeds, 6 and hierarchical zeolite crystals. 7 Among the studied methods, reducing the thickness of the zeolite layer has shown a high potential not only in increasing the permeance but also in reducing the production cost, which makes it competitive with the commercially available polymer membranes.…”

“…7 Among the studied methods, reducing the thickness of the zeolite layer has shown a high potential not only in increasing the permeance but also in reducing the production cost, which makes it competitive with the commercially available polymer membranes. 5 The efficiency of the secondary growth method in synthesizing a thin, smooth and defect-free zeolite layer with proper attachment to the ceramic support strongly depends on the seeding stage in terms of seed size, support coverage, and seed orientation. 6 According to the literature, controlling the seed orientation on the surface of the support can effectively reduce the thickness of the membrane and increase its uniformity by eliminating defects.…”