Template-free synthesis of beta zeolite membranes on porous α-Al2O3 supports

2014 ◽  
Vol 50 (64) ◽  
pp. 8834-8837 ◽  
Author(s):  
Yanting Tang ◽  
Xiufeng Liu ◽  
Shifeng Nai ◽  
Baoquan Zhang
Keyword(s):  
Seed Layer ◽  
Secondary Growth ◽  
Zeolite Membrane ◽  
Beta Zeolite ◽  
Zeolite Membranes ◽  
Organic Templates ◽  
Template Free ◽  
Α Al2o3

The preferentially (h0l)-oriented beta zeolite membrane was prepared on the porous α-Al2O3 support by secondary growth of a beta seed layer in the absence of organic templates.

Microwave-Assisted Synthesis and Permeation Performance of NaA Zeolite Membrane by Secondary Growth Method

2014 ◽  
Vol 1053 ◽  
pp. 389-393
Author(s):  
Zhi Lin Cheng ◽  
Ying Ying Liu
Keyword(s):  
Gas Permeability ◽  
Knudsen Diffusion ◽  
Secondary Growth ◽  
Zeolite Membrane ◽  
Microwave Assisted Synthesis ◽  
Vapor Phase Transport ◽  
Zeolite Membranes ◽  
Synthesis Time ◽  
Naa Zeolite ◽  
Naa Zeolite Membrane

The highly intergrown NaA zeolite membranes on seeded α-Al2O3substrate were synthesized by microwave heating method. The preparation of seeds with the size of ca.120nm employed the vapor phase transport method (VPT). The XRD patterns indicated that the pure NaA zeolite membranes formed on the seeded α-Al2O3substrate for varied synthesis times. However, the peak intensity of NaA zeolite membrane with synthesis time of 50min obviously decreased, suggesting that the NaA membrane could take place the dissolution at that time. The SEM images indicated that the NaA zeolite membranes with synthesis time of 15-30min had a good integrity and consisted of highly intergrown zeolite crystals, but the NaA membrane with synthesis time of 50min appeared some large defects, further verifying the result of XRD pattern. The gas permeability showed that the maximum of H2/N2and H2/C3H8permselectivities attained 4.23 and 8.24, respectively, higher than those of the corresponding Knudsen diffusion. These results suggested that the diffusion of gases, at least in part, are affected by the pore size of zeolite and the function of molecular sieving can be embodied on the synthesized membrane.

Scale-up of NaA zeolite membranes on α-Al2O3 hollow fibers by a secondary growth method with vacuum seeding

2015 ◽  
Vol 23 (7) ◽  
pp. 1114-1122 ◽  
Author(s):  
Yanmei Liu ◽  
Xuerui Wang ◽  
Yuting Zhang ◽  
Yong He ◽  
Xuehong Gu
Keyword(s):  
Scale Up ◽  
Secondary Growth ◽  
Hollow Fibers ◽  
Zeolite Membranes ◽  
Naa Zeolite ◽  
Growth Method ◽  
Α Al2o3

scholarly journals Prevention in Thermal Crack Formation in Chabazite (CHA) Zeolite Membrane by Developing Thin Top Zeolite and Thick Intermediate Layers

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2113
Author(s):  
Min-Zy Kim ◽  
Syed Fakhar Alam ◽  
Devipriyanka Arepalli ◽  
Aafaq ur Rehman ◽  
Won-Youl Choi ◽  
...  
Keyword(s):  
Intermediate Layer ◽  
Secondary Growth ◽  
Particle Diameter ◽  
Zeolite Membrane ◽  
Average Particle ◽  
Alumina Support ◽  
Infiltration Process ◽  
Zeolite Membranes ◽  
Thermal Cracks ◽  
Intermediate Layers

Chabazite (CHA) zeolite membranes with an intermediate layer of various thicknesses were prepared using planetary-milled seeds with an average particle diameter of 300, 250, 200, 140, and 120 nm. The 120 nm seed sample also contained several smaller particles with a diameter of 20 nm. Such small seeds deeply penetrated into the pore channels of the α-alumina support during the vacuum-assisted infiltration process. During the secondary growth, the penetrated seeds formed a thick intermediate layer exiting between the zeolite layer and support. A decrease in seed size increased the penetration depth of seeds and the thickness of the intermediate layer, while the thickness of seed coating and zeolite layers was decreased. CHA zeolite membranes with a thin top zeoliate layer and a thick intermediate layer showed an excellent water/ethanol separation factor (>10,000) for 90 wt.% ethanol at 70 ℃ with a total flux of 1.5 kg m−2 h−1. There was no observation of thermal cracks/defects on the zeolite separation layer. The thick intermediate layer effectively suppressed the formation of thermal cracks during heating, since the tensile stress induced in the zeolite layer was well compensated by the compressive stress on the support. Therefore, it was successfully proven that controlling the microstructure of top surface and intermediate layers is an effective approach to improve the thermal stability of the CHA zeolite membrane.

scholarly journals Pervaporative Dehydration of Organic Solvents Using High-Silica CHA-Type Zeolite Membrane

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 229
Author(s):  
Yasuhisa Hasegawa ◽  
Chie Abe ◽  
Ayumi Ikeda
Keyword(s):  
Acetic Acid ◽  
Organic Solvents ◽  
Acetic Acid Solution ◽  
Secondary Growth ◽  
Zeolite Membrane ◽  
Separation Factors ◽  
Al2o3 Support ◽  
Type Zeolite ◽  
High Silica ◽  
Α Al2o3

A high-silica chabazite (CHA) type zeolite membrane was prepared on the porous α-Al2O3 support tube by the secondary growth of seed particles. The dehydration performances of the membrane were determined using methanol, ethanol, 2-propanol, acetone, acetic acid, methyl ethyl ketone (MEK), tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methyl-2-pyrolidone (NMP) at 303–373 K. As a result, the dehydration performances of the membrane were categorized to following three types: (1) 2-propanol, acetone, THF, and MEK; (2) ethanol and acetic acid; and (3) methanol, DMF, and DMSO, and NMP. The adsorption isotherms of water, methanol, ethanol, and 2-propanol were determined to discuss the influences of the organic solvents on the permeation and separation performances of the membrane. For 2-propanol, acetone, MEK, and THF solutions, the high permeation fluxes and separation factors were obtained because of the preferential adsorption of water due to molecular sieving. In contrast, the permeation fluxes and separation factors were relatively low for methanol, DMF, and DMSO, and NMP solutions. The lower dehydration performance for the methanol solution was due to the adsorption of methanol. The permeation fluxes for ethanol and acetic acid solution were ca. 1 kg m−2 h−1. The significantly low flux was attributed to the similar molecular diameter to the micropore size of CHA-type zeolite.

Synthesis of Potassium Ion Sieve Membrane by Secondary Growth Method

2011 ◽  
Vol 396-398 ◽  
pp. 2279-2284
Author(s):  
Li Hui Sun ◽  
Jun Sheng Yuan ◽  
Yun Peng Fu ◽  
Jin Hou ◽  
Kong Xiu Zhu
Keyword(s):  
Hydrothermal Synthesis ◽  
Secondary Growth ◽  
Potassium Ion ◽  
Zeolite Membrane ◽  
Ammonium Bromide ◽  
Tetrabutyl Ammonium Bromide ◽  
Tetrabutyl Ammonium ◽  
Growth Method ◽  
Α Al2o3

potassium ionic sieve membrane was synthesized employing the secondary hydrothermal synthesis using tetrabutyl ammonium bromide as templates on the porous α-Al2O3 support.The zeolite membrane were characterized by XRD and SEM. The results show that the prepared membranes is potassium ionic sieve membrane, dense and continuous membrane could be obtained after crystallization synthesis was carried out at 423K for 12h and for three times.

scholarly journals Synthesis and Performance of Deca- Dodecasil 3 Rhombohedral (DDR)-Type Zeolite Membrane In CO2 Separation– A Review

2015 ◽  
Vol 14 (2) ◽  
pp. 48 ◽  
Author(s):  
Muhammad Mubashir ◽  
Yeong Yin Fong ◽  
Lau Kok Keong ◽  
Mohd. Azmi Bin Sharrif
Keyword(s):  
Secondary Growth ◽  
High Energy ◽  
Zeolite Membrane ◽  
Co2 Separation ◽  
Inorganic Membranes ◽  
Zeolite Membranes ◽  
Type Zeolite ◽  
And Performance ◽  
Cryogenic Distillation ◽  
Growth Methods

CO2 capture technologies including absorption, adsorption, and cryogenic distillation are reported. Conventional technologies for CO2 separation from natural gas have several disadvantages including high cost, high maintenance, occupy more space and consume high energy. Thus, membrane technology is introduced to separate CO2 due to their several advantages over conventional separation techniques. Inorganic membranes exhibit high thermal stability, chemical stability, permeability and selectivity for CO2 and CH4 separation as compared to other type of membranes. Zeolite membranes are potential for CO2 separation due to their characteristics such as, well define the pore structure and molecular sieving property. Among the zeolite membranes, DDR membranes exhibit highest selectivity for CO2 and CH4 separation. DDR membranes are synthesized by conventional hydrothermal and secondary growth methods. These methods required very long synthesis duration (25 days) due to extremely low nucleation and crystal growth rate of DDR zeolite. In this review, synthesis and performance of DDR membrane in CO2 separation from CH4 reported by various researchers are discussed. Challenges and upcoming guidelines related to the synthesis DDR membrane and performance of DDR membrane also included.

The Investigation of Preparing the Beta Zeolite Membrane by the Way of Secondary Growth

2012 ◽  
Vol 608-609 ◽  
pp. 1463-1466 ◽  
Author(s):  
Guo Lin Shao ◽  
Chun Ling Yu ◽  
Ying Huan Fu ◽  
Hong Yi Dai ◽  
Li Ping Zhang
Keyword(s):  
Secondary Growth ◽  
Dip Coating ◽  
Zeolite Membrane ◽  
Beta Zeolite ◽  
Self Assembling ◽  
Large Pore ◽  
Coating Method ◽  
Support Tube ◽  
Dip Coating Method ◽  
The Way

Beta zeolite membrane was prepared on the surface of α-Al2O3support tube with large pore by the way of secondary growth. Different seeding techniques, such as ultrasonic surge, self-assembling and dip-coating, were investigated, and the results indicated that the best one was dip-coating method for the support with large pore. The prepared membrane was characterized by SEM and XRD. It was proved that the beta zeolite membrane prepared by the way of secondary growth is continuous, dense and defect-free.

Preparation of ZSM-5 Zeolite Membranes by Combined Hydrothermal Synthesis and Electrophoretic Deposition

2015 ◽  
Vol 654 ◽  
pp. 47-52 ◽  
Author(s):  
Hideyuki Negishi ◽  
Stephanie Reuß ◽  
Wilhelm Schwieger ◽  
Aldo Roberto Boccaccini
Keyword(s):  
Hydrothermal Synthesis ◽  
Electrophoretic Deposition ◽  
Deposition Time ◽  
Secondary Growth ◽  
Zeolite Membrane ◽  
Zeolite Membranes ◽  
Porous Stainless Steel ◽  
Seeding Method ◽  
Micron Size

The preparation of a ZSM-5 zeolite membrane on porous stainless steel disk by hydrothermal synthesis with electrophoretic deposition (EPD) as a seeding method was investigated. Micron size ZSM-5 crystal powder was seeded by EPD on the support disk by using ZSM-5 powder dispersed in ethanol. The seeded amounts were easily controlled by the deposition time during EPD. The membrane after secondary growth had a low amount of zeolite in comparison with the in situ seeding method and the permeance of single gas such as He, N2 and CO2 was also low in comparison with that of the in situ seeding method.

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