The Preparation and Characterization of Zeolite LTA Membrane with Microwave-Assisted Method

2014 ◽  
Vol 809-810 ◽  
pp. 682-688
Author(s):  
Li Xia Long ◽  
Hui Ling Du ◽  
Qun Li An ◽  
Xiang Shi ◽  
Jun Liu
Keyword(s):  
Secondary Growth ◽  
Precursor Solution ◽  
Zeolite Membrane ◽  
Molar Ratio ◽  
Microwave Assisted ◽  
Growth Method ◽  
Type Zeolite ◽  
Zeolite Seeds ◽  
Zeolite Lta ◽  
Controllable Process

A facial method to prepare zeolite LTA membrane via microwave-assisted heating method was reported. The A-type zeolite seeds were prepared by hydrothermal method from a precursor solution composed of A2O3:SiO2:Na2O:H2O with molar ratio of 1:5:40:1000. The optimized process parameters for synthesizing the zeolite seeds are reaction for 10 min, microwave power of 135 W, and the ratio of H2O/Na2O is 25. Zeolite LTA membrane was prepared via secondary growth method by microwave heating on the silicane and zeolite seed modified ceramic supports. The prepared zeolite seeds and membrane were characterized with X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) and scanning electron microscopy (SEM). The results show that the size of the zeolite seeds are in the range of 100-400 nm with regular cubic morphology, and the zeolite membrane have homogeneous thickness of 1.5 μm and perfect morphology without defects and pinholes. The easy operation and controllable process make the zeolite membrane by this method properly have wide application for the gas sensor and devices.

Preparation of Membrane Zeolite MCM-22 and Evaluation Process Oil/Water Separation

2015 ◽  
Vol 820 ◽  
pp. 605-608
Author(s):  
A. Santos Barbosa ◽  
A.S. Barbosa ◽  
M.G.F. Rodrigues
Keyword(s):  
Continuous Flow ◽  
Membrane Separation ◽  
Secondary Growth ◽  
Evaluation Process ◽  
Zeolite Membrane ◽  
Water Separation ◽  
Oil Emulsion ◽  
X Ray ◽  
Growth Method ◽  
Oil Water

The objective of this work was prepared by secondary growth method, and evaluate the ability of the MCM-22 zeolite membrane separation system in oil / water in a continuous flow system. The zeolite membrane MCM-22 was characterized by different techniques: X-Ray Spectrometry Energy Dispersive (EDX), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). A continuous flow was used. The test for measuring mass flow of water / oil emulsion was conducted in peristaltic pump, wherein the membrane zeolite MCM-22 was tested. Through the results, we can observe the efficiency of the method used in the preparation of zeolite membrane and was also observed that the zeolite MCM-22 membrane, obtained by secondary growth method showed removal percentages equivalent to the standards required by Resolution 392 CONAMA.

Production of SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powders via microwave processing route

2017 ◽  
Vol 46 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Mohammadreza Johari ◽  
Masoud Rajabi ◽  
Vahid Mohammadi
Keyword(s):  
Sol Gel ◽  
Research Work ◽  
Precursor Solution ◽  
Heating System ◽  
Molar Ratio ◽  
Processing Route ◽  
X Ray Diffraction ◽  
Content Type ◽  
Microwave Assisted ◽  
Gel Processing

Purpose The present paper aims to synthesize SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powder using a combination of citrate – gel processing and microwave-assisted heating route. Design/methodology/approach Microwave-assisted citrate – gel processing of SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powder has been carried out by varying the pH and the molar ratio of H3Cit/Al3+ + Sr2+ +Eu2++Dy3+ (f/o). X-ray diffraction analysis showed that the produced powders were nearly pure SrAl2O4 phase, in which the SrAl2O4 host phase has the maximum fraction of green-emitting monoclinic SrAl2O4 phase. Findings Spectrophotometer results revealed that two excitation peaks appeared at 238 and 339 nm and an emission peak at 515 nm. The crystallite size of the green-emitting phosphor nano-pigment powder was about 37 nm as determined by Scherrer’s formula. The best conditions for formation of monoclinic SrAl2O4 phase with high purity were achieved at pH of precursor solution equal to 7 and the molar ratio of f/o equal to 3. Originality/value The present research work for the first time (to the best of the authors’ knowledge) has used microwave and sol–gel combination techniques to produce green-emitting phosphor nano-pigment powder (without using any other heating system).

scholarly journals 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

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Aynaz Meshkat ◽  
Mohammad Javad Vaezi ◽  
Ali Akbar Babaluo
Keyword(s):  
Secondary Growth ◽  
Dip Coating ◽  
Sem Analysis ◽  
Gas Permeation ◽  
Zeolite Membrane ◽  
Alumina Support ◽  
Suspension Concentration ◽  
Coating Method ◽  
Growth Method ◽  
Modified Surface

In this study, seeding of DD3R particles as an important step in the synthesis of DD3R membrane with secondary growth method was investigated. Dip-coating method is used for seeding of DD3R particles on the modified surface of α-alumina supports. 0.1, 0.2 and 0.3 wt% aqueous suspensions of the DD3R seeds were prepared and each support was coated three times with dipping time of 240 s. Scanning electron microscopy (SEM) analysis was used for the investigation of the quality of seed layer formed on the support. It is shown that the uniform layer of seeds was formed with 0.2 wt% seed suspension concentration. DD3R zeolite membrane was synthesized via hydrothermal method on the support seeded with 0.2 wt% seed suspension concentration. The X-ray diffraction and SEM analysis confirmed the synthesis of uniform DD3R zeolite membrane layer on the support which can be due to the uniform distribution of the DD3R seeds. Single gas permeation tests of N2, CO2 and CH4 were carried out, so that good perm-selectivity for gas mixtures was observed.

scholarly journals Facile Preparation of Bilayer Titanium Silicate (TS-1) Zeolite Membranes by Periodical Secondary Growth

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 850
Author(s):  
Qi Zhang ◽  
Yong Liu ◽  
Xuguang Liu ◽  
Laibo Ma
Keyword(s):  
Room Temperature ◽  
Secondary Growth ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zeolite Membrane ◽  
Distribution Analysis ◽  
The Novel ◽  
Titanium Silicate ◽  
Water Contact ◽  
Growth Method

A facile periodical secondary growth method, based on conventional secondary growth, is proposed to prepare bilayer TS-1 membranes. The novel periodical secondary growth consists of two or several periods, which involve three steps: the temperature is programmed to a desired crystallization temperature as the first stage, followed by holding for a certain duration, and finally cooling to room temperature. This periodical crystallization model enables a bilayer TS-1 membrane to be produced, while the conventional secondary growth method produces a monolayer TS-1 membrane. The bilayer TS-1 membrane exhibits a superior defect-free structure and hydrophobic properties, as illustrated by SEM, gas permeance, pore size distribution analysis, and water contact angle measurement. It displays an earlier desalination separation factor compared to the monolayer TS-1 membrane. This work demonstrates that the periodical secondary growth is an advanced approach for preparing a bilayer zeolite membrane with excellent properties.

scholarly journals Catalytic combustion of isopropanol over Co–ZSM-5 zeolite membrane catalysts in structured fixed-bed reactor

2018 ◽  
Vol 5 (8) ◽  
pp. 180587 ◽  
Author(s):  
Xiaotong Zhang ◽  
Ying Yan
Keyword(s):  
Catalytic Combustion ◽  
Secondary Growth ◽  
Fixed Bed ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Zeolite Membrane ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Feed Concentration ◽  
Growth Method

Catalytic combustion of isopropanol in the structured fixed-bed reactor was investigated over Co–ZSM-5 zeolite membrane catalysts. Firstly, ZSM-5 zeolite membrane catalysts with different Si/Al ratios were coated onto the surface of stainless steel fibres via secondary growth method and wet lay-up paper-making method. Then, cobalt oxides were loaded onto the zeolite membranes by impregnation method. The performance of catalytic combustion of isopropanol was conducted over the prepared zeolite membrane catalysts, and the experimental results showed that the catalyst with infinite Si/Al ratio has the highest catalytic activity for the combustion with the lowest T 90 of isopropanol (285°C). Finally, the effects of bed structure, feed concentration, gas hourly space velocity and reaction temperature on the catalytic performance were investigated to analyse the kinetics of isopropanol over the catalyst with infinite Si/Al ratio in the structured fixed-bed reactor. The results showed that the longer residence time could cause higher reaction contact efficiency of isopropanol combustion. T 90 of isopropanol can be dramatically decreased by 105°C in the fixed-bed reactor packed with Co–ZSM-5 zeolite membrane catalysts, compared to the fixed-bed reactor packed with granular catalyst.

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 Preparation of PHI Zeolite Membrane with High Separation Performance by the Secondary Growth Method

2011 ◽  
Vol 27 (10) ◽  
pp. 2493-2498
Author(s):  
YUAN Wen-Hui ◽  
◽  
CHANG Ran-Ran ◽  
LIU Xiao-Chen ◽  
LI Li ◽  
...  
Keyword(s):  
Secondary Growth ◽  
Zeolite Membrane ◽  
Separation Performance ◽  
Growth Method ◽  
High Separation
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