Preparation of NaY zeolite membranes in fluoride media and their application in dehydration of bio-alcohols

Zhang, Fei; Xu, Longnv; Hu, Na; Bu, Na; Zhou, Rongfei; Chen, Xiangshu

doi:10.1016/j.seppur.2014.03.018

Cited by 35 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Attempts to increase the rate of nucleation by adding zeolite seeds were successful but resulted in products with lower Si/Al ratios (Figure S3), while increasing temperature resulted in the formation of zeolite GIS impurity above 100 °C (Table S1 and Figure S4). A FAU-to-GIS interzeolite transformation is commonly reported at 100 °C; however, our results align with previous studies demonstrating that the presence of zinc in growth media stabilizes zeolite FAU. , In our parametric study, we tested different zinc sources and found that zinc acetate does not lead to FAU formation, whereas zinc nitrate and zinc oxide both produce ZnO-FAU. For this study, we report syntheses solely with ZnO owing to its significant enhancement of the crystallization rate (Figure S5).…”

supporting

confidence: 91%

Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions

Parmar

Mallette

Linares

et al. 2022

ACS Materials Lett.

View full text Add to dashboard Cite

The hydrothermal stability and catalytic activity of zeolite Y (faujasite, FAU) is highly dependent on its composition. High silicon content is often desirable for catalytic applications; however, direct synthesis of faujasite with high silicon content (Si/Al > 2.5) is nontrivial. Here, we present an organic-free synthesis of FAU-type zeolite with Si/Al = 3.4 using zinc oxide as a modifier. A combination of spectroscopy and microscopy techniques confirms that ZnO is well-distributed within zeolite pores as extra-framework species, and the nature of these species differs from bulk ZnO and framework zinc in Zn-FAU crystals. We demonstrate that the increased Si/Al ratio leads to improved hydrothermal stability, while catalytic cracking of 1-hexene and cumene show that ZnO-FAU exhibits a significantly longer lifetime compared to in-house and commercial zeolite Y. Collectively, this study presents a facile and efficient method to prepare more siliceous FAU with enhanced catalytic performance.

show abstract

supporting

confidence: 91%

Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions

Parmar

Mallette

Linares

et al. 2022

ACS Materials Lett.

View full text Add to dashboard Cite

show abstract

“…Moreover, the rate and size of crystal formation increase with an increase in hydrothermal time (Fig. 9 e) 84 – 86 .…”

Section: Box–behnken Response Surface Methodology (Bbrsm)mentioning

confidence: 97%

Pore size engineering of cost-effective all-nanoporous multilayer membranes for propane/propylene separation

Dehghan,

Rashidi,

Parvizian

et al. 2023

Sci Rep

View full text Add to dashboard Cite

In this study, a new multi-layer hybrid nanocomposite membrane named MFI/GO/ZIF-8 has been synthesized. This membrane combines three nanoporous materials with different morphologies in one membrane without using polymer materials. This allows access to a previously accessible region of very high permeability and selectivity properties. In addition to introducing a new and efficient MFI/GO/ZIF-8 membrane in this work, controlling the pore size of the zeolite layer has been investigated to increase the selectivity and permeability of propylene. The membrane was made using a solvent-free hydrothermal method and a layer-by-layer deposition method. To control the pore size of the MFI layer, a two-step synthesis strategy has been implemented. In the first step, three key parameters, including crystallization time, NaOH concentration and aging time of initial suspension, are controlled. In the second step, the effect of three additional parameters including hydrothermal time, hydrothermal temperature and NH4F concentration has been investigated. The results show that the optimal pore size has decreased from 177.8 nm to 120.53 nm (i.e., 32.2%). The MFI/GO/ZIF-8 membrane with fine-tuned crystal size in the zeolite layer was subjected to detailed tests for propylene selectivity and permeability. The structural characteristics of the membrane were also performed using FT-IR, XRD, FESEM and EDS techniques. The results show that the synergistic interaction between the three layers in the nanocomposite membrane significantly improves the selectivity and permeability of propylene. The permeability and selectivity of propylene increased from 50 to 60 GPU and from 136 to 177, respectively, before and after precise crystal size control. MFI/GO/ZIF-8 membrane by controlling the pore size of the zeolite layer shows a significant increase of 23.1% in selectivity and 16.7% in propylene permeability compared to the initial state. Also, due to the precise synthesis method, the absence of solvent and the use of cheap support, the prepared membrane is considered an environmentally friendly and low-cost membrane. This study emphasizes the potential of increasing the selectivity and permeability of propylene in the MFI/GO/ZIF-8 hybrid membrane by controlling the crystal size of the zeolite layer.

show abstract

“…[15][16][17] The NaA zeolite membrane has been used for dehydration on a large scale. [32][33][34][35] In addition, the cubic structure of zeolite NaY has a good intergrowth. [25][26][27] As for zeolite T (OFF-ERI intergrowth), the effective pore size is 0.36 × 0.51 nm, which is also the pore size between water and most organic matters.…”

Section: Introductionmentioning

confidence: 99%

“…35,36 Thus, both zeolites have a good stability under acidic conditions. The Si/Al ratio of zeolite T and zeolite NaY are 3-4 and 1.5-3, respectively.…”

Section: Introductionmentioning

confidence: 99%

Design and Synthesis of Acid‐resistant Zeolite T/NaY Composite Membrane for Water/Ethanol Separation

Zhou

Chen

et al. 2019

Bulletin Korean Chem Soc

View full text Add to dashboard Cite

The random distribution of zeolite T on the porous α-Al 2 O 3 tube during growth greatly limits its application in the industry. In this study, the defective zeolite T layer is modified with zeolite NaY. A continuous and dense zeolite T/NaY composite membrane is obtained through characterization by scanning electron microscope and X-ray diffraction. The resulting composite membrane exhibits high selectivity and high permeation flux for 90 wt % ethanol/water solution at 75 C. Water concentration in the permeation side of the as-synthesized zeolite T/NaY composite membrane is >99.9 wt %, whereas that of primary zeolite T layer is only 60.4 wt %. The water permeation flux of the composite membrane reaches 4.35 kg/m 2 /h 1 . The composite membrane displays good stability in acid solution when the pH of the solution is >5.

show abstract

Preparation of NaY zeolite membranes in fluoride media and their application in dehydration of bio-alcohols

Cited by 35 publications

References 37 publications

Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions

Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions

Pore size engineering of cost-effective all-nanoporous multilayer membranes for propane/propylene separation

Design and Synthesis of Acid‐resistant Zeolite T/NaY Composite Membrane for Water/Ethanol Separation

Contact Info

Product

Resources

About