Готові списки джерел за темами / Zeolite SAPO-34

Добірка наукової літератури з теми "Zeolite SAPO-34"

Автор: Grafiati
Опубліковано: 14 березня 2023

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Статті в журналах з теми "Zeolite SAPO-34"

1

Zhou, Yida, Jiani Zhang, Wenyan Ma, Xin Yin, Guangrui Chen, Yinghao Liu, and Jiyang Li. "Small pore SAPO-14-based zeolites with improved propylene selectivity in the methanol to olefins process." Inorganic Chemistry Frontiers 9, no. 8 (2022): 1752–60. http://dx.doi.org/10.1039/d2qi00155a.

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2

Xiao, Xia, Zhongliang Xu, Peng Wang, Xinfei Liu, Xiaoqiang Fan, Lian Kong, Zean Xie, and Zhen Zhao. "Solvent-Free Synthesis of SAPO-34 Zeolite with Tunable SiO2/Al2O3 Ratios for Efficient Catalytic Cracking of 1-Butene." Catalysts 11, no. 7 (July 10, 2021): 835. http://dx.doi.org/10.3390/catal11070835.

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Анотація:
Solvent-free synthesis methodology is a promising technique for the green and sustainable preparation of zeolites materials. In this work, a solvent-free route was developed to synthesize SAPO-34 zeolite. The characterization results indicated that the crystal size, texture properties, acidity and Si coordination environment of the resulting SAPO-34 were tuned by adjusting the SiO2/Al2O3 molar ratio in the starting mixture. Moreover, the acidity of SAPO-34 zeolite was found to depend on the Si coordination environment, which was consistent with that of SAPO-34 zeolite synthesized by the hydrothermal method. At an SiO2/Al2O3 ratio of 0.6, the SP-0.6 sample exhibited the highest conversion of 1-butene (82.8%) and a satisfactory yield of light olefins (51.6%) in the catalytic cracking of 1-butene, which was attributed to the synergistic effect of the large SBET (425 m2/g) and the abundant acid sites (1.82 mmol/g). This work provides a new opportunity for the design of efficient zeolite catalysts for industrially important reactions.
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3

Usman, Muhammad. "Recent Progress of SAPO-34 Zeolite Membranes for CO2 Separation: A Review." Membranes 12, no. 5 (May 10, 2022): 507. http://dx.doi.org/10.3390/membranes12050507.

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Анотація:
In the zeolite family, the silicoaluminophosphate (SAPO)-34 zeolite has a unique chemical structure, distinctive pore size, adsorption characteristics, as well as chemical and thermal stability, and recently, has attracted much research attention. Increasing global carbon dioxide (CO2) emissions pose a serious environmental threat to humans, animals, plants, and the entire environment. This mini-review summarizes the role of SAPO-34 zeolite membranes, including mixed matrix membranes (MMMs) and pure SAPO-34 membranes in CO2 separation. Specifically, this paper summarizes significant developments in SAPO-34 membranes for CO2 removal from air and natural gas. Consideration is given to a variety of successes in SAPO-34 membranes, and future ideas are described in detail to foresee how SAPO-34 could be employed to mitigate greenhouse gas emissions. We hope that this study will serve as a detailed guide to the use of SAPO-34 membranes in industrial CO2 separation.
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4

Junaidi, M. U. M., C. P. Leo, S. N. M. Kamal, and A. L. Ahmad. "Fouling mitigation in humic acid ultrafiltration using polysulfone/SAPO-34 mixed matrix membrane." Water Science and Technology 67, no. 9 (May 1, 2013): 2102–9. http://dx.doi.org/10.2166/wst.2013.098.

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Анотація:
Although ultrafiltration (UF) membranes are applicable in wastewater and water treatment, most UF membranes are hydrophobic and susceptible to severe fouling by natural organic matter. In this work, polysulfone (PSf) membrane was blended with silicaluminophosphate (SAPO) nanoparticles, SAPO-34, to study the effect of SAPO-34 incorporation in humic acid (HA) fouling mitigation. The casting solution was prepared by blending 5–20 wt% of SAPO-34 nanoparticles into the mixture of PSf, 1-methyl-2-pyrrolidinone and polyvinyl alcohol at 75 °C. All membrane samples were then prepared using the phase inversion method. Blending SAPO-34 zeolite into PSf membranes caused augmentation in surface hydrophilicity and pore size, leading to higher water permeation. In the HA filtration test, mixed matrix membranes (MMMs) with SAPO-34 zeolite showed reduced HA fouling initiated from pore blocking. The MMM with 20 wt% SAPO-34 loading exhibited the highest increment of water permeation (83%) and maintained about 75% of permeate flux after 2.5 h. However, the SAPO-34 fillers agglomerated in the PSf matrix and induced macrovoid formation on the membrane surface when excessive zeolite was added.
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5

Wang, Bin, Ying Zhang, Fu Bo Gu, Min Zuo, and Guang Sheng Guo. "Acid Strength Measurement of Zeolites by the TPD-IR Technique with Ammonia as Probe Molecule." Applied Mechanics and Materials 475-476 (December 2013): 1270–74. http://dx.doi.org/10.4028/www.scientific.net/amm.475-476.1270.

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Анотація:
An improved TPD-IR technique was developed recently. By which means, acid properties of Brønsted acid sites on HY zeolite and SAPO-34 zeolite were studied by an advanced TPD-IR technique with ammonia as probe molecule. Desorption activation energy (DAE) of the probe molecule adsorbed on zeolite was used as a measure of the acid strength. The result indicates the Brønsted acid sites of HY Zeolite or SAPO-34 zeolite were divided into two types with the strength of DAE of ammonia 43.4KJ/mol, 24.4KJ/mol and 33.2KJ/mol, 20.5KJ/mol. It is concluded that HY zeolite has the stronger Brønsted acid sites than that of SAPO-34 zeolite.
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6

Usman, Muhammad, Jiang Zhu, Kong Chuiyang, Muhammad Tahir Arslan, Abuzar Khan, Ahmad Galadima, Oki Muraza, et al. "Propene Adsorption-Chemisorption Behaviors on H-SAPO-34 Zeolite Catalysts at Different Temperatures." Catalysts 9, no. 11 (November 5, 2019): 919. http://dx.doi.org/10.3390/catal9110919.

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Анотація:
Propene is an important synthetic industrial product predominantly formed by a methanol-to-olefins (MTO) catalytic process. Propene is known to form oligomers on zeolite catalysts, and paramters to separate it from mixtures and its diffusion properties are difficult to measure. Herein, we explored the adsorption–chemisorption behavior of propene by choosing SAPO-34 zeolites with three different degrees of acidity at various adsorption temperatures in an ultra-high-vacuum adsorption system. H-SAPO-34 zeolites were prepared by a hydrothermal method, and their structural, morphological, and acidic properties were investigated by XRD, SEM, EDX, and temperature-programmed desorption of ammonia (NH3-TPD) analysis techniques. The XRD analysis revealed the highly crystalline structure which posses cubic morphology as confirmed by SEM images. The analysis of adsorption of propene on SAPO-34 revealed that a chemical reaction (chemisorption) was observed between zeolite and propene at room temperature (RT) when the concentration of acidic sites was high (0.158 mmol/g). The reaction was negligible when the concentration of the acidic sites was low (0.1 mmol/g) at RT. However, the propene showed no reactivity with the highly acidic SAPO-34 at low temperatures, i.e., −56 °C (using octane + dry ice), −20 °C (using NaCl + ice), and 0 °C (using ice + water). In general, low-temperature conditions were found to be helpful in inhibiting the chemisorption of propene on the highly acidic H-SAPO-34 catalysts, which can facilitate propene separation and allow for reliable monitoring of kinetic parameters.
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Chen, Xueshuai, Rongli Jiang, Huilin Hou, Zihan Zhou, and Xingwen Wang. "Synthesis of ZSM-5/SAPO-34 zeolite composites from LAPONITE® and their catalytic properties in the MTO reaction." CrystEngComm 22, no. 37 (2020): 6182–88. http://dx.doi.org/10.1039/d0ce01002b.

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8

Chen, Yanping, Yiming Xu, Dang-guo Cheng, Yingcai Chen, Fengqiu Chen, Xiaoyong Lu, Yiping Huang, and Songbo Ni. "Synthesis of CuO–ZnO–Al2O3 @ SAPO-34 core@shell structured catalyst by intermediate layer method." Pure and Applied Chemistry 86, no. 5 (May 19, 2014): 775–83. http://dx.doi.org/10.1515/pac-2013-1121.

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Анотація:
AbstractThe present study focuses on synthesis of SAPO-34 zeolite membrane on the surface of CuO–ZnO–Al2O3 (CZA) catalyst particles to form CZA@SAPO-34 core@shell structured catalyst. In contrast to the traditional support of porous alumina, CZA catalyst particles have a relatively brittle surface, which leads to a big challenge to coat SAPO-34 zeolite membrane on their surface. Moreover, the hydrothermal synthesis of SAPO-34 zeolite membrane is carried out under weakly alkaline condition at 200 °C for hours, which causes part of the surface of CZA to be fragmented. To overcome these shortcomings, the intermediate layer of alumina is introduced to the surface of the CZA particles and acts as a barrier to the high-temperature hydrothermal and alkaline condition. It also takes as a transition to enhance SAPO-34 zeolite seeds adherence to the surface of CZA particles. With the help of an alumina layer, a continuous and dense zeolite membrane has been obtained on the surface of CZA particles. The prepared core@shell structured catalyst has better selectivity in CO hydrogenation for producing light hydrocarbons because of the synergetic effects between the membrane and core catalyst.
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9

Xia, Wei, Qi Sun, Shang Wen Liu, Lin Ping Qiang, and Yuan Cun Cui. "SAPO-34/SiO2 Catalysts for the Transformation of Ethanol into Propylene." Advanced Materials Research 1004-1005 (August 2014): 707–10. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.707.

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Анотація:
Ethanol has great potential to be a candidate for the source of light olefins such as ethylene and propylene. However, ethanol to olefin (ETO) process has not been fully investigated. In this work, the conversion reactions of ethanol were carried out at 673 K under atmospheric pressure on SAPO-34 and SAPO-34/SiO2 catalysts. SAPO-34 and SAPO-34/SiO2 exhibit higher selectivity for propylene than H-ZSM-5 zeolite catalysts do. The SAPO-34 with silica binder showed better catalytic performance for the transformation of ethanol to propylene than the SAPO-34 catalyst.
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10

Li, Duichun, Bin Xing, Baojun Wang, and Ruifeng Li. "Theoretical Study of Zirconium Isomorphous Substitution into Zeolite Frameworks." Molecules 24, no. 24 (December 5, 2019): 4466. http://dx.doi.org/10.3390/molecules24244466.

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Анотація:
Systematic periodic density functional theory computations including dispersion correction (DFT-D) were carried out to determine the preferred location site of Zr atoms in sodalite (SOD) and CHA-type topology frameworks, including alumino-phosphate-34 (AlPO-34) and silico-alumino-phosphate-34 (SAPO-34), and to determine the relative stability and Brönsted acidity of Zr-substituted forms of SOD, AlPO-34, and SAPO-34. Mono and multiple Zr atom substitutions were considered. The Zr substitution causes obvious structural distortion because of the larger atomic radius of Zr than that of Si, however, Zr-substituted forms of zeolites are found to be more stable than pristine zeolites. Our results demonstrate that in the most stable configurations, the preferred favorable substitutions of Zr in substituted SOD have Zr located at the neighboring sites of the Al-substituted site. However, in the AlPO-34 and SAPO-34 frameworks, the Zr atoms are more easily distributed in a dispersed form, rather than being centralized. Brönsted acidity of substituted zeolites strongly depends on Zr content. For SOD, substitution of Zr atoms reduces Brönsted acidity. However, for Zr-substituted forms of AlPO-34 and SAPO-34, Brönsted acidity of the Zr-O(H)-Al acid sites are, at first, reduced and, then, the presence of Zr atoms substantially increased Brönsted acidity of the Zr-O(H)-Al acid site. The results in the SAPO-34-Zr indicate that more Zr atoms substantially increase Brönsted acidity of the Si-O(H)-Al acid site. It is suggested that substituted heteroatoms play an important role in regulating and controlling structural stability and Brönsted acidity of zeolites.
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Дисертації з теми "Zeolite SAPO-34"

1

Molina, Gonzalez Sonia. "Analyse du couplage des fonctions de filtration des suies et de réduction des NOx pour moteur diesel." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1290.

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Анотація:
Les systèmes de post-traitement qui combinent diverses fonctionnalités dans un même dispositif catalytique sont considérées comme une solution efficace pour réussir l’objectif définie par les restrictives futures normes qui régulent les émissions de l'industrie automobile. Ils permettent non seulement de réduire les coûts intrinsèques dus à l’encombrement mais aussi, dans certains cas, de favoriser les réactions catalytiques par des effets thermiques ou synergiques. Ce concept est particulièrement étudié pour les moteurs Diesel dont la ligne d'échappement peut comprendre jusqu'à quatre éléments. La réduction des NOx peut être réalisée par réduction catalytique sélective de l'ammoniac sur filtre (NH3-SCRF) en utilisant des catalyseurs à base de zéolite échangée par Cu ou Fe. Ce filtre à suie catalysé assume simultanément deux fonctions: l'élimination des particules et la réduction des espèces de NOx vers N2 et de l’eau. En ce qui concerne les catalyseurs SCR, la couche active est classiquement déposée sur les parois d'un substrat de grande porosité dont les canaux sont bloqués à des extrémités alternatives. Une porosité accrue du substrat du filtre (tel que la cordiérite ou SiC) est nécessaire pour permettre le dépôt de la quantité de phase de catalyseur nécessaire pour le traitement des émissions gazeuses en assurant une filtration efficace et sans produire un effet de contre-pression du system. En plus, il est nécessaire de remarquer que des nouvelles réactions se produiront dans ce système puisque la suie Diesel, le NOx et l'agent réducteur sont présents dans la même unité pour la première fois. Selon la littérature actuellement disponible, les polluants et la suie peuvent interagir de trois manières principales: 1) la suie bloque l'accessibilité du flux gazeux aux sites actifs «classiques» du catalyseur; 2) possibilité de réduction des NOx sur les particules de suie; et enfin, 3) la présence de suie affecte les performances des réactions SCR ou, au contraire, les réactions SCR affectent le processus d'oxydation des particules jusqu'à ce que la compétition pour le NO2 soit produite
Aftertreatment systems that combine various functionalities into the same catalytic device are considered to be an efficient solution to reach the target defined by the restrictive future emission standards that regulate the automotive industry emissions. They are able not only to reduce the intrinsic costs due to the packaging but also, in some cases, to promote catalytic reactions by thermal or synergistic effects. This concept is being particularly explored for Diesel engines whose exhaust line may comprise up to four separate elements. NOx abatement can be accomplished by ammonia selective catalytic reduction on filter (NH3-SCRF) using Cu or Fe-exchanged zeolite-based as catalysts. This catalysed soot filter assumes two functions, simultaneously: removal of particles and reduction of NOx species towards N2. Regarding the SCR catalysts, the active layer is conventionally deposited onto the walls of a high porosity substrate whose channels are blocked at alternative ends. An increased porosity of the filter (such as cordierite or SiC) substrate is required to allow the deposition of the amount of catalyst phase needed for the treatment of gaseous emissions while efficient filtration and without producing a backpressure effect. Furthermore, it is necessary to remark that new reactions will occur in this system as Diesel soot, NOx and the reductant agent are present in the same unit for the first time. Accordingly to the literature currently available, there are three main ways that NOx pollutants and soot may interact: 1) soot blocking the accessibility of gas flow to “classic” active sites of the catalyst; 2) possibility of NOx reduction takes place over the soot particles; and finally, 3) soot presence affects SCR reactions performance or, contrarily, SCR reactions affects PM oxidation process as far as competition for NO2 will be produced
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2

Onder, Aylin. "Synthesis Of Zeolite Membranes In Flow System." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614815/index.pdf.

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Анотація:
Zeolite membranes are formed as a thin zeolitic layer on the supports. They are usually synthesized by hydrothermal methods in batch systems. In this study, MFI and SAPO-34 type zeolite membranes were produced on macroporous tubular alumina supports in a recirculating flow system at elevated temperatures for the first time in the literature. During the synthesis, the synthesis mixture is flown between the reservoir and the membrane module which includes the support material. The synthesis temperatures were 180°
C and 220°
C, and the corresponding system pressures were approximately 20 and 30 bars for MFI and SAPO-34, respectively. The CH4 and n-C4H10 single gas permeances were measured through MFI membranes and the performance of membranes was investigated in the separation of equimolar CH4/n-C4H10 mixtures. The best MFI membrane had a CH4 single gas permeance of 1.45x10-6 mol/m2-s-Pa and CH4/n-C4H10 ideal selectivity of 35 at 25oC. The membranes preferentially permeated n-C4H10 in the separation of mixtures. The n-C4H10/CH4 separation selectivity was 43.6 with a total permeance of approximately 0.8x10-6 mol/m2-s-Pa at 25oC. The ideal selectivities of CO2/CH4 of SAPO-34 membrane synthesized in stagnant medium were 227, and >
1000 at 220 and 200oC, respectively. Formation of amorphous structure and the additional secondary phases (impurities) were observed on SAPO-34 membranes synthesized in recirculating flow system. The results showed that it is possible to produce SAPO-34 and high quality MFI membranes by a recirculating flow system operating at elevated temperature.
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3

Cakal, Ulgen. "Natural Gas Purification By Zeolite Filled Polyethersulfone Based Mixed Matrix Membranes." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611206/index.pdf.

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Анотація:
This research investigates the effect of feed composition on the separation performance of pure polyethersulfone (PES) and different types of PES based mixed matrix membranes (MMMs) in order to develop high performing membranes for CO2/CH4 separation. MMMs were prepared by solvent evaporation method using PES as the polymer matrix with SAPO-34 particles as fillers, and 2-hydroxy 5-methyl aniline (HMA) as the low molecular weight additive. Four types of membranes were used throughout the study, namely pure PES membrane, PES/HMA (4, 10%w/w) membrane, PES/SAPO-34 (20%w/w) MMM, PES/SAPO-34 (20%w/w)/HMA (4, 10%w/w) MMM. The effect of CO2 composition on the performance of the membranes was investigated in detail with a wide feed composition range changing between 0 and 100%. In addition to separating CO2/CH4 binary gas mixtures, the separation performances of these membranes were determined by measuring single gas permeabilities at 35º
C, with a feed pressure of 3 bar. Moreover, the membranes were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analyzer (TGA). The separation selectivities of all types of membranes generally observed to be independent of feed composition. The composition independency of these membranes eliminates the need of investigating at which feed gas composition the prepared membranes are best performing for practical applications. PES/SAPO-34/HMA MMMs with HMA loading of 10% and SAPO-34 loading of 20% demonstrated the highest separation selectivity of about 40, and the ideal selectivity of 44, among the used membranes.
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4

Oral, Edibe Eda. "Effect Of Operating Parameters On Performance Of Additive/ Zeolite/ Polymer Mixed Matrix Membranes." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612957/index.pdf.

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Анотація:
Membrane based separation techniques have been widely used and developed over decades. Generally polymeric membranes are used in membrane based gas separation
however their gas separation performances are not sufficient enough for industrial feasibility. On the other hand inorganic membranes have good separation performance but they have processing difficulties. As a consequence mixed matrix membranes (MMMs) which comprise of inorganic particles dispersed in organic matrices are developed. Moreover, to enhance the interaction between polymer and zeolite particles ternary mixed matrix membranes are introduced by using low molecular weight additives as third component and promising results were obtained at 35 °
C. Better understanding on gas transport mechanism of these membranes could be achieved by studying the effect of preparation and operating parameters. This study investigates the effect of operation temperature and annealing time and temperature on gas separation performance of MMMs. The membranes used in this study consist of glassy polyethersulfone (PES) polymer, SAPO-34 particles and 2- v hidroxy 5-methyl aniline (HMA) as compatibilizer. The membranes fabricated in previous study were used and some membranes were used as synthesized while post annealing (at 120°
C, 0.2atm, N2 atm, 7-30 days) applied to some membranes before they are tested. The temperature dependent gas transport properties of the membranes were characterized by single gas permeation measurements of H2, CO2, and CH4 gases between 35 °
C-120 °
C. The membranes also characterized by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Annealing time and temperature affected the reproducibility and stability of the mixed matrix membranes and by applying post annealing step to mixed matrix membranes at higher temperatures and longer times, more stable membranes were obtained. For pure PES membranes thermally stable performances were obtained without any need of extra treatment. The permeabilities of all studied gases increased with increasing operation temperature. Also the selectivities of H2/CO2 were increased while CO2/CH4, H2/CH4 selectivities were decreased with temperature. The best separation performance belongs to PES/SAPO-34/HMA mixed matrix membrane at each temperature. When the temperature increased from 35 °
C to 120 °
C H2/CO2 selectivity for PES/SAPO- 34/HMA membrane was increased from 3.2 to 4.6 and H2 permeability increased from 8 Barrer to 26.50 Barrer. This results show that for H2/CO2 separation working at higher temperatures will be more advantageous. The activation energies were found in the order of
CH4 >
H2>
CO2 for all types of membranes. Activation energies were in the same order of magnitude for all membranes but the PES/SAPO-34 membrane activation energies were slightly lower than PES membrane. Furthermore, PES/SAPO-34/HMA membrane has activation energies higher than PES/SAPO-34 membrane and is very close to pure membrane which shows that HMA acts as a compatibilizer between two phases.
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5

Crawford, Phillip Grant. "Zeolite membranes for the separation of krypton and xenon from spent nuclear fuel reprocessing off-gas." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50383.

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Анотація:
The goal of this research was to identify and fabricate zeolitic membranes that can separate radioisotope krypton-85 (half-life 10.72 years) and xenon gas released during spent nuclear fuel reprocessing. In spent nuclear fuel reprocessing, fissionable plutonium and uranium are recovered from spent nuclear fuel and recycled. During the process, krypton-85 and xenon are released from the spent nuclear fuel as process off-gas. The off-gas also contains NO, NO2, 129I, 85Kr, 14CO2, tritium (as 3H2O), and air and is usually vented to the atmosphere as waste without removing many of the radioactive components, such as 85Kr. Currently, the US does not reprocess spent nuclear fuel. However, as a member of the International Framework for Nuclear Energy Cooperation (IFNEC, formerly the Global Nuclear Energy Partnership), the United States has partnered with the international nuclear community to develop a “closed” nuclear fuel cycle that efficiently recycles all used nuclear fuel and safely disposes all radioactive waste byproducts. This research supports this initiative through the development of zeolitic membranes that can separate 85Kr from nuclear reprocessing off-gas for capture and long-term storage as nuclear waste. The implementation of an 85Kr/Xe separation step in the nuclear fuel cycle yields two main advantages. The primary advantage is reducing the volume of 85Kr contaminated gas that must be stored as radioactive waste. A secondary advantage is possible revenue generated from the sale of purified Xe. This research proposed to use a zeolitic membrane-based separation because of their molecular sieving properties, resistance to radiation degradation, and lower energy requirements compared to distillation-based separations. Currently, the only commercial process used to separate Kr and Xe is cryogenic distillation. However, cryogenic distillation is very energy intensive because the boiling points of Kr and Xe are -153 °C and -108 °C, respectively. The 85Kr/Xe separation step was envisioned to run as a continuous cross-flow filtration process (at room temperature using a transmembrane pressure of about 1 bar) with a zeolite membrane separating krypton-85 into the filtrate stream and concentrating xenon into the retentate stream. To measure process feasibility, zeolite membranes were synthesized on porous α-alumina support discs and permeation tested in dead-end filtration mode to measure single-gas permeance and selectivity of CO2, CH4, N2, H2, He, Ar, Xe, Kr, and SF6. Since the kinetic diameter of krypton is 3.6 Å and xenon is 3.96 Å, zeolites SAPO-34 (pore size 3.8 Å) and DDR (pore size 3.6 Å) were studied because their pore sizes are between or equal to the kinetic diameters of krypton and xenon; therefore, Kr and Xe could be separated by size-exclusion. Also, zeolite MFI (average pore size 5.5 Å) permeance and selectivity were evaluated to produce a baseline for comparison, and amorphous carbon membranes (pore size < 5 Å) were evaluated for Kr/Xe separation as well. After permeation testing, MFI, DDR, and amorphous carbon membranes did not separate Kr and Xe with high selectivity and high Kr permeance. However, SAPO-34 zeolite membranes were able to separate Kr and Xe with an average Kr/Xe ideal selectivity of 11.8 and an average Kr permeance of 19.4 GPU at ambient temperature and a 1 atm feed pressure. Also, an analysis of the SAPO-34 membrane defect permeance determined that the average Kr/Xe selectivity decreased by 53% at room temperature due to unselective defect permeance by Knudsen diffusion. However, sealing the membrane defects with polydimethylsiloxane increased Kr/Xe selectivity by 32.8% to 16.2 and retained a high Kr membrane permeance of 10.2 GPU at ambient temperature. Overall, this research has shown that high quality SAPO-34 membranes can be consistently fabricated to achieve a Kr/Xe ideal selectivity >10 and Kr permeance >10 GPU at ambient temperature and 1 atm feed pressure. Furthermore, a scale-up analysis based on the experimental results determined that a cross-flow SAPO-34 membrane with a Kr/Xe selectivity of 11.8 and an area of 4.2 m2 would recover 99.5% of the Kr from a 1 L/min feed stream containing 0.09% Kr and 0.91% Xe at ambient temperature and 1 atm feed pressure. Also, the membrane would produce a retentate stream containing 99.9% Xe. Based on the SAPO-34 membrane analysis results, further research is warranted to develop SAPO-34 membranes for separating 85Kr and Xe.
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6

GENTILE, VINCENZO MARIA. "Innovative Adsorption Heat Exchangers for Desiccant Cooling and Atmospheric Water Harvesting." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2861334.

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7

Li, Zhibin. "New micro and mesoporous materials for the reaction of methanol to olefins." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/44229.

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Анотація:
(1) We will show that nano sized samples of SAPO-34 synthesized by microwave heating presents much higher lifetime than standard-SAPO-34 synthesized by conventional hydrothermal method for the reaction of methanol to olefins. (2) We will stabilize the Nano SAPO-34 in the ways such as steaming with water or calcinated in H2 condition. (3) The treatment of mix alkali treatment with proper TPAOH/NaOH could make composites with mesopore and microporous structure in the zeolite ZSM-5 to reduce strong acid quantity and the change the selectivity of the main product. (4) Different 8MR zeolite show different selectivity and lifetime in the same condition in the reaction of methanol to olefins.
Li, Z. (2014). New micro and mesoporous materials for the reaction of methanol to olefins [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/44229
TESIS
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8

Kgaphola, Kedibone Lawrence. "Synthesis and performance evaluation of Nanocomposite SAPO-34/ceramic membranes for CO₂/N₂ mixture separation." Thesis, 2017. https://hdl.handle.net/10539/24188.

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School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa August 2017
Global warming, resulting from emission of greenhouse gases (GHGs), is the cause of drastic climate changes that threatens the economy and living conditions on the planet. Currently, recovery and mitigation of these greenhouse gases remains a technological and scientific challenge. Various recovery processes for the mitigation of GHGs have been reported including among others carbon capture and storage (CCS). The most mature and applied technology in CCS process involves the absorption of carbon dioxide on amine based solvents. However, studies have shown that this process has several drawbacks that include low stability and high energy required to strip off the absorbed CO2 and regenerate the solvent. This presents an opportunity for the development of new materials for CO2 capture such as zeolite membranes. Previous studies have shown that the separation of CO2 can be achieved with high selectivity at low temperatures using thin-film SAPO-34 membranes (thin layers on supports). This is because CO2 adsorbs strongly on the membranes compared to other gases found in flue gas. In the thin-film membranes supported on ceramic or sintered stainless steel, thermal expansion mismatch may occur at higher operating temperatures resulting in loss of membrane selectivity due to the formation of cracks. A new method is required to overcome the aforementioned problems, thereby enhancing the separation application of the membranes at higher temperatures. The effective separation and capture of CO2 from the coal-fired power plant flue gas is an essential part in the CCS process (Figueroa et al., 2016; Yang et al., 2008). Currently, the capture stage is a huge contributor to the overall cost of CCS (Yang et al., 2008). This is due to the high-energy intensity and inefficient thermal processes applied in the separation and capture in various industrial applications (Yang et al., 2008). This work presents the use of nanocomposite SAPO-34 zeolite membranes synthesized via the pore-plugging hydrothermal method for the separation of CO2 during post-combustion CO2 capture. The SAPO-34 membranes used were supported on asymmetric α-alumina as membrane supports. The membranes were characterized with a combination of dynamic and static physicochemical techniques such as Basic Desorption Quality Test (BDQT), X-ray diffraction (XRD) spectroscopy, Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The characteristic peaks at 2θ = 21°, 26°, and 32° on the XRD pattern confirmed the presence of SAPO-34 with a rhombohedral crystalline structure. The SEM images showed the formation of the cubic crystalline which were consistent with the reported morphology of SAPO-34. FTIR spectra showed the presence of the essential double-6 membered rings (D6R) and TO4 structural groups in surface chemistry of crystalline materials further confirming the presence SAPO-34. The TGA confirmed that the membranes possessed high thermal stability. To assess the feasibility of the synthesis process, the nanocomposite zeolites were grown within the tubular supports. The SEM images of the cross-section of the membrane confirmed the presence of the zeolites within the pores of the support confirming the fabrication of nanocomposite membranes by the pore-plugging synthesis method. The permeation tests used a dead-end filtration mode to measure the single gas permeance and the ideal selectivity of CO2 and N2 were calculated. The BDQT was essential in the study of the quality of the as-synthesized nanocomposite membranes. The quality of the membranes increased with an increase in the synthesis layers of the membranes. However, with an increase in synthesis layers, the membrane thickness also increases. The membrane thickness affected the gas permeance for CO2 and N2 significantly. The permeance of the N2 gas decreased from 10.73 x10-7 mol.s-1.m2Pa-1 after the first synthesis to 0.31 x10-7 mol.s-1.m2Pa-1 after seven synthesis layers. Alternatively, the more adsorbing gas CO2 decreased from 12.85 x10-7 mol.s-1.m2Pa-1 to 2.44 x10-7 mol.s-1.m2Pa-1. The performance of these zeolite membranes depends significantly on the operating conditions. Hence, we studied extensively the influence of the various operating conditions such as temperature, feed pressure and feed flowrate in this work. Results indicated that the membrane separation performance in this study is largely dependent on the temperature. In addition, the ideal selectivity decreased significantly with an increase in temperature. High temperatures results in less adsorption of the highly adsorbing CO2 gas, the permeance reduces significantly, while the permeance of the less adsorbing N2 increased slightly. The feed flow rate has less effect on the adsorbing gas while the non-absorbing gas increased resulting in a decrease in the ideal selectivity as well. The nanocomposite membranes in this study have a low flux compared to their thin film counterparts. An increase in feed pressure significantly increased the flux significantly as well as the ideal selectivity. Maxwell-Stefan model simulation was done in this study to describe the permeance of pure CO2 single gas permeance as a function of temperature. This model considered explicitly the adsorption-diffusion mechanism, which is the transport phenomenon, involved in the transport of CO2 through the zeolite membrane. The description of the support material was included in the model as well. However, the model was only applied to the CO2 gas permeation well within the experimental data. We then compared the model was with the experimental results and a good correlation was observed. In conclusion, SAPO-34 nanocomposite zeolite membranes were obtained at low temperatures (150 °C) with a short synthesis time (6 h). In addition, the high thermal stability of the as-synthesized SAPO-34 membranes makes them ideal for high temperature CO2 separation such as the intended post-combustion carbon capture. The BDQT revealed that the quality of the membranes was related to the thickness of the membranes. Therefore, better membrane quality was obtained with relatively thicker membranes. The separation performance evaluation was conducted on the membrane with the greatest quality. Our findings demonstrate that the performance of the membranes depends extensively on the operating conditions.
MT2018
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Частини книг з теми "Zeolite SAPO-34"

1

Hernández-Palomares, A., Y. Reyes-Vidal, and F. Espejel-Ayala. "SAPO-34 Zeolite and Membranes for Biogas Purification." In Bio-Clean Energy Technologies: Volume 1, 181–208. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-8090-8_8.

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2

Barthomeuf, Denise. "Generation of Acidity (Amount and Strength) in Silicoaluminophosphates (SAPO Zeolites). Examples of SAPO-5, -11, -34 and - 37." In Acidity and Basicity of Solids, 375–90. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0986-4_17.

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3

Li, Jinzhe, Yue Qi, Dazhi Zhang, and Zhongmin Liu. "Propylene production by co-reaction of ethylene and chloromethane over SAPO-34." In From Zeolites to Porous MOF Materials - The 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference, 1578–82. Elsevier, 2007. http://dx.doi.org/10.1016/s0167-2991(07)81033-0.

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Zhao, G. L., J. W. Teng, Z. K. Xie, W. M. Yang, Q. L. Chen, and Y. Tang. "Catalytic cracking reactions of C4-olefin over zeolites H-ZSM-5, H-mordenite and H-SAPO-34." In From Zeolites to Porous MOF Materials - The 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference, 1307–12. Elsevier, 2007. http://dx.doi.org/10.1016/s0167-2991(07)80992-x.

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Jiang, Y., J. Huang, W. Wang, and M. Hunger. "Formation of methylamines by the reaction of ammonia with surface methoxy species on zeolite H-Y and the silicoaluminophosphate H-SAPO-34." In From Zeolites to Porous MOF Materials - The 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference, 1331–37. Elsevier, 2007. http://dx.doi.org/10.1016/s0167-2991(07)80996-7.

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6

Jiang, Y., J. Huang, J. Weitkamp, and M. Hunger. "In situ MAS NMR and UV/VIS spectroscopic studies of hydrocarbon pool compounds and coke deposits formed in the methanol-to-olefin conversion on H-SAPO-34." In From Zeolites to Porous MOF Materials - The 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference, 1137–44. Elsevier, 2007. http://dx.doi.org/10.1016/s0167-2991(07)80970-0.

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7

Yu, Jong-Sung, Gern-Ho Back, Vadim Kurshev, and Larry Kevan. "Electron spin resonance and electron spin echo modulation spectroscopic study of Pd(I) location and adsorbate interactions in PdH-SAPO-34 molecular sieve." In Zeolite Science 1994: Recent Progress and Discussions - Supplementary Materials to the 10th International Zeolite Conference, Garmish-Partenkirchen, Germany, July 17-22, 1994, 77–78. Elsevier, 1995. http://dx.doi.org/10.1016/s0167-2991(06)81094-3.

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"CHA SAPO-34 Al(47), P(32), Si(21)." In Verified Syntheses of Zeolitic Materials, 129–31. Elsevier, 2001. http://dx.doi.org/10.1016/b978-044450703-7/50134-4.

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9

"CHA SAPO-44 Al(48), P(34), Si(18)." In Verified Syntheses of Zeolitic Materials, 132–33. Elsevier, 2001. http://dx.doi.org/10.1016/b978-044450703-7/50135-6.

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10

Ihm, S. K., S. W. Baek, Y. K. Park, and K. C. Park. "24-P-26-The nature of medium acidity in [CuO/ZnO/ZrO2]SAPO-34 hybrid catalyst for CO2 hydrogenation: study of the interactions between metal oxides and acid sites in zeolite." In Studies in Surface Science and Catalysis, 277. Elsevier, 2001. http://dx.doi.org/10.1016/s0167-2991(01)81608-6.

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Тези доповідей конференцій з теми "Zeolite SAPO-34"

1

Xiao, Wencan, Bo Zhang, Hao Xu, Song Xiao, and Yanna Liu. "Influence of dual template on the synthesis of size controllable zeolite SAPO-34." In 2016 International Conference on Civil, Transportation and Environment. Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/iccte-16.2016.181.

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2

Yang, L., S. C. Zhang, Y. P. Feng, Z. T. Zhu, Y. B. Song, and Y. W. Fang. "Synthesis of SAPO-34 Zeolite with Different Template Agents and DTO Catalytic Studies." In The International Workshop on Materials, Chemistry and Engineering. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0007441305450551.

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Yu, Lemeng, Qin Zhong, and Shule Zhang. "Solvent-Free synthesis of Cu-SAPO-34 zeolite for NH3-SCR DeNOx with Cu-TEPA." In Annual International Conference on Sustainable Energy and Environmental Sciences. Global Science & technology Forum ( GSTF ), 2016. http://dx.doi.org/10.5176/2251-189x_sees16.41.

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Malone, Nathan, Sourav Chakravarty, Shiyu Zhang, Dorsa Talebi, Sri Vignesh Sankarraman, Erick Pool, Deokgeun Park, et al. "Investigation of Mass Savings Potential of Zeolite Integrated Motor Thermal Management Systems in All-Electric Commercial Aircraft." In ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-96671.

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Abstract This study investigates a novel hybrid cooling method for more weight efficient thermal management of aerospace electric propulsion motors using thermal energy storage (TES) elements. The proposed system utilizes the latent heating of TES in the form of SAPO-34 zeolite slabs hydrated with water to maintain stable operating temperatures during takeoff. The TES operates in parallel with a fluid cooling system comprised of minichannel heatsinks attached to the stator windings and exterior air heat exchanger. Thermoelectric performance benefits of TES inclusion are evaluated using network analysis under assumed flight path load. Complex non-linear thermofluid and electromagnetic behaviors in the network are replaced with lookup table interpolants generated using results of numerical simulations swept across a series of input parameters. Subsequent solution of two-hundred systems with varying TES volume indicated a maximum TMS mass savings of 14.8% compared to the lightest thermal management system without TES inclusion.
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Ng, Won Huei, Nor Naimah Rosyadah Ahmad, Choe Peng Leo, and Abdul Latif Ahmad. "Polysulfone/SAPO-34 zeolite membrane impregnated with 1-ethyl-3-methyl imidazolium bis(tri-fluoromethylsulfonyl)imide ionic liquid for CO2 removal." In 6TH INTERNATIONAL CONFERENCE ON ENVIRONMENT (ICENV2018): Empowering Environment and Sustainable Engineering Nexus Through Green Technology. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5117126.

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