Extrusion Molding of Sorbents Based on Synthesized Zeolite

Gordina, N. E.; Prokof’ev, V. Yu.; Il’in, A. P.

doi:10.1007/s10717-005-0092-3

Cited by 19 publications

(14 citation statements)

References 1 publication

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“…The optimum water content was ranged from 25 to 30 wt% and was controlled by the depth of immersion of the cone. The method for determining the optimum molding moisture is described in [13,14]. The granules with diameter of 3 ± 0.1 mm were molded from the paste using the piston extruder.…”

Section: Preparation Of Zeolitementioning

confidence: 99%

Mechanochemical synthesis of granulated LTA zeolite from metakaolin

et al. 2012

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LTA zeolite can be prepared from dry mixes in a vibratory mill with an impact-shear loading conditions. For the synthesis of LTA zeolite, it is necessary to use the anhydrous ingredients (Al 2 Si 2 O 7 -metakaolin, c-Al 2 O 3 ). The process of synthesis is controlled by X-ray diffraction, IR-spectroscopy, and atomic-force microscopy. The presence of structural water in the initial ingredients (Al 2 Si 2 (OH) 4 -kaolin or Al(OH) 3 ) leads to the formation of feldshpatoids (nepheline, sodalite). It was established that the process of mechanical activation requires the synthesis of sodium aluminate of cubic and/or tetragonal crystal systems with a lattice parameters close to those for LTA zeolite. These sodium aluminate acts as a steric template for an ''assembly'' of the zeolite. The presence of sodium aluminate with some other crystal structure results in the formation of sodalite. There is an optimal time of mechanochemical activation, which is determined by the synthesis of sodium aluminate with cubic or tetragonal crystal structure. A model of the mechanochemical synthesis of LTA zeolite was proposed.

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Section: Preparation Of Zeolitementioning

confidence: 99%

Mechanochemical synthesis of granulated LTA zeolite from metakaolin

et al. 2012

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“…The above-mentioned characteristics are controlled by the active component synthesis per se and shaping steps. Not surprising, the main attention of the academic research groups has been focused on the synthesis of active components, as reported for example in some of the previous studies, − while significantly less attention has been paid to catalyst forming or scaling-up to an industrial level. − …”

Section: Introductionmentioning

confidence: 99%

“…In fact zeta-potential has already been linked to the rheology of catalyst shaping; ,, however, up to now no clear conclusions about an optimal zeta-potential for extrusion have been made. Many studies are devoted to the rheology of ceramics − and zeolites, ,,, unfortunately not focusing on the tensile strength and texture characteristics of final materials. There are very few studies , of impact of rheological behavior of molding masses on textural properties of extrudates.…”

Section: Introductionmentioning

confidence: 99%

Shaping of Sulfated Zirconia Catalysts by Extrusion: Understanding the Role of Binders

Devyatkov

Zinnurova

Aho

et al. 2016

Ind. Eng. Chem. Res.

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Sulfated zirconia hydroxide shaping by extrusion is studied based on elucidating the impact of zeta-potential and rheological characteristics on physical and chemical properties of technical catalysts. Zeta potential measurements of sulfated zirconium hydroxide prior and after poly(vinyl alcohol) (PVA) additions were made. Rheological curves of sulfated zirconium hydroxide suspensions with different amounts of PVA were recorded at different zeta-potential values. The addition of PVA nonlinearly decreased shear yield stress. Experimental data were quantified with the Krieger–Dougherty equation. The influence of a boehmite-type binder on the zeta-potential confirmed that the surface properties of the particles to a large extent are determined by the presence of binder. The pore structure of shaped catalysts was unaffected by rheological parameters when zeta-potential is close enough to zero. At the same time deviations of the zeta potential from the zero-value afforded more uniform pore size distribution.

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“…Well-shaped bodies have been produced in the forms of pellets, tablets, monoliths, granules, and spheres [13][14][15][16]. However, to utilize shaped MOFs successfully for industrial applications, they should have sufficient mechanical strength, chemical stability, attrition resistance, maximal bulk density, and minimal wasted space in the storage vessel [17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Granulation and Shaping of Metal-Organic Frameworks

Lee

Valekar

Hwang

et al. 2016

The Chemistry of Metal-Organic Frameworks: Synthesis, Characterization, and Applications

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IntroductionShaping and forming of metal-organic frameworks (MOFs) are essential for practical applications like adsorption/separation and catalysis, which require structuring of the nano-/microcrystalline fine powders of MOFs into a macroscopic body [1][2][3][4][5][6][7]. When a process for catalysis or adsorptive separation is scaled up to the pilot or commercial scale, the form in which an active catalyst or adsorbent is used is decisive in determining the ultimate performance of the unit [8][9][10]. In this respect, the size and shape of the target material require a compromise between minimizing pore diffusion effects in the material particles, for which small particles are necessary, and minimizing the pressure drop across the reactor, which requires large particle sizes [11]. The shaped MOFs should maintain excellent performance shown by the original powder forms based on their high porosity, crystallinity, and flexibility [12]. Therefore, the proper selection of the shaping or forming process is important in the MOF research field for chemical engineering and industrial applications. As the shaping methods are often proprietary and often more of an art than a science, the exact procedures are rarely disclosed.The shaped MOFs can also be prepared using techniques (Figure 18.1) that have typically been utilized for synthesizing catalysts and adsorbents from porous materials, such as pressing, extrusion, granulation and spray drying, foaming, casting, and coating. Well-shaped bodies have been produced in the forms of pellets, tablets, monoliths, granules, and spheres [13][14][15][16]. However, to utilize shaped MOFs successfully for industrial applications, they should have sufficient mechanical strength, chemical stability, attrition resistance, maximal bulk density, and minimal wasted space in the storage vessel [17][18][19][20][21][22][23][24]. As the performance of shaped MOFs for industrial or large-scale applications depends on several parameters, including the mass-and heat-transfer properties, gas diffusion kinetics, pressure drop across material, mechanical strength, and volumetric efficiency, achieving high mechanical integrity of the structured MOF is critical to the performance in real engineering processes. The Chemistry of Metal-Organic Frameworks: Synthesis, Characterization, and Applications, First Edition. Edited by Stefan Kaskel.

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Extrusion Molding of Sorbents Based on Synthesized Zeolite

Cited by 19 publications

References 1 publication

Mechanochemical synthesis of granulated LTA zeolite from metakaolin

Mechanochemical synthesis of granulated LTA zeolite from metakaolin

Shaping of Sulfated Zirconia Catalysts by Extrusion: Understanding the Role of Binders

Granulation and Shaping of Metal-Organic Frameworks

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