Synthesis and characterization of zeolite beta

Tamer, Nadir Hakan
Zeolite beta has been synthesized using hydrothermal methods. In order to synthesize zeolite beta an aqueous gel having a molar batch composition of 2.2 Na2O Al2O3 x SiO2 4.6 (TEA)2O 444 H2O was utilized. The synthesis parameters were SiO2/Al2O3 ratio (20 ≤ x ≤ 50) and crystallization time (6 ≤ t ≤ 16 days). Pure zeolite beta was crystallized from the experiments which were performed with the batch composition having SiO2/Al2O3 of 20 and 30 in 6 to 16 days period. For SiO2/Al2O3 of 20 and 30, the highest yield was obtained for 12 days. Therefore, the rest of the experiments, in which SiO2/Al2O3 was 40 and 50, were carried out keeping the synthesis time constant (12 days). Pure zeolite beta was also synthesized for SiO2/Al2O3 of 40 and 50. The highest yield and the most crystalline zeolite beta sample were obtained from the experiment performed at SiO2/Al2O3 of 50 with a synthesis time of 12 days. The morphology and crystal size of the zeolite beta samples were identified by using scanning electron microscope (SEM). It was observed that, zeolite beta samples had spheroidal morphology with the crystal size of about 0.5 ́m. According to the thermogravimetric analyses (TGA), it was found that template molecules and moisture constituted nearly 18 % by weight of the zeolite beta samples. The surface area of the calcined zeolite beta sample was determined by N2 adsorption and was found to be 488 m2/g. Gravimetric sorption analyses yield that, the limiting sorption capacity of Na-Beta for methanol, ethanol, isopropanol and n-butanol at 0°C was about the same with a value of 0.25 cm3/g. For o-xylene, m-xylene and p-xylene that value was 0.21 cm3/g, 0.22 cm3/g and 0.24 cm3/g, respectively.


Synthesis of low silica/alumina zeolite membranes in a flow system
Akbay, Sezin; Kalıpçılar, Halil; Department of Chemical Engineering (2007)
Zeolite A-type membranes are usually synthesized from hydrogels and rarely synthesized from clear solutions mostly in batch systems. Few studies were carried out using semi-continuous systems for zeolite A membrane synthesis. Zeolite A membranes are mainly used in pervaporation processes for separation of water from water/organic mixtures because of their hydrophilic property. In this study, zeolite A membranes were synthesized on -alumina supports from a clear solution with a molar composition of 49Na2O: ...
Dynamic and steady-state analysis of oxidative dehydrogenation of ethane
Karamullaoğlu, Gülsün; Doğu, Timur; Department of Chemical Engineering (2005)
In this research, oxidative dehydrogenation of ethane to ethylene was studied over Cr-O and Cr-V-O mixed oxide catalysts through steady-state and dynamic experiments. The catalysts were prepared by the complexation method. By XRD, presence of Cr2O3 phase in Cr-O; and the small Cr2O3 and V2O4 phases of Cr-V-O were revealed. In H2-TPR, both catalysts showed reduction behaviour. From XPS the likely presence of Cr+6 on fresh Cr-O was found. On Cr-V-O, the possible reduction of V+5 and Cr+6 forms of the fresh sa...
Synthesis and enhanced photocatalytic activity of nitrogen-doped triphasic TiO2 nanoparticles
Erdogan, Nursev; Bouziani, Asmae; PARK, JONGEE; Micusik, Matej; Kim, Soo Young; Majkova, Eva; Omastova, Maria; Öztürk, Abdullah (Elsevier BV, 2019-05-15)
TiO2 nanoparticles of the single anatase phase, binary anatase-brookite phases, and ternary anatase-brookite-rutile phases were synthesized using an HNO3-catalyzed hydrothermal process. The types and amounts of phases varied depending on the hydrothermal synthesis conditions. The results revealed that N dissolves in different amounts and chemical states, depending on the phases present and their proportions in the nano particles. Brookite and rutile nanoparticles oriented through one direction were found to...
Dissolution of colemanite and crystallization of gypsum during boric acid production in a batch reactor
Erdoğdu, Anıl; Eroğlu, İnci; Department of Chemical Engineering (2004)
One of the most commonly used boron compounds, boric acid, is produced by dissolving colemanite (2CaO₉3B2O3₉5H2O) in aqueous sulfuric acid whereby gypsum (CaSO4₉2H2O) is formed as a byproduct and must be separated from the main product. This process consists of two steps, dissolution of colemanite and formation of gypsum. The amount of boric acid formed depends on the first step, dissolution of colemanite. In the latter step, gypsum crystals are formed and stay in the reaction mixture to grow up to a size l...
Synthesis and Characterization of Aluminum Containing Silica Aerogel Catalysts for Degradation of PLA
Sivri, Seda; Dilek Hacıhabiboğlu, Çerağ; Sezgi, Naime Aslı (Walter de Gruyter GmbH, 2019-05-01)
Aluminum loaded silica aerogel based catalysts were synthesized by impregnation of aluminum into silica aerogel produced using sol-gel method in different aluminum loadings (2.5-15 wt%) to investigate their performances in degradation of polylactic acid (PLA).
Citation Formats
N. H. Tamer, “Synthesis and characterization of zeolite beta,” M.S. - Master of Science, Middle East Technical University, 2006.