Synthesis of nanosized ZSM-5 zeolite using extracted silica from rice husk without adding any alumina source (original) (raw)
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A facile synthesis of ZSM-11 zeolite particles using rice husk ash as silica source
Materials Letters, 2012
a b s t r a c t ZSM-11 zeolite particles were prepared through in-situ extraction (extraction and conversion in a single step process) of silica from rice husk ash in the presence of other aqueous-based precursors (sodium aluminate and tetrabutyl ammonium hydroxide) following a simple hydrothermal condition at 100 1C. The particles were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA) and field emission scanning electron microscopy (FESEM). XRD pattern confirmed the crystallization of ZSM-11 obtained at 100 1C/12 days. The vibration bands at around 548 and 1221 cm À 1 indicated the presence of double 5-ring (D5R) in the pentasil zeolite structure of ZSM-11. The exothermic peak at 463 1C in DTA curve indicated the removal of tetrabutyl ammonium ion (TBA þ ) which was used as a structure directing agent (SDA). FESEM image showed that nano-sized ZSM-11 particles were agglomerated in the crystals. The Si/Al ratio of ZSM-11 particles was found to be 51 as indicated by the elemental analysis with energy dispersive X-ray (EDX).
Organic template-free synthesis of ZSM-5 zeolite particles using rice husk ash as silica source
Ceramics International, 2013
ZSM-5 zeolite particles were synthesized through in-situ extraction of silica from rice husk ash in the absence of organic template by a simple hydrothermal condition at 150 1C/72-96 h. The powders were characterized by XRD, TGA, DTA, FTIR, N 2 physisorption studies, and field emission scanning electron microscopy (FESEM). Crystallization of ZSM-5 started at 150 1C/72 h. The vibration bands at around 540 and 1220 cm À 1 indicated the presence of characteristic double 5-ring of ZSM-5. The BET surface area and pore volume increased with increase in synthesis time from 72 to 96 h at 150 1C. FESEM images showed coffin-shaped morphology of ZSM-5 particles.
Materials Science Forum, 2019
ZSM-5 has been successfully synthesized by seeding method using coal bottom ash and rice husk as the sources of silica and alumina.Synthesis ZSM-5 were performed by the hydrothermal method in autoclave autogenous at 180 °C for 36 h with molar ratio 10Na : 50SiO : 2Al2O3 : 500H2O with the addition of ZSM-5 commercial as seed. In this experiments, investigated variations seed amounts of 5, 10, 15, and 20% of weight silica. The product was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and Brunauer-Emmet-Teller (BET). Resulted showed that ZSM-5 succeed formed in all variation of seed contain. At variation seed amount 5%, crystallinity obtained still low in which content of quartz phase still be high. Percent crystallinity highest obtained at the variation of seed amount 20% with the result percent crystallinity relative 106%. The experimental results revealed that phase transformation has occurred, in which an amorpho...
Synthesis of ZSM−5 zeolite using Bayat natural zeolite as silica and alumina source
AIP Conference Proceedings
Zeolite ZSM-5 has been successfully synthesized from natural zeolite Bayat without further purification. The silica and alumina source are taken from the natural zeolite through submolten depolimerization method. Ludox 40% was used as additional silica source to reach Si/Al ratio of 32 in the starting gel and tetrapropylammonium hydroxide (TPAOH) was used as a structure directing agent (SDA). Synthesis was carried out hydrothermally with aging and crystallization temperature at 150°C. The as-synthesized zeolite was characterized with XRD, FTIR and SEM-EDX. The XRD patterns of the resulted synthesis showed diffraction peaks at 2θ = 7.9°-8.8° (doublet peaks) and diffraction peaks at 2θ = 22°-25° (triplet peaks) which are characteristic for ZSM-5 structure. The SEM image showed that the ZSM-5 zeolite from Bayat natural zeolite had morphology of hexagonal crystalls with some debris of impurities. The elemental analysis using EDX gave Si/Al molar ratio of 18.5.
2021
Utilizing of ash extracted from Iraqi common water reeds as an inexpensive effective silica source in the preparation of ZSM-5 zeolite was investigated for the first time in the present work. This study was conducted using a hydrothermal treatment at autogenous pressure. The molar content of silica (17.84-26.76), sodium oxide (1.71-2.4), water (76.92-304.6), organic template (0.55-2.73), organic solvent (23.46-140.76), and synthesis conditions (crystallization time (24-72 h) and temperature (130-180 • C)) were investigated to obtain high purity ZSM-5 zeolite microspheres. The zeolite samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-Ray (EDAX), N 2 adsorption/desorption isotherms, Thermogravimetric Analyzer (TGA), and Fourier transform infrared spectroscopy (FTIR). XRD pattern of all synthesized samples was compared to XRD pattern of the commercial ZSM-5 zeolite. This work allows using locally available solid waste resulted from a dry natural plant as an inexpensive silica source without using an external source of silica. Also, this is the first report of the direct synthesis of a high purity ZSM-5 zeolite microspheres from common water reeds ash containing highly reactive silica. A gel composition of 2Na 2 O: 26.76SiO 2 : Al 2 O 3 : 2.73TPAOH: 23.46EtOH: 304.6H 2 O gave an outstanding final product of ZSM-5 zeolite microspheres at 180 • C and 27 h. This high crystallinity ZSM-5 zeolite porous microspheres possess Si/Al ratio of 17, a crystal size of 61.419 nm, BET surface area of 277.482 m 2 /g, a total pore volume of 0.1659 cm 3 /g, micropore volume of 0.1131 cm 3 /g, pore width of 5.28 nm, and hierarchical factor of 0.14.
Fabrication of High Purity Silica from Rice Husk and Its Conversion Into ZSM-5
2016
A white rice husk ash with a silica content of more than 99% was produced from a rice husk by a citric acid treatment before heating the rice husk at 700 oC to 1000 oC. The white ash mostly consisted of an amorphous phase, and cristobalite usually found after heating rice husk was not detected. The amorphous phase was still formed although the rice husk was burned at 1000 oC. These indicated that the citric acid dissolved part of the carbon compounds in the rice husk, followed by releasing of potassium and other alkali cations, and as a result, an amorphous high silica ash was formed without incorporation of crystal phases such as cristobalite. The white rice husk ash was successfully converted into ZSM5, a zeolite widely used as a catalyst in the petroleum industries.
Synthesis and characterization of zeolite LSX from rice husk silica
Suranaree Journal of …, 2007
Silica powder with approximately 98% purity was extracted from rice husk (RH), converted to a sodium silicate solution, and used as a silica source for the synthesis of low silica type X (LSX) by hydrothermal process. The synthesized zeolite in the form of Na and K cations, referred to as NaK-LSX, was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), which confirmed the success of the synthesis. Images from scanning electron microscopy (SEM) of NaK-LSX displayed multi-faceted spherulite particles composed of polycrystal particles with different sizes along with small amorphous particles. The particle size distribution of NaK-LSX from a laser diffraction particle size analyzer (DPSA) was in the range of 0.2-50 μ μ μ μ μm and nitrogen adsorption indicated a surface area around 400 m 2 /g. The structure of LSX did not change after the ion-exchange to produce an ammonium form but collapsed after subsequent calcination.
Preparation and characterization of ZSM-5 zeolite
International journal of computational and experimental science and engineering, 2023
The research for new energy sources has promoted hydrocarbon production from biomass and solid wastes over ZSM-5 zeolites. The metal incorporation by different methods has led to a variety of chemical applications. In this way, the combination of the shape selectivity and acidity properties of the pentasil zeolites with the activity of metal oxide under different environments may influence the product distribution in diverse catalytic reactions. In this work, ZSM-5 zeolites were prepared by hydrothermal synthesis employing aluminum nitrate and AIP as aluminium sources and TPAOH as structure director agent at atmospheric pressure and low temperature (90 ºC). In addition, these materials were modified with iron and titanium cations by direct synthesis at 170 °C and autogenous pressure to promote the crystallinity. The characterization of the samples was performed by XRD, XRF, SEM, TPD-NH 3 and nitrogen adsorption. It was observed that the use of AIP and the metal incorporation decreases the crystallinity of the zeolites under synthesis conditions, which leads to increase the specific area value in the BET because of the presence of amorphous material. On the other hand, acidity of the modified zeolites was found to be lower than that of ZSM-5 zeolite.
Microporous and Mesoporous Materials, 2004
Partially crystalline and X-ray amorphous ZSM-5 zeolite-based aluminosilicates have been synthesized and thoroughly characterized by chemical analysis, XRD, FT-IR, solid state MAS NMR, N 2 adsorption, TEM, NH 3 -TPD and isopropanol dehydration as the catalytic test reaction. The X-ray amorphous and low-crystallinity samples were hydrothermally synthesized at temperatures as low as 25°C and consisted of nanosized well-formed particles of almost spherical shape and with dimensions of about 20-30 nm. These samples exhibited very low microporosity and remarkably high meso/macropore volume (pore diameters P30 nm) and/or high external surface area. The first Bragg peaks were observed in the XRD patterns of the samples synthesized at 90°C and their position on the 2h-axis was the same as those of a reference highly crystalline ZSM-5 zeolite sample. The particle/crystal size and microporosity of the partially crystalline materials increased with increasing hydrothermal synthesis temperature and % relative XRD crystallinity. Incorporation of aluminum in the ZSM-5 zeolitic framework was significantly enhanced at higher relative crystallinities, i.e. >60%. The X-ray amorphous aluminosilicates possessed tetrahedral aluminum atoms which were more zeolitic in character and induced a higher number of acidic framework hydroxyls (Brønsted acid sites), as compared to those found in a conventional silica-alumina.
Synthesis of ZSM-5 zeolite from lignite fly ash and rice husk ash
Fuel Processing Technology, 2004
The lignite fly ash from the Mae-Moh power plant, Thailand, and rice husk ash were used as raw materials for ZSM-5 zeolite synthesis. Factors affecting the yield of ZSM-5 zeolite synthesized from fly ash, i.e., the SiO 2 /Al 2 O 3 mole ratio, the presence of tetrapropyl ammonium bromide (TPABr, the structure-directing material for ZSM-5 zeolite synthesis), the holding temperature and time, and the initial pressure were investigated. It was found that without TPABr only zeolite P could be synthesized at SiO 2 /Al 2 O 3 mole ratios of 2.8 -200. In order to synthesize ZSM-5 zeolite, sodium silicate solution was added to adjust the SiO 2 /Al 2 O 3 mole ratio in raw ash. The yield of ZSM-5 zeolite was as high as 59 wt.% when following conditions were used: SiO 2 /Al 2 O 3 mole ratio, 40; the holding temperature, 210 jC; the holding time, 4 h and the initial pressure, 4 bar. The catalytic performance for CO 2 hydrogenation reaction of the ZSM-5 zeolite was preliminary tested and compared with that of commercial one. It was observed that there was no significant difference in the catalytic performance between these two catalysts.