scholarly journals Membran Reaktor untuk Pembuatan dan Pemurnian Isomer Xylene

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Wahyudin Wahyudin ◽  
Hens Saputra
Keyword(s):  
Pore Size Distribution ◽  
Zeolite Membrane ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Alumina Catalyst ◽  
Mfi Zeolite ◽  
Entire Surface ◽  
X Ray ◽  
Silica Alumina ◽  
Scanning Electron

Abstrak Membran reaktor merupakan konsep perpaduan dari sistem reaksi dan proses pemisahan/pemurnian. Membran ini disebut juga sebagai membran katalis atau sistem katalis-membran. Dengan membran reaktor ini diharapkan konversi suatu reaksi dapat ditingkatkan dan diperoleh suatu produk yang memiliki tingkat kemurnian lebih tinggi. Sebagai katalis digunakan silica alumina yang berukuran 1,0 mm. Membran anorganik  zeolit MFI dilapiskan menutupi seluruh permukaan katalis. Bahan baku yang digunakan antara lain tetraethylortosilicate (TEOS) sebagai sumber silikat dan template organik tetraprophyl ammonium bromide (TPABr). Proses kristalisasi dilakukan pada temperatur 453 K di dalam autogeneous autoclave, dilanjutkan dengan kalsinasi pada temperatur 873 K selama 1 jam. Karakterisasi membran zeolit yang dihasilkan dilakukan dengan X-ray diffraction (XRD) dan pengamatan dengan Scanning Electron Mycroscope (SEM). Karakteristik pori dipelajari menggunakan metode physisorption dan BJH pore size distribution. Selain itu dilakukan pula uji selektifitas dan alkilasi toluena dan xylene. Berdasarkan pengamatan menggunakan XRD mengindikasikan adanya struktur zeolit MFI pada sampel membrane katalis yang dihasilkan. Diperkuat dengan obserbasi SEM menunjukkan bahwa membran zeolit MFI melapisi seluruh permukaan pelet silika alumina dan terdapat indikasi terjadinya komposit terhadap silika alumina pada daerah perbatasan antara membran zeolit atau lapisan bagian luar dengan katalis silika alumina. Hasil pengujian menunjukkan hasil bahwa membran reaktor zeolit MFI berpotensi untuk diaplikasikan sebagai membran katalis yang bersifat sangat selektif terhadap bentuk suatu molekul. Kata kunci: membran reaktor, isomer, xylene, zeolit, silika alumina, hidrotermal   Abstract Membrane fusion reactor is the concept of system reactions and separation processes of purification. These membranes are called also catalyst membrane or catalyst-membrane system. With the reactor membrane is expected conversion of a reaction can be increased and obtained a product having a higher purity. As the silica alumina catalyst used measuring 1.0 mm. MFI zeolite coated inorganic membranes covering the entire surface of the catalyst. The raw materials used include tetraethylortosilicate (TEOS) as the source of silicates and organic template tetrapropyl ammonium bromide (TPABr). Crystallization process carried out at a temperature of 453 K in the autogeneous autoclave, followed by calcination at a temperature of 873 K for 1 hour. Characterization of zeolite membranes produced performed by X-ray diffraction (XRD) and scanning electron observations with Mycroscope (SEM). Pore ​​characteristics were studied using physisorption method and BJH pore size distribution. In addition, the selectivity of the test is also conducted and alkylation of toluene and xylene. Based on observations using XRD indicates a structure of MFI zeolite membrane on the resulting catalyst samples. Reinforced with SEM showed that the MFI zeolite membrane coating the entire surface of the silica alumina pellets and there are indications of the silica alumina composites in the border area between zeolite membrane or outer coating with silica alumina catalyst. The results show that the results of MFI zeolite reactor  membrane has the potential to be applied as a catalyst membrane that is highly selective to form a molecule. Keywords : reactor membrane, isomers, xylene, zeolite, silica alumina, hydrothermal

scholarly journals Pembuatan dan Karakteristik Membran Reaktor Zeolit

2019 ◽  
Vol 8 (1) ◽  
pp. 11-16
Author(s):  
Hens Saputra
Keyword(s):  
Pore Size ◽  
Membrane Reactor ◽  
Reaction System ◽  
Zeolite Membrane ◽  
Ammonium Bromide ◽  
Alumina Catalyst ◽  
Mfi Zeolite ◽  
Entire Surface ◽  
X Ray ◽  
Silica Alumina

Membran reaktor merupakan konsep perpaduan dari sistem reaksi dan proses pemisahan/pemurnian. Membran ini disebut juga sebagai membran katalis atau sistem katalis-membran. Dengan membran reaktor ini diharapkan konversi suatu reaksi dapat ditingkatkan dan diperoleh suatu produk yang memiliki tingkat kemurnian lebih tinggi. Sebagai katalis digunakan silica alumina yang berukuran 1,0 mm. Membran anorganik zeolit MFI dilapiskan menutupi seluruh permukaan katalis. Bahan baku yang digunakan antara lain tetraethylortosilikat (TEOS) sebagai sumber silikat dan template organik tetraprophyl ammonium bromide (TPABr). Proses kristalisasi dilakukan pada temperatur 453 K di dalam autogeneous autoclave, dilanjutkan dengan kalsinasi pada temperatur 873 K selama 1 jam. Karakterisasi membran zeolit yang dihasilkan dilakukan dengan X-ray diffraction (XRD) dan pengamatan dengan Scanning Electron Mycroscope (SEM). Karakteristik pori dipelajari menggunakan metode physisorption dan BJH pore size distribution. Selain itu dilakukan pula uji selektifitas dan alkilasi toluena dan xylene. Berdasarkan pengamatan menggunakan XRD mengindikasikan adanya struktur zeolit MFI pada sampel membrane katalis yang dihasilkan. Diperkuat dengan obserbasi SEM menunjukkan bahwa membran zeolit MFI melapisi seluruh permukaan pelet silika alumina dan terdapat indikasi terjadinya komposit terhadap silika alumina pada daerah perbatasan antara membran zeolit atau lapisan bagian luar dengan katalis silika alumina. Hasil pengujian menunjukkan hasil bahwa membran reaktor zeolit MFI berpotensi untuk diaplikasikan sebagai membran katalis yang bersifat sangat selektif terhadap bentuk suatu molekul. Sebagai contoh kasus, suatu isomer dapat dipisahkan satu sama lain secara selektif, sehingga dapat meningkatkan konversi reaksi.Kata kunci : Membran reaktor, isomer, xylene, zeolit, silika alumina, hydrothermal.AbstractMembrane fusion reactor is the concept of the reaction system and the process of separation/purification . These membranes are called also as membrane catalysts or catalyst - membrane system . With the membrane reactor is expected conversion reaction can be improved and obtained a product which has a higher degree of purity . As used silica alumina catalyst measuring 1.0 mm . MFI zeolite coated inorganic membranes covering the entire surface of the catalyst . The raw materials used include tetraethylortosilikat (TEOS ) as a source of silicate and organic template tetraprophyl ammonium bromide ( TPABr ) . Crystallization process carried out at a temperature of 453 K in the autogeneous autoclave , followed by calcination at a temperature of 873 K for 1 hour . Characterization of zeolite membranes produced by X - ray done diffraction ( XRD ) and scanning electron observations with Mycroscope ( SEM ) . Pore characteristics studied physisorption using BJH pore size and distribution . Test will be conducted and the selectivity of toluene and xylene alkylation . Based on observations using XRD indicates the MFI zeolite structure on the resulting catalyst membrane samples . Reinforced with obserbasi SEM showed that the MFI zeolite membrane coating the entire surface of the silica- alumina pellets and there are indications of the silica- alumina composite in the border area between the zeolite membrane or outer layer of silica alumina catalyst . The results show that the results of the MFI zeolite membrane reactor has the potential to be applied as the membrane is highly selective catalyst to form a molecule . As an example case , an isomer can be separated from each other selectively , so as to increase the reaction conversionKeywords : Membrane reactors, isomers, xylene, zeolite, silica alumina, hydrothermal.

scholarly journals Effect of H2O Activity on Zeolite Formation

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4780
Author(s):  
Claudia Belviso ◽  
Francesco Cavalcante
Keyword(s):  
Liquid Nitrogen ◽  
Sodium Aluminate ◽  
Drying Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lta Zeolite ◽  
Zeolite Formation ◽  
Silica Alumina ◽  
Over Time ◽  
Scanning Electron

In an effort to understand the effects of H2O activity on zeolite formation, we have synthesized LTA zeolite using a combination of freezing processes and varying drying temperatures. Sodium aluminate and sodium silicate were used to form LTA zeolite, according to the IZA (International Zeolite Association) protocol. The synthesis steps were modified by adding the precursor frozen process by a rapid liquid nitrogen (−196 °C) treatment or slow conventional freezer treatment (−20 °C). The samples were subsequently sonicated and then dried at 80 °C or 40 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed on the samples immediately after the drying process as well as after 2 weeks and 1 month of aging the solid products. The results indicated that LTA zeolite does not form. The silica-alumina precursor after both freezing processes and after being dried at 80 °C showed the presence of sodalite displaying stable behavior over time. Both sets of samples dried at 40 °C and did not show the presence of zeolite immediately after the drying process. However, after 2 weeks, the liquid nitrogen–frozen precursor was characterized by the presence of EMT whereas zeolites never formed in the −20 °C samples. These results suggest that freezing processes differently control the H2O activity during the drying and aging processes in the solid state. Thus, although the precursor chemical composition is the same, the type of zeolite formed is different.

Effect of Co Doping on the Properties of Ce0.75Zr0.25O2 Nanocatalyst

2014 ◽  
Vol 575 ◽  
pp. 93-96 ◽  
Author(s):  
S. Hanim Md Nor ◽  
M. Nazri Abu Shah ◽  
Abdul Hadi ◽  
Kamariah Noor Ismail
Keyword(s):  
Particle Distribution ◽  
Preparation Method ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Adsorption Desorption ◽  
Scanning Electron ◽  
Structure Properties

5wt% Co deposited on a support catalyst Ce0.75Zr0.25O2 mixed oxide were prepared by combination of microemulsion and deposition-precipitation method followed by calcinations at temperature 500°C. The microemulsion component comprise of cetyl trimetyl ammonium-bromide (CTAB), 1-butanol, n-octane and aqueous solution. Sodium hydroxide (NaOH) was used as precipitation precursor for the preparation of water-in-oil microemulsions method. The particles were characterized by X-ray diffraction (XRD), N2 adsorption-desorption analysis and Field Emission Scanning Electron Microscopy (FESEM). The results showed the preparation method has significant influences on the textural and structure properties of Co/Ce0.75Zr0.25O2. The formation of Co/Ce0.75Zr0.25O2 inhibit the better performance based on the particles size, specific surface area and particle distribution of cobalt into Ce0.75Zr0.25O2.

IMPACT OF SURFACTANTS ON PHYSICAL PROPERTIES OF BaTiO3 NANOPARTICLES

2013 ◽  
Vol 12 (01) ◽  
pp. 1350003 ◽  
Author(s):  
R. VIJAYALAKSHMI ◽  
V. RAJENDRAN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Average Particle Size ◽  
Ammonium Bromide ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Nanocrystalline BaTiO3 particles of about 20–35 nm have been successfully synthesized by using cationic, anionic and nonionic surfactants such as cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS) and poly ethylene glycol (PEG) via hydrothermal method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and photoluminescence (PL) spectroscopy. The average particle size, measured by powder X-ray diffraction was determined to be 20–35 nm and was confirmed by transmission electron microscopy. Spherical-like morphologies were obtained by scanning electron microscopy (SEM) analysis. Optical properties of products were investigated by ultraviolet-visible (UV-Vis) absorption and PL spectroscopies.

scholarly journals Investigation of Intercalation of Sodium-Montmorillonite with Octadecyl Trimethyl Ammonium Bromide Surfactant

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Chanra J.B Soegijono
Keyword(s):  
Aqueous Suspension ◽  
Interlayer Spacing ◽  
Xrd Analysis ◽  
Dispersion Analysis ◽  
Sem Analysis ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Sodium Montmorillonite ◽  
X Ray ◽  
Scanning Electron

Sodium-montmorillonite (Na+-MMT) was intercalation modified with octadecyl trimethyl ammonium bromide (OTAB) in aqueous suspension via an ion exchange mechanism. Fourier transform infrared spectroscopy (FTIR) study indicates that OTAB is successfully intercalated into Na+-MMT layers and/or adsorbed on the surface of Na+-MMT. X-ray diffraction (XRD) analysis revealed that the interlayer spacing of the Na+-MMT was extended with the content of OTAB increasing, and the maximum spacing can reach about 3.80 nm. Results of scanning electron microscopy (SEM) analysis reveals the morphologies change from spherical-like particles to high-aspect ratio flakes after modification. Different configurations of OTA+ chains within MMT interlayer are proposed based on the above analysis. The results of contact angle and the dispersion analysis show that the surface wettability of Na+-MMT is converted from hydrophilic to organophilic.

MFI Zeolite Membrane from Rice Husk for Biofuels Production

2012 ◽  
Vol 165 ◽  
pp. 104-108 ◽  
Author(s):  
Bakri Jufriadi ◽  
Hens Saputra ◽  
Agus Geter E. Sutjipto
Keyword(s):  
Rice Husk ◽  
Membrane Structure ◽  
Zeolite Membrane ◽  
Organic Template ◽  
X Ray Diffraction ◽  
Mfi Zeolite ◽  
X Ray ◽  
Mass Transfer Mechanism ◽  
High Silica ◽  
Alpha Alumina

High silica MFI zeolite membrane was synthesized by hydrothermal method at 313 K on asymetri pore structure alpha alumina substrate, utilizing natural rice husk as the sources of silica. The top layer of substrate was about 0.1 µm. The calcination was conducted at 773 K to remove the organic template. This membrane has a good stability at high temperature and in organic solvent. The membrane structure was identified by X-ray diffraction (XRD). The permeation of some pure gases was carried out to detect pinhole or cracking by studying mass transfer mechanism in the membrane. The pervaporation performance of as-synthesized membrane showed good results. This process was able to produce fuel grade bioethanol (99.2%) with the separation factor about 14.

Synthesis of In2Se3/CuSe Composite Powder by Solvothermal Method

2012 ◽  
Vol 512-515 ◽  
pp. 211-214
Author(s):  
J. Gao ◽  
Z.G. Zou ◽  
F. Long ◽  
C.Y. Xie ◽  
S.S. Chi
Keyword(s):  
Atmospheric Pressure ◽  
Composite Powder ◽  
Solvothermal Method ◽  
Ammonium Bromide ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
X Ray ◽  
Average Size ◽  
Scanning Electron

The In2Se3/CuSe composite powders with the size in the range of 2-8µm for solar cell were successfully synthesized via using relatively simple solvothermal method at atmospheric pressure by the reaction between InCI3.4H2O, CuCI2.2H2O and Selenious acid and hydrazine hydrate in ethylene glycol.The influences of reaction temperature, reaction time, concentration of solution on the phase and morphology of In2Se3/CuSe composite powders were investigated. The phase and morphology of the products hSubscript textave been well studied by X-ray diffraction (XRD)and scanning electron microscope (SSubscript textEM) techniques.The study revealed that under the conditions of solvothermal method at atmospheric pressure, relative pure In2Se3 and CuSe powder were synthesized at temperatures of 160°C and 100°C respectively. The In2Se3/CuSe of irregular flake composite powders with the average size of 2-8µm had been obtained.The morphology of the products can be controlled by adding different kinds of surfactants such as PVP (Polyvinylpyrrolidone), CTAB (Hexadecyl trimethyl ammonium Bromide) and so on.

Synthesis of Nano-Microsphere Titania with CTAB Assisted by Hydrothermal Method

2014 ◽  
Vol 722 ◽  
pp. 42-45
Author(s):  
Yun Fei Zhuang ◽  
Ya Lan Bian
Keyword(s):  
Hydrothermal Method ◽  
Ammonium Bromide ◽  
Titanium Oxides ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
X Ray ◽  
Structure And Morphology ◽  
Titanium Trichloride ◽  
Cetyltrimethyl Ammonium ◽  
Scanning Electron

Using titanium trichloride (TiCl3) as the precursor, sodium chloride (NaCl) as the mineralizer, cetyltrimethyl ammonium bromide (CTAB) as surfactant, titanium oxides (TiO2) nanomicrospheres were synthesized by hydrothermal method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the crystal structure and morphology of the microspheres. The results indicate that the spheres were rutile with diameters of about 1μm ~5μm. The spheres were composed of radially aligned nanorods with diameters of about 40nm and lengths of 500nm. The influences of the concentration of surfactant and the concentration of mineralizer were also researched. The microsphere diameter and grain size both reduce with the increase of the concentration of CTAB. The microspheres get larger and more complete with the higher mineralizer concentration.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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