Bifunctional Pt-Molecular Sieve Catalysts for Hydroisomerization of Long-Chain Olefins

2011 ◽  
Vol 418-420 ◽  
pp. 2250-2254
Author(s):  
Fei Ding ◽  
Cai Rong Luo ◽  
Hai Rong Zhang ◽  
Lian Xiong ◽  
Xin De Chen

Bifunctional Pt/HZSM-5, Pt/HBeta, Pt/HMCM-41 and Pt/HSAPO-11 catalysts were prepared using pseudoboehmite as a binder. The H2-TPR profiles, scanning electron microscope (SEM) and brunauer-emmett-teller (BET) pointed out that reducibility of catalysts and textural properties. These bifunctional catalysts have been tested in long-chain olefins hydroisomerization. The experiments were carried out at 320oC under 2.0 MPa of hydrogen and at 3.0 h-1WHSV. Complete hydrogenation of long-chain olefins was observed over Pt/HMCM-41 and Pt/HSAPO-11. Hydroisomerization reactions also occured in the case of Pt supported strong acidic molecular sieves (HZSM-5 and HBeta). The result suggests product distribution of long-chain olefins hydroisomerization is dependent on the balance between the acid and metallic functions in catalysts.

2013 ◽  
Vol 329 ◽  
pp. 45-50 ◽  
Author(s):  
Xin Zhang ◽  
Xi Dong Liu

At refluence temperature, ferric chloride impregnated molecular sieves were prepared by impregnation of FeCl3 through ion-exchanging methods. The above catalysts were characterized by the means of SEM/EDS (scanning electron microscope/energy dispersion spectrometer) and BET. The catalytic properties on isopropylation of naphthalene and effect of reaction conditions were carried out with fixed-bed flow micro-reactor. We obtained the optimum conditions of this reaction. At this condition, the conversion of naphthalene reaches 44.1%, the yield of 2, 6-DIPN is 41.2% and the selectivity of β,β-DIPN is 85.2%.


2020 ◽  
Vol 4 (2) ◽  
pp. 121
Author(s):  
Yulius Dala Ngapa ◽  
Jumilah Gago

Ketergantungan akan pemakaian bahan bakar fosil yang terus meningkat telah mengubah pola pikir manusia untuk mengembangkan penelitian terkait energi alternatif terbarukan. Bioetanol yang berasal dari hasil fermentasi nira tanaman aren (Arenga pinnata MERR), dan dikenal sebagai minuman tradisional Moke di Flores dapat dimanfaatkan sebagai bahan bakar alternatif jika memiliki kemurnian di atas 99,5%. Proses adsorpsi merupakan salah satu metode yang dilakukan untuk menghasilkan bioetanol dengan kadar di atas titik azeotrop. Adsorben yang efektif digunakan sebagai molecular sieve adalah zeolit alam yang berasal dari kabupaten Ende – NTT. Peningkatan efisiensi penyerapan zeolit alam dalam pemurnian bioetanol berbahan baku Moke sudah dilakukan melalui proses aktivasi kimia. Penelitian ini bertujuan untuk mengetahui kadar dan kualitas bioetanol setelah pemurnian menggunakan adsorben zeolit alam Ende – NTT yang telah diaktivasi NaOH pada berbagai konsentrasi. Kadar bioetanol yang terdapat pada Moke sebelum dan sesudah proses adsorpsi ditentukan dengan instrumen gas kromatografi, karakterisasi zeolit alam menggunakan X-Ray Diffraction (XRD) dan Scanning Electron Microscope (SEM). Zeolit alam Ende dapat digunakan sebagai adsorben dalam meningkatkan kadar bioetanol berbahan baku Moke.The reliance on increasing use of fossil fuels has changed the human mindset to develop research related to renewable alternative energy. Bioethanol derived from fermented palm sugar sap (Arenga pinnata MERR), and known as Moke, traditional drink in Flores can be used as an alternative fuel if it has a purity above 99.5%. The adsorption process is one method used to produce bioethanol with a level above the azeotrope point. The effective adsorbent used as molecular sieve is natural zeolite originating from Ende - NTT. Increased efficiency of absorption of natural zeolite in bioethanol purification made from Moke has been done through a chemical activation process. This study aims to determine the level and quality of bioethanol after purification using Ende-NTT natural zeolite adsorbent which has been activated by NaOH at various concentrations. Bioethanol levels found in the Moke before and after the adsorption process were determined by gas chromatography instruments, natural zeolite characterization using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Ende natural zeolite can be used as an adsorbent to increase the level of bioethanol made from Moke.


Author(s):  
I. Kaufman Arenberg ◽  
W. F. Marovitz ◽  
A. P. Mackenzle

Increasing use is now being made of the scanning electron microscope for soft biologic tissues. The use of chemical fixation followed by freeze-drying, facilitates surface observations of tissues which otherwise would not be possible.Four hours following necropsy a sample of human tongue was removed. This specimen was fixed in 10% neutral formalin, postfixed in 1% osmic acid, dehydrated in graded series of alcohol, and evaporated, in vacuo, over a Linde molecular sieve at -30 ± 1°C. The specimen was plated with gold: palladium (40: 60) in a vacuum evaporator to an approximate 200 Å thickness. The emissive mode of the Cambridge Stereoscan Mark II scanning electron microscope was used for this study.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.


Author(s):  
Emil Bernstein

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.


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