scholarly journals A BET Surface Area Measurement Technique for Evaluation of Crack Extension in Alumina Pellets Subjected to Thermal Shock

1989 ◽  
Vol 97 (1128) ◽  
pp. 778-782 ◽  
Author(s):  
Masaomi OGUMA ◽  
Takeo MOTOMIYA
Keyword(s):  
Thermal Shock ◽  
Surface Area ◽  
Measurement Technique ◽  
Crack Extension ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Surface Area Measurement

Assessment of the Hydrophilic-Hydrophobic Balance of Alumina Oxidized at Different Temperatures via H2O and C4H10 Vapor Adsorption

2019 ◽  
Vol 397 ◽  
pp. 161-168 ◽  
Author(s):  
Naouel Hezil ◽  
Mamoun Fellah ◽  
Ridha Djellabi ◽  
Mohamed Zine Touhami ◽  
Alex Montagne ◽  
...  
Keyword(s):  
Surface Area ◽  
Hydrophobic Surface ◽  
Treatment Temperature ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Alumina Powder ◽  
Surface Samples ◽  
Surface Area Measurement ◽  
Different Temperatures ◽  
Adsorption Of Water

The hydrophilic-hydrophobic surface area of alumina powder (Al2O3) oxidized at different temperatures was determined on the base of adsorption of water and butane vapor at 25°C. In the order to study the influence of thermal oxidation upon hydrophilic/hydrophobic character of the surface, samples of Al2O3 were characterized using granulometry, SEM and BET surface area measurement. SEM results showed that the thermal treatment does not affect the morphology of the Alunima. However, the increase of treatment temperature from 250 to 900°C results in changing of the hydrophilic-hydrophobic balance of Al2O3 surface.

scholarly journals The Effect of Using H4P2O7 as Phosphorus Source for Synthesizing Vanadyl Pyrophosphate Catalysts

2017 ◽  
Vol 6 (3) ◽  
pp. 207
Author(s):  
Y.H. Taufiq-Yap ◽  
A. Raslan ◽  
R. Irmawati
Keyword(s):  
Surface Area ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Vanadyl Pyrophosphate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Area Measurement ◽  
Phosphorus Source ◽  
Temperature Programmed ◽  
Two Peaks

<p>Vanadyl pyrophosphate (VO)<sub>2</sub>P<sub>2</sub>O<sub>7</sub> catalysts synthesized via VOPO<sub>4</sub>·2H<sub>2</sub>O were investigated by using BET surface area measurement, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Temperature-Programmed Techniques (TPD and TPRS). H<sub>3</sub>PO<sub>4</sub> and H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> were used as the phosphorus source. Only pyrophosphate phase was observed for both final catalysts after 75 hours of calcination in a reaction flow of <em>n</em>-butane/air mixture (0.75% <em>n</em>-butane/air). However, catalyst derived from H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> based preparation (denoted VPD<sub>pyro</sub>) exhibit better crystallinity and slightly higher BET surface area compared to the H<sub>3</sub>PO<sub>4</sub> based preparation (denoted VPD<sub>ortho</sub>). The nature of the oxidants for both catalysts was investigated by O<sub>2</sub>-TPD. For VPD<sub>pyro</sub>, TPD showed an oxygen peak maximum at 986 K and a shoulder at 1003 K, whereas for VPD<sub>ortho</sub>, the oxygen was desorbed as two peaks maxima at 966 and 994 K. The total amount of oxygen desorbed thermally from VPD<sub>pyro</sub> (3.60×10<sup>20</sup> atom×g<sup>-1</sup>) is higher than that obtained for VPD<sub>ortho</sub> (3.07×10<sup>20</sup> atom×g<sup>-1</sup>). VPD<sub>pyro</sub> displayed a slightly improved activity and selectivity for <em>n</em>-butane oxidation. A proper amount of V<sup>5+</sup> species may have an effect on the enhancement of the catalytic activity.</p>

Effect of Calcinations Temperature on Physical Properties of Zeolite ZSM-5 Produced from Natural Granite

2015 ◽  
Vol 1113 ◽  
pp. 534-538
Author(s):  
Ku Halim Ku Hamid ◽  
Kamariah Noor Ismail ◽  
Adilah Jamaludin ◽  
Muhammad Aslam Zainudin ◽  
Muhammad Syafiq Md Nasruddin ◽  
...  
Keyword(s):  
Physical Properties ◽  
Surface Area ◽  
Aluminium Oxide ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Ftir Analysis ◽  
Granite Sample ◽  
Surface Area Measurement ◽  
Granite Samples

The effects of calcinations temperature toward physical properties of ZSM-5 were determined by treatment with different temperature for 24 hour. The main properties of these samples were characterized by means of XRD, FTIR, BET surface area measurement and TGA. The hydrothermal treatments were carried out at various temperature of 200°C-500°C. The content in the natural granite sample were also performed .Throughtout this experiment, from the XRD and FTIR analysis the natural granite samples shows the existing of zeolite component which is SiO2 and aluminium oxide.

Preliminary Study of the Effect Microwave-Heating on the Morphology and Surface Area of NaX Zeolite

2017 ◽  
Vol 895 ◽  
pp. 69-72 ◽  
Author(s):  
Hilman Imadul Umam ◽  
Akfiny Hasdi Aimon ◽  
Ferry Iskandar
Keyword(s):  
Microwave Heating ◽  
Surface Area ◽  
Heating Time ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Nax Zeolite ◽  
Surface Area Measurement ◽  
Long Time ◽  
Zeolite Formation ◽  
Preliminary Study

The effect of microwave-heating on the morphology and surface area of NaX zeolite was studied. The characteristics of NaX zeolite, which has a porous structure, make NaX zeolite applicable as a catalyst. Generally, the process of NaX zeolite formation with an FAU-type structure, either naturally or synthetically, requires quite a long time. Therefore, in this research the effect of microwave heating on the produced sample was investigated using XRD, SEM, and BET surface area measurement. The heating time parameter was varied to determine the optimal conditions for the synthesis of NaX zeolite. The results indicated that microwave-heating is capable of accelerating the crystallization process and reduce the agglomeration of NaX zeolite, as shown by the XRD and SEM results. Based on the SEM result, the particle size distributions of the samples microwave-heated for 1, 3, and 5 minutes, were 350.5, 262.5, and 243.9 nm respectively. In addition, prolonging the microwave-heating time made the surface area of the samples become larger. The specific surface area of the samples microwave-heated for 1, 3, and 5 minutes, 55.9, 153.5, and 204.1 m2/g respectively.

scholarly journals A Proposed Surface Area Measurement Module for Rural Folks: Desing Concept and trial Setup

2006 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Woraratana Pattarapaprakorn ◽  
Makoto Tono ◽  
Hiro Niyama
Keyword(s):  
Surface Area ◽  
Pressure Measurement ◽  
Simple Module ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Sample Tube ◽  
Dry Ice ◽  
Cooking Oil ◽  
Surface Area Measurement ◽  
Bet Equation

A simple module for surface area measurement based on CO2 adsorbtion.at dry-ice methanol temperrature was designed. The designed consists a sample tube, a glass syiringe for pressure measurement, and an anspirator for evacuation. No shopiscate electronic de w used. Dry ice was used Dry ice was coolent in place of liquid nitrogen, which is widely wed in ordinary BET surface area measument. Vacuum tighess w confied acceptable when cooking oil was used a seal liquid at the contact suace of the singe. Error anaIes were done for both vacuum tighness and the prence of riduaI gases due to the use of water-driven aspiration. Adsorbtion measurements of CO2 were conducted using the simple module and a conventional apparatus. Results confirmed that the modue works well within reasonable eximental error, if the weight of sampIe and the initial intake of sample gas are chosen properly. However since the adsorption isotherms of several carbon samples shawed a pleteau at high preure, the BET equation was not applicble. Instead, the Langmuir one-point method would be rocommended for sudface area mesurement.

Titanium nitride nanopowders produced via sodium reductionin liquid ammonia

2009 ◽  
Vol 24 (2) ◽  
pp. 448-451 ◽  
Author(s):  
Boyan Yuan ◽  
Mei Yang ◽  
Hongmin Zhu
Keyword(s):  
Titanium Nitride ◽  
Surface Area ◽  
Liquid Ammonia ◽  
Heating Temperature ◽  
Chemical Reduction ◽  
Atomic Ratio ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Cubic Phase ◽  
Tem Analysis

Titanium nitride nanopowders were synthesized through a chemical reduction of titanium tetrachloride by sodium in liquid ammonia. The products of the reaction were the mixture of sodium chloride and titanium nitride nanopowders. The mixture was then separated by ammonia extraction. The nanopowders were heated under vacuum up to 1200 °C and were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET) surface area measurement, and chemical analysis. The results show that the product is nanocrystalline cubic phase TiN with Ti/N atomic ratio performed 1:1, and the surface area is from 20 to 50 m2 ·g−1 depending on the heating temperature. The particle sizes estimated by the TEM analysis correspond well with the results of the surface area measurements. The XRD pattern indicates that the crystal size grows with an increase in heating temperature.

scholarly journals Influence of the precursor chemical composition on heavy metal adsorption properties of hemp (Cannabis Sativa) fibers based biocarbon

2017 ◽  
Vol 82 (12) ◽  
pp. 1417-1431 ◽  
Author(s):  
Marija Vukcevic ◽  
Biljana Pejic ◽  
Ivana Pajic-Lijakovic ◽  
Ana Kalijadis ◽  
Mirjana Kostic ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Chemical Composition ◽  
Surface Area ◽  
Active Sites ◽  
Cannabis Sativa ◽  
Lignin Content ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Homogeneous Distribution ◽  
Hemp Fibers

Waste hemp (Cannabis sativa) fibers were used as sustainable and renewable raw materials for production of low-cost biocarbon sorbent for heavy metals removal. Carbon precursors of different chemical composition were obtained by oxidative and alkaline treatments of hemp fibers. Influence of lignocellulosic precursor chemical composition on hemp fibers-based biocarbon (HFB) characteristics was examined by BET surface area measurement, scanning electron microscopy and mass titration. It was found that lignin content and polymorphic transformation of cellulose increase the SBET of microporous HFBs, while hemicelluloses induce more homogeneous distribution of adsorption active sites. Heavy metal ions adsorption onto HFBs is primarily influenced by the amount of surface oxygen groups, while specific surface area plays a secondary role. Equilibrium data obtained for lead ions adsorption were analyzed by different nonlinear adsorption isotherms, and the best fitting model was chosen using standard deviation and Akaike information criterion (AICC). The maximum adsorption capacities of HFBs ranged from 103.1 to 116.3 mg Pb/g. Thermodynamic parameters showed that Pb2+ adsorption onto HFBs is a spontaneous and complex endothermic process, suggesting the coexistence of physisorption and chemisorption mechanisms.

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