scholarly journals SYNTHESIS AND CHARACTERIZATION OF UNSUPPORTED CATALYST FOR GAS OIL DESULFURIZATION

2019 ◽  
Vol 11 (3) ◽  
pp. 357-371
Author(s):  
Mohammad F. Abid ◽  
Mohammed A. Hamza ◽  
Shakir M. Ahmed ◽  
Salah M. Ali ◽  
Sattar J. Hussein
Keyword(s):  
Molybdenum Trioxide ◽  
Operating Conditions ◽  
Gas Oil ◽  
First Order Kinetics ◽  
Different Temperatures ◽  
Mos2 Catalysts ◽  
Al2o3 Catalyst ◽  
Better Than ◽  
Mos2 Catalyst

Unsupported MoS2 catalysts were synthesized for the hydrodesulfurization (HDS) of real feed gas oil using different temperatures and pressures. Hydrothermal method was utilized to prepare by using molybdenum trioxide and sodium sulfide. The characterization of the catalyst was identified by XRD, SEM, and BET techniques. It was found that BET surface and pore volume were positively affected by pressure and temperature that could improve the activity of MoS2. Kinetic analysis showed that HDS reaction over MoS2 follow pseudo-first order kinetics. Experimental results revealed that the HDS activity of the unsupported MoS2 catalyst was better than supported CoMo/Al2O3 catalyst under the same operating conditions.

Synthesis and Characterization of Green Tea Stabilized Iron Nanocatalysts for Brymothymol Blue (BTB) Degradation

2016 ◽  
Vol 42 ◽  
pp. 1-13
Author(s):  
David Mutuku Katithi ◽  
Immaculate N. Michira ◽  
Peterson M. Guto ◽  
Priscilla Gloria Lorraine Baker ◽  
Geoffrey N. Kamau ◽  
...  
Keyword(s):  
Green Tea ◽  
Dye Degradation ◽  
Degradation Kinetics ◽  
Environmental Pollutant ◽  
X Ray Diffraction ◽  
Tunneling Microscopy ◽  
X Ray ◽  
First Order Kinetics ◽  
Different Temperatures

Iron nanoparticles (FeNPs) were prepared from the green tea extracts at different temperatures through green synthesis procedure and characterized by various physicochemical techniques like UV-Visible spectroscopy, FTIR Spectroscopy, energy dispersive X-ray spectrometry (EDS), X-ray diffraction and high resolution tunneling microscopy (HRTEM) and the results confirmed the synthesis of polydisperse and stable FeNPs by the tea extracts. The catalytic activity of FeNPs was investigated using a common environmental pollutant BTB often used in textile industries for dyeing purposes. In these tests, catalytic degradation of BTB with FeNPs at a 10 μL or 30 μL concentration was done in the presence of 2% hydrogen peroxide. Results show no BTB degradation in the absence of the FeNPs. However, a 38% and 68% degradation of BTB was realized in the presence of 10μL and 30 μL FeNPs respectively indicating that the iron nanocatalysts were responsible for the dye degradation. The BTB degradation kinetics was found to follow pseudo-first order kinetics with rate constants at the two catalyst concentrations being 0.023 min-1 and 0.063 min-1 respectively.

Test Bench for Characterization and Durability Tests of Motorbike Clutches

2021 ◽  
Author(s):  
G. Previati ◽  
M. Gobbi
Keyword(s):  
Test Bench ◽  
Friction Material ◽  
Operating Conditions ◽  
Test Rig ◽  
Automatic Transmissions ◽  
Different Temperatures ◽  
Durability Assessment ◽  
Good Repeatability ◽  
The One

Abstract In the paper, a new test bench for characterization and durability assessment of multi disc wet clutches for motorbike applications is presented. The design of the new test bench is inspired by the current SAE standards J2490 and J286 that refer to the testing of friction material for automatic transmissions wet clutches. Differently from the test bench described in the two standards, which is mainly designed to test the friction material, the test bench presented in this paper has been designed for testing the whole clutch, comprising all discs and the actuation mechanism. The lubrication system of the clutch utilized on the test bench is very similar to the one present on the actual motorbike. The design and instrumentation of the new test rig is analysed and discussed in the paper. The test bench has been used for the characterization of different motorbike clutches. The bench has proved to be able to measure the clutch characteristic for different temperatures and clutch wear levels. A very good repeatability of the tests has been achieved allowing for a comparison of different clutches design, friction material properties and operating conditions (temperature, ..). Some experimental results are presented and discussed in the paper.

scholarly journals Synthesis and Characterization of New nano catalyst Mo-Ni /TiO2- γAl2O3 for Hydrodesulphurization of Iraqi Gas Oil

2021 ◽  
Vol 18 (4(Suppl.)) ◽  
pp. 1557
Author(s):  
Dalya Jasim Ahmed ◽  
Basim Ibrahim Al-Abdaly ◽  
Sattar Jalil Hussein
Keyword(s):  
Sulfur Content ◽  
Sol Gel ◽  
Sulfur Removal ◽  
Operating Conditions ◽  
Bet Surface Area ◽  
Vacuum Impregnation ◽  
Gas Oil ◽  
Laboratory Unit ◽  
Nano Catalyst ◽  
Al2o3 Catalyst

   A new nano-sized NiMo/TiO2-γ-Al2O3 was prepared as a Hydrodesulphurization catalyst for Iraqi gas oil with sulfur content of 8980 ppm, supplied from Al-Dura Refinery. Sol-gel method was used to prepare TiO2- γ-Al2O3 nano catalyst support with 64% TiO2, 32% Al2O3, Ni-Mo/TiO-γ-Al2O3 catalyst was prepared under vacuum impregnation conditions to loading metals with percentage 3.8 wt.% and 14 wt.% for nickel and molybdenum respectively while the percentage for alumina, and titanium became 21.7, and 58.61 respectively. The synthesized TiO2- γ-Al2O3 nanocomposites and Ni-Mo /TiO2- γ-Al2O3 Nano catalyst were then characterized by XRD, AFM, and BET surface area, SEM, XRF, and FTIR. The performance of the synthesized catalyst for removing sulfur compounds was conducted through the pilot HDS laboratory unit, various temperatures range 275oC to 375°C, LHSV 1 h-1 were studied; moreover, the effect of LHSV 1 to 4 h-1 on the percentage of sulfur removal was also studied at the temperature of the best removal with constant pressure 35 bar and H2/HC ratio 200cm3/200cm3. The sulfur content results generally revealed that there was a substantial decrease at all operating conditions used, while the maximum sulfur removal was 87.75% in gas oil on Ni-Mo/TiO2-γ-Al2O3 catalyst at temperature 375˚C and LHSV 1h-1.

A Neural Network Approach for Prediction of the CuO-ZnO-Al2O3 Catalyst Deactivation

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Gholamreza Zahedi ◽  
Abdolhossein Jahanmiri ◽  
M. R. Rahimpor
Keyword(s):  
Experimental Data ◽  
Catalyst Deactivation ◽  
Prediction Performance ◽  
Operating Conditions ◽  
Training Algorithms ◽  
Neural Network Approach ◽  
Modeling Techniques ◽  
Different Temperatures ◽  
Inlet Conditions ◽  
Al2o3 Catalyst

In this work an Artificial Neural Networks (ANN) approach for estimation of catalyst deactivation during methanol synthesis has been proposed. The approach predicts deactivation of the catalyst at different operating conditions as a function of time. Experimental data of a typical differential reactor were pre-scaled and used for training. Among the various training algorithms, Exact Radial Basis (RBE) method had the best prediction performance and was used for simulation of the reactor. The proposed approach interprets deactivation data, while there are not enough data versus time at different inlet conditions. By using the model, sufficient data were generated which vary with time and agree very well with experimental data. Capability of the model in generating deactivation data at different temperatures, pressures and feed compositions was excellent. The proposed method has great potential as a means to compensate for lack of the phenomenological kinetic modeling techniques.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

Treatment system response to transient AOX (adsorbable organic halogen) loadings

1997 ◽  
Vol 35 (2-3) ◽  
pp. 85-91
Author(s):  
D. A. Barton ◽  
J. D. Woodruff ◽  
T. M. Bousquet ◽  
A. M. Parrish
Keyword(s):  
Paper Industry ◽  
Model Development ◽  
Operating Conditions ◽  
System Response ◽  
Additional Information ◽  
Organic Halogen ◽  
Aox Removal ◽  
Variable Operating Conditions ◽  
Plant Shutdown

If promulgated as proposed, effluent guidelines for the U.S. pulp and paper industry will impose average monthly and maximum daily numerical limits of discharged AOX (adsorbable organic halogen). At this time, it is unclear whether the maximum-day variability factor used to establish the proposed effluent guidelines will provide sufficient margin for mills to achieve compliance during periods of normal but variable operating conditions within the pulping and bleaching processes. Consequently, additional information is needed to relate transient AOX loadings with final AOX discharges. This paper presents a simplistic dynamic model of AOX decay during treatment. The model consists of hydraulic characterization of an activated sludge process and a first-order decay coefficient for AOX removal. Data for model development were acquired by frequent collection of influent and effluent samples at a bleach kraft mill during a bleach plant shutdown and startup sequence.

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Direct Thermal Decomposition Route Using Zinc Nitrate Hexahydrate

2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana
Keyword(s):  
Thermal Decomposition ◽  
Crystallization Temperature ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Absorption Peak ◽  
Synthesis And Characterization ◽  
Nitrate Hexahydrate ◽  
Different Temperatures ◽  
Zno Powders

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

Synthesis and characterization of flame-retardant-wrapped carbon nanotubes and its flame retardancy in epoxy nanocomposites

2021 ◽  
pp. 096739112110245
Author(s):  
Jiangbo Wang
Keyword(s):  
Carbon Nanotubes ◽  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Total Heat Release ◽  
Pristine Cnts ◽  
Peak Heat Release Rate ◽  
Ep Matrix ◽  
Better Than

A novel phosphorus-silicon containing flame-retardant DOPO-V-PA was used to wrap carbon nanotubes (CNTs). The results of FTIR, XPS, TEM and TGA measurements exhibited that DOPO-V-PA has been successfully grafted onto the surfaces of CNTs, and the CNTs-DOPO-V-PA was obtained. The CNTs-DOPO-V-PA was subsequently incorporated into epoxy resin (EP) for improving the flame retardancy and dispersion. Compared with pure EP, the addition of 2 wt% CNTs-DOPO-V-PA into the EP matrix could achieve better flame retardancy of EP nanocomposites, such as a 30.5% reduction in peak heat release rate (PHRR) and 8.1% reduction in total heat release (THR). Furthermore, DMTA results clearly indicated that the dispersion for CNTs-DOPO-V-PA in EP matrix was better than pristine CNTs.

scholarly journals Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 759
Author(s):  
Andrea Mariscotti
Keyword(s):  
Time Distribution ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Transportation Systems ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Intrinsic Variability ◽  
Statistical Characterization ◽  
Electromagnetic Emissions

Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity. The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches. Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts. This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena). In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, e.g., by means of Amplitude Probability Distribution and including time distribution information. The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (e.g., rolling stock operating conditions, synchronization issues, and electric arc intermittence).

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