The role of nanosized zeolite Y in the H2-free catalytic deoxygenation of triolein

2019 ◽  
Vol 9 (3) ◽  
pp. 772-782 ◽  
Author(s):  
Min-Yee Choo ◽  
Joon Ching Juan ◽  
Lee Eng Oi ◽  
Tau Chuan Ling ◽  
Eng-Poh Ng ◽  
...  
Keyword(s):  
Crystal Size ◽  
Zeolite Y ◽  
Conversion Yield ◽  
Catalytic Deoxygenation ◽  
Nanosized Zeolite

The reduction in zeolite Y crystal size has improved the triolein conversion, yield of deoxygenated product and diesel range hydrocarbon selectivity.

scholarly journals Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3104
Author(s):  
Min-Yee Choo ◽  
Lee Eng Oi ◽  
T. Jean Daou ◽  
Tau Chuan Ling ◽  
Yu-Chuan Lin ◽  
...  
Keyword(s):  
Crystal Size ◽  
Zeolite Y ◽  
Lewis Acidity ◽  
One Pot ◽  
Preparation Methods ◽  
Green Diesel ◽  
Zeolite Nay ◽  
Yield And Quality ◽  
Nanosized Zeolite

Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition–precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h−1) was 1.5 times higher than that of the IM method (9.6 goil·h−1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Brönsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.

Surviving Under Pressure: The Role of Solvent, Crystal Size, and Morphology During Pelletization of Metal–Organic Frameworks

2021 ◽  
Author(s):  
Timothy C. Wang ◽  
Ashley M. Wright ◽  
William J. Hoover ◽  
Kevin J. Stoffel ◽  
Rachelle K. Richardson ◽  
...  
Keyword(s):  
Crystal Size ◽  
Metal Organic Frameworks ◽  
Metal Organic ◽  
Size And Morphology ◽  
Role Of Solvent

SDA-Free Hydrothermal Synthesis of High-Silica Ultra-nanosized Zeolite Y

2017 ◽  
Vol 17 (3) ◽  
pp. 1173-1179 ◽  
Author(s):  
Maeva Borel ◽  
Mathias Dodin ◽  
T. Jean Daou ◽  
Nicolas Bats ◽  
Bogdan Harbuzaru ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Zeolite Y ◽  
High Silica ◽  
Nanosized Zeolite

The role of ZnO in reactive desulfurization of diesel over ZnO@Zeolite Y: Classification, preparation, and evaluation

2021 ◽  
Vol 256 ◽  
pp. 117784
Author(s):  
Yu YANG ◽  
Samira Mandizadeh ◽  
Hao ZHANG ◽  
Masoud Salavati-Niasari
Keyword(s):  
Zeolite Y ◽  
Preparation And Evaluation

scholarly journals Strain-rate enhancement at Dye 3, Greenland

1999 ◽  
Vol 45 (150) ◽  
pp. 338-345 ◽  
Author(s):  
Throstur Thorsteinsson ◽  
E. D. Waddington ◽  
K. C. Taylor ◽  
R. B. Alley ◽  
D. D. Blankenship
Keyword(s):  
Crystal Size ◽  
Ice Sheets ◽  
Ion Concentration ◽  
Strain Rates ◽  
Anisotropic Flow ◽  
Enhancement Factors ◽  
Measured Strain ◽  
Soluble Ion ◽  
Flow Laws

AbstractIce at depth in ice sheets can be softer in bed-parallel shear than Glen’s flow law predicts. For example, at Dye 3, Greenland, enhancement factors of 3 4 are needed in order to explain the rate of borehole tilting Previous authors have identified crystal fabric as the dominant contributor, but the role of impurities and crystal size is still incompletely resolved. Here we use two formulations of anisotropic flow laws for ice (Azuma’s and Sachs’ models) to account for the effects of anisotropy, and show that the measured anisotropy of the ice at Dye 3 cannot explain all the detailed variations in the measured strain rates, the jump in enhancement across the Holocene–Wisconsin boundary is larger than expected from the measured fabrics alone. Dust and soluble-ion concentration divided by crystal size correlates well with the residual enhancement, indicating that most of the “excess deformation” may be due to impurities or crystal size. While the major features of the deformation at Dye 3 are explained by anisotropy and temperature, results also suggest that further research into the role of impurities and crystal size is warranted.

The Role of Au Doping on the Structural and Optical Properties of Cu2O Films

2019 ◽  
Vol 58 ◽  
pp. 49-67 ◽  
Author(s):  
Emine Güneri
Keyword(s):  
Optical Properties ◽  
Crystal Size ◽  
Structural Parameters ◽  
Lattice Parameter ◽  
Skin Depth ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Polycrystalline Form ◽  
Doping Ratio

The changes in structural and optical properties of the Cu2O films obtained on the glass with different concentrations of Au by the chemical bath method were studied in this work. Lattice parameter, crystal size, preferential orientation and surface tension of the films were calculated using X-ray diffraction data which showed that all of the films were in polycrystalline form. It was determined that the structural parameters of all films were changed with the doping ratio. The surface morphology of the films was imaged using a field emission scanning electron microscope. The optical properties of the films were discovered using the optic spectrometer. Changes in the optical properties were discovered as a function of Au ratio. It was determined that the energy band gap value (2.12 eV-2.02 eV), the refractive index, the extinction coefficient, the real and dielectric coefficients, the optical conductivity, and the skin depth of films varied with Au doping ratio.

scholarly journals In Situ IR Characterization of CO Interacting with Rh Nanoparticles Obtained by Calcination and Reduction of Hydrotalcite-Type Precursors

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
F. Basile ◽  
I. Bersani ◽  
P. Del Gallo ◽  
S. Fiorilli ◽  
G. Fornasari ◽  
...  
Keyword(s):  
Crystal Size ◽  
Liquid Nitrogen Temperature ◽  
Transmission Electron ◽  
In Situ Ir ◽  
Ft Ir ◽  
Co Disproportionation ◽  
Ft Ir Spectroscopy

Supported Rh nanoparticles obtained by reduction in hydrogen of severely calcined Rh/Mg/Al hydrotalcite-type (HT) phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at room temperature (r.t.) and nominal liquid nitrogen temperature] and Transmission Electron Microscopy (TEM). The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750°C to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbs at r.t., CO disproportionation occurs on Rh and it accompanies the formation of RhI(CO)2. The role of interlayer anions in the HT precursors to affect the properties of the final materials has been also investigated considering samples prepared from silicate-instead of carbonate-containing precursors. In this case, formation of RhI(CO)2 and CO disproportionation do not occur, and this evidence is discussed in terms of support effect.

Hydrogen Storage in Nanostructured Mg-Base Alloys

2009 ◽  
Vol 5 ◽  
pp. 213-221 ◽  
Author(s):  
A.F. Palacios-Lazcano ◽  
J.L Luna-Sánchez ◽  
J. Jiménez-Gallegos ◽  
Francisco Cruz-Gandarilla ◽  
J. Gerardo Cabañas-Moreno
Keyword(s):  
Hydrogen Storage ◽  
Single Phase ◽  
Crystal Size ◽  
Argon Atmosphere ◽  
Nanocrystalline Alloys ◽  
Nominal Composition ◽  
Alloyed Powder ◽  
Mechanically Alloyed ◽  
Powder Alloys

Powders of elemental Mg, Zn, Al and Ag were milled in order to produce nanocrystalline alloys with nominal composition Mg98M2 (M=Zn, Al and Ag). Pure Mg was also mechanically milled without any additions. Single-phase nanocrystalline (crystal size 24-26 nm) Mg98M2 alloys were produced after 216 ks of milling. A passivity procedure was followed immediately after milling, by gradually exposing the alloy powders to air (~ 12 hrs). After this procedure, the mechanically alloyed powders were kept under argon atmosphere before being hydrided at 200 and 300 °C under 0.5 and 3 MPa P for 10 min. Previously milled (~ 1.5 years before) and passivated powder alloys (stored in air and referred to as “AE” samples) were also hydrided under the same conditions. No hydriding was observed in the as-received Mg powders (crystal size >> 100 nm), but the as-milled, passivated nanocrystalline alloys were partially hydrided (even the AE samples). The amounts of the MgH2 phase in the hydrided samples were larger in the Ar-stored than in the AE samples under all hydriding conditions. The possible role of MgO and Mg hydroxides, as well as of the alloying elements, on the hydriding behavior of the nanostructured, mechanically alloyed powder alloys is discussed.

Beta Zeolite as a Catalyst for the Preparation of Alkyl Glucoside Surfactants: The Role of Crystal Size and Hydrophobicity

1997 ◽  
Vol 172 (1) ◽  
pp. 76-84 ◽  
Author(s):  
M.A. Camblor ◽  
A. Corma ◽  
S. Iborra ◽  
S. Miquel ◽  
J. Primo ◽  
...  
Keyword(s):  
Crystal Size ◽  
Beta Zeolite ◽  
Alkyl Glucoside ◽  
Alkyl Glucoside Surfactants
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