Catalytic Dehydration of Ethanol over W/TiO2 Catalysts Having Different Phases of Titania Support

This study aims to investigate the catalytic behaviors on W/TiO2 catalysts having different phases of TiO2 towards catalytic dehydration of ethanol to higher value products including ethylene, diethyl ether, and acetaldehyde. In fact, TiO2 support with different crystalline phases can result in differences of physico-chemical properties of the catalyst. Therefore, the present work reports on the catalytic behaviors that were altered with different phases of TiO2 in catalytic ethanol dehydration to diethyl ether or ethylene as a major product. To prepare the catalysts, three different phases [anatase (A), rutile (R), and mixed phases (P25)] of TiO2 supports were impregnated with 10 wt% of tungsten (W). It was found that the W/TiO2-P25 catalyst revealed higher activity among other catalysts. At 300 °C, all catalysts can produce the diethyl ether yield of 24.1%, 22.8%, and 10.6% for W/TiO2-P25, W/TiO2-A, and W/TiO2-R catalysts, respectively. However, when the reaction temperature was increased to 400°C, ethylene is the major product. The W/TiO2-P25 and W/TiO2-A catalysts render the ethylene yield of 60.3% and 46.2%, respectively, whereas only 15.9% is obtained from W/TiO2-R catalyst. The most important parameter influencing their catalytic properties appears to be the proper pore structure, acidity, and distribution of W species. Copyright © 2019 BCREC Group. All rights reserved

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Influence of hydrotalcite preparation conditions on its physico-chemical properties

Acta Chimica Slovaca ◽

10.2478/acs-2019-0017 ◽

2019 ◽

Vol 12 (1) ◽

pp. 119-126

Author(s):

Miroslava Mališová ◽

Michal Horňáček ◽

Pavol Hudec ◽

Jozef Mikulec ◽

Vladimír Jorík ◽

...

Keyword(s):

Catalytic Properties ◽

Chemical Properties ◽

Synthesis Temperature ◽

Optimal Synthesis ◽

Preparation Process ◽

Optimal Conditions ◽

Temperature Range ◽

Preparation Conditions ◽

Physico Chemical ◽

Ph Range

Abstract The aim of the research was to prepare and characterize hydrotalcite synthesized under different preparation conditions. The most common hydrotalcite preparation is the co-precipiaton method. The preparation process strongly influences the catalytic properties of hydrotalcite; therefore, optimal conditions have to be determined. During the study, seven samples of the catalyst were prepared in the pH range from 8 to 12 and the synthesis temperature range from 25 to 55 °C. Based on several catalyst properties, optimal synthesis pH 10 was found. Ideal temperature of the preparation was determined to be 35 °C, but the temperature does not have a significant effect on the catalyst properties.

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Research on Physico-Chemical Properties of Diethyl Ether/Linseed Oil Blends for the Use as Fuel in Diesel Engines

Energies ◽

10.3390/en13246564 ◽

2020 ◽

Vol 13 (24) ◽

pp. 6564

Author(s):

Krzysztof Górski ◽

Ruslans Smigins ◽

Rafał Longwic

Keyword(s):

Surface Tension ◽

Low Temperature ◽

Diethyl Ether ◽

Diesel Fuel ◽

Diesel Engines ◽

Kinematic Viscosity ◽

Linseed Oil ◽

Chemical Properties ◽

Fuel Blends ◽

Physico Chemical

Physico-chemical properties of diethyl ether/linseed oil (DEE/LO) fuel blends were empirically tested in this article for the first time. In particular, kinematic viscosity (ν), density (ρ), lower heating value (LHV), cold filter plugging point (CFPP) and surface tension (σ) were examined. For this research diethyl ether (DEE) was blended with linseed oil (LO) in volumetric ratios of 10%, 20% and 30%. Obtained results were compared with literature data of diethyl ether/rapeseed oil (DEE/RO) fuel blends get in previous research in such a way looking on differences also between oil types. It was found that DEE impacts significantly on the reduction of plant oil viscosity, density and surface tension and improve low temperature properties of tested oils. In particular, the addition of 10% DEE to LO effectively reduces its kinematic viscosity by 53% and even by 82% for the blend containing 30% DEE. Tested ether reduces density and surface tension of LO up to 6% and 25% respectively for the blends containing 30% DEE. The measurements of the CFPP showed that DEE significantly improves the low temperature properties of LO. In the case of the blend containing 30% DEE the CFPP can be lowered up to −24 °C. For this reason DEE/LO blends seem to be valuable as a fuel for diesel engines in the coldest season of the year. Moreover, DEE/LO blends have been tested in the engine research. Based on results it can be stated that the engine operated with LO results in worse performance compared with regular diesel fuel (DF). However, it was found that these disadvantages could be reduced with DEE as a component of the fuel mixture. Addition of this ether to LO improves the quality of obtained fuel blends. For this reason, the efficiency of DEE/LO blend combustion process is similar for the engine fuelled with regular diesel fuel. In this research it was confirmed that the smoke opacity reaches the highest value for the engine fuelled with plant oils. However, addition of 20% DEE reduces this emission to the value comparable for the engine operated with diesel fuel.

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Hydrogen peroxide decomposition on a non-irradiated and gamma pre-irradiated NiO-U3O8 catalyst

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19811886 ◽

1981 ◽

Vol 46 (8) ◽

pp. 1886-1897 ◽

Cited By ~ 5

Author(s):

Viliam Múčka

Keyword(s):

Hydrogen Peroxide ◽

Gamma Rays ◽

Catalytic Properties ◽

Chemical Properties ◽

Oxidation States ◽

Hydrogen Peroxide Decomposition ◽

Physico Chemical ◽

Peroxide Decomposition ◽

Charge Interaction ◽

Observed Behaviour

This paper deals with some physico-chemical properties of a two component catalyst NiO-U3O8, prepared with varying ratio of both components. Special interest was given to the catalytic properties - tested by decomposition of aqueous solution of hydrogen peroxide. The study presented evidence of mutual charge interaction between both components of the catalyst. This enables one to explain the observed behaviour of the studied system on the basis of the principle of bivalent sites. A pre-irradiation of a catalyst by gamma rays leads to significant increase of the oxidation states of both catalyst components.

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Mechanical/thermal dewatering of lignite. Part 4: Physico-chemical properties and pore structure during an acid treatment within the MTE process

Fuel ◽

10.1016/j.fuel.2011.08.049 ◽

2012 ◽

Vol 93 ◽

pp. 433-442 ◽

Cited By ~ 44

Author(s):

Christian Vogt ◽

Thomas Wild ◽

Christian Bergins ◽

Karl Strauß ◽

Janine Hulston ◽

...

Keyword(s):

Pore Structure ◽

Acid Treatment ◽

Chemical Properties ◽

Physico Chemical

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SYNTHESIS OF СеО2–МоО3 CATALYSTS OF SELECTIVE ETHANOL OXIDATION BY NON-TRADITIONAL METHODS

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.85.10.2019.91-101 ◽

2019 ◽

Vol 85 (10) ◽

pp. 91-101

Author(s):

Olena Sachuk

Keyword(s):

Oxidation Reaction ◽

Ethanol Oxidation ◽

Catalytic Properties ◽

Chemical Properties ◽

Core Shell ◽

Ethanol Oxidation Reaction ◽

N2 Adsorption ◽

Oxide Mixture ◽

Physico Chemical ◽

Dehydrogenation Of Ethanol

The influence of mechanochemical (MChT) and ultrasonic (UST) treatment on physic-chemical properties of СеО2-МоО3=1:1 composition was studied. The prepared samples were characterized by methods of XRD, ESR, N2 adsorption, SEM and TEM methods. The catalytic properties of obtained samples were studied in selective ethanol oxidation reaction. It was established the increase of specific surface area, decrease crystallites size and nanostructures formation of type “core-shell” due to MCh and US treatment. The change of physico-chemical properties of the compositions as a result of their mechano- and sonochemical treatment leads to increase their catalytic properties. The samples obtained after MCh and US treatments demonstrate very promising results in oxidative dehydrogenation of ethanol to acetaldehyde and the treated compositions permit to obtain the acetaldehyde selectivity equal 97 % at reaction temperature about 200ºC. It was shown that mechno- and sonochemical treatments of oxide mixture allow to obtain a high acetic aldehyde yield (97%) at 215°C and productivity on this product 1.8 mol/kg·h.

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Collation Efficiency of Poly(Vinyl Alcohol) and Alginate Membranes with Iron-Based Magnetic Organic/Inorganic Fillers in Pervaporative Dehydration of Ethanol

Materials ◽

10.3390/ma13184152 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4152

Author(s):

Gabriela Dudek ◽

Roman Turczyn ◽

David Djurado

Keyword(s):

Separation Factor ◽

Vinyl Alcohol ◽

Chemical Properties ◽

Poly Vinyl Alcohol ◽

Ethanol Dehydration ◽

Iron Particles ◽

Physico Chemical ◽

Iron Based ◽

Inorganic Fillers ◽

Best Parameters

Hybrid poly(vinyl alcohol) and alginate membranes were investigated in the process of ethanol dehydration by pervaporation. As a filler, three types of particles containing iron element, i.e., hematite, magnetite, and iron(III) acetyloacetonate were used. The parameters describing transport properties and effectiveness of investigated membranes were evaluated. Additionally, the physico-chemical properties of the resulting membranes were studied. The influence of polymer matrix, choice of iron particles and their content in terms of effectiveness of membranes in the process of ethanol dehydration were considered. The results showed that hybrid alginate membranes were characterized by a better separation factor, while poly(vinyl alcohol) membranes by a better flux. The best parameters were obtained for membranes filled with 7 wt% of iron(III) acetyloacetonate. The separation factor and pervaporative separation index were equal to 19.69 and 15,998 g⋅m−2⋅h−1 for alginate membrane and 11.75 and 14,878 g⋅m−2⋅h−1 for poly(vinyl alcohol) membrane, respectively.

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Decoration of specific sites on freeze-fractured membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081565 ◽

1978 ◽

Vol 36 (2) ◽

pp. 140-141

Author(s):

H. Gross ◽

H. Moor

Keyword(s):

Pure Water ◽

Freeze Fracture ◽

Chemical Properties ◽

Surface Forces ◽

Sulfate Pentahydrate ◽

Copper Sulfate Pentahydrate ◽

Physico Chemical ◽

Water Of Hydration ◽

Small Container ◽

Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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PHYSICO CHEMICAL PROPERTIES OF NICKEL OXIDE AT HIGH TEMPERATURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1976798 ◽

1976 ◽

Vol 37 (C7) ◽

pp. C7-438-C7-442 ◽

Cited By ~ 2

Author(s):

R. FARHI ◽

G. PETOT-ERVAS

Keyword(s):

High Temperature ◽

Nickel Oxide ◽

Chemical Properties ◽

Physico Chemical

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Physico-Chemical Properties of Recombinant Desulphatohirudin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645073 ◽

1990 ◽

Vol 63 (03) ◽

pp. 499-504 ◽

Cited By ~ 4

Author(s):

A Electricwala ◽

L Irons ◽

R Wait ◽

R J G Carr ◽

R J Ling ◽

...

Keyword(s):

Molecular Weight ◽

Gel Filtration ◽

Chemical Properties ◽

Alpha Helix ◽

Apparent Molecular Weight ◽

Correlation Spectroscopy ◽

Nmr Studies ◽

Recombinant Hirudin ◽

Physico Chemical ◽

Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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