Composition and Structure Changes of Asphaltenes of Oil from the Usinsk Field during Sequential Stepwise Thermal Decomposition

2018 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Structure Changes ◽  
Composition And Structure

The thermal decomposition of aromatic compounds - II. Dichlorobenzenes

1954 ◽  
Vol 224 (1159) ◽  
pp. 544-551 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Thermal Stabilities ◽  
Carbonaceous Deposit ◽  
Chain Processes ◽  
Composition And Structure ◽  
Gaseous Decomposition Product ◽  
Molecular Reaction ◽  
Complete Exclusion ◽  
The Stability ◽  
Kinetic Features

A kinetic study of the thermal decomposition of the dichlorobenzenes shows that the three isomers behave similarly. The compounds differ strikingly from chlorobenzene, inasmuch as the rate of decomposition is not reduced by nitric oxide or ammonia. Other kinetic features suggest that the reaction is unimolecular, and that chain processes do not occur to an appreciable extent. The main gaseous decomposition product is hydrogen chloride, and nearly all the combined chlorine can be accounted for as this product. Very small amounts of gaseous hydrogen are also found, but the balance of the combined hydrogen remains in the carbon deposited on the walls of the reaction vessel; this carbonaceous deposit is of similar composition and structure to that formed from chlorobenzene. Comparison of the thermal stabilities of benzene, chlorobenzene and the dichlorobenzenes shows that the stability is dependent on the extent of substitution of the aromatic ring but is little influenced by the relative positions of the substituents. The increased rate of decomposition caused by a second chlorine atom is evidently due to its ability to facilitate a molecular reaction, which apparently operates to the complete exclusion of chain processes.

Surface composition and structure changes in GaAs compounds due to low‐energy Ar+ ion bombardment

1989 ◽  
Vol 7 (6) ◽  
pp. 3251-3255 ◽  
Author(s):  
H. J. Kang ◽  
Y. M. Moon ◽  
T. W. Kang ◽  
J. Y. Leem ◽  
J. J. Lee ◽  
...  
Keyword(s):  
Surface Composition ◽  
Ion Bombardment ◽  
Low Energy ◽  
Structure Changes ◽  
Composition And Structure

scholarly journals Solubility and Activation of Hydrogen in the Non-Catalytic Upgrading of Venezuela Orinoco, China Liaohe, and China Fengcheng Atmospheric Residues

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2274
Author(s):  
Shunfeng Ji ◽  
Anran Zeng
Keyword(s):  
Gas Phase ◽  
Hydrogen Solubility ◽  
Reaction Conditions ◽  
Hydrogen Activation ◽  
Catalytic Upgrading ◽  
Positive Effects ◽  
Structure Changes ◽  
Composition And Structure ◽  
Reaction Proceeds ◽  
Positive Effect

The solubility of hydrogen in the Venezuela Orinoco, China Liaohe, and China Fengcheng atmospheric residues under reaction conditions of 400 °C, 4 MPa for 20 min was analyzed by determining the composition and structure changes of the products. Activation of hydrogen during the upgrading process was also determined and discussed by the probe method. The results show that lighter components produced in the reaction can increase the hydrogen solubility as the reaction proceeds, and the lighter components present at the liquid level have positive effects on the transfer of hydrogen from the gas phase to the liquid phase. Naphthenic aromatic structures, sulphur and metals have a positive effect on hydrogen activation in the trend of naphthenic aromatic structures > sulphur > metals. Moreover, when sulphur is present, nickel tetraphenylporphyrin has a better effect on hydrogen activation than Vanadium tetraphenylporphyrin. During upgrading, the Venezuela Orinoco atmospheric residue with more sulphur, metals and naphthenic aromatic structures can activate more hydrogen. Both the hydrogen solubility and residue composition have significant effect on the upgrading process.

ANALYSIS OF COMPOSITION AND STRUCTURE OF MAMMOTH TUSK THE MAMMUTHUS PRIMIGENIUS BY THERMOGRAMMETRIC AND X-RAY SPECTROSCOPY

2021 ◽  
Vol 0 (2) ◽  
pp. 9-12
Author(s):  
T.M. Solovev ◽  
◽  
E.S. Petukhova ◽  
G.V. Botvin ◽  
T.A. Isakova ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Phase Transformation ◽  
Chemical Composition ◽  
Elemental Analysis ◽  
Wide Temperature Range ◽  
Magnesium Ions ◽  
Spectroscopy Analysis ◽  
Mammuthus Primigenius ◽  
X Ray ◽  
Composition And Structure

The article represents the results of the research of the chemical composition of mammoth tusk Mammuthus Primigenius and its phase transformation using thermogrammetric (TGA) and X-ray spectroscopy analysis (XRD). The elemental analysis of mammoth tusk showed, that besides basic elements in the structure of hydroxyapatite (HAP) contains magnesium ions, i.e. hydroxyapatite in the studied samples is presented in magnesium-substituted form. The thermal decomposition of mammoth tusk components occurs in wide temperature range with a change in the structure of the mineral part from hydroxyapatite to whitlockite. It was found that this process is caused by the presence of magnesium ions.

scholarly journals LANDIS PRO: a landscape model that predicts forest composition and structure changes at regional scales

Ecography ◽  
2014 ◽  
Vol 37 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Wen J. Wang ◽  
Hong S. He ◽  
Jacob S. Fraser ◽  
Frank R. Thompson ◽  
Stephen R. Shifley ◽  
...  
Keyword(s):  
Forest Composition ◽  
Landscape Model ◽  
Structure Changes ◽  
Composition And Structure ◽  
Landis Pro

Modified Sol-Gel Synthesis of Vanadium Oxide Nanocomposites Containing Surfactant Ions, and Their Partial Removal

2000 ◽  
Vol 658 ◽  
Author(s):  
Arthur Dobley ◽  
Peter Y. Zavalij ◽  
Jürgen Schulte ◽  
M. Stanley
Keyword(s):  
Vanadium Oxide ◽  
Transition Metal Oxides ◽  
Sol Gel ◽  
Interlayer Spacing ◽  
Initial Compound ◽  
Structure Changes ◽  
Composition And Structure ◽  
Layered Transition Metal ◽  
Synthesis Composition ◽  
Sol Gel Synthesis

ABSTRACTRecently, there has been much interest in creating new layered transition metal oxides. Vanadium oxides may be used as sorbents, catalysts, and cathodes in lithium batteries. The modified sol-gel technique allows for some control towards the final structure of the compound. Using this technique, a new layered vanadium oxide phosphate material, containing the surfactant dodecylphosphate, has been synthesized. The compound was analyzed using powder XRD, TGA, SEM, FTIR, TEM, and solid state NMR for both 51V and 31P. V2O3(PO4C12H25)3Na2−xKx(H2O)3.2 is the general formula of the layered product with an interlayer spacing of 36.6 Å The initial compound is composed of a vanadium oxide phosphate layer sandwiched between two hydrocarbon layers. The synthesis, composition, and structure of the initial compound will be discussed. Interestingly, when this compound is calcined to 400°C, the structure changes and is possibly hexagonal. Preliminary results are presented on this calcined material.

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