scholarly journals The combustion of aromatic and alicyclic hydrocarbons. III. Ignition and cool-flame characteristics

1940 ◽  
Vol 174 (958) ◽  
pp. 379-393 ◽  
Keyword(s):  
Temperature Coefficient ◽  
Experimental Technique ◽  
Aromatic Hydrocarbons ◽  
High Pressures ◽  
The Other ◽  
General Survey ◽  
Cool Flame ◽  
Slow Combustion ◽  
Ignition Characteristics ◽  
Butyl Benzene

In a previous communication (Burgoyne 1937), attention was drawn to certain apparently anomalous features of the slow combustion of n -butyl benzene, and it was shown, inter alia , that the observed irregularities in the temperature coefficient of the reaction could be accounted for by the occurrence of cool-flame ignitions of the same type as those exhibited by the higher aliphatic hydrocarbons (Townend and Chamberlain 1936). These circumstances suggested that a general survey of the ignition characteristics of the aromatic hydrocarbons would be desirable as an aid to elucidating the mechanism of their combustion; and the present paper embodies the results for the series previously studied, together with two members of the alicyclic series which have been included to serve as a connecting link with the paraffins and olefines. Owing to the wide variations in reactivity towards oxygen of the compounds in question, it was found impracticable to employ the same experimental technique throughout the series; for whilst the ignitions of the more reactive members could safely be studied in silica and glass vessels, the remainder involved high pressures and required the use of steel apparatus. Comparative experiments, however, showed that no essential alteration in the ignition characteristics resulted from the substitution of one material for the other.

scholarly journals The oxidation of aromatic hydrocarbons at high pressures. I— Benzene. II— Toluene. III— Ethyl Benzene

1936 ◽  
Vol 153 (879) ◽  
pp. 448-462 ◽  
Keyword(s):  
Aromatic Hydrocarbons ◽  
High Pressures ◽  
Vapour Phase ◽  
Complete Analysis ◽  
Ethyl Benzene ◽  
Open Chain ◽  
Slow Combustion ◽  
Benzene Toluene ◽  
A Chain ◽  
Oxidation Of Benzene

It has been shown in previous papers of this series that during the slow combustion of the aliphatic hydrocarbons at high pressure conditions are particularly favourable to the isolation of the intermediate compounds involved, and that such oxidations take place by successive stages of hydroxylation. The work has now been extended to include the aromatic hydrocarbons, and the present paper embodies the results for benzene, toluene, and ethyl benzene. The homogeneous slow oxidation of benzene in the vapour phase has been studied by Fort and Hinshelwood, who concluded that at atmospheric pressure it proceeds by a chain mechanism somewhat analogous to that which they postulated for ethylene. Although a complete analysis of the products of combustion was not made, other circumstances suggested that during an "apparent period of induction" the first products were formed without pressure increase, and that, to quote their words, 'hydroxylation of the double bonds may be assumed to occur, followed by rapid further oxidation of the open chain unsaturated compound so produced to a substance like glyoxal. The remaining stages would then be analagous to the oxidation of acetylene

A mathematical model for hydrocarbon autoignition at high pressures

1975 ◽  
Vol 346 (1647) ◽  
pp. 515-538 ◽  
Keyword(s):  
Mathematical Model ◽  
High Pressures ◽  
The Other ◽  
Chain Mechanism ◽  
Rapid Compression Machine ◽  
High Pressure And Temperature ◽  
Cool Flame ◽  
Induction Periods ◽  
Branched Chain ◽  
Low Pressures

We have developed a generalized mathematical model for the autoignition of hydrocarbons under the conditions of high pressure and temperature achieved in a rapid-compression machine. The model is able to simulate the essential phenomena of the two-stage autoignition of alkanes under these conditions; these are a well-defined cool flame that is often quenched rapidly and completely before the onset of a sharp ignition. It also pre­dicts correctly the transition to single-stage autoignition at even higher temperatures and the variation with temperature of the characteristic induction periods. The model is based on a degenerate-branched-chain mechanism. We show that it must contain as necessary features two termination processes, one linear and the other quadratic in radial concen­tration, and two routes for the formation of branching agent, one of which involves intermediate products of oxidation. The model also predicts, without any adjustment of the kinetic parameters, the essential pheno­mena of cool-flame and ignition behaviour that are observed at low pressures.

Reconstruction of electron holograms recorded in a non-FEG, non-biprism TEM

1995 ◽  
Vol 53 ◽  
pp. 618-619
Author(s):  
Z.L. Wang
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Experimental Technique ◽  
Transmission Electron Microscope ◽  
The Other ◽  
Electron Holography ◽  
Transmission Electron ◽  
Coherent Sources ◽  
Imaging Theory ◽  
Normal Specimen

An experimental technique for performing electron holography using a non-FEG, non-biprism transmission electron microscope (TEM) has been introduced by Ru et al. A double stacked specimens, one being a single crystal foil and the other the specimen, are loaded in the normal specimen position in TEM. The single crystal, which is placed onto the specimen, is responsible to produce two beams that are equivalent to two virtual coherent sources illuminating the specimen beneath, thus, permitting electron holography of the specimen. In this paper, the imaging theory of this technique is described. Procedures are introduced for digitally reconstructing the holograms.

Studies on the Toxicity of Aromatic Hydrocarbons on Chorella Vulgaris by 3D-QSAR Using CoMFA and CoMSIA Methods

2012 ◽  
Vol 610-613 ◽  
pp. 3574-3579
Author(s):  
Cui Hua Wang ◽  
Sheng Long Yang ◽  
Chao Lu ◽  
Hong Xia Yu ◽  
Lian Shen Wang ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Aromatic Hydrocarbons ◽  
Common Factor ◽  
3D Qsar ◽  
The Other ◽  
Contour Maps ◽  
Substituent Group ◽  
Donor And Acceptor ◽  
The Common ◽  
Insight Into

By using CoMFA and CoMSIA methods, the new quantitative structures of 25 aromatic hydrocarbons and the 96 hr-EC50 data with C. vulgaris have been investigated to obtain more detailed insight into the relationships between molecular structure and bioactivity. Compared to CoMFA (the average Q2LOO option =0.610), CoMSIA (the average Q2LOO =0.736) has the better results with robustness and stability. CoMSIA analysis using steric, electrostatic, hydrophobic, and H-bond donor and acceptor descriptors show H-bond donor is the common factor for influencing the toxicity, the steric and electrostatic descriptors are next and the hydrophobic descriptor was last. From the contour maps, the number of benzene ring is more crucial for the compound toxicity and the compounds with more benzene ring make toxicity increased. Under the same number of benzene ring, the kind of substituent group and the formed ability of H-bond are the other parameters to influencing the aromatic hydrocarbons toxicity.

scholarly journals The relation between the crystal symmetry of the simpler organic compounds and their molecular constitution. —Part II

1913 ◽  
Vol 89 (611) ◽  
pp. 327-339 ◽  
Keyword(s):  
Aromatic Hydrocarbons ◽  
The Other ◽  
Optical Observations ◽  
Monoclinic Crystal System ◽  
Sulphur Compounds ◽  
Monoclinic Crystal ◽  
Optical Character ◽  
Halogen Compounds ◽  
Optical Axes ◽  
Molecular Constitution

In this paper the experimental results concerning the crystalline properties of the unsaturated aliphatic hydrocarbons, the simpler oxygen- and sulphur-compounds of carbon, the halogen-compounds, and the simpler aromatic hydrocarbons are given. Ethylene . —Ethylene, prepared from alcohol and sulphuric acid, was purified by liquefying it and distilling it twice. It crystallises very well, large prisms being formed. Two distinct cleavage systems occur, one parallel to a prism and the other parallel to the basal plane (or an orthodome). The doublerefraction is of middle strength; the extinction is in some sections parallel to the prismatic cleavage, in others it is not. The angle of the optical axes is large, and the optical character negative. These optical observations show that ethylene crystallises in the monoclinic crystal system.

Catalytic Pyrolysis of Waste Achyranthes Root Over Al-MCM-41

2021 ◽  
Vol 21 (7) ◽  
pp. 4081-4084
Author(s):  
Seul-Bee Lee ◽  
Young-Min Kim ◽  
Ji-Hui Park ◽  
Young-Kwon Park
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Aromatic Hydrocarbons ◽  
Catalytic Pyrolysis ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Acidic Properties ◽  
Achyranthes Root ◽  
Formation Efficiency ◽  
Mcm 41

This study examined the thermal and catalytic pyrolysis of waste Achyranthes Root (AR) using pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The non-catalytic pyrolysis of waste AR produced various kinds of oxygenates, such as acetic acid, hydroxy propanone, furfural, phenol, cresol, guaiacols, syringols, and so on. By applying nanoporous Al-MCM-41 with acidic properties and mesopores to the pyrolysis of waste AR, the levels of furan and aromatic hydrocarbons production increased with a concomitant decrease in the other oxygenates. The formation efficiency of furans was improved further by increasing the amount of Al-MCM-41 applied to the catalytic pyrolysis of waste AR.

XXIV.—On the Temperature Coefficient of Concentration Cells, in which the same salt is dissolved in two different solvents

1912 ◽  
Vol 31 ◽  
pp. 375-396
Author(s):  
A. P. Laurie
Keyword(s):  
Temperature Coefficient ◽  
Potassium Iodide ◽  
Royal Society ◽  
Platinum Electrode ◽  
The Other ◽  
Absolute Alcohol ◽  
Concentration Cell ◽  
New Type ◽  
The One ◽  
Concentration Cells

In a paper read before the Royal Society of Edinburgh (Proc. Roy. Soc. Edin., xxviii., part v., p. 382 (1908); Zeit. phys. Chem., lxiv. 5) I described a new type of concentration cell, in which the one platinum electrode was surrounded by a solution of ·025 molecules of KI containing ·001 molecules of iodine dissolved in absolute alcohol, and the other electrode was surrounded by ·025 molecules of KI and ·001 molecules of iodine, dissolved in water. This cell developed a considerable E.M.F. of ·198 volts at 25° C. in the direction which would transfer the iodine from water to alcohol and potassium iodide from alcohol to water.

Sign in / Sign up

Export Citation Format

Share Document