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

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 combustion of aromatic and alicyclic hydrocarbons. IV. The kinetics of the slow combustion of benzene and its mono-alkyl derivatives at low temperatures

1940 ◽  
Vol 174 (958) ◽  
pp. 394-409 ◽  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Low Temperatures ◽  
Side Chain ◽  
Oxidation Reactions ◽  
Alkyl Derivatives ◽  
Single Side ◽  
Slow Combustion ◽  
Benzene Toluene ◽  
Kinetics Of

In previous papers of this series the ignition and slow-combustion reactions of a number of aromatic hydrocarbons have been examined, mainly from the kinetic standpoint. In the present and following communications it is proposed further to consider benzene and its single side-chain derivatives, in relation particularly to the oxidation reactions occurring below 400° C, and to correlate this mode of combustion by kinetic and analytical observations with the types previously examined. The hydrocarbons to which attention is chiefly directed are benzene, toluene, ethylbenzene, n -propylbenzene and n -butylbenzene.

scholarly journals The formation of ethers by the interaction of primary alcohols and olefines at high pressure

1936 ◽  
Vol 157 (891) ◽  
pp. 348-358 ◽  
Keyword(s):  
High Pressure ◽  
Equilibrium Constant ◽  
High Pressures ◽  
Equilibrium Constants ◽  
Vapour Phase ◽  
Aliphatic Alcohols ◽  
Primary Alcohols ◽  
Ethylene Propylene ◽  
Slow Combustion ◽  
Direct Inter

Although it is known that olefines will condense with phenols in the presence of catalysts to give aromatic ethers, and that tertiary olefines will react with aliphatic alcohols in a similar manner, no corresponding reaction between the simple olefines and aliphatic alcohols has hitherto been reported. In some recent work upon the slow combustion o olefines at high pressures, however, we have detected ethers in the products in circumstances suggesting that they arise from the direct inter actions of the olefine with alcohol produced during the combustion and on testing the matter further it has been found that in the presence of a suitable catalyst and at high pressures ethylene, propylene, and buty lene will combine with aliphatic alcohols in the vapour phase, the reaction C n H 2 n +1 . OH + C n´ H 2 n´ ⇌ C n H 2 n +1 . O . C n´ H 2 n´ +1 , (1) being reversible and slightly exothermic with respect to ether formation At temperatures between 200° and 300°C. and pressures of about 50 atms., all three components of the system are present in measurable quantities at equilibrium and the equilibrium constant can be determined by approach from either side. In the present paper the results are given of experiments with ethylene propylene, and butylene, and a number of the lower aliphatic alcohols the equilibrium constants for the system alcohol-olefine-ether having been determined in each case.

scholarly journals The combustion of aromatic and alicyclic hydrocarbons I—The slow combustion of benzene, toluene, ethylbenzene, n -propylbenzene, n -butylbenzene, o -xylene, m -xylene, p -xylene and mesitylene

1937 ◽  
Vol 161 (904) ◽  
pp. 48-67 ◽  
Keyword(s):  
Gaseous Phase ◽  
Aromatic Compounds ◽  
Chain Mechanism ◽  
Induction Periods ◽  
Slow Combustion ◽  
Benzene Toluene ◽  
Chain Theory ◽  
Characteristic Features ◽  
A Chain ◽  
Kinetics Of

Recent work upon the kinetics of the oxidation of aliphatic hydrocarbons has led to the recognition of certain characteristic features that find a ready interpretation in terms of the chain theory of chemical reaction. Thus, for example, both paraffins and olefines exhibit well-defined induction periods, pressure limits of inflammability and a marked sensitivity to the influence of surface, that point directly to the intervention of reaction chains; and although the precise nature of the chain mechanisms is somewhat uncertain a great deal of information is available as to their length, branching characteristics, mutual interactions and stability. Corresponding data for alicyclic and aromatic compounds are, however, very scanty and only in one instance has a comprehensive systematic kinetic study been made. Fort and Hinshelwood (1930) and Amiel (1933 a, b , 1936) have investigated the slow combustion of benzene and find that whilst it shows a general resemblance to ethylene there are certain respects in which significant differences occur. Fort and Hinshelwood concluded that benzene is oxidized by a chain mechanism, the chains initiated predominantly in the gaseous phase being of short continuation.

Performance of Ag-HZSM-5 Zeolite Catalysts in n-heptane Conversion

2017 ◽  
Vol 68 (1) ◽  
pp. 116-120
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Lucian Mihail Birsa ◽  
Ioan Gabriel Sandu ◽  
Laura Gabriela Sarbu ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Metal Content ◽  
Pulse Method ◽  
Acid Strength ◽  
Strength Distribution ◽  
Zeolite Catalysts ◽  
Benzene Toluene ◽  
Acid Strength Distribution ◽  
Silver Cations ◽  
Heptane Conversion

The conversion of n-heptanes into aromatic hydrocarbons benzene, toluene and xylenes (BTX), by the chromatographic pulse method in the temperature range of 673 - 823K was performed over the HZSM-5 and Ag-HZSM-5 zeolites modified by ion exchange with AgNO3 aqueous solutions. The catalysts, HZSM-5 (SiO2/Al2O3 = 33.9), and Ag-HZSM-5 (Ag1-HZSM-5 wt. % Ag1.02, Ag2-HZSM-5 wt. % Ag 1.62; and Ag3-HZSM-5 wt. % Ag 2.05 having different acid strength distribution exhibit a conversion and a yield of aromatics depending on temperature and metal content. The yield of aromatic hydrocarbons BTX appreciably increased by incorporating silver cations Ag+ into HZSM-5.

Catalytic oxidation of benzene, toluene and p-xylene over colloidal gold supported on zinc oxide catalyst

2011 ◽  
Vol 12 (10) ◽  
pp. 859-865 ◽  
Author(s):  
Hongjing Wu ◽  
Liuding Wang ◽  
Jiaoqiang Zhang ◽  
Zhongyuan Shen ◽  
Jinghui Zhao
Keyword(s):  
Zinc Oxide ◽  
Catalytic Oxidation ◽  
Colloidal Gold ◽  
Oxide Catalyst ◽  
Benzene Toluene ◽  
Oxidation Of Benzene

scholarly journals The combustion of aromatic and alicyclic hydrocarbons. II. The ignition of aromatic hydrocarbons at high temperatures

1939 ◽  
Vol 171 (946) ◽  
pp. 421-433 ◽  
Keyword(s):  
High Temperatures ◽  
Aromatic Hydrocarbons ◽  
Isothermal Oxidation ◽  
Present Communication ◽  
Temperature Range ◽  
Benzene Toluene ◽  
The Subject ◽  
Kinetics Of

In the first paper of this series (Burgoyne 1937) the kinetics of the isothermal oxidation above 400° C of several aromatic hydrocarbons was studied. The present communication extends this work to include the phenomena of ignition in the same temperature range, whilst the corresponding reactions below 400° C form the subject of further investigations now in progress. The hydrocarbons at present under consideration are benzene, toluene, ethylbenzene, n -propylbenzene, o-, m - and p -xylenes and mesitylene.

scholarly journals Directed Evolution of Biphenyl Dioxygenase: Emergence of Enhanced Degradation Capacity for Benzene, Toluene, and Alkylbenzenes

2001 ◽  
Vol 183 (18) ◽  
pp. 5441-5444 ◽  
Author(s):  
Hikaru Suenaga ◽  
Mariko Mitsuoka ◽  
Yuko Ura ◽  
Takahito Watanabe ◽  
Kensuke Furukawa
Keyword(s):  
Amino Acids ◽  
Aromatic Hydrocarbons ◽  
Burkholderia Cepacia ◽  
Large Subunit ◽  
Site Directed Mutagenesis ◽  
Biphenyl Dioxygenase ◽  
Pseudomonas Pseudoalcaligenes ◽  
Benzene Toluene ◽  
Related Compounds ◽  
Enhanced Degradation

ABSTRACT Biphenyl dioxygenase (Bph Dox) catalyzes the initial oxygenation of biphenyl and related compounds. Bph Dox is a multicomponent enzyme in which a large subunit (encoded by the bphA1 gene) is significantly responsible for substrate specificity. By using the process of DNA shuffling of bphA1 of Pseudomonas pseudoalcaligenes KF707 and Burkholderia cepaciaLB400, a number of evolved Bph Dox enzymes were created. Among them, anEscherichia coli clone expressing chimeric Bph Dox exhibited extremely enhanced benzene-, toluene-, and alkylbenzene-degrading abilities. In this evolved BphA1, four amino acids (H255Q, V258I, G268A, and F277Y) were changed from the KF707 enzyme to those of the LB400 enzyme. Subsequent site-directed mutagenesis allowed us to determine the amino acids responsible for the degradation of monocyclic aromatic hydrocarbons.

COMPLEXES OF STANNIC IODIDE WITH AROMATIC HYDROCARBONS

1965 ◽  
Vol 43 (5) ◽  
pp. 1272-1278 ◽  
Author(s):  
J. F. Murphy ◽  
D. E. Baker
Keyword(s):  
Carbon Tetrachloride ◽  
Complex Formation ◽  
Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbons ◽  
Extinction Coefficient ◽  
Regular Solutions ◽  
Benzene Toluene ◽  
Yield Values ◽  
Complex Stabilities ◽  
Iodide Complex

Spectrophotometric measurements on solutions of stannic iodide were found to provide evidence for complex formation with aromatic hydrocarbons. Calculations, based on spectra for mixed solutions of benzene and stannic iodide in carbon tetrachloride, yield values of 0.26 for the equilibrium constant (mole fraction), 28 400 1/mole cm for the molar extinction coefficient of the benzene – stannic iodide complex. Kinetic evidence indicates that the order of decreasing complex stabilities is from xylene to toluene to benzene. The formation of stannic iodide – aromatic hydrocarbon complexes provides an explanation for the discrepancy between measured solubilities of stannic iodide in benzene, toluene, and xylene, and the solubilities predicted by the Hildebrand theory of regular solutions.

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