PYROLYSIS OF ETHYL MERCAPTAN

1955 ◽  
Vol 33 (8) ◽  
pp. 1281-1285 ◽  
Author(s):  
Jean L. Boivin ◽  
Roderick MacDonald
Keyword(s):  
Hydrogen Sulphide ◽  
Carbon Disulphide ◽  
Optimum Temperature ◽  
Mass Spectral Analysis ◽  
Mass Spectral ◽  
Ethyl Mercaptan ◽  
Catalyst Metal ◽  
Free Sulphur ◽  
Carbonyl Sulphide ◽  
By Products

The decomposition of ethyl mercaptan to ethylene and hydrogen sulphide was studied at various temperatures, with and without a catalyst. Metal sulphides (copper, nickel, and cadmium) proved to be the most efficient catalysts for cracking ethyl mercaptan into unsaturated end products, the optimum temperature being 500–600 °C. When no catalyst was used a 40–50% yield of ethylene and a nearly quantitative conversion to hydrogen sulphide was observed between 600 and 700 °C. Other products identified in the exit gas were carbon disulphide, carbonyl sulphide, methane, hydrogen, ethane, thiophene, diethyl sulphide, and free sulphur. Identification of these products was aided by infrared and mass spectral analysis of the gas. A tentative mechanism for the reaction justifying the presence of the above by-products is outlined.

THE ACTION OF CARBON DISULPHIDE ON ALUMINA GEL

1933 ◽  
Vol 9 (5) ◽  
pp. 424-431 ◽  
Author(s):  
L. A. Munro ◽  
J. W. McCubbin
Keyword(s):  
Room Temperature ◽  
Carbon Disulphide ◽  
Residual Water ◽  
Reaction Products ◽  
Yellow Color ◽  
Alumina Gel ◽  
Yellow Coloration ◽  
Higher Temperature ◽  
Carbonyl Sulphide ◽  
By Products

The authors have investigated the yellow color observed when carbon disulphide was adsorbed by c.p. alumina at room temperature. The color is due to by-products of the reactions of carbon disulphide with residual water in the gel. The investigators of the CS2 + H2O reaction at higher temperature attribute the yellow to sulphur or aluminium sulphide. The color formed at room temperature is not due to either of these. The reaction products consist largely of hydrogen sulphide, water, and carbon dioxide, with small amounts of carbonyl sulphide and carbon monoxide. The yellow coloration has been found to be a mixture of sodium sulphide, sodium hydrosulphide, and sodium polysulphide. A mechanism is proposed for its formation.

Kinetic spectroscopy in the vacuum ultra-violet region I. The dissociation energy of SO and the combustion of hydrogen sulphide, carbon disulphide and carbonyl sulphide

1964 ◽  
Vol 278 (1375) ◽  
pp. 490-504 ◽  
Keyword(s):  
Wavelength Range ◽  
Dissociation Energy ◽  
Hydrogen Sulphide ◽  
Flash Photolysis ◽  
Carbon Disulphide ◽  
Ultra Violet ◽  
Potential Curve ◽  
Isomeric Form ◽  
Carbonyl Sulphide ◽  
Vacuum Ultra Violet

A flash-photolysis apparatus is described which is capable of detecting transient reaction intermediates by means of their absorption spectra in the vacuum ultra-violet region. With this equipment studies have been made of the combustion of carbon disulphide, hydrogen sulphide and carbonyl sulphide under adiabatic and isothermal conditions. At the shortest delay time obtainable, a new spectrum appears in all of the reactions studied, in the wavelength range 2400 to 1900 Å. This spectrum has been shown to be that of the SO radical and in the case of the hydrogen sulphide reactions the spectrum can be seen to merge into a dissociation continuum, the convergence limit lying at 53677 cm -1 , corresponding to a dissociation energy for SO of 127.1 kcal/mole. Irregularities in the vibrational intervals of the 3 Σ- upper state of SO show that some of the levels are strongly perturbed, indicating a crossing or attempted crossing of this 3 Σ- curve with another potential curve. This is confirmed in the plot of Δ G v'+1/2 against v ' which has a point of inflexion between v ' = 14 and v ' = 17. It is shown that the potential curve responsible for these vibrational perturbations is the 3 II which is also responsible for the predissociation previously observed by Martin in the emission spectrum of SO, and that this state must dissociate to ground-state atomic products, i.e. O( 3 P ) and S( 3 P ). A new transient spectrum has been observed in the wavelength range 1840 to 1740 Å in the hydrogen sulphide and carbon disulphide reactions and these same bands have also been detected in the flash photolysis of SO 2 . It has been possible to fit the bands into a vibrational scheme and to assign them to an isomeric form of SO 2 . Reaction mechanisms for the combustion of H 2 S, CS 2 and COS and a mechanism for the formation of SO 2 are discussed.

THE THERMAL DECOMPOSITION OF DIMETHYL DISULPHIDE

1954 ◽  
Vol 32 (8) ◽  
pp. 768-779 ◽  
Author(s):  
John A. R. Coope ◽  
W. A. Bryce
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Sulphide ◽  
Carbon Disulphide ◽  
Main Reaction ◽  
Methyl Mercaptan ◽  
Primary Reaction ◽  
Gaseous State ◽  
Dimethyl Disulphide ◽  
Volatile Products ◽  
Free Sulphur

The thermal decomposition of dimethyl disulphide has been studied in the gaseous state by a static method. The primary reaction, which follows a reproducible induction period, produces one mole of methyl mercaptan per mole of disulphide, together with a product of low volatility believed to be a thioformaldehyde polymer:[Formula: see text]There is also a competing reaction producing a large quantity of hydrogen sulphide. The remaining volatile products, hydrocarbons of two or more carbon atoms (believed to be chiefly ethylene), free sulphur, polysulphides, and carbon disulphide are formed either by the latter reaction or by the extensive decomposition of products. The decomposition is catalyzed by hydrogen sulphide, and more strongly by the complete reaction mixture. A mechanism is proposed for the main reaction.

scholarly journals SYNTHESIS, CHARACTERIZATION, AND ANTHELMINTIC ACTIVITY OF NOVEL BENZOTHIAZOLE DERIVATIVES CONTAINING INDOLE MOIETIES

2019 ◽  
pp. 321-325
Author(s):  
ALETI RAJAREDDY ◽  
SRINIVAS MURTHY M
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Fourier Transform Infrared Spectroscopy ◽  
Anthelmintic Activity ◽  
Mass Spectral Analysis ◽  
Standard Drug ◽  
Mass Spectral ◽  
Benzothiazole Derivatives

Objective: The objective of this study was to synthesize and evaluate the anthelmintic activity (AA) of novel benzothiazole derivatives containing indole moieties (BDIM). Methods: The present works which involve the substituted isatin Schiff bases undergo acetylating and reacting with 2-aminobenzothiazole to give novel BDIM. Results: All the newly synthesized molecules (5a-5o) were characterized by Fourier-transform infrared spectroscopy, H_nuclear magnetic resonance, and mass spectral analysis along with physical data. The biological potentials of the newly synthesized compounds are evaluated for their AA using an Indian earthworm (Pheretima posthuma), and albendazole was used as standard drug. Conclusion: The synthesized compound 5f, 5n, and 5o showed good AA, whereas others exhibited significant activities.

Amorphous Polymeric Dithiazine apDTZ Solid Fouling: Critical Review, Analysis and Solution of an Ongoing Challenge in Triazine-Based Hydrogen Sulphide Mitigation

2021 ◽  
Author(s):  
Grahame Taylor ◽  
Jonathan Wylde ◽  
Walter Samaniego ◽  
Ken Sorbie
Keyword(s):  
Hydrogen Sulphide ◽  
Reaction Pathway ◽  
Theoretical Calculations ◽  
Mechanism Of Formation ◽  
Review Analysis ◽  
Operational Problem ◽  
Depth Study ◽  
The Common ◽  
By Products ◽  
A Current

Abstract Despite attempts to inhibit or avoid the formation of fouling deposits (polymeric amorphous dithiazine or apDTZ for short) from the use of MEA triazine, this remains a major operational problem and limits the use of this most popular and ubiquitous hydrogen sulphide (H2S) scavenger. This paper (a) reviews and summarizes previous work, (b) provides fresh insights into the reaction product and mechanism of formation, (c) proposes an effective method of removal, and (d) proposes some mechanisms of apDTZ digestion. The mechanism of apDTZ formation is discussed and reasoning is provided from a variety of perspectives as to the mechanism of MEA-triazine reaction with H2S. These include basicity and nucleophilic substitution considerations, steric properties and theoretical calculations for electron density. Novel procedures to chemically react with and destroy this solid fouling are presented with an in-depth study and experimental verification of the underlying chemistry of this digestion process. A review of agents to chemically destroy apDTZ is undertaken and a very effective solution has been found in peroxyacetic acid, which is much more powerful and effective than previously suggested peroxides. The structure of amorphous polymeric dithiazine is emphasized and the reason why this fouling cannot be 1,3,5-trithiane is stressed. This work therefore overcomes a current industry misconception by providing insight on two major paradoxes in the reaction pathway; namely i) why the thiadiazine reaction product from tris hydroxyethyl triazine (MEA triazine) is never observed and ii) why does the dithiazine in all cases never progress to the trithiane (3rd sulphur molecule substitution)? The latter issue is probably the biggest misconception in the industry and literature regarding triazine and H2S reactions. Many reasons for this are put forward and the common misconception of "overspent" triazine is refuted. A very effective chemical reaction that results in soluble by-products, counteracting the problems produced by this intractable polymer is found and their composition is proposed and experimentally verified.

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