Oxidation of hydrogen sulphide

Choi J, Hirai M, Shoda M. 1991. Catalytic oxidation of hydrogen sulphide by air over an activated carbon fibre. Applied Catalysis A General 79 241-248. 

Vainstein BM. 1977. [Oxidation of hydrogen sulphide by thionic bacteria.] Mikrobiologiia 46(6) 111 1-116. (Russian)... 

Partial oxidation of hydrogen sulphide into insoluble elemental sulphur... 

Novak, M. Zadrazil, M. (1991) Oxidation of hydrogen sulphide over ferric oxide/alumina catalyst. Collection Czech. Chem. Comm. 56 1893-1899... 

In the so-called Superclaus process, the last catalytic converter of the conventional Claus process is replaced by a catalytic converter containing the Superclaus catalyst . This catalyst consists of an a-alumina support with iron and chromium oxides as catalytic material. The Superclaus catalyst is highly selective for the direct oxidation of hydrogen sulphide ... 

The conventional Claus reaction involves the partial oxidation of hydrogen sulphide to sulphur and water. In practice the reaction is generally viewed as a two step sequence involving a highly exothermic oxidation step followed by a less exothermic redox reaction but the overall reaction can be expressed as... 

In 1942, soon after demobilization from the army, he had defended his PhD thesis on the theme, Oxidation of Hydrogen Sulphide . He generalized this research in the book Intermediate Products of Complex Reactions in Gaseous Phase (Moscow-Leningrad, Publishing house AS USSR, 1946) where, for the first time, it has been shown that such intermediate products as sulfur oxide possess properties of free radicals and can propagate oxidation. It was an important scientific benchmark. 

In their roles as catalysts, the activity of carbons has been ascribed to several factors, depending on the reaction that is promoted. Hence, for example, Coughlin has attempted to describe most catalytic properties in terms of electronic effectshowever it has been suggested that the decomposition of hydrogen peroxide and nitrous oxide is controlled by the presence of surface complexes. On the other hand, the microporosity of carbons has been suggested to be very important in the catalysed oxidation of hydrogen sulphide. ... 

Cariaso and Walker did find that impurities in the carbon could also have a strong influence on the catalytic reaction. It is very difficult indeed completely to purify carbon, and carbons useful on an industrial scale usually have a large ash content. In many cases, of which the oxidation of hydrogen sulphide is one, these impurities may have a significant effect on the properties and catalytic activity of the carbon. 

Klein, J. and Henning, K-D. (1984). Catalytic oxidation of hydrogen sulphide on activated carbons. Fuel, 63, 1064-7. 

Mikhalovsky, S.V., Zaitsev, and Yu. P. (1997). Catalytic properties of activated carbons I. Gas-phase oxidation of hydrogen sulphide. Carbon, 35, 1367—74. 

Although less energetically efficient than the oxidation of hydrogen sulphide (Fig. 8.4), the oxidation of metal sulphides could potentially support chemo-synthesis at seafloor massive sulphide deposits long after hydrothermal activity had ceased, even in well-buffered seawater (Eberhard etal., 1995 Juniper Tebo, 1995). Newly formed sulphide deposits are rapidly subjected to oxidation upon contact with ambient seawater, and some show micro-scale weathering features (e.g. etch pits on mineral surfaces Verati etal., 1999),... 

Directions (a) Thrust a burning splinter into a bottle of hydrogen sulphide and at once invert a dry bottle of air over it. (1) What happened (2) What was deposited on the sides of the bottles (3) Is hydrogen sulphide stable at the temperature of the flame (4) What is the evidence (5) Write the equation for the complete oxidation of hydrogen sulphide. 

We now consider hydrogen sulphide and its ionic forms. Sulphidic sulphur can occur in waters in the form of either non-dissociated hydrogen sulphide, H2S, simple HS and ions, or some complex ions, e.g. [HgS2] Within the range of pH 7.5-12 the HS" ion predominates. At pH < 6 non-dissociated H2S predominates in water. The second dissociation of H2S is significant only in strongly alkaline media. Apart from these forms, polysulphides can also be present in water probably as intermediates in the oxidation of hydrogen sulphide. 

Hydrogen sulphide and its ionic forms are labile in waters since they can be oxidized to sulphates via chemical or biochemical reactions. In waters they can occur permanently only in anaerobic media and therefore they are evidence of reduction processes taking place in such waters. Chemical oxidation of hydrogen sulphide by oxygen dissolved in water is a very com-... 

Figure 4 Self-healing accompanying oxidation of hydrogen sulphide. Contour lines for temperature rises of 0, 10, 20, 30, and 40 K. The line L corresponds to the predicted ignition limit from purely thermal theory...

Hoffmann, M. R. (1977) Kinetics and mechanism of oxidation of hydrogen sulphide by hydrogen peroxide in acidic solution. Environmental Science and Technology 11, 61-66 Hoffmann, M. R. (1986) On the kinetics and mechanism of the oxidation of aquated sulfur dioxide by ozone. Atmospheric Environment 20, 1145-1154 Hoffmann, M. R. (1990) Catalysis in aquatic environment. In Aquatic chemical kinetics (Ed. 

Oxidation of Hydrogen Sulphide to Sulphur in a Gas-Solid Trickle Flow Reactor, Ph.D. thesis. University of Twente, Enschede, The Netherlands, 1984. With permission.)... 

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