Gas, hydrogen sulfide

The concentrated hydrogen sulfide gas is then sent to the sulfur production unit (Claus process). 

USSR Pat. 1,466,781 (Mar. 23, 1989), F. R. Ismagilov and co-workers (to Volga-Ural Scientific Research Institute for the Extracting and Processing of Hydrogen Sulfide Gas). 

Corrosion products and deposits. All sulfate reducers produce metal sulfides as corrosion products. Sulfide usually lines pits or is entrapped in material just above the pit surface. When freshly corroded surfaces are exposed to hydrochloric acid, the rotten-egg odor of hydrogen sulfide is easily detected. Rapid, spontaneous decomposition of metal sulfides occurs after sample removal, as water vapor in the air adsorbs onto metal surfaces and reacts with the metal sulfide. The metal sulfides are slowly converted to hydrogen sulfide gas, eventually removing all traces of sulfide (Fig. 6.11). Therefore, only freshly corroded surfaces contain appreciable sulfide. More sensitive spot tests using sodium azide are often successful at detecting metal sulfides at very low concentrations on surfaces. 

Current methods for removing sulfur from the hydrogen sulfide gas streams are typically a combination of two processes the Claus Process followed by the Beaven Process, SCOT Process, or the Wellman-Land Process. 

Chemical Reactivity - Reactivity with Water. Reacts with liquid water or atmospheric moisture to liberate toxic hydrogen sulfide gas Reactivity with Common Materials No reaction Stability During Transport Can be ignited by friction Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Hydrogen sulfide gas Hydrogen sulfide is a gas with a rotten egg odor. This gas is produced under anaerobic conditions. Hydrogen sulfide is particularly dangerous because it dulls your sense of smell so that you don t notice it after you have been around it for a while and because the odor is not noticeable in high concentrations. The gas is very poisonous to your respiratory system, explosive, flammable, and colorless. 

S12.15 Part I, Performance Requirements, Hydrogen Sulfide Gas Detectors (Draft Standard)... 

In the second and following passes through the press, water was added to the pulp to increase the efficiency of the extraction procedure. The crude juice was screened to remove the coarse particles. Hydrogen sulfide gas was bled into the collected juice to partially saturate it. 

Hydrogen sulfide gas (H2S) is responsible for die fiwl odor of rotten eggs. When it reacts with oxygen, sulfur dioxide gas and steam are produced. 

As a third oxidation-reduction example, suppose a strip of metallic zinc is placed in a solution of copper nitrate, Cu(N03)j. The strip becomes coated with reddish metallic copper and the bluish color of the solution disappears. The presence of zinc ion, Zn+2, among the products can be shown when the Cu+2 color is gone. Then if hydrogen sulfide gas is passed into the mixture, white zinc sulfide, ZnS, can be seen. The reaction between metallic zinc and the aqueous copper nitrate is... 

As a more complex case, suppose we want to write the equation for the reaction that occurs when hydrogen sulfide gas, H2S, is bubbled into an acidified potassium permanganate solution, KMn04. When we do this, we observe that the purple color of the MnO ion disappears and that the resulting mixture is cloudy (sulfur particles). From Appendix 3 we find the two halfreactions... 

Nevertheless, as pressures increase, the steam and condensate pH levels begin to drop significantly. This pH depression is accelerated with higher BW sulfite levels. At 700 psig, with a BW sodium sulfite reserve of, say, 40 ppm, the condensate can dip to as low as pH 4.2. This ultimately produces a very corrosive situation caused by the production of sulfur dioxide gas (S02) and hydrogen sulfide gas (H2S). 

A popular source of sulfide ions is hydrogen sulfide gas. This is a versatile reagent capable of precipitating a number of metal sulfides, some of which can be precipitated selectively from solution by suitably adjusting the solution pH. In the aqueous medium the following reactions take place by which hydrogen sulfide releases, in two stages, sulfide ions to the medium ... 

This approach of using the sulfide as the cathode implies that while nickel metal is directly formed on the cathode, the sulfur is continuously removed as hydrogen sulfide gas. In the former case there is a build up of sulfur in the cell. 

To make hydrogen sulfide gas, pieces of iron(II) sulfide (instead of zinc) are placed in the center bowl of a Kipp s apparatus ... 

Hydrogen sulfide gas is used in analytical chemistry laboratories to detect certain metal ions in a solution. If the solution contains a Group IIA metal, such as calcium, a precipitate will form when an acidic solution containing hydrogen sulfide is added to it. The precipitate forms because one of the products of the chemical reaction is insoluble (which means it does not dissolve). 

Hydrogen sulfide is a colorless gas that smells like rotten eggs. Because of its smell, it is often called stink gas or sewer gas. It is also poisonous. Because of its toxic nature, and smell, a Kipp s apparatus generating hydrogen sulfide gas should always be kept under a fume hood. 

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