Hydrogen sulfide reactions atmosphere

Air sparging or reaction of dissolved hydrogen sulfide with atmospheric oxygen could yield elemental sulfur. 

The ternary phases AMX2 (A = Li, Na, or K M = Cr, Ti, or V X = S or Se) have been synthesized by the reaction of mixtures of the alkali metal carbonate and the transition metal oxide in a hydrogen sulfide gas atmosphere at elevated temperature [73]. The reactions are carried out in graphite crucibles and it is usually found to be advantageous to use an excess of the metal carbonate. Structural characterization by X-ray and neutron diffraction confirmed their layered structure. These ternary phases may serve as a synthetic intermediate to new metastable layered metal dichalcogenides by oxidative removal (i.e., deintercalation) of the alkali metal. For example, this method has been used to prepare VS2 and CrSe2, which are difficult to synthesize by conventional high-temperature combination of the elements [74,75]. 

Sulfurization of unsaturated compounds and meicaptans is normally carried out at atmospheric pressure, in a mild or stainless steel, batch-reaction vessel equipped with an overhead condenser, nitrogen atmosphere, an agitator, heating media capable of 120—215°C temperatures and a scmbber (typically caustic bleach or diethanolamine) capable of handling hydrogen sulfide. If the reaction iavolves the use of H2S as a reactant or the olefin or mercaptan is a low boiling material, a stainless steel pressurized vessel is recommended. 

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. 

Although hydrogen sulfide does not react photochemically, it may be transformed to sulfur dioxide and sulfate by nonphotochemical oxidation reactions in the atmosphere. Its atmospheric residence time is typically less than 1 day (Hill 1973), but may be as high as 42 days in winter (Bottenheim and Strausz 1980). 

The parent hexathiaadamantane (185) is obtained preparatively when a solution of formic acid and hydrochloric acid in nitrobenzene is allowed to stand for several weeks in a hydrogen sulfide atmosphere the product which separated is almost insoluble in all common solvents and purification presents a problem. Only large volumes of dimethyl sulfoxide at reflux serve for recrystallization.224 The reaction of thioacetic acid with formic acid in the presence of zinc chloride gives tetramethyl-(186), monomethyl-, dimethyl-and trimethylhexathiaadamantane derivatives (187).225 Other variations include the reaction of thioacetic acid with a /i-diketone,226 and the use of boron trifluoride227 or aluminum chloride as a catalyst.228... 

The second term in Equation (6.8) corresponds to the sinks for sulfide in the water phase that, according to Figure 4.4, are primarily caused by oxidation in the water phase and emission into the sewer atmosphere. Pomeroy and Parkhurst (1977) propose values for Nat two levels,/V=0.96 and A=0.64. The first value corresponds to a median buildup of sulfide, whereas the last value is a conservative estimate for prediction of sulfide buildup in a sewer. The second term of Equation (6.8) shows that the removal of sulfide from the water phase is considered a 1-order reaction in the sulfide concentration. The term also includes elements related to the reaeration and, thereby, the emission of hydrogen sulfide [cf. Equations (3) and (6) in Table 4.7 and Section 4.3.2],... 

A similar reaction occurs with bromine at first copper(ll) bromide is formed which at red heat converts to copper(I) bromide. Fluorination yields CuF2. Heating the metal with iodine and concentrated hydriodic acid produces copper(l) iodide. When copper is heated in an atmosphere of hydrogen sulfide and hydrogen, the product is copper(I) sulfide, CU2S. 

Hydrogen sulfide in the reaction atmosphere has been reported to accelerate liquefaction directly, in addition to controlling the extent of sulfiding of iron, Ni-Mo, and Co-Mo catalysts (39, 40). 

ABSORPTION (Process). Absorption is commonly used in the process industries for separahng materials, notably a specific gas from a mixture of gases and in the production of solutions such as hydrochloric and sulfuric adds. Absorption operations are very important to many air pollution abatement systems where it is desired to remove a noxious gas, such as sulfur dioxide or hydrogen sulfide, from an effluent gas prior to releasing the material to the atmosphere. The absorption medium is a liquid in which (1) the gas to be removed, i.e., absorbed is soluble ill the liquid, or (2) a chemical reaction takes place between the gas and the absoibing liquid. In some instances a chemical reagent is added to the absorbing liquid to increase the ability of the solvent to absorb. 

ANALYZER (Reagent-Tape). The key to chemical analysis by this method is a tape (paper or fabric) that has been impregnated with a chemical substance that reacts with the unknown to form a reaction product on the tape which lias some special characteristic, e.g., color, increased or decreased opacity, change in electrical conductance, or increased or lessened fluorescence. Small pieces of paper treated with lead acetate, for example, have, been used manually by chemists for many years to determine the presence of hydrogen sulfide in a solution or in the atmosphere. This basic concept forms the foundation for a number of sophisticated instruments that may pietreat a sample gas, pass it over a cyclically advanced tape, and, for example, photo-metrically sense the color of the exposed tape, to establish a relationship between color and gas concentration. Depending upon tile type uf reactiun involved, the tape may he wet or dry and it may be advanced continuously or periodically. Obviously, there are many possible variations within the framework of this general concept. 

Caution. The apparatus should be set up in a hood, since hydrogen sulfide and hydrogen chloride are liberated during the reactions. The preparation of 0,0 -diethyl dithiophosphate is done in a nitrogen atmosphere because of the reactivity of the acid toward air and water. 

First, it should be noted that pyrite, Fe 2, if finely divided, is usually completely converted to pyrrhotite at temperatures above 350°C in an atmosphere of hydrogen and steam or of synthesis gas within reaction times of less than thirty minutes. The reaction products are a very finely divided pyrrhotite, with a stoichiometry of approximately FeS, and hydrogen sulfide. 

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