Sulfur ratio, hydrogen sulfide

The overall effect is to separate natural water into DjO and water depleted in hydrogen, with reflux provided by consumption of aluminum metal and production of aluminum oxide. Sulfur and hydrogen sulfide circulate internally and are not consumed by the process. The minimum molar ratio of DjS reflux G to D2O product P may be evaluated from Eq. (12.80) ... 

The principal function of the catalytic reduction system is to maximize use of the reductant while producing both sulfur and hydrogen sulfide, so the hydrogen sulfide/sulfur dioxide ratio in the gas stream leaving the system is essentially that required for the subsequent Claus reaction. Although the chemistry of the primary reaction system is extremely complex and includes reactions involving 11 different elements and compounds, it may be summarized in the following equations ... 

The basic difference between the formation of sulfur and the carbon gases and its influence on the isotopic ratios of kerogen, bitumen, oil and gas lies in the chemical activity of the thermally derived fragments. Both elemental sulfur and hydrogen sulfide formed at elevated temperatures could re-react with all fractions (Stoler et al., 2003). Research on changes in both carbon and... 

Depending on the H2S/CH4 ratio, hydrogen sulfide reforming occurs at a temperature higher than 850°C. At these temperatures, the elemental sulfur produced is in the vapor phase and cannot cause deactivation of metal sulfide-based catalysts. However, the formation of solid carbon can be harmful for the catalysts. To avoid coking effect, the molar ratio of H2S/CH4 must be greater than 4. As indicated by thermodynamic analyses [21], a higher H2S/CH4 ratio can reduce carbon formation to zero at lower temperatures. 

In the reducing atmosphere of the reactor, sulfur compounds form hydrogen sulfide and small amounts of carbonyl sulfide [463-58-1J, COS, in a molar ratio of approximately 24 1. 

Reaction with Sulfur Nucleophiles, Because sulfai is highly nucleophilic, reactions of aziridines with sulfur nucleophiles generally proceed rapidly (111) and with good yields. The reaction of hydrogen sulfide [7783-06S-J with ethyleneimine yields cysteamine [60-23-1] (2-mercaptoethylamine) or bis(2-aminoethyl)sulfide [871-76-1] (2,112) depending on the molar ratio of the reactants. The use of NaHS for the synthesis of cysteamine has also been described (113). 

Gas purification processes fall into three categories the removal of gaseous impurities, the removal of particulate impurities, and ultrafine cleaning. The extra expense of the last process is only justified by the nature of the subsequent operations or the need to produce a pure gas stream. Because there are many variables in gas treating, several factors must be considered (/) the types and concentrations of contaminants in the gas (2) the degree of contaminant removal desired (J) the selectivity of acid gas removal required (4) the temperature, pressure, volume, and composition of the gas to be processed (5) the carbon dioxide-to-hydrogen sulfide ratio in the gas and (6) the desirabiUty of sulfur recovery on account of process economics or environmental issues. 

When hydrogen sulfide reacts, with mercuric chloride in neutral or acid solution, or when mercury and sulfur are ground together, black mercuric sulfide is formed. Under certain conditions, this material can be converted into the red modification by the continued action of soluble alkali sulfides. The reaction of mercuric chloride and sodium thiosulfate gives the red form if the ratio of the concentrations is higher than 1 4d The red sulfide is also produced when the substance Hg(SH)NCS is boiled with concentrated ammonium thiocyanate solution or when hydrogen sulfide is conducted into a warm mercuric salt solution in the presence of acetic acid and an excess of ammonium thiocyanate, or thiourea.2,3... 

Asinger s studies demonstrated that product formation is sensitive to the ratio of sulfur to ketone (1), the structure of the ketone, the replacement of ammonia by amines, the temperature and the medium. Room temperature (20-25 °C) reactions in which the ratio of sulfur to ketones is 0.5 favors the formation of 3-thiazoline, 2, as shown in Figure 1. The formation of 5-alkylidene-3-thiazolines, 3, sometimes competes with the formation of 3-thiazolines such is the case when aryl ketones such as l-phenylpropan-2-one and l-phenylbutan-2-one are employed (4). Also the additional presence of hydrogen sulfide promotes the generation of 1,2,4-trithiolanes and 1,2,4,5-tetrathiolanes from ketones ana aldehydes at the expense of 3-thiazoline formation (11-12). Increasing the S/ketone ratio to 8 favors the formation of the 3-imidazoline-5-thione (5), a product which has a greater tendency to result from aryl methyl ketones (3). 

Sulfur, carbon and hydrogen stable isotope ratios of pyrite, kerogens, and bitumens of two high-sulfur Monterey formation samples from the onshore Santa Maria Basin in California were determined. Kerogens from these were pyrolyzed at 300°C for periods of 2, 10 and 100 hours in closed systems and the yields and isotopic compositions of S-containing fractions (residual kerogens, bitumens and hydrogen sulfide) were determined. 

For 1,3-butadiene hydrogenation, the toxicity of sulfur is 3 (Fig. 13). which is lower than the toxicity for olefin hydrogenation. The hydrogenation of 1-butyne has also been studied for various ratios of sulfur over palladium. As was already published (86), the 1-butyne hydrogenation rate increases with time. The same effect has been observed on sulfided palladium. The turnover number is consequently presented for 1-butyne hydrogenation versus the sulfur content for various 1-butyne conversions (see Fig. 14). During the first minutes of reaction (0-25% conversion), the toxicity of sulfur appears close to 1 the rates are proportional to the free surface. However, at higher conversion, the rate becomes independent from the sulfur ratio. The toxicity is zero. 

Some of the factors that contribute to the internal corrosion of tin plate cans are (i) the ratio and concentrations of citric to malic acids which in turn depend upon the strain of fruit, the extent of ripeness (ii) nitrate present in the fertilizers may find its way into fruits and vegetables and the nitrate may be reduced to hydroxylamine and support the detinning process (iii) pesticides containing dithiocarbomates may find their way in and attack iron (iv) phosphates, citrates and the low pH of cola-type beverage may dissolve iron (iv) meats, fish and peas contain sulfur-bonded protein molecules, which can decompose to H2S and attack the tin and iron, forming the respective sulfides. Hydrogen sulfide can react with Sn and Fe, yielding FeS and SnS, which are not poisonous, but impart some color to the canned product. 

The isotope ratios of the sulfur isotopes are also affected by kinetic and equilibrium isotope effects. Kinetic isotope effects are marked in the reduction of sulfates to hydrogen sulfide by bacteria (enrichment of the lighter isotopes in H2S). The equilibrium isotope effect in the reaction... 

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