From sulfur compounds

Prior to methanation, the gas product from the gasifier must be thoroughly purified, especially from sulfur compounds the precursors of which are widespread throughout coal (23) (see Sulfurremoval and recovery). Moreover, the composition of the gas must be adjusted, if required, to contain three parts hydrogen to one part carbon monoxide to fit the stoichiometry of methane production. This is accompHshed by appHcation of a catalytic water gas shift reaction. 

Gou, Z. Liu, Y., and Xing, J., Gordona nitida and application of removing sulfur element from sulfur compound. Patent No. CN1445361. 2003, Oct. 01. 

As would be expected, the chemistry is complex. Unpleasant, off flavor odors usually derive from sulfur compounds, such as MT, DMS, DMDS, and DMTS, formed either enzymatically or non-enzymatically from sulfur-containing amino acids.35 Enzymatic routes to MT are essentially those previously considered (Section 11.1.2.4.5). Some DMS may derive by methylation of MT (Equation 8) with the donor, 5-adenosylmethionine, AdoMet ... 

The lifetime of the RSSR radical anions is usually very short on the microsecond timescale in water. However, they have been detected and characterized by time-resolved optical methods. In one early study, y irradiation of matrices containing alkyl and aryl disulfides provided spectroscopic evidence for the formation of the corresponding radical anions. Subsequently, the formation of RSSR radical anions has been well documented, particularly by EPR, flash photolysis, and pulse radiolysis. In fact, 2a/ a three-electron bonded radical anion species, particularly from sulfur compounds, constitute significant and interesting intermediates. The RSSR radical anions may be obtained from different approaches. One is by one-electron reduction of disulfides (equation 75), such as by pulse radiolysis. However, the most common approach is by association of RS and RS (equation 79). ... 

Both the natural clay and the synthetic types of catalyst undergo normal aging. Abnormal aging, due to sulfur compounds, has been found only with natural clay catalyst the synthetic types are stable under similar conditions. Natural clay catalysts can be protected against abnormal aging from sulfur compounds by hydrating with steam after regeneration. Certain types of iron-free clays and bentonitic clays treated to remove iron do not show sulfur deactivation. 

The CNG acid gas removal process is distinguished from existing AGR processes by three features. The first feature is the use of pure liquid carbon dioxide as absorbent for sulfurous compounds the second feature is the use of triple-point crystallization to separate pure carbon dioxide from sulfurous compounds the third feature is the use of a liquid-solid slurry to absorb carbon dioxide below the triple point temperature of carbon dioxide. Pure liquid carbon dioxide is a uniquely effective absorbent for sulfurous compounds and trace contaminants triple-point crystallization economically produces pure carbon dioxide and concentrated hydrogen sulfide for bulk carbon dioxide absorption the slurry absorbent diminishes absorbent flow and limits the carbon dioxide absorber temperature rise to an acceptable low value. The sequence of gas treatment is shown in Figure 1, an overview of the CNG acid gas removal process. 

To 1 g sample, add 100 mL of 10% caustic soda solution and stir for 12 h. (This treatment is required only if iron cyanides are suspected to be present in the sample.) After this, adjust the pH to less than 8.0 with 1 1 H2S04. Add about 0.2 g sulfamic acid to avoid nitrate/nitrite interference. This is followed by addition of 25 mg lead carbonate (to prevent interference from sulfur compounds). The mixture is distilled and collected over NaOH solution. This distillate is analyzed for CN by colorimetric, titrimetric, or ion-selective electrode method. 

Sulfur compounds are used to make rubber strong enough to be used in tires, in a process called vulcanization. Sulfur is also used to make detergent, paper, fertilizers, and medicines. Several sulfur compounds have a strong odor to them. Onions, garlic, skunk spray, and even bad breath get their unique odor from sulfur compounds. Sulfur by itself has no smell. 

A typical Py-mass spectrum of vulcanized rubber is given in Figure 6.2.1 [13]. The values m/z = 32, 34, 48 and 64 are probably with contribution from sulfur compounds. 

Photo-biological Hydrogen Production from Sulfuric Compounds... 

Much of the sulfur used in the United States is recovered from sulfur compounds in natural gas and oil. During the oil-refining process, these compounds are reduced to hydrogen sulfide, which is then oxidized to sulfur in the Claus furnace. 

Pilot plant experiments. Pilot plant operations (Roelen, 14) were carried out with a gas throughput of 5-10 m.3/hr. (compared with 4 l./hr. in the laboratory scale). Two important problems had to be solved in particular in this operation (a) the purification of the synthesis gas from sulfur compounds and (b) the removal of the exothermic heat. 

It appears from several reactions that sulfur stabilizes a negative charge better than does oxagen. In general anions derived from sulfur compounds are also formed more easily than the oxygen analogues. Thus, if methyl vinyl sulfide is added at... 

The situation is enhanced by the synergetic influence of acidification loading from sulfur compounds, which is also dramatic in this area. Increasing acidity of soils and surface waters is known to be accompanied by the increasing mobility of most HM. This, in turn, leads to possible accumulation of HM in the food chains of both terrestrial and aquatic ecosystems (Bashkin and Wongyai, 2002). 

In 1869, Salet observed that the blue emission from sulfur compounds and the green emission from phosphorous compounds within a hydrogen flame are intensified when a cool body is introduced into the hot environment of the flame. The importance of the discovery was realized during the development of the flame photometric detector for gas chromatography and is now known as Salet phenomenon. The phenomenon is due to the stabilization of the excited molecules on the cool surface. 

In direct sunlight or in the presence of photosensitisers (such as riboflavin and polyphenols), the side chain is cleaved, which gives dehydrohumulinic acids (Figure 8.92). Decarbonylation of the formed acyl radical and recombination with a thiol radical, originating from sulfur compounds in beer, yields but-2-en-1-thiol, causing the so-called light-struck off-flavour (Section 8.2.9.1.2). 

Tin bronze is less susceptible to SCC than brass, but has less resistance to corrosion from sulfur compounds. The addition of 8-10% tin provides good resistance to impingement attack. Tin bronze has good resistance to flowing seawater and some nonoxidizing acids (except hydrochloric acid). 

Generally, it is accepted that the mechanism of bacterium oxidation process can be categorized into direct and indirect mechanisms. The direct mechanism assumes that sulfuric compounds are directly oxidized in the process, and ions are transferred directly from sulfuric compounds to oxygen ... 

Purification of gases from sulfur compounds in gas fields. Moscow Nedra 1985 [in Russian]. 

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