Industrial production sulfur sources

The production of nitrogen fertilizers is a major activity of the chemical industry. Every year, the top 15 chemicals in industrial production in the United States include several nitrogen-containing compounds whose major use is in fertilizers. Molecular nitrogen serves as the primary source of nitrogen for chemical production. Gaseous ammonia (NH3), which is synthesized from N2 and H2, can be injected directly into the ground, where it dissolves in moisture in the soil and serves as a fertilizer. Ammonia is more widely used in reactions with acids to produce other fertilizers Ammonia and nitric acid produce ammonium nitrate (NIL) NO3), while ammonia and sulfuric acid produce ammonium sulfate. These chemicals and urea,... 

Chang and co-workers isolated strain Nocardia sp. CYKS2 from a dyeing industry wastewater using DBT as the sole sulfur source [27]. This strain also desulfurized DBT to the same product 2-HBP however, it had broader substrate specificity and was reported to desulfurize thiophenes, sulfides, and disulfides (Table 3) in addition to DBT. However, it did not desulfurize trithiane, thianthrene and 4,4 -thiodiphenol. The desulfurization experiments were conducted in batch with the rate reported as 0.279 mg-sulfur/L dispersion/h for DBT conversion. 

Therefore, we believe that the cost position of Frasch producers will determine the trend in sulfur prices, so long as the Frasch industry remains the marginal supply source - a condition that will continue over the forecast period. If, at some future date, the supplies of by-product sulfur reach a level which will fully satisfy the demand, this assumption may no longer be valid. 

Most work discussed here regarding standard Antek on-line/at process analyzers, laboratory based equipment, and the High Speed Sulfur (HSS) on-line analyzer was carried out in the PAC Houston R D Laboratory and Production facility. Other data were collected from various industry and public sources and are so identified in the associated text and graphics. Various solvents, sulfur sources, and standard reference materials were used in association with both historical and new data. Solvents and chemicals, such as iso-octane, toluene, and dibutyl sulfide, were of typically reagent grade purity and were obtained from readily available commercial sources, such as Aldrich chemicals. When appropriate, these materials were analyzed before use. 

Black Powder. Black powder is mainly used as an igniter for nitrocellulose gun propellant, and to some extent in safety blasting fuse, delay fuses, and in firecrackers. Potassium nitrate black powder (74 wt %, 15.6 wt % carbon, 10.4 wt % sulfur) is used for military appHcations. The slower-burning, less cosdy, and more hygroscopic sodium nitrate black powder (71.0 wt %, 16.5 wt % carbon, 12.5 wt % sulfur) is used industrially. The reaction products of black powder are complex (Table 12) and change with the conditions of initia tion, confinement, and density. The reported thermochemical and performance characteristics vary greatly and depend on the source of material, its physical form, and the method of determination. Typical values are Hsted in Table 13. 

It has been shown in these studies that the principal, and probably only significant source of NDMA, is malt which had been dried by direct-fired drying (21, 73). It is well known that malts kilned by indirect firing have either low or non-detectable levels of NDMA (74). Consequently, changes in malting procedures have been implemented in both the U.S. and Canada which have resulted in marked reductions in N-nitrosamine levels in both malts and beer (70,74). For example, sulfur dioxide or products of sulfur combustion are now used routinely by all maltsters in the U.S. to minimize N-nitrosamine formation (70). The Canadian malting industry, on the other hand, has... 

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