Sulphur dioxide abundance

Hydrogen sulphide is present in many mineral springs, and even free sulphur is occasionally found therein.2 Many metallic sulphides, for example, iron pyrites, galena, zinc blende, stibnitc and cinnabar, occur abundantly. Sulphur dioxide, sulphites, sulphuric acid and sulphates are also found in nature, more especially in waters springing from volcanic earth, whilst the sulphates of certain metals such as calcium, barium and magnesium exist in large deposits. 

At very high temperatures the sulphates of metals such as copper, zinc, iron, aluminium and chromium tend to lose sulphur trioxide (largely in the form of sulphur dioxide and oxygen) and to give residues of the corresponding oxides.7 Calcium sulphate is stable up to 1300° C., above which temperature it melts and immediately undergoes almost complete decomposition with abundant evolution of fumes.8 Very slight decomposition has been observed with barium sulphate at 1300° C.9... 

Sulphur colouring matters are more or less soluble in water, but readily soluble in alkalies or alkaline sulphides when treated with hydrochloric acid or, better, with hydrochloric add and stannous chloride, they emit hydrogen sulphide when burnt they give an odour of sulphur dioxide and leave a more or less abundant residue containing alkaline sulphates and sulphites. 

The burning of coal in thermal power plants results in major pollutants such as suspended particulate matter (SPM), sulphur dioxide (SO2), oxides of nitrogen (NOx) etc, of vdiich NOx is believed to be a key con nent responsible for several hazards associated with ecology and human health(l). Given the relative abundance of coal in India, coal-based thermal power plants will continue to play a dominant role in the power sector. Therefore NOx abatement through primary and secondary measures assumes great importance. Post combustion techniques such as selective catalytic reduction (SCR) can reduce NOx emissions by >95% (2). 

The presence of abundant deposits of organic or inorganic sediments could be expected to have an influence on the corrosion resistance of certain metals and alloys, because of the release of sulphur dioxide, carbon dioxide and ammonia as a consequence of the bacterial decomposition of these sediments. Experience with supports of landing stages embedded in the mud and in the sediments at the coast shows that the corrosion resistance of 5000 series alloys is not significantly affected by this medium. This also applies to great depths (Table D.3.3) [19]. 

Along with natural gas, oil fields have other products. Hydrogen sulphide is the most abundant of the impurities. A small quantity in natural gas is desirable as a warning of leakage. When large quantities are present this sour gas is used to manufacture carbon black or is processed for sulphur recovery. Sometimes helium is present in useful quantities. Carbon dioxide is found in some fields. It is recovered and used in the manufacture of dry ice. 

The dissociation of carbon dioxide induced by both a silent electric discharge and photons of wavelength 812—1216 A has been investigated. The photoionization of inter alia CO2 by soft A"-rays has also been studied the total and relative abundances of the thermal-energy ions produced by absorption of 0.28, 1.25, and 1.5 keV A -rays in CO2 (CO2, CO, CO+, C+, 0+, C +) have been measured using a mass-spectroscopic technique. Measurements of relative 83 concentrations following the flash photolysis of OCS diluted with COg have been used to investigate the mechanism of the polymerization of atomic sulphur, one of the principal products of the photolysis ... 

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