Claus-Chance process

By the early 1890 s, Britain had become the second largest sulfur producer in the world, by using the Claus-Chance process. In 1893, British sulfur production by this technology was 35,000 tonnes. The process would be famous again, when it became the standard technology for converting hydrogen sulfide in sour gas and oil into recovered sulfur. Then it would only be called the Claus process, since the Chance modification was applicable only to the Leblanc process. 

Herman Frasch developed a process to recover cheap natural sulfur in 1891 that was used first in Louisiana and then in Texas, and eventually became the major source of supply, particularly in the United States. The recoveiy of refinery sulfur by the modified Claus-Chance process now provides a further enormous supply of pure sulfur throughout the world, and this has largely replaced the Frasch process. 

Chance Also called Chance-Claus. A process for recovering sulfur from the calcium sulfide residues from the Leblanc process. Treatment of a suspension of the residues with carbon dioxide generates hydrogen sulfide, which is converted to sulfur dioxide by the Claus proces. The sulfur dioxide is converted to sulfuric acid. Developed by A. M. and J. F. Chance 1882 to 1887 and widely used until the Leblanc process was superseded by the Solvay process. 

Excess of ammonia must be present to prevent formation of sulphocarbonate. At the end ol the process this is distilled off, CO., gas is driven through the liquid to expel the sulphuretted hydrogen (as in the Claus-Chance treaiment.of alkali.waste), and any precipitated calcium carbonate is filtered off. The soluble calcium sulphocyanide is treated with sodium carbonate and converted into sodium sulphocyanide, thus —... 

Measuring employee understanding of appropriate quality objectives is again a subjective process. Through the data analysis carried out to meet the requirements of clause 4.1.5 and 4.2.8 you will have produced metrics that indicate whether your quality objectives are being achieved. If they are being achieved you could either assume your employees understand the quality objectives or you could conclude that it doesn t matter. However, it does matter as the standard requires a measurement. Results alone are insufficient evidence. The results may have been achieved by pure chance and in six months time your performance may have declined significantly. The only way to test... 

Chance-Claus process. The process recovers sulfur from sulfide waste by treatment with carbon dioxide and oxidation of the resulting hydrogen sulfide with air in the presence of a catalyst. 

Fig. V/4.0.1-1B shows how one after another, IPL reduces the chances of risk and the system is brought back to ALARP region. A typical actual process example has been presented in Clause 1.1.2 (Fig. Vll/1.1-3) of Chapter Vll.

The Claus process to recover and recycle sulfur in the Le Blanc process, based on the procedure suggested by C. F. Claus in 1883, was introduced in 1887 by A. M. Chance. Alkali waste containing calcium sulfide was suspended in water, and hydrogen sulfide was generated by pumping carbon dioxide through the sluny ... 

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