Solvay process chlorine dioxide

Sodium bicarbonate may be prepared by the ammonia-salt (Solvay) process. Carbon dioxide is passed through a solution of sodium chloride in ammonia water. Sodium bicarbonate is precipitated and the ammonium chloride remains in solution. The ammonium chloride is heated with lime to regenerate ammonia (see Alkali AND CHLORINE PRODUCTS). 

A.mmonia-Soda Process. Ammonium chloride is made as a by-product of the classic Solvay process, used to manufacture sodium carbonate (12,13) (see Alkali and chlorine products, sodium carbonate). The method iuvolves reaction of ammonia, carbon dioxide, and sodium chloride ia water... 

Solvay (2) A pulp-bleaching process using chlorine dioxide, generated by reducing sodium chlorate with methanol. In 1962, 20 paper mills in the United States were using this process. See also Mathieson (1). 

Exit gases from the Mathieson process are passed through a scrubber to remove any unreacted sulfur dioxide. The Solvay process uses sodium chlorate and sulfuric acid, with methanol as the reducing agent. Products from this process are chlorine dioxide, formic acid, and carbon dioxide. In improved Solvay processes, sulfuric acid demand is reduced by crystallizing out the by-products sodium sulfate, sodium sesquisulfate, or sodium bisulfate (Kaczur and Cawlfield 1993 Vogt et al. 1986). 

The LeBlanc Process was the first large-scale industrial chemical process. The process produced large quantities of gaseous hydrochloric acid as a by-product that released into the air and caused what was probably the first large-scale industrial pollution. It was later found that this waste gas could be captured and reacted with manganese dioxide to produce gaseous chlorine. The LeBlanc Process was used until about 1861, after which it began to be replaced by the more efficient Solvay Process. [7]... 

The Leblanc process was replaced by the ammonia soda (Solvay - 1860 ) process, in which sodium chloride brine is treated with ammonia and carbon dioxide to produce sodium bicarbonate and ammonium chloride. Sodium carbonate is obtained from the bicarbonate by heating. Ammonium chloride treated with lime gives calcium chloride and ammonia. The chlorine in the original salt becomes calcium chloride that is used for melting snow and ice. The ammonia is reused in the process (99.9% recovery). 

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