Ammonia—soda, manufacture

He would have to do the routine work of daily analyses in the laboratory this would take little time, however, and I am looking for a young man who would be able to work under my direction on various problems, such as the cause of ammonia loss in ammonia soda manufacture ( c., c). ... 

Carbon dioxide is used in the manufacture of sodium carbonate by the ammonia-soda process, urea, salicyclic acid (for aspirin), fire extinguishers and aerated water. Lesser amounts are used to transfer heat generated by an atomic reactor to water and so produce steam and electric power, whilst solid carbon dioxide is used as a refrigerant, a mixture of solid carbon dioxide and alcohol providing a good low-temperature bath (195 K) in which reactions can be carried out in the laboratory. 

Sodium bicarbonate precipitates from solution and is recovered by filtration. Ammonium chloride is then crystallised from the filtrate, separated, washed, and dried. The exact proportion of ammonium chloride recovered depends on the relative demands for sodium carbonate and ammonium chloride. If economic conditions requite, part of the ammonia can be recovered and returned to the hrine-ammoniation step by distillation of the ammonium chloride solution ia the presence of lime. The spent calcium chloride Hquor, a final product ia manufacture of sodium carbonate by the ammonia—soda process, can also be used to obtain ammonium chloride. This Hquor is treated with ammonia and carbon dioxide... 

Ammonia or its salts are employed in a variety of ways in many trades. From it nitric acid, the vital necessity for the manufacture of all high explosives, can be made it is an essential for the Brunner Mond or Solvay ammonia soda process for the production of alkali in the liquid form it is employed all over the world in refrigerating machinery, but its enormous and increasing use is in agfriculture, where, in the form of sulphate of ammonia, it constitutes one of, if not the most important chemical manures known to man. During the year 1916 350,000 tons of ammonium sulphate were produced in this country, the larger proportion of which was consumed in agriculture—a proportion likely to increase and not diminish if the demand for home production of food continues. 

Calcium chloride is obtained as a by-product in the manufacture of sodium carbonate (soda ash) by ammonia-soda (Solvay) process. The process involves the reaction of sodium chloride with calcium carbonate and ammonia. Calcium chloride is currently produced in bulk amounts by evaporation of natural underground brines. In the laboratory, calcium chloride can be prepared by treating bmestone with hydrochloric acid followed by evaporation of solution to obtain crystals. The crystals are dehydrated to obtain anhydrous salt. Calcium oxide or hydroxide may be used instead of carbonate. 

Sodium carbonate at present is mostly mined from its natural deposits. It also is manufactured syntheticallly by Solvay (or ammonia-soda) process. The natural production of sodium carbonate currently has supassed its synthetic production. 

It can hardly be affirmed that the scientific treatment of the ammonia-soda process through recent progress in physical chemistry has given the practical manufacturer any hints on the direction in which he might make his processes more rational and advantageous than before, but there remains the hope that the desired success will be ultimately obtained by a co-operation of theory and practice.—G. Ltjnge (1911). 

Sodium carbonate is manufactured from sodium chloride by three processes Le Blanc s process, Solvay s ammonia-soda process, and the electrolytic process.4... 

Manufacture. Sodium carbonate is an important product of the alkali industry. It is obtained naturally by the purification of sal soda which is found in the water of lakes Magadi of Kenya in East Africa, Owens of California in the USA etc. Industrially it is obtained by the Solvay process (ammonia-soda process) sodium chloride solution is saturated by ammonia which is forced into the solution. Carbon dioxide gas is then blown into the solution to form the bicarbonate (NaHCO 3) and ammonium chloride (NH<,.C1). When the bicarbonate is separated and heated, water and carbon dioxide are driven off and sodium carbonate is obtained. The ammonium chloride is mixed with milk of lime and distilled to form calcium chloride and ammonia solution. The recovered ammonia is used repeatedly. 

Sodium bicarbonate is manufactured either by passing carbon dioxide into a cold saturated solution of sodium carbonate, or by the ammonia-soda (Solvay) process, in which first ammonia and then carbon dioxide is passed into a sodium chloride solution to precipitate sodium bicarbonate while the more-soluble ammonium chloride remains in solution. 

Solvay process. (ammonia soda process). Manufacture of sodium carbonate (soda ash, Na O,) from salt, ammonia, carbon dioxide, and limestone by an ingenious sequence of reactions involving recovery and reuse of practically all the ammonia and part of the carbon dioxide. Limestone is heated to produce lime and carbon dioxide. The latter is dissolved in water containing the ammonia and salt, with resultant precipitation of sodium bicarbonate. This is separated by filtration, dried, and... 

The following year, in 1807, the big glass manufacturer St Gobain started to use Leblanc soda for mirror glass. The method spread over the European continent and reached a production maximum of 545 000 tonnes in 1880. Then the Solvay method, the ammonia-soda process, gradually took over. 

Whereas in the past sodium hydroxide was prepared from sodium carbonate, the reverse, to some extent, is now true. However, the bulk of sodium carbonate is manufactured by a modem version of the Solvay Ammonia Soda process, which uses sodium chloride as its basic raw material. 

Other uses are in water purification, polymer production, tanning, effluent neutralization and sugar extraction. It is manufactured industrially by the Solvay (or ammonia-soda) process, which relies on the precipitation of sodium bicarbonate (sodium hydrogen carbonate) from the reaction of ammonia and carbon dioxide (produced by the action of heat on limestone) with a solution of sodium chloride. The bicarbonate is then heated to produce soda ash. This may appear to be a rather convoluted process for a reaction which may be represented as ... 

Manufacture. The history of ammonium chloride manufacture is linked to the birth of the soda and synthetic ammonia iadustries. Consequendy this haUde has always been a by-product ia great supply. Production by direct reaction of ammonia and hydrochloric acid is simple but usually economically unattractive a process based on metathesis or double decomposition is generally preferred. 

---