Continuous process of sodium bicarbonate production by Solvay method

Sodium carbonate (commonly called as soda ash or washing soda) is the primary product of the chemical industry since the year one. It was used in antiquity for the manufacture of soap and glass, using the mineral appears in some lakes of Africa, Asia and North America being a natural soda, so-called trona (Na2CO3·NaHCO3·2H2O). In Europe, the most important was the soda ash produced in Spain, Normandy and Scotland from the ashes of some marine plants. With the development of industry as well as many wars causing restrictions on trade demand for other methods of producing soda ash grew very rapidly, so that in 1755 the French Academy of Sciences announced a competition for the economical method of producing soda ash from sodium chloride. Only 45 years later, in 1790 the French physician Nicholas Leblanc developed method for satisfying this requirement. His method has been used for over 120 years. Economic considerations supported by modern, for those days, of technical solutions led to new method developed by Ernest Solvay. This method was used for the first time in 1865 in a chemical factory in Belgium Couillet. Leblanc method was completely supplanted by Solvay method which remains to this day, despite the existence of significantly modified its variants, the main means of production of soda ash (about 80% of total production in the world). It should be mentioned that due to economic and technical aspects plants producing soda ash also produces: caustic soda (NaOH), sodium bicarbonate (NaHCO3), crystalline soda (Na2CO3·10H2O) as well as other products such as CaCl2, CaCO3 and dry ice (CO2). The use of soda in different forms mentioned above is very broad. About 30% is used in the manufacture of various inorganic salts such as: borax, sodium sulphite, sodium oxalate, sodium dichromate or sodium nitrate. Soda is used among others in the industry: glass, steel, metal, paper and leather, dyes, rubber, food (approximately 30%) and soap industry and washing powders (about 20%).