METHOD OF PRODUCING CARBON DIOXIDE FOR PRODUCTION OF CALCINED SODA BY AMMONIA METHOD Russian patent published in 2020 - IPC C01B32/50 

FIELD: inorganic chemistry; environmental protection.

SUBSTANCE: invention can be used in large-tonnage production of soda ash by ammonia method. Flue gases of enterprises, including thermal power stations, containing 7–14 vol. % of carbon dioxide can be mixed with carbon dioxide obtained by treatment of calcium-containing raw material with hydrochloric acid with content of not less than 95 vol. %. Content of CO₂ after mixing is not less than 45 vol. %. Concentration is then carried out in an apparatus with regenerative blocks at temperature of 45 °C by absorbing 34–42 % aqueous solutions of absorbents, in form of mixtures of diethanolbenzylamine and monoethanol amine or ethylene diamine and monoethanol ethylene diamine. Carbon dioxide obtained in regenerative blocks containing not less than 50 vol. % CO₂ is subjected to drying at 145 °C or mixed with carbon dioxide containing 35–38 vol. % CO₂, obtained during limestone burning. Obtaining carbon dioxide with content of CO₂ of not less than 40–44 vol. % corresponding to norms for soda production.

EFFECT: invention enables to recycle flue gas from enterprises, including thermal power stations.

1 cl, 5 dwg