CARBON DIOXIDE ABSORBER, METHOD FOR PREPARATION THEREOF, AND A METHOD FOR REMOVING CARBON DIOXIDE FROM GAS MIXTURES Russian patent published in 2004 - IPC

FIELD: gas treatment. SUBSTANCE: carbon dioxide absorber is a mixture of calcium oxide with eutectic mixture of alkali metal carbonates prepared in the form of grains with a predetermined size and containing surface protective layer made from material resistant to influence alkali metal carbonate melt. Carbon dioxide absorber is prepared by mechanically mixing powders of calcium carbonate and eutectic mixture of alkali metal carbonates at weight ratio between 10:1 and 1:1 followed by calcining resulting mixture at temperature by 50-200^(r)' higher than melting point of eutectic mixture, cooling melt below crystallization temperature of eutectic mixture, breaking up crystals, isolating absorber grains with required size, and applying protective layer. Carbon dioxide is removed from gas mixtures at 400 to 900^(r)' using absorber in cycling mode at temperature superior to melting point of eutectic mixture. Carbon dioxide is absorbed under conditions favoring formation of calcium carbonate from calcium oxide and carbon dioxide, while regeneration of absorber is carried out under conditions favoring degradation of calcium carbonate into calcium oxide accompanied by release of absorbed carbon dioxide. EFFECT: enabled preparation of high-temperature regenerable calcium oxide-based carbon dioxide absorber for use in carbon dioxide absorption processes carried out at 400-900^(r)'. 8 cl, 3 dwg, 7 ex