METHOD FOR OBTAINING ZIRCONIUM HYDROXIDE-BASED RECOVERABLE CARBON DIOXIDE ABSORBER Russian patent published in 2021 - IPC B01J20/06 B01J20/30 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for obtaining a zirconium hydroxide-based recoverable carbon dioxide absorber, and can be used in the technology for producing recoverable carbon dioxide absorbers for carbon dioxide concentration systems, for purifying the atmosphere of sealed objects from carbon dioxide, wherever production of purified carbon dioxide-free gases is required. The method for obtaining a zirconium hydroxide-based recoverable carbon dioxide absorber consists in mixing basic zirconium carbonate with zinc oxide and mechanically activating the mixture. Hydrogen peroxide and a binding agent are then added, wherein a water dispersion of a carboxylated copolymer of acrylic and methacrylic acid esters is used as a binding agent in an amount of 5 to 10% relative to the dry matter. The granules are formed, hydrotreated and dried. The basic zirconium carbonate is pre-ground for at least 30 minutes, wherein ceramic balls with a diameter of 30 mm are used as the grinding bodies in a ball drum mill. The reagents of the mixture are mechanically activated at a ratio of zirconium ions to hydrogen peroxide of 1:0.8 and a moisture content of the absorbent granules of at least 25±2% wt. The dried mixture is ground through a sieve with a mesh of 0.3 mm in size. The resulting product is mixed in the mixing equipment to a homogeneous condition with a binding agent, wherein a water dispersion of a carboxylated copolymer of acrylic and methacrylic acid esters is used as a binding agent in an amount of 5 to 10% relative to the dry matter. The granules are then formed in a granulator with a die of 2.8 mm in size. The granules are dried to a moisture content of 25±2% wt. and screen on sieves to remove dust. The dried granules are then loaded into an autoclave in a layer of up to 10 cm and sustained over distilled water at a temperature of 120°C for 6 hours. Ammonia is washed off by boiling in distilled water in a mesh container, supplying steam from the bottom up through the granule layer until the ammonia odour is eliminated. The granules are then redried at a temperature of 20 to 80°C to a moisture content of the product of 25±2% wt.

EFFECT: invention allows excluding isolation of ammonia while maintaining the mechanical properties of the absorber granules, increasing the dynamic activity of the absorber with respect to carbon dioxide, the granule strength, improving the operational characteristics of the zirconium hydroxide-based recoverable carbon dioxide absorber.

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