CATALYSTS FOR REDUCTION OF NITROGEN OXIDES FROM COPPER, APPLIED ON FINELY-POROUS MOLECULAR SIEVE, RESISTANT TO AGEING IN CASE OF POOR/RICH MIXTURE COMPOSITION VARIATIONS Russian patent published in 2015 - IPC B01J29/72 B01J29/83 B01D53/94 

FIELD: chemistry.

SUBSTANCE: invention relates to system for purification of spent gases. Said system contains catalyst- NO_x absorber, located upstream from catalyst for selective catalytic reduction (SCR), in which said SCR catalyst contains copper, applied on molecular sieve. Molecular sieve (a) has maximal ring size of eight tetrahedral atoms; (b) is selected from the group, consisting of alumosilicate molecular sieves, metal-substituted alumosilicate molecular sieves and alumophosphate molecular sieves; and (c) is subjected to processing aimed at improvement of hydrothermal stability with application of at least one technology, selected from the group, consisting of dealumination, cation exchange or processing with phosphorus-containing compounds. Invention also relates to method of said system application and method of spent gas purification with its application.

EFFECT: claimed system of purification makes it possible to increase effectiveness of NO_x conversion.

14 cl, 4 dwg, 2 tbl, 2 ex