CATALYTIC SYSTEM, AND ALSO METHOD FOR CATALYTIC COMBUSTION OF AMMONIA TO NITROGEN OXIDES IN MEDIUM PRESSURE INSTALLATION Russian patent published in 2023 - IPC B01J23/42 B01J23/46 B01J35/00 C01B21/26 

FIELD: catalytic systems.

SUBSTANCE: present invention relates to a catalytic system for the catalytic combustion of ammonia to form nitrogen oxides in a medium pressure unit and to a method for the catalytic combustion of ammonia to nitrogen oxides in a medium pressure unit. A catalytic system (1) is described for the catalytic combustion of ammonia to nitrogen oxides in a medium-pressure unit, with single- or multi-layer catalyst meshes (6; 7), woven or knitted or crocheted from metal wire based on the precious metal platinum, which, located one after another in the fresh gas flow direction (5), form a front group of mesh layers (7) and at least one downstream group of mesh layers (6) located behind the front group, wherein the front group contains at least one mesh layer (7) from the first rhodium-rich precious metal wire, wherein said at least one mesh layer (7) of rhodium-rich precious metal wire is the most forward mesh layer (7) facing the fresh gas, wherein the the downstream group contains mesh layers (6) of a second rhodium-poor precious metal wire, wherein the rhodium-rich precious metal wire and the rhodium-poor precious metal wire are composed primarily of platinum and rhodium, and the rhodium content of the rhodium-rich precious metal wire metal is greater than or equal to 7 wt.% and less than or equal to 9 wt.%, and the rhodium content of the rhodium-poor precious metal wire is in the range of 4 to 6 wt.%. Also described is a method for the catalytic combustion of ammonia to nitrogen oxides in a medium pressure unit by passing fresh gas containing ammonia and oxygen through the catalytic system (2), wherein the ammonia is burned, the fresh gas having an ammonia content of 9.5 to 12% by volume. under pressure in the range from 3.5 to 7 bar and catalyst grid temperature in the range from 870°C to 920°C is carried out with a flow rate in the range from 6 to 16 tN/m²⋅ days through the above-described catalytic system (2).

EFFECT: provision of a catalytic system for use in a medium pressure installation, with which it is possible to achieve a high service life and a high yield of the main product NO.

12 cl, 6 tbl, 3 dwg