SYSTEM AND METHOD OF CONVERTING AQUEOUS UREA SOLUTION INTO AMMONIA VAPOUR USING SECONDARY COMBUSTION PRODUCTS Russian patent published in 2015 - IPC B01D53/94 

FIELD: chemistry.

SUBSTANCE: invention generally relates to monitoring harmful NOx emissions and particularly to a method and a system for converting aqueous urea solution into ammonia vapour, used to activate SCR catalysts for efficient purification of exhaust gases containing NOx and other pollutants. The urea-to-ammonia vapour reactor housing is enclosed in a bypass flow cover which receives a secondary flue gas stream tapped at a split point from a main flue gas stream containing nitrogen oxides (NOx) emanating from a boiler. The bypass flow cover allows the secondary flue gas stream to flow past the enclosed reactor housing where injected aqueous urea solution in atomised or non-atomised form, is converted to ammonia vapour. The resulting gaseous mixtures of ammonia, by-products and the secondary flue gas stream subsequently rejoin the main stream, before the main flue gases are treated through a selective catalytic reduction (SCR) reactor system. The dwell time of the secondary stream in the bypass flow cover, which may be increased by a recirculation loop, enables effective conversion of urea to ammonia to be used in the SCR system.

EFFECT: invention provides an incineration system which uses a urea-to-ammonia vapour reactor system.

20 cl, 50 dwg