METHOD OF PURIFYING COKE OVEN GAS FROM AMMONIA BY CIRCULAR PHOSPHATE METHOD Russian patent published in 2018 - IPC B01D53/14 

FIELD: technological processes; chemistry.

SUBSTANCE: invention relates to chemical solid fuel processing technology and can be used in the coke industry to purify coke oven gas from ammonia (NH₃). In a process for purifying coke oven gas from ammonia in a circular phosphate process, comprising washing thereof with a solution of ammonium phosphate in a two-stage absorber equipped with a block of trays on the upper stage and nozzles at the lower stage, regeneration of the solution by settling the impurities, followed by the separation of ammonia from the solution and return of the monoammonium phosphate (MAP) solution to the upper stage of the absorber, treatment of coke oven gas with a solution of diammonium phosphate (DAP) circulating through the lower stage of the absorber by feeding the solution to the nozzles, coke oven gas is further treated in the absorber with a solution of diammonium phosphate (DAP) with a molar ratio of ammonia to phosphoric acid of 1.63 to 1.83 and density of the solution from 1.214 to 1.234 kg/m³ by feeding a portion thereof after settling the impurities and purification from resin to the block of trays in the upper stage of the absorber, wherein the DAP solution after the absorber is sent to a settler in full to settle impurities, providing, after cleaning, the level of ammonia in the coke oven gas not more than 0.028 g/m³. Additionally purified solution of diammonium phosphate (DAP) is returned to the first stage of the absorber to the tray located from the first tray in the direction of movement of the coke oven gas at a distance of 50–60 % of the total height of the block of trays of the tray stage of the absorber.

EFFECT: object of invention is to develop a method for purifying coke oven gas from ammonia, which allows to increase mass exchange by supplying an additional amount of a solution of diammonium phosphate (DAP) to the tray stage of the absorber, prevent the reduction of hydraulic resistance in the tray stage of the absorber and the falling of the solution from the trays, which will improve the quality of coke oven gas purification and will reduce the consumption of the solution used for purification.

1 cl, 1 dwg