METHOD AND THE DEVICE FOR REDUCTION OF THE CONTENTS OF NITROGEN OXIDES IN THE GASES Russian patent published in 2008 - IPC B01D53/86 B01J8/04 B01J29/06 B01J29/46 

FIELD: chemical industry; other industries; methods and the devices for reduction of the nitrogen oxides content in the technological and effluent gases.

SUBSTANCE: the invention is pertaining to the method of reduction of the nitrogen oxides content in the gases, in particular, to the technological and effluent gases and also to the device used for realization of this purpose. The method provides for gating of N₂O - and NO_х-containing gas through the row of two catalyst layers containing one type or some types of zeolites loaded with iron, addition of the reducing agent foe NO_x between these layers of the catalyst, maintenance of the temperature less, than 500°С in first layer of the catalyst and in the second layer of the catalyst, maintenance of the gas pressure, at least of 2 bar in both layers of the catalysts, selection of a such volumetric speed flow in the first and second catalyst layers, that in first layer of the catalyst the decomposition of N₂O till its content of no more then 90 % with the respect to the contents of N₂O at the inlet of the first layer of the catalyst and set the content of N₂O more, than 200 parts per million, and that in the second layer of the catalyst the further decomposing of N₂O contained in the gas, at least, by 30 % with the respect to the contents of N₂O at the inlet of the second catalyst layer. The device used for reduction of the contents of NO_X and N₂O in the gases, in particular, in the technological gases and the effluent gases includes: two catalyst layers disposed one after another and containing one type or some types of the iron loaded zeolites, through which the gas containing NO_X and N₂O passes. At that the device is disposed between catalyst layers for injection of the gaseous reducing agent in the stream containing NO_X and N₂O of the gas includes the mixer, through which the gas is gated after passing the first layer of the catalyst and including the pipe duct for the reducing agent, which enters in the space after the first layer of the catalyst in front of the mixer or in the mixer. The subjected to purification gas after passing through the mixer is gated through the second layer of the catalyst. At that at least, one of the layers of the catalyst is made in the form of the hollow cylinder, through which the gas containing NO_X and N₂O passes radially. The technical result of the invention consists in development of the simple and cheap method, which ensures the good degree of conversion both at decomposition of NO_X, and at decomposition of N₂O, which are differing by the minimum operation and investment expenditures.

EFFECT: the invention presents the simple and cheap method, which ensures the good degree of conversion both at decomposition of NO_X, and at decomposition of N₂O, which are differing by the minimum operation and investment expenditures.

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