DEVELOPMENT OF NEW FORMS OF CATALYTIC ELEMENTS IN AMMONIA OXIDATION REACTORS WITH A FIXED GRANULAR BED

Abstract

Partitioning coaxial cylinders with permeable walls and with radial partitions can significantly reduce the degree of irregularity of the gas distribution over the cross section of the fixed granular layer in the contact apparatus of two-stage ammonia oxidation in the production of nitric acid. Studies of the influence of the geometric characteristics of the catalyst grain on the technological parameters of the ammonia oxidation process for different forms of catalyst grain showed that loading the second stage of the reactor with an oxide catalyst with optimal grain sizes would reduce the required amount of catalyst by 30% for the estimated reactor capacity. Developed recommendations on the choice of optimal grain sizes of different shapes for the developed multioxide catalysts Co-Fe-Ce-O, Co-Zr-Cr-Li-O and Fe-Zr-Mn-Bi-O and the use of sectioning to improvement of gas distribution uniformity over the cross-section of a fixed catalyst bed can be used for developing new and optimizing the operation of existing reactors for two-stage ammonia oxidation and predicting their operation based on establishing the relationship of physicochemical characteristics, kinetic parameters and diffusion complications of the process in a fixed catalyst bed. The use of new forms of catalytic elements in reactors with a two-stage catalyst will optimize the NH3 oxidation in the production of nitric acid by reducing the load of platinum group metals, reducing the amount of harmful emissions, in particular the powerful greenhouse gas N2O, by increasing the yield of NO as a target product and reducing energy intensity production in general.