Investigation of ammonia oxidation reactor in the mode of maximum nitrogen productivity

Abstract

The production of nitric acid is quite complex and complicated by different stages of production, the main stages are the preparation of ammonia-air mixture to ensure and carry out the oxidation process at the stage of obtaining nitric oxide with subsequent use at the stage of absorption to obtain the final product of nitric acid. In the production of nitric acid, special attention is paid to the oxidation stage, at this stage the main product is formed, which provides nitric acid during the reaction of nitrogen with water at the stage of adsorption. The oxidation stage is the main cost part in the formation of the price function of the cost of the product, so the task of improving the productivity of equipment at this stage, one of the important tasks in building a control system and operation of the ammonia oxidation reactor.The article considers the use of a simplified mathematical [1] model of reactor space dynamics. Based on this model, studies were conducted and the acceleration curve of the APS oxidation reactor was constructed. One of the important features of the oxidation reactor is its complex multi-section structure [2]. The oxidation takes place on three series-mounted layers in the reactor. This design allows you to increase the flow rate of the load and increase the yield of nitrogen from the reactor. Therefore, the mathematical model provides a simplified system of equations with a sequential calculation of each layer in the dynamics of the reactor and the technological parameters of the process at a given time.The oxidation reactor is considered in the article as an object of automatic control and is described by a mathematical model of dynamics in the form of differential equations. The reaction volume dynamics model reflects the dependence of the temperature in the contact layer on the load flow, as well as the dependence of the concentration of nitric oxide on the flow rate and temperature of the reaction mixture at the time of contact with the catalyst.This mathematical model, adequate to the actual course of the oxidation process, will investigate the dependence of the yield of nitric oxide on the specified input values of the flow rate in each section of the reactor. Increasing the yield of nitric oxide will increase the productivity of the reactor, by meeting the quality requirements of the starting product [3] and reducing the economic costs of nitric acid production.The proposed mathematical model allows us to consider a reactor with three layers of contact in the mode of maximum load, which allows to obtain the maximum degree of conversion of ammonia-air mixture. The obtained results of the research allow to form the requirements for the automatic control system and to reflect the reaction of the object to the change of the controlled parameters.