Conversion augmentation of an industrial NH3 oxidation reactor by geometry modification to improve the flow and temperature pattern uniformity using CFD modeling

Abstract

Background

The optimization of flow and temperature patterns in industrial reactors is crucial for achieving efficient and uniform chemical reactions. This study's major goals are to pinpoint possible areas for improvement in the NH₃ oxidation reactor's performance and to deal with the problem of uneven flow distribution inside the reactor.

Methods

In this study, the reactor building design has been changed by extending the feed pipeline vertically and increasing the number of incoming feed streams in order to achieve uniformity in the property distribution on the catalyst surface of an industrial NH₃ Oxidation reactor. Thus, using the CFD approach and the finite volume method, a three-dimensional model has been suggested. The results are contrasted with the actual geometrical configuration. The property alteration along the catalyst surface and the reactor length have been assessed.

Significant findings

By expanding the feed pipeline, the flow pattern at the reactor entry is fully developed and becomes uniform. As a result, NO₂ production could go up by as much as 11 %. The rates of NH₃ conversion, NO yield, and HNO₃ generation consequently increased by 12.5 %, 3.1 %, and 8.0 %, respectively. Additionally, this alteration results in a uniform distribution of temperature and pressure across the catalytic surface, prolonging the lifetime of the catalyst. The pressure and temperature difference over the surface of the catalyst with the original reactor configuration was also found to be approximately 250 Pa and 423.15 K, according to the data. Pressure and temperature difference were reduced to 15 Pa and 273.15 K, respectively, as the feed line's length was increased at the same time.