Keywords: Nitric acid, Modelling the converter, Platinum recovery, Nitrous gas absorption.

Summary:
The authors’ company has developed an economic model of the nitric acid process to optimise operating conditions. This required the construction of mathematical models of the main process operations, the oxidation of ammonia and the absorption of nitrous gas. The work which went into constructing these models and data provided by running them have indicated points where improvements can be made and have stimulated technical development.

The models are described in general terms and some of the more interesting developments are discussed. In particular air and ammonia filtration and mixing, catalyst recovery and the uses of the absorption model are highlighted.

J K Bradley, MSc, CChem, FRSC, and G Drake, MA, SM, CEng, FIChemE, Fisons Ltd, UK.

37 Pages, 15 Figures, 2 Tables, 14 References.