Nitric Acid Manufacture – A Comparison between High and Medium Pressure Processes

Keywords: Nitric acid, Comparison of nitric acid production processes. Description of HNO₃ production.

General conclusions:

In this paper we are far from having exhausted the problem of the choice of a nitric acid unit. Our purpose was to outline some differences between various processes.

We have seen that compared to the high pressure, the medium pressure has a better combustion efficiency, a lower platinum loss, an important excess steam, but this does not mean that the medium process is the best of all.

The high pressure processes lead to lower investments and the advantages of the medium pressure system may be minimised when the price for ammonia is low as is produced in big units with cheap natural gas, and when there is no need for steam in the factory.

However we can say that very big nitric acid units are in operation or being built according to each of the three main processes we have dealt with.

Ing J M Lerolle, Pechiney-Saint-Gobain, France.

42 Pages, 7 Plates, 4 Figures, 2 Tables.