Mass balance calculations of processes of ammonia saltpeter thermal decomposition and nitric acid absorption of ammonia

Abstract

The ability of ammonia saltpeter to decompose at elevated temperatures causes a rather serious concern both its manufacturers and its consumers as for this reason the ammonia saltpeter quality and value meet the modern market requirements in incomplete measure. The purpose of present research is the material assessment of effect of the ammonia saltpeter solution concentration on its thermal decomposition degree, and also determination of conditions of as much as possible complete recycling of the product of its decomposition — ammonia — using a water solution of nitric acid. Scientific-applied importance of the research lies in the fact that its results will allow us to solve the questions concerning the quantitative dependence of ammonia saltpeter thermal decomposition degree and ammonia recycling on initial concentration of ammonia saltpeter and nitric acid solutions. During the experiments the quantitative and qualitative changes, observed in the ammonia saltpeter and nitric acid solutions, were judged by readout of the pH instrument placed in the absorption medium. It was established, that the higher the ammonium nitrate concentration and the lower the nitric acid concentration in their initial solutions are, the lower the ammonia saltpeter thermal decomposition degree is. And vice versa, the lower the ammonium nitrate concentration and the higher the nitric acid concentration in their initial solutions are, the higher the ammonia saltpeter decomposition degree is. The experimental study was implemented using a modelling laboratory installation, which can be recommended to use at the development of an industrial technological line of ammonia recycling.