METHOD AND PLANT FOR RECYCLING SULPHUR DIOXIDE AND OXYGEN IN AN INSTALLATION FOR PRODUCING THE ISOTOPEN BY ISOTOPIC EXCHANGE IN ()()-HNO() SYSTEM

摘要

The invention relates to a method and a plant for recycling sulphur dioxide and oxygen within an installation for producing the isotopeN by isotopic exchange in the gaseous phase nitrogen oxides - nitric acid solution system. According to the invention, the method consists in that the sulphuric acid, as a waste of the separation installation, is concentrated up to 96...98% by distillation and decomposed, at the temperature of 320°C, into sulphur trioxide and water vapours which pass through a catalyst bed where the sulphur trioxide is reduced to sulphur dioxide, this gaseous mixture being compressed at 15 at for liquefying the sulphur dioxide which is collected and then recycled in the nitrogen oxide refluxer of the installation for separation of the isotopeN, while the gaseous oxygen separated from the liquid sulphur dioxide is recycled in the nitric acid refluxer of the installation for separation of the isotopeN. The plant, as claimed by the invention, comprises a quartz reactor (2) provided with a catalyst bed (3), an electric furnace (4) for increasing the temperature of the catalyst bed (3), a sulphuric acid reservoir (1) and a dosing pump (5) which are both positioned at the inlet of the reactor (2), a heat exchanger for condensing the water which is then collected into the vessel (7) along with the sulphuric acid not converted into sulphur dioxide, a drying tower (8), a compressor (9), a heat exchanger (10) and a pressurized container (11) for collecting the sulphur dioxide and separating the same from the gaseous oxygen.