Method for manufacturing organic nitro compounds

摘要

In a process for the manufacture of organic nitro compounds, e.g. nitroglycerine by nitration with nitrating acid, the heat content of the reaction components is adjusted to a value suitable for the nitrating reaction and the components are brought together in an injector into which the nitrating acid is introduced under pressure, the other reaction component being drawn by suction from a supply container into the injector under such conditions that the mixing of the reaction components and the reaction take place instantly and substantially completely immediately in the injector and thus within a very limited volume, whereupon the reaction mixture is transferred to a separator where the nitro products produced are separated from the remaining acid (waste acid). A portion of the waste acid, if required after cooling or heating is re-introduced into the process by adding to the nitrating acid. In the Figure glycerine is supplied through conduit 2 and heat exchanger 24 to the injector 1 and nitrating acid which may comprise 40-65 per cent HNO3 and 60-35 per cent H2SO4 is supplied to an injector mixer 4 where it is mixed with waste acid which is recycled from the separator 10. The mixture of nitrating acid and waste acid is cooled in the cooler 7 to between +5 DEG C. and -20 DEG C. and the cooled mixture then introduced under pressure into the reaction injector 1. The injector (Fig. 2) consists of a circular Venturi-shaped chamber 20 into which projects a conical nozzle or injector jet 21 for supplying the nitrating acid under pressure. Between the jet 21 and the wall of the chamber 20 is an annular space 201 into which the glycerine supply conduit discharges. In front of the discharge opening of the venturi chamber is a perforated plate 22 beyond which the injector is prolonged with a cylindrical discharge member 23. The reaction takes place substantially completely in the venturi chamber and is discharged into a chamber 25 from which it passes to the separator 10 which is equipped with a cooling coil. If desired, separation-promoting agents may be added to the mixture via the chamber 25. The upper nitroglycerine layer is then passed to the washing plant comprising three washing units each composed of an injector 13, into which washing liquid is supplied through conduit 14, and a separator 15 from which waste washing liquid passes out through the conduit 16. The washing may be carried out with water or with water containing a weak alkaline substance such as ammonia, soda, or sodium bicarbonate and the washed nitroglycerine is removed through conduit 17. Reference is made to using glycol instead of glycerol and examples of other nitro compounds which may be produced are dinitrodiethylene glycol, ethyl nitrate, mononitrobenzene and mononitrotoluene.