GB919717A - Apparatus for the nitration of organic compounds - Google Patents

Abstract

<PICT:0919717/III/1> A crystallizer and solvent recovery unit for use in a nitration process (see Group IV(b)) comprises two columns 71 and 72 fitted with rotating agitator blades 78 and 82. The solution of nitration product (e.g. tetryl) in solvent is fed to 71 by line 48, and steam and water are fed through lines 91 and 89 respectively. Solvent is distilled off and taken off through pipe 49 for recovery, and the crystals of product in suspension in water pass through pipe 84 to 72 and are taken off via 53.ALSO:<PICT:0919717/IV (b)/1> Apparatus for the continuous nitration of organic compounds, e.g. for use in the process of Specification 919,718, in which the nitration products are solid, comprises a circulation loop containing a heat exchanger (e.g. 14 in the Figure), means for continuously introducing the organic compound, sulphuric acid, a nitrating agent (e.g. HNO3) and a solvent for the nitration product (e.g. the pipes intersecting at the mixing cross 19), means for recirculating the mixture (e.g. pump 10), means for withdrawing reaction mass from the loop, means for separating the waste acid from the solution of the nitration product (e.g. separator 26), and means for crystallising the product (e.g. crystallising unit 34; see Group III). In 34 the solvent is distilled off and recovered in condenser 51 and returned to the circulation loop, and water introduced via pipe 89 carries the crystals out through 53.