Aniline hydrogen sulphate and sulphanilic acid mixt. continuous prodn. - by mixing aniline and sulphuric acid in stoichiometric ratio intensively in reactor with free overflow

• Main Authors: IKIER, HENDRIK., O-4440 WOLFEN, DE, LANGE, ECKEHARD., O-4500 DESSAU, DE, PIESCHEL, FRIEDEMANN., O-4500 DESSAU, DE
• Format: Patent
• Language: English; German
• Published: 23.09.1993
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

Continuous prodn. of a mixt. (I) of aniline hydrogen sulphate (IA) and sulphanilic acid (IB) comprises reacting aniline (II) and 94-100% H2SO4 in approx. stochiometric ratio at 160-200 deg.C, so that the mixt. is largely homogeneous, i.e. there are almost no regions with too little or too much (II) and a mixt. with a constant (IB) concn. of 2-20 (wt.)% can be obtd. The novel features are that (a) (II) and H2SO4 are supplied simultaneously and continuously at an inlet temp. up to 30 deg.C into a reaction zone with intensive mixing, which can be kept at the required temp.; (b) the (I) formed is allowed to flow freely from the reaction zone at an overflow; and (c) the ratio of (I) throughput and reaction vol. is 1.5-20 kg/h.1. (II) is run in freely onto the surface of the reaction mixt. and H2SO4 is supplied below the surface. USE/ADVANTAGE - (I) is used as precursor for (IB) prodn. The quality is better, throughput higher, technical-economic cost and energy consumption lower and stoppages fewer than usual.