Ammonium sulphate production on industrial scale

Abstract

The invention provides a process for the production of crystalline ammonium sulfate, wherein the process comprises performing a Beckmann rearrangement reaction, neutralizing the Beckmann rearrangement reaction mixture, separating a first aqueous ammonium sulfate phase and an aqueous ε-caprolactam phase, charging the first ammonium sulfate phase to a first evaporative type crystallization section wherein crystalline ammonium sulfate is obtained, discharging from the first evaporative type crystallization section mother liquor enriched in organic components, extracting the aqueous ε-caprolactam phase to obtain an extracted ε-caprolactam phase and a second aqueous ammonium sulfate phase, discharging the mother liquor that is discharged from the first evaporative type crystallization section and/or the second aqueous ammonium sulfate phase to a second evaporative type crystallization section wherein evaporative type crystallization is performed so that a three-phase system occurs. At least a liquid oily phase is recovered from the three-phase system. The invention further provides a plant suitable to carry out the process of the invention, crystalline ammonium sulfate and a liquid oily phase obtained by the process of the invention.