Purification of crude isophoronediamine by partial condensation in series with total condensation

US10392340B2 · kind B2 · utility

Assignee

• EVONIK DEGUSSA GMBH · DE

Inventors

• Anne Rittsteiger · Olfen, DE
• Jan Caßens · Recklinghausen, DE
• Axel Hengstermann · Senden, DE
• Cord Knoop · Haltern am See, DE
• Anja Müller · Bad Oldesloe, DE
• Alexander Martin Rüfer · Recklinghausen, DE

Key dates

• Filing date: Jul 6, 2017
• Grant date: Aug 27, 2019
• Expiry date: Mar 28, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/14
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present invention is directed to a process for fine purification of isophoronediamine from the production of isophoronediamine wherein the crude isophoronediamine I is subjected to a fine purification by means of two vacuum distillation columns, wherein I. in the first vacuum distillation column K I low-boiling by-products still present are removed, and a crude IPDA II is transferred from the bottom of K I into the vacuum distillation column K II, II. and in the second vacuum distillation column K II the isophoronediamine is obtained in pure form overhead and separated from the organic residues, wherein the first condenser is a partial condenser and the pure IPDA is removed therein, and wherein the second condenser is a total condenser and the residual portion of the vapor stream from K II is completely condensed therein and recycled as return stream into the first vacuum distillation column K I.