Method for distilling mixtures comprising ethylenediamine, N-methylethylenediamine, and water, and mixtures of ethylenediamine and N-methylethylenediamine having a low content of N-methylethylenediamine obtainable thereby

US8766010B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Michael Jödecke · Frankenthal (Pfalz), DE
• Jörg Pastre · Bensheim, DE
• Randolf Hugo · Dirmstein, DE

Key dates

• Filing date: Nov 30, 2010
• Grant date: Jul 1, 2014
• Expiry date: Jan 6, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/84
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a mixture of ethylenediamine (EDA) and N-methylethylenediamine (Me-EDA) with a low content of Me-EDA, which comprises at least 99.5% by weight of ethylenediamine, and wherein the concentration of N-methylethylenediamine is in the range from 0.005 to 0.15% by weight.The present invention further relates to a process for distillative workup of a mixture comprising EDA, Me-EDA and water, by introducing the mixture into a distillation column which is operated at a column top pressure of 10 mbar to 4 bar, wherein the weight ratio of water to ethylenediamine in the mixture used is a*X:Y where X is the proportion by weight of water and Y is the proportion by weight of ethylenediamine at the azeotropic point of a binary mixture of water and ethylenediamine at the column top pressure in question, and a is a real number with a value of 0.9 or more.The present invention further provides a process for preparing a distillable mixture comprising EDA, Me-EDA and water, which is suitable for preparing EDA with a low Me-EDA content.