Process for the preparation of a powder comprising one or more derivatives of glycine-N,N diacetic acid and/or one or more derivatives of glutamine-N,N diacetic acid and methylglycine-N,N diacetic acid trisodium salt powder

US8628684B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Frank Mrzena · Mutterstadt, DE
• Hans-Juergen Kinder · Speyer, DE
• Michael Schoenherr · Wausau, US
• Gerhard Cox · Bad Dürkheim, DE
• Thomas Schmidt · Neustadt, DE
• Volker Huett · Hockenheim, DE

Key dates

• Filing date: May 19, 2010
• Grant date: Jan 14, 2014
• Expiry date: Aug 19, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/50
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process is proposed for the preparation of a powder comprising one or more derivatives of glycine-N,N-diacetic acid and/or one or more derivatives of glutamine-N,N-diacetic acid with a degree of crystallinity of ≧30%,starting from an aqueous solution comprising the one or more derivatives of glycine-N,N-diacetic acid and/or the one or more derivatives of glutamine-N,N-diacetic acid in a concentration range from 20 to 60% by weight, based on the total weight of the aqueous solution, wherethe aqueous solution is concentrated in a first process step in an evaporator with rotating internals, which are arranged at a distance relative to the inside wall of the evaporator of ≦1% of the diameter of the evaporator, to give a crystal slurry with a solids concentration in the range from 60 to 85% by weight, based on the total weight of the crystal slurry, and wherein a second process step the crystal slurry is left to ripen in a paste bunker and then in a thin-film contact dryer, and where the residence time in the paste bunker and in the thin-film contact dryer is in total ≧15 minutes.