Production of high-concentration formaldehyde solutions

US7345207B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Eckhard Stroefer · Mannheim, DE
• Neven Lang · Mannheim, DE
• Hans Hasse · Kaiserslautern, DE
• Thomas Grützner · Stuttgart, DE
• Michael Ott · Newark, US

Key dates

• Filing date: Mar 4, 2004
• Grant date: Mar 18, 2008
• Expiry date: Jun 18, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C45/82
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for preparing high-concentration formaldehyde solutions having a CH2O content of ≧50% by weight from an aqueous formaldehyde solution having a lower CH2O content by evaporation of part of this solution (partial evaporation), in which the aqueous formaldehyde solution is heated to an evaporation temperature T at which the gas phase becomes enriched in water relative to the liquid phase and the gas phase formed is taken off continuously or discontinuously, wherein the evaporation temperature T obeys the relationship:T[° C.]<Tmax[° C.]where Tmax(c)=A+B×(c/100)+C×(c/100)2+D×(c/100)3and