Method for producing highly concentrated formaldehyde solution

US7342139B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Bernd Rumpf · Hockenheim, DE
• Eckhard Ströfer · Mannheim, DE
• Ortmund Lang · Quirnbach, DE
• Neven Lang · Mannheim, DE

Key dates

• Filing date: Feb 10, 2005
• Grant date: Mar 11, 2008
• Expiry date: Mar 21, 2025

Classification

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

Abstract

A process for preparing a high-concentration formaldehyde solution by removing water from a lower-concentration formaldehyde solution having a formaldehyde content of from 5 to 50% by weight, in which the lower-concentration formaldehyde solution is fed to a preheater and heated in the preheater, depressurized via a pressure maintenance device and concentrated in a helical tube evaporator to give a vapor stream and the high-concentration formaldehyde solution as bottom stream, wherein the heated lower-concentration formaldehyde hyde solution is depressurized in the pressure maintenance device to give a two-phase mixture which is fed into the helical tube evaporator, is proposed.