Aqueous formaldehyde solutions with a low tetroxane content

US6471928B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Eckehard Danz · Ludwigshafen, DE
• Klaus Pandl · Ludwigshafen, DE

Key dates

• Filing date: Apr 27, 2001
• Grant date: Oct 29, 2002
• Expiry date: Apr 27, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C47/04
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The claimed invention relates to a process for preparing an aqueous formaldehyde solution comprising absorbing a formaldehyde-loaded gas stream, in an absorption zone, in an aqueous solution comprising from 0.000% to 0.01% by weight of a Bronsted base, based on the formaldehyde absorbed. The produced aqueous formaldehyde solution comprises: a) from 10 to 75% by weight of formaldehyde, b) from 0 to 500 ppm by weight of tetroxane, c) from 50 to 400 ppm by weight of formic acid, based on the formaldehyde absorbed, and d) from 0.2 to 5.0% by weight of methanol, based on the formaldehyde absorbed.