Process and device for preparing pure formaldehyde

US6414196B1 · kind B1 · utility

Assignee

• Ticona LLC · US

Inventors

• Werner Sievers · Frankfurt, DE
• Elke Schweers · Bad Soden, DE
• Michael Rosenberg · Niedernhausen, DE

Key dates

• Filing date: May 25, 2000
• Grant date: Jul 2, 2002
• Expiry date: May 25, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C45/82
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the post-purification in particular of pyrolysis gases for preparing pure formaldehyde, hemiformal being pyrolyzed in an evaporator, the resulting formaldehyde vapor being passed through a condensed liquid component collected in the bottom area of the evaporator, the condensed liquid component being passed out as a falling film situated on the inner wall through a cooled outlet tube disposed in the bottom area of the evaporator and the formaldehyde vapor being passed through the cooled outlet tube in cocurrent and the liquid component and the formaldehyde being taken off separately at the outlet tube end remote from the evaporator.