Process for the preparation of formaldehyde

US5990358A · kind A · utility

Assignee

• BASF SE

Inventors

• Bernhard Knuth · Ludwigshafen, DE
• Rainer Diercks · Schifferstadt, DE

Key dates

• Filing date: Mar 13, 1998
• Grant date: Nov 23, 1999
• Expiry date: Mar 13, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C45/38
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for preparing formaldehyde by oxidative dehydrogenation of methanol comprises passing a gas mixture (i) comprising PA1 a) from 0.1 to 50% by volume of methanol, PA1 b) from 0.1 to 30% by volume of oxygen, PA1 c) from 0 to 50% by volume of nitrogen oxide and PA1 d) from 0 to 60% by volume of water at from 150 to 800.degree. C. through a phosphorus-doped silver catalyst fixed bed (a) and applying from 0.01 to 100 ppm by weight of phosphorus, based on the phosphorus-doped silver catalyst fixed bed, in the form of a finely divided phosphorus compound having a melting point or decomposition temperature of more than 500.degree. C. (phosphorus compound P) to the phosphorus-doped silver catalyst fixed bed (a) per kg of methanol which is passed through in the form of the gas mixture (i) per cm.sup.2 of the cross-sectional area of the phosphorus-doped silver catalyst fixed bed (a).