Process for the production of a tungsten carbide catalyst by carburization of tungsten oxides

US4172808A · kind A · utility

Assignee

• Licentia Patent-Verwaltungs-GmbH · DE

Inventors

• Harald Bohm
• Robert Fleischmann · Neu-Ulm, DE
• Jochen Heffler · Großkrotzenburg, DE

Key dates

• Filing date: Mar 17, 1978
• Grant date: Oct 30, 1979
• Expiry date: Mar 17, 1998

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J27/22
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the production of a tungsten carbide catalyst by carburization of tungsten oxides, comprises, directing a mixture of carbon monoxide and carbon dioxide over tungsten oxide while heating it in a heated reactor at a heating rate and gas flow rate such that the reduction of the tungsten oxide occurs more slowly than the diffusion of the carbon into the tungsten and into tungsten carbide which is formed during the reaction with the diffusion being faster than the separation of carbon from the gaseous phase according to the rate of adjustment of the Boudouard equilibrium. The carbon monoxide is charged at a rate of 560 1tr/h and the carbon dioxide is charged at a rate of 40 1tr/h and, after a reactor containing the sample of tungstic acid is positioned in a closed reactor, the reactor is flushed with the gases for around ten minutes and then placed into a muffle furnace. The reactor is heated to a temperature of 670.degree. C. in the furnace and the temperature is then reduced to a reaction temperature of 620.degree. C. First, all of the water is eliminated, and then there is a reduction of the tungsten oxides and a diffusion of the carbon into tungsten or into tungsten ca…