Kinetics of the reduction of nickel oxide by hydrogen

✍ Scribed by Jan Bandrowski; C.R. Bickling; K.H. Yang; O.A. Hougen

• Publisher: Elsevier Science
• Year: 1962
• Tongue: English
• Weight: 894 KB
• Volume: 17
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(62)80039-6

✦ Synopsis

The reaction model for the reduction of NiO pellets by hydrogen has been postulated to consist of two simultane.ous reactions, first, a reaction between NiO and hydrogen gas adsorbed on NiO, and second, a reaction at the boundary between the two solid phases NiO and Ni with hydrogen adsorbed on nickel. The first reaction rate varies with the @43 exponent of hydrogen pressure indicating a surface reaction with adsorbed hydrogen where surface coverage increases with pressure. The second reaction rate is nearly independent of pressure indicating that the surface of nickel is nearly completely covered with adsorbed hydrogen at atmospheric pressure and above. Reaction rates have been established as a function of temperature and pressure. At temperatures below 300°C the resistance offered to internal diffusion was negligible for pellets 4.3 mm in diameter but became significant at higher temperatures.