ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Modelling of nanocrystalline iron nitriding process — influence of specific surface area

Rafał Pelka and Walerian Arabczyk

Institute of Chemical and Environment Engineering, West Pomeranian University of Technology, Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland

E-mail: rpelka@zut.edu.pl

Abstract: Samples of iron catalysts of various specific surface areas for ammonia synthesis underwent nitriding with ammonia in a tubular reactor where continuous thermogravimetric measurement and measurements of hydrogen concentration in the gaseous phase were simultaneously performed. The nitriding process was performed under atmospheric pressure at 475°C. It was observed that, along with an increase in the mean size of iron nano-crystallites, the minimum nitriding potential (at which the iron nitriding reaction is initiated) of the gaseous phase also increased. The degree of nitriding of the catalyst samples increased with the increase in the mean size of iron crystallites. On the basis of the values of nitriding potential, nano-crystallite size distributions can be determined.

Keywords: nitriding reaction – catalytic ammonia decomposition – nano-crystalline iron – ammonia synthesis iron catalyst – nano-crystallite size – active surface area

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-010-0105-8

Chemical Papers 65 (2) 198–202 (2011)