Effects of Catalyst Tubes Characteristics on a Steam Reforming Process in Ammonia

Authors: M.Boumaza

Abstract:

The tubes in an Ammonia primary reformer furnace operate close to the limits of materials technology in terms of the stress induced as a result of very high temperatures, combined with large differential pressures across the tube wall. Operation at tube wall temperatures significantly above design can result in a rapid increase in the number of tube failures, since tube life is very sensitive to the absolute operating temperature of the tube. Clearly it is important to measure tube wall temperatures accurately in order to prevent premature tube failure by overheating.. In the present study, the catalyst tubes in an Ammonia primary reformer has been modeled taking into consideration heat, mass and momentum transfer as well as reformer characteristics.. The investigations concern the effects of tube characteristics and superficial tube wall temperatures on of the percentage of heat flux, unconverted methane and production of Hydrogen for various values of steam to carbon ratios. The results show the impact of catalyst tubes length and diameters on the performance of operating parameters in ammonia primary reformers.

Keywords: Catalyst, tubes, reformer, performance

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1080522

References:

[1] Appl. .M : Ammonia principles and industrial practice, 1999, Wiley- VCH Ed.
[2] Dunn A.J, Yustos.J, Mujtaba.I.M: Pap - 6th WCCE, Melbourne,2001.
[3] Ravi.K, Joshi.Y.K, Dhingra.S.C, Guha.B.K:Chem.Eng.Tech 1989, 12, 358-364.
[4] Singh. C. P, Saraf. D.N; Ind. Eng. Chem, 1979, 12, 1-7.
[5] Freemont Ammonia Plant, Algeria..
[6] Numaguchi.T, Shoji.K, Yoshida.S: Applied catalyst, 1995, 133, 241- 262.
[7] Heinzel.A, Vogel.B, Hubner.P: J of Power Sources, 2002, 105, 202-207.
[8] Rostrup-Nielsen J.R: Catalysis today, 2002, 71, 243-247.
[9] J.M.Smith, H.C Van Ness, M.M.Abott: Introduction to Chemical Engineering Thermodynamics, 7th edition, McGraw-Hill, 2005.
[10] Levent.M, Gunn.D.J, ELBousiffi M.A: I.J of Hydrogen Energy 2003, 28, 945-0959.