Diffusion Processes Affecting the Performance of Heterogeneous Catalysts: Part 1

Mohammad Ebrahim Zeynali; S. Hakim

doi:10.4028/www.scientific.net/DDF.319-320.107

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Diffusion Processes Affecting the Performance of Heterogeneous Catalysts: Part 1

Abstract:

The diffusion processes taking place in heterogeneous catalytic systems have been discussed. Various diffusion mechanisms such as Knudsen diffusion, molecular diffusion, configurational diffusion and surface diffusion sensitivity in catalytic systems were investigated. The concentration gradients inside the catalyst pellet were obtained for various Thiele modulus. The Knudsen number was calculated and discussed for large and small pores. The transitional diffusion coefficient was determined for diethylbenzene. The experimental pore size distribution carves for an industrial and synthesized catalyst was obtained and the effect of pore size distribution on diffusion coefficient was discussed.

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Periodical:

Defect and Diffusion Forum (Volumes 319-320)

Pages:

107-115

DOI:

https://doi.org/10.4028/www.scientific.net/DDF.319-320.107

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Online since:

October 2011

Authors:

Mohammad Ebrahim Zeynali, S. Hakim

Keywords:

Diffusion Mechanism, Effectiveness Factor, Heterogeneous Catalyst, Pore Size

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References

[1] Bensetiti Z., Schweich D., and. Abreu C.A. M, The sensitivity of catalyst effectiveness factor to pore size Distribution, Brazilian Journal of Chemical Engineering, 14.

DOI: 10.1590/s0104-66321997000300013

Google Scholar

[3] (1997).

Google Scholar

[2] Derjani-Bayeh S., Rodgers V.G.J., Sieving variations due to the choice in pore size distribution model, Journal of Membrane Science, 209 (2002).

DOI: 10.1016/s0376-7388(01)00737-2

Google Scholar

[3] Szczygieł J., Enhancement of reforming efficiency by optimising the porous structure of reforming catalyst: Theoretical considerations, Fuel, 85 (2006) 10-11.

DOI: 10.1016/j.fuel.2005.11.016

Google Scholar

[4] Heun Kim D., Lee J., A Simple Formula for Estimation of the Effectiveness Factor in Porous Catalysts, AICHE Journal, 52 (2006) 10.

DOI: 10.1002/aic.10971

Google Scholar

[5] Hoyos B., Guillermo Cadavid J., and Rangel H., Formulation and numeric calculation of non-isothermal effectiveness factor for finite cylindrical catalysts with bi-dimensional diffusion, Lat. Am. Appl. Res., 34 (2004) 1.

Google Scholar

[6] Sahin E., Dogu T., and Mürtezaolu K., Thermal effects on effectiveness of catalysts having bidisperse pore size distributions, Chemical Engineering Journal, 93 (2003) 2.

DOI: 10.1016/s1385-8947(02)00227-9

Google Scholar

[7] Hong J., Hecker W. C., Fletcher T. H., Predicting effectiveness factor for M-order and Langmuir rate, ACS Division of Fuel Chemistry, 44 (1999) 4.

Google Scholar