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Measurement of Palladium Crust Thickness on Catalysts by Optical Microscopy and Image Analysis

  • Loïc Sorbier (a1), Anne-Sophie Gay (a1), Antoine Fécant (a1), Maxime Moreaud (a1) and Nicolas Brodusch (a2)...

Abstract

Selective hydrogenation is an important process in petrochemistry to purify feedstock for polymer synthesis. For this process, catalysts containing metallic palladium deposited with an eggshell distribution on porous alumina are usually employed. For this kind of catalyst, the activity is known to be in close relation with the thickness of the palladium crust. As palladium oxide is brown and alumina is white, the palladium distribution in a catalyst bead before the reduction step can be characterized by optical microscopy. We propose an original and automatic procedure of optical image analysis to obtain a fast and robust method to measure the mean crust thickness of a catalyst batch and the corresponding standard deviation. The approach is validated by two different methods. First, we compared the crust thickness with those obtained by electron probe microanalysis. Then, catalytic tests of four samples with varying palladium crust thicknesses were performed and confirmed the expected correlation between activity and crust thickness measured by optical microscopy coupled with image analysis.

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* Corresponding author. E-mail: loic.sorbier@ifpen.fr

References

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Berenblyum, A.S., Mund, S.L., Karel'skii, V.V., Goranskaya, T.P., Zolotukhin, V.E. & Lakhman, L.I. (1986). Catalysts for the selective hydrogenation of unsaturated compounds consisting of alumina particles with regular palladium distribution. Kinet Catal 27, 184187.
Beucher, S. & Meyer, F. (1992). The morphological approach to segmentation: The watershed transformation. In Mathematical Morphology in Image Processing, Dougherty, E. (Ed.), pp. 433481. New York: Marcel-Dekker.
Breen, E.J. & Jones, R. (1996). Attribute openings, thinnings and granulometries. Comp Vis Image Understand 64, 377389.
Brunauer, S., Emmet, P.H. & Teller, T. (1938). Adsorption of gases in multimolecular layers. J Am Chem Soc 60, 309319.
Chang, J.C. & Chou, T.C. (1997). Selective hydrogenation of isoprene over δ-alumina-supported eggshell Pd catalysts: Particle size effects. Appl Catal A 156, 193205.
Corbett, W.E. & Luss, D. (1974). The influence of non-uniform catalytic activity on the performance of a single spherical pellet. Chem Eng Sci 29, 14731483.
Fischer, L., Petit-Clair, C., Thomazeau, C., Sorbier, L. & Verdon, C. (2007). Catalyst comprising palladium and selective hydrogenation application thereof. French Patent FR 2922784.
Iglesia, E., Soled, S.L., Baumgartner, J.E. & Reyes, S.C. (1995). Synthesis and catalytic properties of eggshell cobalt catalysts for the Fischer-Tropsch synthesis. J Catal 153, 108122.
Le Page, J.F. (1978). Catalyse de contact. Paris: Technip.
Lin, T.B. & Chou, T.C. (1994). Selective hydrogenation of isoprene on eggshell and uniform palladium profile catalysts. Appl Catal A 108, 719.
Lin, T.B. & Chou, T.C. (1995). Pd migration. 1. A possible reason for the deactivation of pyrolysis gasoline partial hydrogenation catalysts. Ind Eng Chem Res 34, 128134.
Meyer, F. (1991). Method for the processing of images by hierarchically organized queues. French Patent FR 9103384.
Otsu, N. (1979). A threshold selection method from grey-level histograms. IEEE Trans Syst Man Cybern 9, 377393.
Salembier, P., Oliveras, A. & Garrido, L. (1998). Anti-extensive connected operators for image and sequence processing. IEEE T Image Proc 7, 555570.
Salembier, P. & Wilkinson, M.H.F. (2009). Connected operators: A review of region-based morphological image processing techniques. IEEE Signal Proc Mag 26(6), 136157.
Serra, J. (1988). Image Analysis and Mathematical Morphology—Vol. II. Theoretical Advances. London, UK: Academic Press.
Shadman-Yazdi, F. & Petersen, E.E. (1972). Changing catalyst performance by varying the distribution of active catalyst within porous supports. Chem Eng Sci 27, 227237.
Shao, Z., Li, C., Chen, X., Pang, M., Wang, X. & Liang, C. (2010). A facile and controlled route to prepare eggshell pd catalyst for selective hydrogenation of phenylacetylene. ChemCatChem 2, 15551558.
Sorbier, L., Gay, A.-S., Fécant, A., Moreaud, M. & Brodusch, N. (2012). Measurement of palladium crust thickness on catalyst by EPMA. IOP Conf Ser Mater Sci Eng 32 012023.
Sorbier, L., Rosenberg, E. & Merlet, C. (2004). Microanalysis of porous materials. Microsc Microanal 10, 745752.
Tomasi, C. & Manduchi, R. (1998). Bilateral filtering for gray and color images. Proc IEEEInt. Conf. Comput Vision, pp. 839846.
Urbach, E.R. & Wilkinson, M.H.F. (2008). Efficient 2-D grayscale morphological transformations with arbitrary flat structuring elements. IEEE Trans Im Proc 17, 18.
Villadsen, J. (1976). The effectiveness factor for an isothermal pellet with decreasing activity towards the pellet surface. Chem Eng Sci 31, 12121213.
Vincent, L. (1993). Morphological grayscale reconstruction in image analysis: Applications and efficient algorithms. IEEE Trans Image Process 2, 176201.
Walter, T. (2003). Application de la morphologie mathématique au diagnostic de la rétinopathie diabétique à partir d'images couleur. Doctorate Thesis. Paris: Ecole des mines de Paris.

Keywords

Measurement of Palladium Crust Thickness on Catalysts by Optical Microscopy and Image Analysis

  • Loïc Sorbier (a1), Anne-Sophie Gay (a1), Antoine Fécant (a1), Maxime Moreaud (a1) and Nicolas Brodusch (a2)...

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