Industrial reforming

The concept requires that for reversible reactions equilibrium be attained in the center of the catalyst. A numerical simulation of the set of continuity equations for CH4 and CO2 inside a ring-shaped catalyst particle used in an industrial reformer confirmed the presumption that equilibrium is indeed attained within a very thin layer close to the surface. 

Persian Gulf (PG) 90-l40°C cut straight run naphtha is hydrodesulfurised in naphtha pretreater and is being processed in the referred industrial reformer The pretreated naphtha was procured from the refinery and used as charge for pilot plant studies at UP It s characteristics are presented in Table 2... 

Multi-component supported metal catalysts, including industrial reforming catalysts. 

Conversion of n-hexane over Pt-Re/Al203 catalysts depends on the temperature, the velocity of alkane feed, and the catalyst composition. Pt-Re/Al203 catalysts are widely used in industrial reforming. The effect of Pt/Re ratio on the n-hexane aromatization was investigated. 

In discussing microreaction systems, it is helpful to first distinguish the characteristic size of a microreactor in comparison with conventional scale reactors. Two different definitions of the term microreactor are commonly used in the literature. The first defines any reactor that is an order of magnitude or more smaller than its conventional scale coimterpart as a microreactor. For example, an industrial reforming reactor might be 10,000-100,000 L in volume. Using this first definition, a 1 L reforming reactor could be considered a microreactor. This definition is not very useful as it... 

To explain the above results two more cases are chosen for analyzing them the same way as the case presented in Table 3.3. The case which gives optimum overall methane conversion is presented in Table 3.4 and a case of lower steam to methane ratio (S/M = 1.0), is presented in Table 3.5. This low steam to methane ratio may cause carbon deposition in an industrial reformer. However, carbon formation is... 

In this sense, refiners have reduced the severity of the industrial reforming plants in order to decrease the amoimt of aromatics in gasoline, however it adversely affects the reformate octane [1]. 

The effectiveness factor is a global multiplier of the intrinsic reaction rate that accounts for the severe diffusion limitations encountered in industrial reformers. Effectiveness factors of industrial Ni-based catalysts for the methane-steam and shift reactions are of the order of 0.02 this means that the actual reaction rate experienced by the bulk fluid in the reformer is typically only about few percents of the reaction rate measured in the laboratory under the same conditions but writh very small catalyst particle sizes. 

The first patent on a tubular reformer using supported nickel catalysts was obtained by BASF in 1912 [348] [544]. A later patent (1928) dealt with a heated tubular reactor [546]. A license was given to Standard Oil, New Jersey, and the first industrial reformer was started in Baton Rouge in 1930 [93]. Six years later, the first ICI reformer was commissioned at Billingham [203],... 

Fpx is a view factor, which can here be set to unity, since the measured temperature is the one on the front. The furnace temperature varies significantly on the furnaee wall, so an average value recorded by the IR camera is used. In a pilot plant the correction is small if the measurements are made on the eold side of the tube, whereas in an industrial reformer the measured temperatures are those on the hot side along the furnace and larger eorreetions result. 

Theoretically it may be better to correlate the data using the Biot number [157] as a function of Reynolds number, but at the high Reynolds numbers in industrial reformers the two formulations become similar. 

The effective diffusion coefficients of molecules in catalyst pores at the high pressures of industrial reformers are dominated by the bulk diffusion coefficient, whereas the Knudsen diffusion has significant influence at atmospheric pressure. This is illustrated in Figure 3.21. Consequently, low-pressure laboratory tests of large catalyst particles can be misleading for evaluation of the activity of reforming catalysts and they must aim at determination of the intrinsic activity with relatively fine catalyst powders. 

The change in mechanism in operation with carbon dioxide instead of steam would have little practical impact on reforming, because steam will be present not far from the inlet, but also in the centre of the catalyst particle as a consequence of the low effectiveness factors of catalysts in industrial reformers. CO2 reforming results in lower atomic ratio of H/C which means a higher risk of carbon formation (refer to Section 5.2,4). 

Figure 5.38 Regeneration for carbon formation in an industrial reformer [388] [389], Analyses of dry exit gas. Approximately 0.4 tonne of steam per tonne of catalyst per hour. Tcat=450-600°C. P 6 bar. The progress of the regeneration can easily be followed by analysis of the exit gas from the reformer. The additions of air is increased as the production of CO2 decreases. In this way, overheating can be controlled. Reproduced with the permission of Brill and Springer Verlag.

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