Catalytic reactors comparison

Satterfield, C. N., and Yang, S. H., Catalytic Hydrodenitrogenation of Quinoline in A Trickle-Bed Reactor. Comparison With Vapor Phase Reaction. Ind. Eng. Chem. Process Des. Dev, 1984. 23 pp. 11-19. 

Our treatment of Chemical Reaction Engineering begins in Chapters 1 and 2 and continues in Chapters 11-24. After an introduction (Chapter 11) surveying the field, the next five Chapters (12-16) are devoted to performance and design characteristics of four ideal reactor models (batch, CSTR, plug-flow, and laminar-flow), and to the characteristics of various types of ideal flow involved in continuous-flow reactors. Chapter 17 deals with comparisons and combinations of ideal reactors. Chapter 18 deals with ideal reactors for complex (multireaction) systems. Chapters 19 and 20 treat nonideal flow and reactor considerations taking this into account. Chapters 21-24 provide an introduction to reactors for multiphase systems, including fixed-bed catalytic reactors, fluidized-bed reactors, and reactors for gas-solid and gas-liquid reactions. 

Fig. 12.4. Comparison of the space-time yield (STY) of catalytic reactors with the area time yield (ATY) of several inorganic membranes. (Reprinted from Ref. [35], Fig. 11 copyright 1999, with permission of Elsevier.)...

When the values shown in Table 2 are used to calculate the overall molar production rates per unit volume of reactor for monolith reactors, values of 40 mol/mreactor s are foimd. Figure 14 illustrates that this value is very high in comparison with those foimd in conventional catalytic reactors used in industry. 

The countercurrent-flow fixed-bed operation is often used for gas-liquid reactions rather than gas-liquid-solid reactions. Examples of reactions using this type of reactor are given by Danckwerts.29 A comparison between a gas liquid-solid (catalytic) fixed-bed reactor and a gas-liquid-solid (inert) fixed-bed reactor is shown in Table 1-7. The major difference between packed-bed gas-liquid reactors and gas-liquid-solid catalytic reactors is in the nature and size of the packing used and the conditions of gas and liquid flow rates. The packed-bed gas-liquid reactors use nonporous, large-size packing, so that they can be operated at high gas and liquid flow rates without excessive pressure drop. The shape of... 

Catalytic data were obtained over a wide range of CO conversion by varying the space velocity at constant temperature and reactant pressure. In many cases, we choose to report rate and selectivity data at integral reactor conditions (45- 65% CO conversion) because they favor the synthesis of C5+ hydrocarbons. All comparisons among catalysts are made at similar levels of conversion, a requirement imposed by the integral operation of the catalytic reactor. Our conclusions, however, remain valid when similar comparisons are made at much lower conversion levels in differential reactors. 

Comparison of COj hydrogenation in a catalytic reactor and in a dielectric-barrier discharge... 

Gas-solid heterogeneous reactions may be noncatalytic. An example is the hydrofluorination of uranium dioxide pellets referred to in Sec. 7-1. Since one reactant is in the solid phase and is consumed, the rate of reaction varies with time. Hence such processes are basically transient, in comparison with the steady-state operation of gas-solid catalytic reactors. The process for smelting ores such as zinc sulfide,... 

Current and future advancements in materials engineering might, however, lead to a significant reversal of this trend, and in this context the lowering of operating temperatures represents the main target. By comparison, compared to conventional catalytic reactors, SEMRs could be used to produce expensive fine chemicals, with attractive yields. 

Figure 2. The conversion-vs-temperature curves for catalytic activity comparison, using CE ( ), CF (a) and CG (x), and the empty reactor (n)-, GHSV = 577 h". ...

FIGURE 8.19 Reaction network and rate constants at 375°C for quinoline HDN. Source C. N. Satterfield and S. H. Yang, Catalytic Hydrodenitrogenation of Quinoline in a Trickle-Bed Reactor. Comparison with Vapor Phase Reaction, Industrial and Engineering Chemistry Product Research and Development 23 11-19 (1984). With permission. 

Figure 12.4 Methane conversion against temperature for membrane reactor. Comparison between experimental data (symbols) and model results (lines) for a 40 SCCM sweep flow rate. Reprinted from G. Barbieri, G. Mar-igliano, E. Drioli, Simulation of steam reforming process in a catalytic membrane reactor, Ind. Eng. Chem. Res., 36, 6, 2001, with permission of American Chemical Society.

The simultaneous occurrence of two fluid phases in a reactor offers advantages but also disadvantages. If a choice between a gas and a gas-liquid catalytic reactor has to be made, several points must be examined. A comparison of these two classes of reactors is briefly summarized in Table 1. 

Figure 16.24 Comparison of conversion changes between in membrane reactor (MR) and in conventional catalytic reactor (CCR) at a large weight hourly space velocity (WHSV).

Pereira Duarte SI, Barreto GF, Lemcoff NO. Comparison of two-dimensional models for fixed bed catalytic reactors. Chemical Engineering Science 1984 39 1017-1024. 

Bhatia, S., Thien, C.Y., and Mohamed, A.R. (2009) Oxidative coupling of methane (OCM) in a catalytic membrane reactor and comparison of its performance with other catalytic reactors. Chem. Eng. 148 (2-3), 525-532. 

Salmi, T. and WarnJ, J., Modelling of catalytic packed-bed reactors—comparison of different diffusion models. Comp. Chem. Eng., 15, 715-727,1991. 

Amariei, D. Courtheoux, L. Rossignol, S. Kappenstein, C. (2007). Catalytic and thermal decomposition of ionic liquid monopropellants using a dynamic reactor. Comparison of powder and sphere-shaped catalysts. Ghent. Eng. Process., 40,165-174, ISSN 0255-2701... 

SASOLII a.ndIII. Two additional plants weie built and aie in operation in South Africa near Secunda. The combined annual coal consumption for SASOL II, commissioned in 1980, and SASOL III, in 1983, is 25 x 10 t, and these plants together produce approximately 1.3 x lO" m (80,000 barrels) per day of transportation fuels. A block flow diagram for these processes is shown in Figure 15. The product distribution for SASOL II and III is much narrower in comparison to SASOL I. The later plants use only fluid-bed reactor technology, and extensive use of secondary catalytic processing of intermediates (alkylation, polymerisation, etc) is practiced to maximise the production of transportation fuels. 

S. H., and Stitt, E.H. (2007) intensification of the solvent-free catalytic hydroformylation of cydododecatriene comparison of a stirred batch reactor and a heat-exchange reactor. Catal. Today, 128, 18-25. 

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