Reactor configurations, comparison

Comparison of Different Process Routes and Reactor Configurations... 

Figure 1. Comparison of reactor configurations single CSTR (Base Case) versus same size CSTR with small seeding reactor (New Reactor Configuration).

DMH is an intermediate in peroxide chemistry and could be used for synthesis in the field of lubricant or polyester. So far research has mainly focused on the development of different catalysts and the comparison of their performance [1]. Despite intensive optimization of catalysts and reaction conditions, selectivity to DMH is still low, because molecular oxygen in the gas-phase causes deep oxidation. Beside the development of catalysts and the optimization of reaction conditions, the mode of gas-solid contact and the reactor configurations are important issues as well. As in any parallel-series network with valuable intermediate products, the design of the reactor has a strong influence on the selectivity towards DMH. In principle, modes of contact which maintain a low oxygen concentration in the reactor favour the desired reaction and thus improve selectivity. Obviously, the requirement of a low oxygen concentration in the gas phase can be met by using a redox-type operation in which a... 

Reactor configurations other than dead end or CSTR can offer improvements. In Figure 7.13, the performance of a thin channel flat membrane reactor for the hydrolysis of sweet potato by means of a-amylase is reported in terms of filtration rate and product concentration vs time plots. A comparison to Figure 7.11 shows how great the improvements due only to the change of configuration can be. At an appreciably high flow rate and product concentration level, a steady state is also attained. 

Figure 23 Comparison of conversion for different reactor configurations [CMR, IMRCF (PBMR) and FBR (PFR)J uniform catalyst distribution [a(s) = l or a( )=l] and delta-function catalyst distribution ( 8=1 or...

A more recent study of the heat fluxes inside the reactor as well as a comparison of the theoretical data predicted by a radiation heat transfer model showed that radiation is the main mode of heat transfer in the multiple hearth reactor configuration used (10). 

To validate the analysis methodology used here for general spent fuel applications, it is desirable to perform calculations for configurations that are close to those expected in AFR scenarios. Thus, the burnup, fraction of spent fuel, and downtime were important factors in the selection of these reactor configurations as proposed benchmarks for burnup credit applications. The Sequoyah benchmarks were selected primarily for the MOC core, which at the time of startup had experienced a 2.7-year downtime and consisted of a core completely comprised of burned fuel. The other two Sequoyah configurations were evaluated because the data were readily available as a test of consistency with the MOC case. The TMI benchmark was selected for similar reasons. The core consisted primarily of burned fuel, with all fresh fuel located at the core periphery, where its importance is diminished. Startup occurred after an especially long downtime of 6.6 years. The Surry and North Anna benchmarks, on the other hand, were performed as a comparison with earlier... 

Capannelli, G., Carosini, E., Cavani, E., Monticelli, 0. and Trifiro, F., 1996. Comparison of the Catalytic Performance of V20s/Gamma-Al203 in the Oxidehydrogenation of Propane to Propylene in Different Reactor Configurations 1) Packed-Bed Reactor, 2)... 

Gallucci F, Van Sint Annaland M, Kuipers JAM (2008) Autothermal reforming of methane with integrated CO2 capture in a novel fluidized bed membrane reactOT. Part 2 comparison of reactor configurations. Top Catal 51 146-157... 

Gallucci, R, Van Sint Annaland, M. and Kuipers, J.A.M. (2008b) Autothermal reforming of methane in a novel fluidized bed membrane reactor. Part 2 Comparison of reactor configurations. Topics in Catalysis, 51,146-157. 

The studies have proven that both MRs can realize better performance in terms of methane conversion and hydrogen production than the CRs, working also at milder operating conditions. By making a comparison between the two reactor configurations, it has been shown that a PBMR has a very simple configuration whereas an FBMR is typically characterized by enhanced mass and heat transfer rates, which favor more uniform temperature profiles. Nevertheless, possible bubble-to-emulsion mass transfer... 

The results of the comparison of different reactor configurations are fisted in Table 4.23, and they demonstrate a promising trend for nickel membrane (Haag et al., 2007). 

Ultimately, the development of kinetic data involves optimization of the reaction parameters, many obtained with ab initio calculations (Czekaj et al., 2013 Kacprzak et al., 2012 Ludwig and Vlachos, 2008 Maestri and Reuter, 2011), through comparisons with experimental data obtained in the aforementioned reactor configurations. Detailed (mean field) kinetic schemes for the oxidation of H2 over noble metals were thus constructed (Aghalayam et al., 2000 Deutschmann et al., 1996, 2000 FrideU et al., 1994 HeUsing et al., 1991 Kramer et al., 2002 Maestri et al., 2008 Park et al., 1999 Williams et al., 1992). The hydrogen oxidation mechanism on platinum from Deutschmann et al. (2000), which will be used in Sections 5-7, is provided in Table 3.1. 

The effect of the reactor configuration (dual bed vs. physical mixture) seems to strongly depends on the temperature in a preliminary study carried out at 200 °C, Bonzi et al. showed that NOx conversion was significantly higher in the physical mixture configuration, with 390, 610, and 980 pmol NOx removed/g respectively after the NSR catalyst alone, after the NSR-SCR dual bed and after the physical mixture [69], A comparison with the results of Tables 19.6 and 19.7 shows that the differences between the three configurations are more marked at 200 °C than at 250 °C. 

At sufficiently high temperatures (>700°C) and high propane conversions (>40%), the different systems behaved very similarly. Also, by extending the comparison to Pt-coated monoliths, only-washcoated monoliths, uncoated monohths and an empty reactor, high yields to olefins at comparable paraffin conversions were still found. Results from different reactor configurations are reported in Table 28.3. These results indicate unambiguously the great importance of gas-phase reactions. 

Figure 16.28 Comparison of TACs for EtAc production using reactive distillation (RD), single reactive tray reactive distillation (RD-SRT), and side reactor configuration (SRC).

Inert membranes are by far the most widely used in polymeric membrane reactors. Since in PIMRs the catalytic function is absent from the membrane, in comparison with PCMRs this type of membrane reactor represents a lower level in process integration. However, because of this and because the membrane modulus can be separated from the vessel where the chemical reaction takes place, PIMRs allow a much wider range of reactor configurations than PCMRs. 

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