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Methane conversion, pressure profiles

The following heat flux profile was generated from independent simulations of the heat transfer in the firebox. First tube 23 kcal/m s (96 kJ/m s) second tube 20 (84) third tube 19 (80) fourth tube 17 (71) fifth tube 15 (63) sixth, seventh, eighth, ninth, and tenth tubes, 14 (59). With this heat flux profile, the conversion, temperature and total pressure profile of Fig. 2 was obtained. The agreement with the industrial data is really excellent. Also, the product distribution is in complete agreement as can be seen from Fig. 3 the simulated yields for ethylene, hydrogen, and methane, for example, are, respectively, 47.92, 3.79, and 3.49 the... [Pg.416]

Fig. 12 Le/i Effect of the flow configuration and methane conversion fraction (PR) on the stress. Case of an anode-supported cell with LSM-YSZ cathode and compressive gaskets, a Temperature profile and b First principal stress in the anode. The MIC is displayed in transparency, c First principal stress in the cathode (insert alxtve the symmetry line), d Contact pressure on the cathode GDL and compressive gasket and e vertical displacement along the z-axis, with an amplification factor of 2,000. Right column effect of creep in a cell based on a LSCF cathode and a temperature distribution, on b the evolution of the first principal stress in the anode support in operation and c during thermal cycling to RT and d evolution of the first principal stress in the GDC compatibility layer after thermal cycling. The profiles above and below the symmetry axis refer to different operation time [88, 89]. Reproduced here with kind permission from Elsevier 2012... Fig. 12 Le/i Effect of the flow configuration and methane conversion fraction (PR) on the stress. Case of an anode-supported cell with LSM-YSZ cathode and compressive gaskets, a Temperature profile and b First principal stress in the anode. The MIC is displayed in transparency, c First principal stress in the cathode (insert alxtve the symmetry line), d Contact pressure on the cathode GDL and compressive gasket and e vertical displacement along the z-axis, with an amplification factor of 2,000. Right column effect of creep in a cell based on a LSCF cathode and a temperature distribution, on b the evolution of the first principal stress in the anode support in operation and c during thermal cycling to RT and d evolution of the first principal stress in the GDC compatibility layer after thermal cycling. The profiles above and below the symmetry axis refer to different operation time [88, 89]. Reproduced here with kind permission from Elsevier 2012...
Comparison of results between base case permeance (x1) and a five times higher value (a) reforming temperature profiles, methane conversion and HRF along reactor length (b) radial pressure profiles at different lengths of the reactor. [Pg.518]

The second scale which determines the relation between the selectivity and conversion is the diffusion of the reactants through the catalyst poes. Model calculations conducted by McCarty indicated that at 10 atm die coupling of methyl radicals occurs preferentially inside the pores in a particle of 25 mm in diameter. The effect of this time scale is shown in Figure 10(a) in terms of the intraphase and interphase profiles for methane and ethane inside a catalyst pore. Clearly, higha C2 selectivities are obtained on catalysts with an open pore structure and low surface area. A majority of the literature results have been obtained using powdered catalysts in which diffusional effects are not in rtant however, such effects could be relevant at high pressure in fixed-bed reactors requiring the use of catalysts in a pelletized form. [Pg.176]

Figure 6.34 shows the strong effect of steam to methane ratios on the process gas, inner and outer temperature profiles. Increase of the steam to methane ratio decreases the process gas temperature and accordingly the inner and outer wall temperatures (Figure 6.34a). A high pressure drop results from the increase of the steam to methane ratios (Figure 6.34b). Figure 6.34c shows the conversion and yield variation corresponding to the change in the steam to methane ratio while the yield of carbon dioxide is affected more strongly by the change of steam to methane ratio. The conversion of carbon dioxide increases with the increase of steam to methane ratios and this may be due to the enhancement of the water-gas shift reaction. Figure 6.34 shows the strong effect of steam to methane ratios on the process gas, inner and outer temperature profiles. Increase of the steam to methane ratio decreases the process gas temperature and accordingly the inner and outer wall temperatures (Figure 6.34a). A high pressure drop results from the increase of the steam to methane ratios (Figure 6.34b). Figure 6.34c shows the conversion and yield variation corresponding to the change in the steam to methane ratio while the yield of carbon dioxide is affected more strongly by the change of steam to methane ratio. The conversion of carbon dioxide increases with the increase of steam to methane ratios and this may be due to the enhancement of the water-gas shift reaction.
At the conditions reported in this paper where the total pressure is closer to 1000 psig and the feed gas to the FDP reactor is an approximately equimolar mixture of hydrogen and methane, the total carbon conversions are closer to the fraction of carbon that instantaneously reacts and kinetic interpretation is even more difficult. Therefore the kinetic analysis is not yet complete. However for the purposes of FDP reactor simulation, a mathematical model was used that assumed all the carbon reacts at a rate dictated by Equation 1 rather than assuming a portion of this carbon reacts instantaneously. This assumption is felt to be conservative because it does not allow for the fraction of carbon that may react at a considerably faster rate than the final amount of carbon conversion which was used to evaluate the rate constant k. The temperature dependency of k used for our initial reactor simulation studies (11) has been reported (I). While the more detailed kinetic analysis may result in a modified rate equation, the results of our simulation study (11) indicate that radiant heat transfer plays a dominant role in small FDP reactors such as the one used in this study. Because the effect of radiant heat transfer from the reactor walls diminishes as the diameter of the reactor increases, temperature profiles in commercial reactors will be considerably different from those existing in our present 3-inch id FDP reactor this indicates the necessity of using larger diameter pilot plants to obtain reliable scaleup data. [Pg.132]

The calculation model integrates along the reactor in small increments. It maintains a detailed heat and material balance, pressure, methane yield, conversion, volumetric expansion and other factors necessary to calculate a true severity profile. [Pg.315]

The evolution of the total conversion of methane and of the conversion of methane into CO2 is shown in Fig. 11.9.l.A-4, together with the process gas temperature, total pressure, and wall temperature profiles. The temperature drop... [Pg.610]

The increased catalytic reactivity of methane on Pt at elevated pressures allows for significant fuel consumption at lower wall temperatures than those required at atmospheric pressure, thus facilitating an earlier microreactor ignition. This is evidenced in Figs. 8.6 and 8.7, where streamwise methane catalytic conversion rates and channel wall temperature profiles are plotted for Cases 1 and 5, atp = 1 and 5 bar, respectively. [Pg.89]


See other pages where Methane conversion, pressure profiles is mentioned: [Pg.456]    [Pg.127]    [Pg.197]    [Pg.103]    [Pg.154]    [Pg.517]    [Pg.89]    [Pg.126]    [Pg.9]    [Pg.304]    [Pg.444]   
See also in sourсe #XX -- [ Pg.193 ]




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