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Reforming equilibrium

A.3.3 Faradaic Reformer, Equilibrium Constant and Equilibrium Mixture at PqTq... [Pg.153]

Equilibrium is achieved in steam reforming equilibrium is approached for partial oxidation processes 14]. The reactions are given in Table 6.10.. ... [Pg.165]

The temperature profile in Run A corresponds to an ordinary sidewall-fired furnace. The temperature profiles in Run B allow establishment of reforming equilibrium at the outlet due to the reduced firing in the bottom. The profile in Rim C simulates maximum heat flux at the very bottom similar to a bottom-fired reformer. It is evident that such changes can only be performed in a pilot plant. [Pg.188]

The reaction conversion is typically measured in terms of approach to equilibrium. A typical design approach to reforming equilibrium is 20°F. This means that the reforming reaction (equation 1 above) is at equilibrium corresponding to a temperature 20°F lower than the actual temperature. This corresponds to a typical end-of-life catalyst condition. Fresh catalyst t5q)ically runs at essentially a 0°F approach to reforming equilibriiun (that is, for fresh catalyst the reforming reaction is essentially at equilibrium at the actual temperature). The shift reaction (equation 2 above) is rapid and is considered in equilibrium at all times. [Pg.348]

Reforming Chemistry. The main reactions occurring ia a reformer are shown ia Figure 5 (6,13—15) most are reversible iadicating the potential importance of reaction equilibrium. [Pg.309]

The principle of Le Chatelier shows that when the pressure applied to a gaseous system is increased, dre equilibrium composition will chairge in order to reduce tire number of gaseous molecules. In the case of tire steam reforming of metlrane, the partial pressures of methane and steam will increase as the pressure is increased. In the water-gas reaction, where tire number of molecules is the same on both sides of the equation, the effect of increasing... [Pg.131]

Table 4.3 Equilibrium composition in the steam-reforming reaetion at 900 K as afunetion of pressure (molar fraetion)... Table 4.3 Equilibrium composition in the steam-reforming reaetion at 900 K as afunetion of pressure (molar fraetion)...
To fully understand the formation of the N13S2 scale under certain gas conditions, a brief description needs to be given on the chemical aspects of the protective (chromium oxide) Ci 203/(nickel oxide) NiO scales that form at elevated temperatures. Under ideal oxidizing conditions, the alloy Waspaloy preferentially forms a protective oxide layer of NiO and Ci 203 The partial pressure of oxygen is such that these scales are thermodynamically stable and a condition of equilibrium is observed between the oxidizing atmosphere and the scale. Even if the scale surface is damaged or removed, the oxidizing condition of the atmosphere would preferentially reform the oxide scales. [Pg.239]

In order to produce more paraxylene than is available in catalytic reformate, a xylenes-isomerization plant is sometimes included in the processing scheme. The isomerization step uses the effluent (filtrate) from the paraxylene crystallization step as feed. The filtrate contains about 7-9 percent of paraxylene. The isomerization unit brings the concentration back to its equilibrium value of about 20 percent. [Pg.113]

We also give calculations of the performance of some of these various gas turbine plants. Comparison between such calculations is often difficult, even spot calculations at a single condition with state points specified in the cycle, because of the thermodynamic assumptions that have to be made (e.g. how closely conditions in a chemical reformer approach equilibrium). Performance calculations by different inventors/authors are also dependent upon assumed levels of component performance such as turbomachinery polytropic efficiency, required turbine cooling air flows and heat exchanger effectiveness if these are not identical in the cases compared then such comparisons of overall performance become invalid. However, we attempt to provide some performance calculations where appropriate in the rest of the chapter. [Pg.135]

This is also an endothermic reaction, and the equilibrium production of aromatics is favored at higher temperatures and lower pressures. However, the relative rate of this reaction is much lower than the dehydrogenation of cyclohexanes. Table 3-6 shows the effect of temperature on the selectivity to benzene when reforming n-hexane using a platinum catalyst. [Pg.63]

Catalytic reformers are normally designed to have a series of catalyst beds (typically three beds). The first bed usually contains less catalyst than the other beds. This arrangement is important because the dehydrogenation of naphthenes to aromatics can reach equilibrium faster than the other reforming reactions. Dehydrocyclization is a slower reaction and may only reach equilibrium at the exit of the third reactor. Isomerization and hydrocracking reactions are slow. They have low equilibrium constants and may not reach equilibrium before exiting the reactor. [Pg.68]

A promoted nickel type catalyst contained in the reactor tubes is used at temperature and pressure ranges of 700-800°C and 30-50 atmospheres, respectively. The reforming reaction is equilibrium limited. It is favored at high temperatures, low pressures, and a high steam to carbon ratio. These conditions minimize methane slip at the reformer outlet and yield an equilibrium mixture that is rich in hydrogen. ... [Pg.140]

Ethylbenzene (EB) is a colorless aromatic liquid with a boiling point of 136.2°C, very close to that of p-xylene. This complicates separating it from the Cg aromatic equilibrium mixture obtained from catalytic reforming processes. (See Chapter 2 for separation of Cg aromatics). Ethylbenzene obtained from this source, however, is small compared to the synthetic route. [Pg.265]

The frequent breaking and reforming of the labile intermolecular interactions stabilizing the reversed micelles maintain in thermodynamic equilibrium a more or less wide spectrum of aggregates differing in size and/or shape whose relative populations are controlled by some internal (nature and shape of the polar group and of the apolar molecular moiety of the amphiphile, nature of the apolar solvent) and external parameters (concentration of the amphiphile, temperature, pressure) [11], The tendency of the surfactants to form reversed micelles is, obviously, more pronounced in less polar solvents. [Pg.475]

Direct thermal decomposition of methane was carried out, using a thermal plasma system which is an environmentally favorable process. For comparison, thermodynamic equilibrium compositions were calculated by software program for the steam reforming and thermal decomposition. In case of thermal decomposition, high purity of the hydrogen and solidified carbon can be achieved without any contaminant. [Pg.424]

CO2 in Figure 225(c) induces also non-equilibrium state and enhances CO2 production, then H2 productivity and purity are also enhanced. These separation processes would realize not only high-yield of H2, but also decrease of temperature of the endothermic reforming. It means that the separation process is important methodology for energy media transformation and chemical energy conversion. [Pg.388]


See other pages where Reforming equilibrium is mentioned: [Pg.422]    [Pg.58]    [Pg.60]    [Pg.148]    [Pg.664]    [Pg.2935]    [Pg.313]    [Pg.663]    [Pg.340]    [Pg.21]    [Pg.942]    [Pg.95]    [Pg.636]    [Pg.293]    [Pg.196]    [Pg.422]    [Pg.58]    [Pg.60]    [Pg.148]    [Pg.664]    [Pg.2935]    [Pg.313]    [Pg.663]    [Pg.340]    [Pg.21]    [Pg.942]    [Pg.95]    [Pg.636]    [Pg.293]    [Pg.196]    [Pg.328]    [Pg.328]    [Pg.127]    [Pg.131]    [Pg.132]    [Pg.240]    [Pg.25]    [Pg.150]    [Pg.88]    [Pg.226]    [Pg.17]    [Pg.295]    [Pg.422]    [Pg.817]    [Pg.326]    [Pg.226]    [Pg.13]    [Pg.387]    [Pg.388]   
See also in sourсe #XX -- [ Pg.95 , Pg.188 ]




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