Reforming thermodynamic data

Table A.5 Faradaic equilibrium reform, thermodynamic data...

Table 4.2 Thermodynamic data for ideal reforming reactions...

In 2001 Hyprotech and Synetix announced an ammonia plant simulation that can be used for modeling, on-line monitoring and optimization of the plant. The simulation includes Synetix reactor models, customized thermodynamic data and information to simulate the performance of a range of catalysts. The reactor models in the simulation include Primary and Secondary Reformers, High Temperature Shift converter, Low Temperature Shift Converter, Methanator and Ammonia Synthesis Converter80. 

The process of the calculation involves a reformer which gets its exergy not from combustion, but as electrical power generated by supplying CO and Fi2 to separate fuel cells which are able to create an excess above the need of the reformer. The invaluable JANAF thermochemical tables (Chase etah, 1985) provided the thermodynamic data. The excess is the chemical exergy of methane. 

The next step is to inspect the thermodynamic data (Table A.5) for the overall reaction and this is done at three temperatures, 298.15 K, 900 K and 1300 K, representing SPFC, MCFC and SOFC, respectively. Only at PqTq does the thermodynamic data favour the electrically driven reformer. Figure A.4 is for the major calculation route at PqTo. The production of hydrogen at both reformer electrodes in the figure is unusual, if the mind has been concentrating on fuel cells. Moreover, v=l. 

Hydrogen and carbonmonoxide are fuels which must be made at thermodynamic and economic cost. A principal industrial route is via the fired steam reform of natural gas, a highly irreversible process. The related thermodynamically reversible route to methane reform, and electrochemical oxidation, Figure A.3, is examined. An electrically driven electrochemical reformer at standard conditions is the model. The reformer supplies a pair of fuel cells separately utilising carbon monoxide and hydrogen. The thermodynamic data confirm that there is plenty of electricity available... 

Table 2.3. Thermodynamic Data for the Steam Methane Reforming (SMR) Reaction...

Steam reforming reaction of ethane, propane, and n-butane are represented by Equations 2.21-2.23, while the thermodynamic data for these reactions are summarized in Tables 2.1-2.9, respectively ... 

Table 2.7. Thermodynamic Data for the Steam Reforming of Ethane C2H6(g) + 2H20(g) -> 5H2(g) + 2CO(g)...

Table 2.22. Thermodynamic Data Using Lower Heating Values for the Oxidative Steam Reforming of Methanol CH3OH(g) + 0.8H2O(g) + 0.1O2(g) - 2.8H2(g) + C02(g)...

After carbon particulates are removed from the off-gas, it is heated to 700°C and then fed into the bottom of a steam reformer. Literature data and thermodynamic models were employed to evaluate a large number of organic solvents for the extraction of... 

Thermodynamic data for Ce hydrocarbon reactions under catalytic reforming conditions are summarized in Table 3.20. 

Table 2 shows thermodynamic data for typical reforming reactions at 500°C. The equilibrium constant of exothermic reaction decreases as the temperature increases. This is the case of the isomerization reaction. However the heat of reaction in this case is small, and the change in the equilibrium constant is not very large. The hydrogenation reactions are also exothermic with a much higher heat of reaction than the isomerization reactions. The hydrogenation of 1-hexene (the inverse reaction of dehydrogenation of n-hexane) has a heat of reaction of 31,000 cal/mol. This means that the equilibrium conversion in this reaction will be much more affected by temperature than the isomerization. 

Thermodynamic data of the reforming reactions over Pt, Rh and Ru metals were obtained by using MP2/Lanl2dz method, they are hsted in Table 2. 

Figure 2.14 depicts the thermodynamic equilibrium data related to C02 reforming of methane at atmospheric pressure. It is noteworthy that at temperatures below 800°C, elemental... 

Note that all three models give almost the same exit conversion and yield for methane and carbon dioxide and that the second unit (2) is also operating relatively closely to its thermodynamic equilibrium, though further away from it when compared to Plant (1). The close agreement between the industrial performance data and the simulated data for the reformers (1) and (2) that was obtained by three different diffusion-reaction models validates the models that we have used, at least for plants operating near their thermodynamic equilibria. 

The output data from reformer II for the process gas and the calculated results of the dusty gas model and simplified models I and II are presented in Table 6.16. The measured and calculated temperatures, pressures and concentrations of the process gas at the exit of reformer II are in good agreement (Table 6.16). AH models give almost the same exit conversion and yield for methane and carbon dioxide. This unit is operating relatively close to thermodynamic equilibrium, though it is slightly shifted away from equilibrium compared with unit I. 

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