Molar flow rates summary

The next text box to be made is named txtMHR. Please refer again to Fig. 9.12. This name stands for component mol/h flow rates summary. This text box will be a near duplicate of the previous one, replacing the mole fractions with molar rates. Therefore, make a similar text box, sizing it wider as shown on your screen. Make the following inputs to the respective text box Properties menu ... 

In general, mole fractions are not linear functions of conversion because the total number of moles and the total molar flow rate are not constant when 5 = Vi 7 0. For this particular problem, 5 = —2. In summary, the easiest approach to performing a weighted average of heat capacities of all components in the mixture is to use a mass-fraction-weighted sum of the temperature-averaged specific heat of each pure component. Hence,... 

Connecting two inlet streams and one exit stream double click on the inlet streams and enter temperature, pressure, and molar flow rate of each stream. To run the system, click on Solve ME Balance (the calculator icon) or press F9. Click on Toggle Stream Summary Table in the toolbar. Right click on the empty area in the PFD and click on update data. Select all streams. Results should appear like that shown in Figure 3.6. 

Products The molar flow rate of the product stream S2 is set to 4 kgmol/h. One needs to enable the minimum reflux calculations in the shortcut column to see the minimum number of tray and feed location. Once this option is selected then running the simulation, generates a text report. The required results are under the Summary of Underwood Calculations section in the report as shown in Figure 6.11. The stream property table is shown in Figure 6.12 where exit streams molar flow rate and conditions are obtained. 

Using shortcut method in PRO/II, Peng-Robinson EOS is used as a suitable property package. Process flowsheet and the product streams molar flow rates and compositions are shown in Figure 6.50. The summary of the Underwood calculations is shown in Figure 6.51. The minimum reflux ratio is 1.567, the minimum number of trays is 11 and the actual number of stages is 16 trays. Values are close to hand calculation results. 

In the second method the shortcut column is replaced by a distillation column (Figure 9.7). Click on the distillation column the number of trays is 10 and the feed tray is the fifth tray. Click on Feed and Products and set the initial estimate of the bottom stream flow rate as 10 kmol/h. In the performance specifications, the reflux ratio is specified as 2 and the molar fraction of ethyl chloride in the bottom stream is 0.99. The stream summary is shown in Figure 9.8. 

Hence, 0a = 1, by definition. In summary, aU partial pressures in the rate law should be written as a product of total pressure and mole fraction. Then, mole fractions can be expressed in terms of the conversion of CO. Alternatively, the ideal gas law can be used to express partial pressures p, as QRT, and the conversion dependence of molar density C, is tabulated by Fogler (1999, p. 96) for variable-volume gas-phase flow reactors. It should be emphasized that y, ptotai and CiRT generate the same function of conversion when the s parameter in Fogler s expressions is written as... 

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