Heatup path path point

The following example problem shows how a heatup path point is determined. The problem is ... 

The next step in calculating a heatup path point is to develop steady state molar S, O and N balances for Fig. 11.3 s feed and level L gases. 

An efficient method of calculating heatup path points is to put enthalpy equations directly into cells D8 - J8 of Table 11.2. This is detailed in Appendix I. 

Table 11.3 summarizes % S02 oxidized vs gas temperature as calculated by the above described method. The points are equivalent to the heatup path in Fig. 11.1. As expected, high gas temperatures are equivalent to extensive SO2+I/2O2 —> S03 oxidation and vice versa. 

Table 11.3. Heatup path points for 10 volume% S02, 11 volume% 02, 79 volume% N2, 690 K feed gas. The values are represented graphically in Fig. 11.1.

Table 12.1 shows heatup path and equilibrium curve % S02 oxidized-temperature points near a heatup path-equilibrium curve intercept. They are for ... 

Fig. 12.1. Plot of Table 12.1 heatup path points and equilibrium curve, expanded from Fig. 11.7. Below the equilibrium curve, S02 is being oxidized, gas temperature is increasing and equilibrium is being approached up the heatup path. Maximum (equilibrium) oxidation is attained where the heatup path meets the equilibrium curve.

Now determine the %S02 oxidized - temperature point at which the Problem 11.4 heatup path intercepts the Problem 10.4 equilibrium curve. 

This suggests that you should calculate your equilibrium curve and heatup path points at -904,905.911 K. 

Fig. 13.2. 1st catalyst bed heatup path, equilibrium curve and intercept point, from Fig. 12.1. The 1st catalyst bed s exit gas is its intercept gas, Section 12.12. It is cooled and fed to a 2nd catalyst bed for more S02 oxidation.

Table 14.3. Heatup path points for Fig. 14.2 s 2nd catalyst bed. The points are shown graphically in Fig. 14.3. They have been calculated using matrix Table 14.2 with enthalpy equations in cells H15-K15, Appendix K. An increase in gas temperature from 700 K to 760 K in the 2nd catalyst bed is seen to be equivalent to an increase in % SO oxidized from 69.2% to 89.7%.

Table 15.1. 2nd catalyst bed % S02 ox/d/zed/temperature points near heatup path-equilibrium curve intercept. They have been calculated as described in Appendices K and D. 

Appendix N shows a 3rd catalyst bed heatup path matrix with these equations. It also shows several heatup path points. Figs. 16.3 and 16.4 show the entire heatup path. 

Fig. 18.2. Equilibrium curve and straight lines between Fig. 18. l s calculated points. The straight line heatup paths closely approximate the real heatup paths in Chapters 11 through 17.

Insertion of these equations into Table 11.2 (with 690 K and 820 K in cells F10 and J10) automatically gives the Table 11.2 result, as shown below. The temperatures in cells F10 and J10 can then be changed at will - and new heatup path points automatically calculated. Example results are shown after Table 1.1. Matrix solving is described in Appendix H. 

Table 12.1/Fig. 12,1 heatup path points have also been calculated this way. A few are ...

At his point, equilibrium curve temperature = heatup path temperature. But equilibrium curve % S02 oxidized (cell FI 1) heatup path % S02 oxidized (cell 139). So this is not the intercept. 

Several Table 14.3/Fig. 14,3 heatup path points calculated with the above worksheet are ... 

The table s matrix doesn t have to be re-solved for this or any other calculation. A few other heatup path points are ... 

Chapter 11 heatup path plus Chapter 12 intercept point. 

Problem 13.1 heatup path with intercept point ... 

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