Heatup path-equilibrium curve Intercept calculations

6 Heatup Path Equilibrium Curve Intercept Calculation 

All values are per kg-mole of before-H2S04 making catalyst bed feed gas. The matrix shows that a 695 K gas temperature is equivalent to oxidation of 69.3% of the after-H2S04-making catalyst bed s input SO7. Cells D8 to F8 contain -H° values, Eqn. (11.7). Cells G8 to J8 contain H° values. 

12 Matrix resuits per kg-mole of 1 before-H2S04-making feed gas  

This chapter s after-H2S04-making SO2 oxidation intercept is shown in Table 19.2 and Figs. 19.5/19.6. It occurs at 697.3 K with 98.9% of the after-H2S04-making catalyst bed input SO2 oxidized to SO3. 

Temperature, K Heatup path % SO2 oxidized, Equilibrium %S02 oxidized, 

6 Heatup path-equilibrium curve intercept calculation 

Maximum SO2 oxidation in a catalyst bed is obtained where its heatup path intercepts its  

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Appendix J Heatup path-equilibrium curve Intercept calculations... 

Table 12.1 % S02 oxidized-temperature points near heatup path-equilibrium curve intercept. They have been calculated as described in Appendices I and D. They are plotted in Fig. 12.1. and E are defined by Eqns. (10.1) and (10.2).

Fig. 12.4. Effect of pressure on equilibrium curves and heatup path-equilibrium curve intercepts. Equilibrium curves and intercepts are affected by pressure. Heatup paths are not. Intercept temperature and % S02 oxidized both increase slightly with increasing pressure. The intercepts have been calculated as described in Appendix J.

Fig. 17.1. Effect of C02-in-feed-gas on 1st catalyst bed heatup path and heatup path-equilibrium curve intercept. C02 increases heatup path slope and slightly increases intercept (equilibrium) % SO2 oxidized. Section 17.4. Appendix Table R.l describes the 10 volume% C02 intercept calculation.

Fig. 19.5. Equilibrium curve, heatup path and heatup path-equilibrium curve intercept for after-intermediate-FESOj-making catalyst bed. Attainment of equilibrium in the catalyst bed gives 98.9% oxidation of the bed s input S02. The lines apply only to the graph s specified inputs and bed pressure. This graph is a blowup of Fig. 19.6. Its intercept is confirmed by a Goal Seek calculation in Appendix T. The S02 and 02 inputs are equivalent to 0.234 volume% S02 and 7.15 volume% 02.

Table 21.1. Bottom half of Table O.l s 3rd catalyst bed heatup path-equilibrium curve intercept worksheet. Input and output gas enthalpies are shown in rows 43 and 44. Note that they are the same. This is because our heatup path calculations assume no convective, conductive or radiative heat loss during catalytic SO2+V2O2 —> SO3 oxidation, Section 11.9. 1st and 2nd catalyst bed enthalpies are calculated similarly - using Tables J.2 and M.2. 

Catalyst bed gas enthalpies are readily calculated on our heatup path-equilibrium curve intercept worksheets. 

Table J.l. Worksheet for calculating 1st catalyst bed heatup path-equilibrium curve intercept. Preparation instructions are given in Section J.3. Operating instructions are given in Section J.4. Notice that equilibrium curve % S02 oxidized (cell FI 1) heatup path % S02 oxidized (cell 139). So 894.2 K in cells A14 and J30 is not the intercept temperature. The intercept value is calculated in Table J.2. 

Table Q.l is a 1st catalyst bed worksheet for calculating heatup path-equilibrium curve intercepts with S03-in-feed-gas. The worksheet is similar to those in Appendices M and O.

Table R.1 is a worksheet for calculating 1st catalyst bed heatup path-equilibrium curve intercepts with CO and SO in feed gas. It is similar to that in Appendix Q.

Worksheet for Calculating After-Intermediate-H2S04-Making Heatup Path Equilibrium Curve Intercepts... 

Table U.l. Excel worksheet for calculating after-H2S04-making heatup path/equilibrium curve intercept with S03 and CO, in innnt one... 

Table M.l. Worksheei for determining 2" catalyst bed heatup path-equilibrium curve intercept. The non-zero equilibrium curve % SO2 oxidized - heatup path % SO2 oxidized value in cell G47 indicates that cell FI I s suggested 94% SO2 oxidized is not the intercept value. The actual intercept value is calculated in Table M.2. 

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