Two bed SO2 oxidation efficiency

This confirms the efficacy of multibed catalytic oxidation with gas cooling between beds. 

Cooling first catalyst bed exit gas and passing the cooled gas through a second catalyst bed increase SO2 oxidation efficiency from  

Your answer to Problem 14.1 already contains most of the required graph. You only need to calculate the intercept point. 

The equilibrium equation for catalyst bed 2 is the same as for catalyst bed 1 because no gas has been added or removed between beds and because first and second bed equilibrium pressures are the same (1.2 bar). 

Calculate the second catalyst bed intercept point as described in Appendix M. Make sure that you use 685 K for the second catalyst bed gas input temperature. 

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This limitation is overcome industrially by passing T catalyst bed eidt gas through two or more gas cooling/catalytic oxidation steps - bringing SO2 oxidation efficiency up to... 

Fig. 15.1. SO2 oxidation efficiency in two catalyst beds with gas cooling between beds. The 1 bed oxidizes 69.2% of 1 catalyst bed feed SO2 - the 2" bed an additional 25%. Note that the equilibrium curve is exactly the same for both catalyst beds, Section 15.1.1.

The process of SO2 removal on activated coke followed by a simultaneous reduction of NO with ammonia has been successfully applied in industry [176]. Mitsui Mining Process [177] (Table 12) and the Sumitomo Heavy Industry Process [178] are examples of the simultaneous desulphurization and NO removal with the application of moving beds of carbon adsorbents. Apart from the two above mentioned target gases, these processes also exhibit high removal efficiency for heavy metals and dioxins. Removal of NO on activated carbons can also be carried out using two separate processes. As NO2 can be easily removed from gas streams by water, low-temperature oxidation of NO to NO2 on the porous carbon surface is considered as feasible for the removal of NO without the ammonia addition [179]. 

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