Recycle, Bypass, and Purge Calculations

A simplified process for the production of SO3 to be used in the manufacture of sulfuric acid is illustrated in the figure. Sulfur is burned with 100% excess air in the burner, but for the reaction S + O2 — SO2, only 90% conversion of the S to SO2 is achieved. In the converter, the conversion of SO2 to SO3 is 95% complete. Calculate the lb of air required per 100 lb of sulfur burned, and the concentration in mole fraction or percent of the exit gas from the burner and from the converter. 

Draw a flow diagram for problems involving recycle, bypass, and purge. 

Apply the 10-step strategy to solve steady-state problems (with and without chemical reaction) involving recycle, and/or bypass, and/or purge streams. 

Solve problems in which a modest number of interconnected units are involved by making appropriate balances. 

Use the overall conversion and single-pass (once-through) conversion concepts to solve recycle problems involving reactors. 

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