Chapter 5, Problem 5.65P

Hydrogen sul?de has the distinctive unpleasant odor associated with rotten eggs, and it is poisonous. It often must be removed from crude natural gas and is therefore a product of re?ning natural gas. In such instances, the Claus process provides a means of convening H₂S to elemental sulfur.

Consider a feed stream to a Claus process that consists of 10.0 mole% H₂S and 90.0% CO₂. One- third of the stream is sent to a furnace where the H₂S is burned completely with a stoichiometric amount of air fed at 1 atm and 25°C. The combustion reaction is

   ${\text{H}}_{\text{2}}\text{S+}\frac{\text{3}}{\text{2}}{\text{O}}_{\text{2}}\to {\text{SO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}$

The product gases from this reaction are then mixed with the remaining two-thirds of the feed stream and sent to a reactor in which the following reaction goes to completion:

   ${\text{2H}}_{\text{2}}{\text{S+SO}}_{\text{2}}\to 3{\text{S+2H}}_{\text{2}}\text{O}$

The gases leave the reactor at 10.0 m³/min, 320°C, and 205 kPa absolute. Assuming ideal-gas behavior, determine the feed rate of air in kmol/min. Provide a single balanced chemical equation re?ecting the overall process stoichiometry. How much sulfur is produced in kg/min?

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