Gas separation under complete mixing conditions

1 Gas separation under complete mixing conditions Complete mixing implies that the concentrations at the feed side are constant at each point in the module and are equal to the retentate concentrations. Also at the permeate side the concentrations are the same at any point (see figure vni - 33) 

Gas separation with perfect mixing at feed side and permeate side 

The recovery has been defined as the fraction of the feed that has permeated through the membrane (In gas separations often the term cut or stage cut is used instead of recovery). 

Dividing eq. Vin - 38 by qf gives for the permeate concentration the following equation 

The equatioa describing the flux of a gas i through a membrane assuming perfect mixing can be written as 

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