Mole Balances for Chemical Reactors

1 General Mole Balance Equation. The mole balance equation is applied for individual reaction mixture components. The first decision we have to make is the choice of the system, i.e. reactor space, in which 

The general mole balance equation for a reaction component i at a time t in words is 

If i is a reactant, its consumption can be considered as a negative formation. In terms of the right hand side, we should include all incoming and outgoing streams where the component i is present, as well as all reactions where i participates, being either a reactant or product. 

The above general mole balance equation can be expressed in terms of rates as 

From the above mole balance equation we can develop the design equation for various reactor types. By solving the design equation we can then determine the time required for a batch reactor system or a reactor volume for a continuous flow system to reach a specific conversion of the reactant to products. 

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