Gaseous. Variable-Volume Batch Reactors

The variation of the reactor volume with the reaction extent is given by Eq. 6.1.14. For isothermal-isobaric operations with single reactions, and when the initial state is selected as the reference, Eq. 6.1.14 reduces to 

Equation 6.2.22 is solved subject to the initial condition Z(0) = 0. When r depends only on Z, we can obtain analytical solutions by separating the variables and integrating  

To solve the design equation, we have to express the reaction rate r in terms of Z and, to do so we relate the species concentrations to the dimensionless extent From Eq. 6.1.11, for isothermal operations with single reactions, and when the reference state is the initial state  

Note that, when A 0, the species concentrations are not proportional to the reaction extent. To determine Z(t) when Q(t) is given, we rearrange Eq. 6.2.25, 

we analyze the operation of variable-volume, gaseous batch reactors and describe how to apply the design equation for different cases. 

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We continue the analysis of gaseous, variable-volume batch reactors and consider now chemical reactions with two reactants of the general form... 

The design equation for gaseous variable-volume batch reactors was derived under two assumptions (i) AU the species are gaseous, and (ii) the mixture behaves as an ideal gas. In some operations, one or more of the species (especially heavier products generated by the reaction) may be saturated vapor. In this case, any additional amount generated will be in a condensed phase (liquid). While the ideal gas relation provides a reasonable approximation for the volume of species in the vapor phase, it cannot be applied for dieir volume in the liquid phase. Below, we modify the design equations for a variable-volume batch reactor with saturated vapors. 

Discussed the operation of gaseous, variable-volume batch reactors. 

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