Chapter 4 Example

Stoichiometric Table – Measures other than Conversion

Let’s again consider the production of ethyl benzene (click back)

The gas feed consists of 25% toluene and 75% ethylene. Write the rate of disappearance of toluene as a function of the molar flow rate. What are the coupled mole balances and rate laws?

Hint 1: What are the relative rates of reaction?  

Hint 2: Write the volumetric flow rate in terms of the molar flow rates  

Hint 3: Write the concentration of toluene and ethylene in terms of the molar flow rates  

Hint 4: Write the rate of disappearance of A, –r_A solely as a function of the molar flow rates  

Hint 5: Write combined rate laws and mole balances in a form to be solved using an ODE solver such as Polymath.

Hint 1.

For relative rates for measures other than conversion, the stoichiometry comes in relating the relative rates.

For this elementary reaction

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Hint 2.

Write the volumetric flow rate in terms of molar flow rates

                                            Isothermal operation and (T = T₀ and P = P₀)

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Hint 3.

In terms of molar flow rates

For a flow system at constant T and P

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Hint 4.

In terms of molar flow rates

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Hint 5.

                                             Use Polymath to solve these coupled ODEs

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