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Performance Equations in CRE

The performance or design equation is nothing more than a mole balance on one of the species participating in the reaction.

Performance Equation:

Output = f [input, kinetics, contacting]

Take some time to revise your notes and knowledge of Chemical Reactor Design. Especially focus on the key concepts related to the performance equation or design equation of a CSTR and a PFR.

The performance equations or design equations are nothing more than mathematical equations (consisting of mole, energy, and momentum balances) that are used to model chemical reactors. The performance equation relates an input to output for various kinetics and flow patterns. It helps us predict what a reactor can do. Here is a summary of the two main performance equations in CRE.

Ideal Continues Stirred Tank Reactor (CSTR)

Ideal Plug-flow (PFR)

All the molecules leaving the reactor have been inside it for exactly the same amount of time.

Performance Equations in CRE

Examples of Performance Equations

Consider the elementary reaction of A to B with kinetics:
rA = kCA0 (1-x ) [this is a first order type of reaction]
and k = 0.1 min -1
cA0 = 1 mol /L
FA0 = 3 mol /min
What is the volume of a CSTR for 50% conversion?