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Exotherm reaction in PFR
Posted 23 sept. 2019, 13:57 UTC−4 Chemical, Chemical Reaction Engineering 1 Reply
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Hi everyone,
I am really new to Comsol and I am trying to model an exotherm reaction in a plug flow reactor: Species A reacts irreversible (first reaction order), the rate reaction is defined as rA=-krcA* where kr=Aexp(-E/(RT)) Since it is a exotherm reaction, the temperature is going to increase as species A reacts, which changes the value of kr. T is described as a differential function vCpdT/dz=(-HkrcA) - ah(T-Tw) So, these two are coupled since cA depends on kr that depends on T and T depends on cA. The wall of the reactor is held constant (adiabatic).
I assume steady state (time independent), cA & T depend just on Z-axis (along the reactor).
I have used "Transport of Diluted Species" to model the change in concentration since I have diffusivity. I have tried to use Global ODEs & DAEs to solve the differential form of the temperature without success.
Does anybody know how to proceed in order to get concentration and temperature profile along the reactor?
Thank you!
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Why don't you use ready made physics? Combine your reaction with heat transfer in fluids.
Lasse