[Ric_]

Good morning,
Once again, I will disturb you with my CFD model for a packed bed reactor.

I am implementing a CFD model for a packed bed reactor (PBR) for methanol production and comparing it with the performances predicted by a simpler 2D model.
When I switch the chemical reactions off, the two systems perform basically in an identical way. In this case, the chemical reactor behaves as a sort of heat exchanger, where the inlet mixture is progressively heated up by the medium that surrounds the reactor tube.

Then, when I try to add the chemical reactions to the CFD model, the behaviour of the system is completely different from what is normally expected from a chemical reactor (and from my 2D model). I start by saying that the chemical reactions implemented in the CFD model are correct and identical to the ones I have used in my simplified 2D model (I have checked them many times with the "Evaluate" tab), so the error should not lie there.
More in detail, even if I switch the chemical reactions on but I do not introduce any Energy "Source" in the model, the system undergoes strong increases in the temperature profiles, as if heat were produced by the chemical reactions. Moreover, such heat production is not compatible with the involved reactions, as it is definitely too high (3 / 4 times bigger than expected). Two questions arise at this point:
1) Is CFX capable of predicting the reaction heat once chemical reactions are provided and hence there is no need to specify it? In other words, when I select the material "Sources" option in my subdomain (i.e., species formation / consumption due to the reaction), there is no further need to tell the program the corresponding variation of heat?

2) Even if the answer to the first question is positive, why is CFX predicting such a high value for the reaction heat?

I have attached the file of interest (zip. folder).
Let me thank you in advance for your help.

Have a nice day,
Riccardo