Modeling Surface Reaction (CVD) on ANSYS Fluent

AI Thread Summary
The discussion revolves around modeling a surface reaction in Ansys Fluent for a CVD reactor to grow solid carbon from methane. The user is confused about setting up the mixture and reaction parameters, specifically regarding the definitions of 'site' and 'solid' species, as well as how to manage the reaction mechanisms. They seek guidance on how to model the adsorption process and whether additional reactions are necessary to prevent hydrogen generation once the surface is saturated with carbon. The user is looking for basic steps to initiate their modeling efforts despite acknowledging that the process may involve more complexity than initially anticipated. Overall, they are seeking foundational advice to navigate the challenges of their simulation setup.
grapheeene
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Hi guys,

First of all, thank you for your help. I am new in Ansys and Fluent (less than a month), hoping to learn.

I am trying to model a simple and single surface reaction

CH4 (g) -> C(s) + 2H2 (g)

on a "CVD reactor" to grow C(s) (graphene, or graphite). The inlets are gases inyections of Ar and CH4 at the top of the CVD, and two thin parallel Cu surfaces are in the center (the catalyst), where C would be deposited. I am trying to model the growth of C(s) and the amount of H2 on the entire region, with and without thermodifussion (Soret).

The question is that I have some trouble with setting up the mixture and the reaction. I have a confusion with 'site' and 'solid' species in this case, and with reactions and mechanisms (since it's only superficial). I need the system to stop generating H2 when the surface is full of C(s).

Can you guys give me some basic steps to start this?? I don't know how to get the adsorption done. Do I need another reaction??

I guess this problem is not hard to be solved. Thanks so much for your help!
 
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grapheeene said:
I am trying to model a simple and single surface reaction

CH4 (g) -> C(s) + 2H2 (g)
I don't believe the process is that simple. From what I've seen in the literature, the process may be more like:

CH4 (g) -> CH2 (g) + H2 (g)

CH2 (g) -> C(s) + H2 (g)
 
It is even more detailed (20 reactions or more), but I want to compute a single reaction, and I don't know which reactions to write and what 'site' and 'solid' species to create, in order to get the model done.
 
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