In the section below about checking the results, I have made some corrections to the original post.
The previous post developed the function for the Gibbs Free Energy of the system. This function will be minimized to obtain the equilibrium composition at a given temperature. The temperature will be left as a parameter so we can use the result at any temperature (within reason).
The Mathcad solve block shown below is used for the minimization.
The first check is to see how well the atomic conservation constraint was satisfied.
Next, compare an equilibrium coefficient computed from the equilibrium composition with the Keq previously calculated. [This section was edited. I have used fugacities in the composition calculation of the equilibrium coefficient instead of partial pressures. For this example, there is no change in the result shown because the system is close to ideal.]
The checks were satisfactory. Methane conversion and the hydrogen produced per mole of methane fed were then computed from neq(T). The results are shown below.
The main reaction is endothermic so the equilibrium curve has a positive slope. The hydrogen production has a maximum because the shift reaction reverses above 1100 K.
In the next post, I will use the equilibrium curve to get a partial design of staged adiabatic beds for this system.
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