Reactive Flash

Hi all,

I have a few questions about a type of flash column that I never encountered in textbooks: the reactive flash. Let's suppose I have a equilibrium-limited reaction of the type A + B ↔ C + D

Let's imagine we know the equilibrium constant K and the entry molar fractions z_A and z_B as well as the feed flow rate F. Outlet will be composed of A, B, C and D in both liquid (L, x_i molar fraction of each component) and vapour stream (V, y_i molar fraction of each component).

We can suppose - I guess - that the reaction takes places in the liquid phase.

To be honest, I don't really know how I could write the mass balance equation. I would write F = V + L, but I guess I missed a reaction term. How could I write this?

Same with the other equation, F z_i = Lx_i + Vy_i, because otherwise the only solution would be (z_i = 0, x_i = 0, y_i = 0) for all i = A, B, C, D, which is trivial but not the one I accept obviously.

Thanks for your help!