Question

In catalytic reactor dilute solution of solute A in a solvent S is in fully developed, laminar flow in the region z<0. When it encounters the catalytic wall in the region $0 \leq z \leq L$, solute A is instantaneously and irreversibly rearranged to isomer B. Write diffusion equation and find the solution for short distance into the reactor. Assume that the flow is isothermal and neglected the presence of B.

Answer 1

The flowing liquid will always be very nearly pure solvent S. The product rho*Das can be considered constant, and the diffusion of A in S can be considered by a steady state version of the the continuity equation in terms of molar concentration (equation B.11.2). Note that the presence of a small amount of the reaction product B is ignored.