Modeling thin-gap channel flow cells.

A technique is presented for solving the equations describing the current, concentration, and potential distributions in an undivided laminar-flow-channel electrochemical reactor. The equations account for multiple electrochemical reactions, interacting boundary layers, and both axial and normal variations of current, concentration, and potential. Migration is not included in the model. The governing equations are solved using orthogonal collocation extended with an additional set of functions that match the singular behavior near the electrode edges. Thus the method is more accurate than conventional orthogonal collocation, especially for primary and limiting current distributions. Potential distributions calculated by this method show that even for a small aspect ratio (h/L = 0.1), the axial variation of potential is significant.