A study of the performance of a sparged packed bed electrode reactor for the direct electrochemical oxidation of propylene

A non-linear model for the direct electrochemical oxidation of propylene in a new type of reactor — a sparged packed bed electrode reactor (SPBER) is developed. The model consists of a set of second-order ordinary differential equations, which includes a one-dimensional Poisson equation, describing the effect of the electric field on this system, and material balance equations for reactants and products. The model accounts for gas–liquid mass transport, liquid–solid mass transport at the electrode, heterogeneous electrochemical reaction and homogeneous reaction in the bulk solution. The reactant, propylene, undergoes direct oxidation to the epoxide, which undergoes further chemical reaction (saponification), in solution, to the glycol. Numerical solution of this model is used to determine lateral distributions of overpotential, current density and concentrations of products in a SPBER, and to simulate the effects of important operating parameters, such as gas sparging rate and applied overpotential, on these distributions.