Boundary Element Method for Solution of Dispersion Models for Packed Bed Reactors

Simulation of heterogeneous models for a packed reactor is a numerically challenging problem due to highly nonlinear coupling of transport, reaction, and the exponential temperature dependence of the rate constants. A system of differential algebraic equations is needed to model the problem. In this paper, the use of the boundary element methods for the numerical solution of the problem is demonstrated. It is shown that integral formulation of the model can be obtained by the elimination of the diffusion-convection operator part of the differential equations by using adjoint formulation. The resulting set of integrals are solved after approximating the dependent variables in each element by a cubic (Hermite) osculation. The efficiency of the method has been demonstrated for a simple exothermic reaction for both pseudo-homogeneous and heterogeneous models, with and without solid-phase conduction.