A macroscopic modeling of diffusion and chemical reaction in double emulsion systems using the method of volume-averaging is presented. In this three-phase system, chemical reaction takes place in the drops and membrane phases (omega-region) while passive diffusion is considered in the continuous external phase (eta-region). First, a generalized one-equation model, free of the usual length scale constraints, is derived in order to describe the solute transfer in both homogeneous regions and in the omega-eta inter-region. The up-scaling in the omega-region is based in the local mass equilibrium assumption between the two phases. Equations in both homogeneous regions are deduced from the generalized one-equation model. Then, the jump boundary condition at the dividing surface is derived and associated closure problems are established in order to calculate the jump coefficients. (C) 2007 Elsevier B.V. All rights reserved.