Based on the method of direct statistical simulation, a physical-mathematical model has been developed for gas mixture mass transfer in st highly porous body under the conditions of condensation of one of the components and trapping of a non-condensable admixture. Distributions of gas velocities and densities in a porous layer and in the space above it are found, as well as distributions of flows of a condensable component and absorbable admixture along the depth of the porous layer. The efficiencies of the absorption of the admixture in a porous layer and on a plane surface are compared.