In this work, we used two mathematical models of two phases to study the process of supercritical fluid extraction of a solute present in a porous matrix. The two-phase models were obtained based on the differential mass balance of a linear relationship (Henry's Law) and nonlinear (Langmuir isotherm) to describe the equilibrium state. Considering that the solid phase is composed by small spherical particles, an average process in the radial coordinate of the particle transport equation was used to eliminate the radial dependence of these equations. This average process is based on the technique of Coupled Integral Equations Approach (CIEA). After this average process, we employed the Generalized Integral Transform Technique (GITT) in the resulting PDEs, obtaining a new system of Ordinary Differential Equations (ODEs) in time. The reduced model was solved numerically using the routine IVPAG of IMSL Library. The results were then compared with some available in the literature.