In this work, a numerical simulation is presented to study the recovery of volatile organic compounds by condensation (mixture of alcohol vapors), particularly n-butanol-propanol, in the presence of noncondensable gas (air) along a vertical tube with wall cooled by airflow. The model adopted is two-dimensional on the two-phase boundary layer equations and considers inertia terms and shear stresses at the liquid–vapor interface. The numerical problem was solved by using an implicit finite difference method. The calculation carried out made it possible to determine the tube, outlet vapor mass fraction, Nusselt number, film liquid thickness, and condensation rate.