Abstract In this paper, a film-model-based description of multicomponent reactive separation is considered and two different approaches to the solution of the reaction–mass transfer problem in the liquid film are studied and compared. The first approach is based on a numerical treatment of the resulting nonlinear boundary value problem. The second approach requires a simplification of the differential transport equation by linearizing its reaction source term, and further, takes advantage of an analytical technique. To realize numerical solution of a complex matrix-form boundary value problem, a special method has been developed and tested. Both approaches have strengths and weaknesses which are analyzed and discussed. For different systems and process conditions, a comparison of simulation results obtained by both methods is carried out.