The goal of this paper was to create a non-equilibrium model of a reactive distillation column with very fast homogeneous reaction in the liquid phase. When very fast homogeneous reactions proceed in the liquid film and in the bulk liquid phase, a reaction-diffusion model based on the Fick's equation can be used. Within each iteration of the bulk MESH equations solution, the boundary value problem (reaction and diffusion in the liquid film) had to be solved using automatically adjusted discretization grid for the spatial derivatives discretization. The algorithm proved to be a robust tool for modeling both reactive distillation and absorption, mainly in case of the column performance optimization or in safety analysis, when numerical stability of the solution and algorithm robustness are required not to fail when the column parameters and performance conditions are changed in a wide range. (C) 2009 Elsevier B.V. All rights reserved