So far, Marangoni convection is not satisfactorily explained. This work, completing two previous ones, gives the basic mechanism explanation of this effect. Some typical case studies, where Marangoni convection occurs, are regarded through the light of this new theory. The TPT is further used to model a pseudo-Marangoni cell with an ammonia/water absorption process. Special attention has been paid to apply this theory to the cell gas-liquid interface conditions. All modeling results confirm Marangoni convection basic mechanism explanation, which is general. The work emphasizes that TPT is a powerful tool in refined qualitative/quantitative binary two-phase local interaction analysis. Here, it was essential in finding out Marangoni convection true explanation. (C) 2004 Elsevier Ltd. All rights reserved.