A fairly linear optimization model for the synthesis of mass exchange networks has been developed. Superstructure, detailed modeling equations, and solutions of example problems are presented. The predominantly linear character of the model can be kept as long as single-component mass exchange network synthesis problems and packed columns as mass exchangers are considered. At the cost of introducing nonlinear constraints, the optimization model can be extended to handle multicomponent problems and staged columns as well. The new model applies the key ideas of the simultaneous heat exchanger network synthesis model of Yee and Grossmann