Synthesis and design of optimal thermal membrane distillation networks

Thermal membrane distillation is one of the novel separation methods in the process industry. It involves the simultaneous heat and mass transfer through a hydrophobic semipermeable membrane through the use of thermal energy to bring about the separation of a feed mixture into two streams- a permeate and a retentate stream. Traditionally, studies on this technology have focused on the performance of individual modules as a function of material of the membrane and also configuration of the membrane. However, an investigation into the performance of a network of these modules has not been conducted in the past. A hierarchical parametric programming technique for synthesis of an optimal network of these modules is presented. A global mass allocation representation involving sources and sinks was used to solve the problem and derive criteria for optimality in specific regions of the parametric space. Two case studies have been presented to illustrate the applicability of the presented methodology.