Improvement of the Membrane Distillation performance through the integration of different configurations

In this work, the integration of two Membrane Distillation (MD) configurations was investigated as possible means to reduce the specific thermal energy consumption. Tests of Direct Contact Membrane Distillation (DCMD) and Air Gap Membrane Distillation (AGMD) were carried out on 40 cm2 lab-scale modules equipped with a commercial flat polypropylene membrane of 0.2 μm, by sending distilled water as feed. The performance of integrated schemes with the feed exiting from the DCMD module sent as coolant stream in the AGMD module - where it is heated by the permeating vapor, before being recycled back to the DCMD unit - was analyzed. When compared to the single DCMD units, the integrated DCMD-AGMD systems led to lower specific thermal energy consumption, as well as higher Gained Output Ratio (GOR) and permeate production.