Seawater desalination by an innovative solar-powered membrane distillation system: the MEDESOL project

This paper deals with the MEDESOL (Seawater Desalination by Innovative Solar-Powered Membrane Distillation System) project, partially supported by the European Commission under the Horizontal Programme "Global Change and Ecosystems (Global 4)". Despite the advantages of solar membrane distillation (MD) systems, very few experimental systems have been developed compared with the mature technologies of solar PV-driven reverse osmosis and solar distillation. The main objective of the MEDESOL project is the development and experimental assessment of the solar multi-stage MD concept in order to develop a high-efficiency and cost-effective system for seawater desalination. EU and developing country scenarios will be analyzed. The layout involves the integration of several membrane distillation modules into a multistage MD system in order to minimize the specific energy consumption. The aim is to develop systems for a capacity range from 0.5 m(3)/d to 50 m(3)/d. Technical simplicity, long maintenance-free operation periods and high-quality fresh water output are the most important aims which will enable successful application of the systems that are based on MD. The heat source will proceed from an advanced compound parabolic solar concentrator, developed for the specific concentration ratio to achieve the specific needed range of temperatures, and the seawater heater will include the development of advanced non-fouling surface coatings to avoid scaling. Laboratory tests under defined testing conditions of all components will permit the preparation of successful field tests under real conditions, to be performed in Spain and Mexico.