Solar powered membrane-based processes and units for water desalination in tropical areas – MOST

The common laboratory MOST (Solar Powdered membrane-based processes and units for water desalination in tropical areas) relies on creating synergy between a research team of a public laboratory, the Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP: UMR Insa, CNRS, Inra) of Insa Toulouse, and a very small company (VSC), Sunwaterlife (SWL). The research team is experimented on the conventional and innovative membrane processes for sea water desalination and SWL is developing an activity about design and marketing of autonomous small plants for water treatment coupling barometric membrane processes and photovoltaic solar energy. The current market of SWL is the one of small units for treating fresh surface waters, with the aim of their potabilisation, mainly for developing countries. The main issue for SWL is now to develop equipments adapted to sea water desalination, with an acceptable cost for populations of the most remote places and without access to fresh water resources, and this with the lowest possible environmental impact.

MOST aims to:
• acquire original scientific knowledge which will be obtained from experiments and modelling at various scales (from laboratory to industrial prototypes) and from the experimental feedback of various sites of setting-up (presences) of systems of SWL, and thus types of salt waters in tropical zones (North and sub-Saharan Africa, Vietnam). This knowledge will concern the (bio) fouling and its control by strong pretreatment operations, the adaptation of barometric desalination membrane processes to tropical conditions, the optimization of the coupling between solar energy and sea water desalination and on design of an innovative membrane process, which is membrane distillation.
And at the same time:
•support the development of SWL in a new market for her: that of the desalination of sea water or brackish waters by solar-powered autonomous plants, for operation in tropical areas and adapted to a small production capacity (less than 10 m3 / day).

MOST has two complementary objectives:
O1. To improve the current SWL systems, which are based on barometric membrane processes and powered with photovoltaic solar energy, to adapt them for saline resources in tropical areas, to propose sustainable operating conditions for this application, and to develop a tool dedicated to the specific design of these small plants.
O2. To develop an innovative and disruptive technology, with the aim to strengthen the autonomous character of the SWL systems, resting on the expertise of the LISBP on membrane distillation. This will include studying, exploring and making the demonstration of feasibility and the experience feedback of an integrated system based on a coupling between membrane distillation and thermal solar energy.

The scientific approach integrates the selection of commercial membranes and the adaptation of the operating conditions to diverse typologies of saline resources and tropical conditions, the definition of strong, effective pretreatments to prevent membrane biofouling and their adaptation to the tropical conditions, the optimization of the membranes/photovoltaic (cf. O1) or thermal (cf. O2) solar hybrid system and of the process operation, the analysis of prototype operation on various sites and the qualification of their interactions between the quality of the water and their performances, the elaboration of a design and sizing tool, resting on the on-site experimental feedback and on a modelling of the systems that will integrate both mechanistic and statistical knowledges.

MOST will rely on a network of partnership in various countries in tropical areas. This network gathers partners or customers of SWL (local governments, NGO, local companies of the business of the water) and academic partners of the LISBP (University of the Sciences and Technologies of Hanoi, laboratory HILWET (Hanoi International Laboratory on Water for Tropics).