MD MARKET OPPORTUNITIES AND BARRIERS
Initial activities set out to identify and examine the potential markets for MD, and to provide qualitative insights to the consortium on the current technology landscape. The main drivers identified for the adoption of MD technologies are the following:
• Primarily, economic drivers behind brine-mining and resource recovery. MD also has the ability to concentrate brine to almost its saturation point.
• Regulators worldwide are pushing for increased water reuse, improved resource recovery, reduced brine discharge, and stricter discharge quality standards.
• Environmentally and in line with the goals of many global corporate water stewardship programmes, the use of MD to improve process water efficiency can significantly reduce freshwater demand.
• Lithium extraction and acid recovery are the two markets that showed the most promising potential for wastewater mining applications of MD.
Barriers include strong competition, limited commercial track record, and concerns about scalability and energy demand. To overcome these obstacles, the project advanced membrane materials, multi-scale optimisation tools, and high-performance MD demonstrators powered by renewable energy.
To address these technical issues, innovation activities have been performed to develop novel sustainable membranes, to optimize the MD system via multi-scale models, and to integrate the membrane and module components in high-performance MD demonstrators supplied with renewable energy.
SUSTAINABLE MEMBRANES
The core technical research of the first reporting period focused on producing membranes with high hydrophobicity, chemical resistance, and long life, for use in membrane distillation. Research focused on hydrophobic, chemically resistant, long-life membranes manufactured with non-toxic solvents. PVDF membranes were modified to enhance performance and produced as flat-sheet and hollow-fibre formats suitable for sustainable large-scale production. Testing with synthetic and real wastewaters identified strengths and limitations, guiding improvements in membrane formulation, module fabrication, and system design.
MODULE AND SYSTEM MODELING AND OPTIMISATON
A series of modeling tools were developed and adopted to understand and optimize membrane, module, and system performance at different scales. The project established a complete scientific and engineering basis to optimise membrane-distillation technologies across multiple prototype configurations. Simulations and experiments identified optimal layouts, flow regimes, spacer designs, and solar-absorption strategies. Hollow-fibre, air-gap, and vacuum configurations were optimised, and energy-integration studies defined efficient heat-pump coupling, heat-recovery layouts, and solar-driven operating windows. A unified digital-control framework enabled autonomous operation, remote monitoring, and model-based optimisation across all prototypes.
MODULE AND SYSTEM DESIGN AND CONSTRUCTION
Designs of the four prototypes were finalised with the aim of customizing the systems for each of the four specific applications. In particular, different configurations were designed and installed. The first is a hollow-fibre DCMD system using waste heat at Athenian Brewery. The second is a solar-powered flat-sheet VMD system with integrated PV-heat-pump operation for industrial wastewater in Girona. The third is a solar-assisted AGMD desalination pilot combining bulk and direct solar heating to produce 50–100 L/day. The fourth is a compact AGMD emergency-water kit, fully solar-driven, producing 1–10 L/day with simple, robust operation.
