A Ceramic Membrane Based Micro-/Ultra-filtration Subsystem as Pre-treatment to Insure Stable and Economical Operation of An RO System for Desalination

The global desalination market for RO based membrane technology exceeds $12 billion per year. Due to tremendous advances in RO membrane materials and module design in the past 20 years, the technology has reached a productivity plateau in which further development will have far more muted impact on system capital and operating costs. As a result, the focus is shifting to the feed water pretreatment subsystems. Micro- or ultrafiltration (MF/UF) of the feedwater thus far has been recognized as one of the most reliable and environmentally friendly pretreatment methods. Although polymeric membranes dominate this sector due to their low cost, reasonable productivity, standardized package design, and ease of replacement, like RO membranes, the technology has reached a productivity plateau after decades of development. Ceramic membranes offer a range of performance advantages over polymeric competitors that make them a superior materials choice for long term performance and mechanical stability. However, sticker shock, coupled with poor standardization in element design, remain the primary barriers to their penetration into the RO pretreatment market and the broader MF/UF water treatment market. Overcoming these problems remains a significant challenge. Still, in comparison to highly optimized polymeric membrane fabrication and operation, there are a number of areas uniquely available to ceramic membrane technology where advanced manufacturing can be introduced to dramatically reduce fabrication cost, improve productivity, and deliver a cost competitive product. If these goals can be achieved, ceramic membranes will stand alone as the next generation technology for RO pretreatment. In this SBIR program, the focus is to develop advanced manufacturing approaches in three specifically identified areas that reduce the cost of fabrication and increase operational performance and stability of ceramic membrane technology. The preliminary cost target is to reach parity with competing polymeric MF/UF membranes. However, the proposed approaches offer the potential to significantly drive the cost well below this level. Overall, in the Phase I program, we have demonstrated breakthroughs/first of its kind developments in an advanced ceramic membrane fabrication technology, an updated UF/MF industry standardized bundle configuration, and a superhydrophilic fouling resistant coating. Combined these new advances deliver dramatic savings in ceramic membrane cost, making them directly competitive with conventional state of the art polymeric membranes in RO pretreatment and a wide range of additional UF/MF membrane applications. In this proposed Phase II program, the primary focus will be to continue development of a low-cost ceramic membrane product that can compete directly with polymeric MF/UF membranes on an upfront cost basis in RO pretreatment and other water/wastewater applications. As in the Phase I program, the focus in the Phase II program will be on continued development in three critical areas, namely, (i) advanced manufacturing methods to directly reduce membrane fabrication cost, (ii) standardization of the membrane bundle for “drop-in” capability in industry standard Codeline vessels, and (iii) highly fouling resistant superhydrophilic membranes for increased membrane productivity. The focus will be on pilot and field test demonstration of these new membrane developments to validate mechanical and performance stability in actual water and wastewater treatment with our industrial participant. A range of significant existing market opportunities exist for a low-cost high productivity ceramic ultrafiltration membrane technology. Although the RO pretreatment market is substantial, ultrafiltration is much more broadly used in a wide range of non-desalination applications. Further, due to its durability, reliability, and productivity, a low-cost ceramic membrane technology would open doors to broader acceptance and penetration of MF/UF membranes into much more challenging applications in for instance aggressive wastewater, solvent, and oil recovery where no polymeric membranes are available.