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 ultimately 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 proposed Phase I effort, the focus will be 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 by the end of the Phase I program. However, the proposed approaches offer the potential to significantly drive the cost well below this level. Three advanced manufacturing strategies focusing on fabrication automation, standardization of the membrane packaged, and optimization surface properties will be pursued in Phase I. Large surface area membrane packages produced in Phase I will be challenge tested under extreme conditions to demonstrate performance and mechanical stability. The results will inform the program technical approach in the Phase II fabrication scaleup and field demonstration testing. 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 waste water, solvent, and oil recovery where no polymeric membranes are available.