Compact and Efficient Membraneless Water Purification

Local water production for troops using standard membrane filtration processes presents a significant logistics burden because of high energy consumption for removing particles based on size-exclusion methods and the constant need to replace fouled membranes. A membraneless filtration method using dissolved CO2 has been demonstrated to separate charged particles through the mechanism of diffusiophoresis. This novel and ultra-low-power technology requires multiple orders of magnitude less pumping energy than standard membrane processes, per unit of water produced, but requires scale up of 50,000 from the 10-channel experiments reported in literature. The filter must also be implemented in a complete, energy efficient system and tested in real-world conditions. Lynntech will investigate scale-up design alternatives, including spiral-wound and stack-based approaches. Additionally, energy efficiency of the complete system is critical, so atmospheric CO2 capture and management methods will be examined for minimizing total system power consumption. A 1000x scale-up prototype is planned for Phase I with the goal of producing ~1 L/day from a filtration cell. Phase II will scale up via duplication of the cellular unit for a minimum 25 L/day production, as required for the individual soldier, and package the filter unit into a complete, standalone prototype system.