A Sliding Vane Energy Recovery Device (ERD) for Photovoltaic-Powered Brackish Water Reverse Osmosis Desalination (PV-BWRO)

How can we recover wasted energy in the brine stream of brackish water reverse osmosis (BWRO) systems to make photovoltaic (PV)-powered units much more affordable for developing countries?

Research Strategy:
(*) Test a new energy recovery device (ERD) made from off-the-shelf sliding vane pumps on a real RO system to measure long-term performance, efficiency, and degradation of the components.
(*) Perform an autopsy of the prototype system in bullet 1 to determine where improved lubrication, friction reduction, filtration, and membrane preservation may be required in real-life RO systems utilizing sliding vane ERDs.
(*) Investigate sliding vane ERD architectures that can reduce friction and improve system efficiency. We have already identified that a balanced vane pump architecture is a promising option, which should balance shaft loads and reduce friction at high operation pressures.
(*) Articulate the parametric design theory for how to create sliding vane ERDs for desalination systems at various size scales and water compositions. This theory will be relevant to desalination engineers who want to design sliding vane ERDs for their specific applications.

Regions around the world that don’t have access to safe or abundant supplies of freshwater often rely on small-scale, decentralized groundwater desalination devices that use reverse osmosis. Unfortunately, these systems are extremely energy intensive, and therefore are both expensive to operate and environmentally unsustainable. This research team is working on a new design for desalination devices for settings such as these that has the potential to make reverse osmosis water treatment more affordable and better able to be powered by renewable energy. He and his research team will focus on affordability, energy efficiency, and ease of use in their design to ensure that the resulting technology is accessible to poor and rural communities around the world.