Ocean Wave Powered Reverse Osmosis Desalination

Background

• 70% of earth’s surface is covered by water by only 1% of this water is drinkable;

• Over 80% of the world’s population lives in coastal zones;

• Nearly all desalination plants are powered by fossil fuels, which adds a carbon footprint and is thus not sustainable .

• In the USA, the amount of technical available wave energy is equivalent to 34% of the yearly electricity generation.

Innovation

• A novel ocean wave powered reverse osmosis desalination system is introduced;

• A double-acting piston pump is adopted to convert bidirectional motion into unidirectional fluid motion;

• Accumulator and needle valve are used to reduce pressure fluctuation and tune the water recovery ratio based on sea states.

Approach

• Energy-water nexus has been investigated considering energy flow and water flow.

• Numerical modeling has been created to predict the system performance and optimize parameters.

• A 1:10 scaled model has been designed, fabricated and tested based on the Froude scaling law;

• An integrated system demonstration in wave tank is presented and investigated.

Achievement

• The role of key component tuning on performance is experimentally quantified.

• Performance in a real application scenario is predicted via pilot demonstration.

• Pilot experiment results reveal an optimal specific energy consumption of 4.48 kWh per 𝒎^𝟑 of freshwater.