• 01 October 2021

Ailbhe Goodbody

Ailbhe Goodbody

Salinity Solutions, a new spinout company from the University of Birmingham in the UK, is beginning industry field testing of a compact, energy-efficient desalination system that is designed to concentrate the salts in groundwater to extract a mineral-rich brine.

Eco-technology company Cornish Lithium has partnered with Salinity Solutions for the field tests, and has secured agreements with the owners of mineral rights over a large area of the county of Cornwall for the trials.

Salinity Solutions plans to launch a crowd-funding campaign later this month to fund the first field trial at Cornish Lithium’s site in Redruth, Cornwall, by early 2022.

The global demand for lithium is rapidly escalating, as it is used in electric car batteries and static storage devices for electricity. Salinity Solutions noted that lithium is vital to the UK’s industrial strategy as it moves towards a zero-carbon future, but that the country has no indigenous source of this mineral.

The technology for Salinity Solutions’ desalination system is the result of more than 10 years of research by Philip Davies, professor of water technology at the University of Birmingham’s School of Engineering. It was adapted from an established technique called batch reverse osmosis, which separates water from ions and molecules using a partially permeable membrane. 

Professor Davies re-engineered reverse osmosis to produce a system that approaches the theoretical limits for energy efficiency and brine recovery, and then built five prototypes in laboratories at the University of Birmingham and Aston University.

The first application of the technology aims to reduce the high carbon footprint of lithium extraction and help to create a cleaner, more efficient way to fuel the demand for electric vehicle batteries. Salinity Solutions said that the brine concentration technology has two significant advantages: it “achieves the maximum yield of any known available system” and is up to 50% more efficient than traditional reverse osmosis systems, with a 50% smaller footprint.

The company added: “It promises a new, commercially viable, cleaner solution that can be deployed even off-grid.”

The University of Birmingham initially patented the technology in 2018, and licensed it to the newly formed spinout company earlier this year. The technology will soon be tested in four field trials over three continents.

The first automated prototype was built by Tim Naughton, who is now technical director of Salinity Solutions. He approached engineering veteran Richard Bruges, who founded the UK-based engineering, manufacturing and assembly organisation The Proving Factory and the venture engineering company Clean Engineering.

Clean Engineering is now backing Salinity Solutions, providing investment and a structured product development process. In addition, Bruges has become a director of Salinity Solutions.

Salinity Solutions is “quietly confident” that the unit it supplied to Cornish Lithium will pass the rigours of on-site testing in Redruth.

Naughton commented: “The unit we supply to Cornish Lithium has been designed to withstand the elements. We’ve simulated real-world conditions in the laboratory using feed water supplied by Cornish Lithium, and the system is reacting as expected and to the efficiencies predicted by our algorithms.”

Dr Rebecca Paisley, exploration geochemist at Cornish Lithium, said: “We are actively engaging with companies developing innovative, extraction technologies that are energy efficient, with a small footprint, and capable of processing the unique geothermal waters found in Cornwall. The technology being developed by Salinity Solutions meets our criteria and we look forward to testing their pilot system at our geothermal water research site to potentially aid in the production of lithium salts.”

Davies was recently elected to board of directors of the European Desalination Society. He is continuing his water purification research, and is currently working in Germany to develop a system that works at higher pressure and delivers more concentrated brine. Salinity Solutions has secured the intellectual property rights to innovations that result from this research.

He also has funding for further field trials in agricultural and industrial settings, and collaboration with commercial companies to evaluate cost and environmental benefits that are additional to reduced energy consumption compared to traditional reverse osmosis.

University of Birmingham Enterprise helps its researchers turn their ideas into new services, products and enterprises that meet real-world needs. Earlier this week, the Rare Earth Extraction from Audio Products (REAP) project, another project supported by the university that aims to demonstrate a potential domestic sources of recycled rare earths in the UK, was completed.