Technology to extract lithium from oilfield brine adapted for geothermal application

Geothermal plant. Image: Conserve Energy Future

A Vancouver company hoping to pioneer a new process to extract lithium and other elements from oilfield wastewater has tweaked the technology to also apply it to geothermal power projects.

MGX Minerals Inc. said today that engineering partner PurLucid Treatment Solutions Inc. has developed high temperature filtration for the purification of geothermal brines and associated extraction of metals and minerals including lithium, an increasingly sought after commodity thanks to demand for lithium-ion batteries in electric vehicles.

Similar to oilfield brines, geothermal brines contain concentrated amounts of metals and dissolved salts. The presence of these impurities, combined with the necessity to reduce brine temperature in order for traditional filtration to occur, is a large industry barrier known as scaling that severely reduces flow and heat transfer of geothermal heat exchangers.

This in turn negatively impacts the long-term operating performance and in many cases eliminates the economic viability of these systems. Geothermal brines are known to contain lithium, magnesium and other minerals and metals including gold.

After an initial period of research and development, MGX and engineering partner PurLucid have developed a proprietary, low energy design process that removes these scale-forming ions and dissolved salts while not requiring a reduction in brine temperatures for filtration to occur.

The process utilizes PurLucid’s existing patented and exclusively licensed replaceable membrane skin layers (RSL) filtration system, originally developed by David Bromley Engineering, which creates highly charged pore spaces to force dissolved ions into colloidal particles, simultaneously filtered down to 0.01 microns, MGX said in a statement.

The RSL is designed specifically to foul and is removed and replaced in situ, resulting in 100 per cent flux rate recovery. The ultrafiltration can then be followed by a patent-pending membrane distillation system in projects where heat is available.

The matrix is composed of materials capable of operating at up to 700 degrees Celsius. Geothermal temperatures rarely exceed 250 degrees Celsius.

“We believe in investing in technology and innovative processes that disrupt how the energy industry thinks and operates,” Jared Lazerson, MGX president and chief executive officer, said in the statement. “Our newest technological advancement offers yet another first-mover opportunity into a large and often stagnant sector hungry for new ideas.”

The technology also represents an environmentally friendly alternative for geothermal brine disposition, which is largely limited to non-treated reinjection. Similar to MGX’s existing wastewater treatment and rapid petrolithium recovery units, MGX and PurLucid are conducting engineering studies to fabricate treatment systems capable of being integrated into existing geothermal infrastructure or incorporated as standalone systems for mineral and metals extraction, the company said.

MGX currently owns a 34 per cent interest in Purlucid and has the right to acquire 100 per cent through successive future investments. MGX owns the global rights to the minerals extraction technology jointly developed. The intellectual property is patent pending with core water treatment technology covered under a variety of patents and licenses patents.