Looking for lithium in oil field brines is a bit like looking for a needle in a haystack. Yet retrieving this scarce, valuable metal makes sense in a place like Alberta, the heart of Canada’s oil and gas industry.
“Concentrations are low, but there’s a lot of brine out there and a lot of opportunity in western Canada and the U.S.,” says University of Alberta geochemist Daniel Alessi.
Most oil and gas wells in Alberta produce very saline waters, often five to 10 times saltier than the ocean. The brine’s lithium concentrations on the other hand amount to a mere “dusting,” usually between 50 and 150 parts per million.
But Alessi and his former post-doctoral fellow Salman Safari have developed a selective process for separating out lithium in as pure a form as possible, creating a potential source for use in electronic batteries in computers, cellphones and electric cars.
In doing so, they hope to augment the supply of this in-demand metal from hard rock mines and brine pools known as salars, found mostly in South America. Lithium extraction technologies are chemically intensive and slow, producing large volumes of waste. Mining practices can lead to water shortages, which can damage local ecosystems.
“The advantage here is that we already have the infrastructure in place and the brine would normally be a waste product,” says Alessi. “There is a very substantial side stream of lithium revenue that could be generated.”
Alessi and Safari founded a start-up called Recion Technologies to perfect and commercialize their system, which uses metal oxide sorbents to extract lithium from brine.
“The sorbents function as materials that can swap lithium in the brine for hydrogen,” says Safari, the company’s president and chief technology officer. “There is no other effect on the brine.”
There are other methods for retrieving lithium from brine – including solvents and nanofiltration – but metal oxide sorbents result in a purer stream.
“It’s not just about extraction,” says Safari. “The purity of the final product matters because any trace impurities will affect battery performance.”
While sorbent technology is used commercially to retrieve lithium from salars, its use in oil field brines is still at the pilot stage. Recion is looking for industry partners to help it perfect the technology.
Part of the challenge is the chemical instability of metal oxide sorbents. Recion is working on overcoming this, but exactly how is a trade secret. In general, the technology’s efficiency depends not only on the brine’s lithium concentration, but its pH levels and temperature.
One of Recion’s key advantages is that its system is modular, which means it can be transported to oil fields across the province to process brine on-site.
“We are in fact testing brines from all around the world,” says Alessi. “Different brines have different chemistries. We’re not married to one particular extraction technique.”
Roy Eccles, a geologist with Edmonton-based geological consulting firm Apex Geoscience who is not involved in the project, says the key is coming up with an efficient and cost-effective process “in which lithium can be extracted from the waste product steam in real time before it is injected back down into the subsurface reservoir as part of the normal brine recycling process.”
If successfully commercialized, he says it could breathe new life into a waning petroleum industry: “The technology could extend the life of wells, delay abandonment fees and issues, and provide new jobs, opportunities and spinoff industries.”