German lithium supply may be in hot water
Scientists find way to extract battery metal from geothermal Metal Tech News Weekly Edition – July 15, 2020
Last updated 8/5/2020 at 5:09am
Scientists at Karlsruhe Institute of Technology (KIT) in Germany have developed a patent-pending process for what may be a cost-effective and environmentally friendly way to extract lithium from the geothermal waters on the German and French sides of the Upper Rhine Trench.
Lithium, a key ingredient in the batteries powering electric vehicles, renewable energy storage and a plethora of rechargeable electric devises. This battery metal is primarily recovered from South American brines, salt rich waters with lithium in them, or Australian spodumene, a hard rock mineral.
KIT said the process to recover lithium from the deep geothermal waters of the Upper Rhine hold several environmental advantages over mining South American salt lakes or Australian hard rock.
The KIT scientists point out that the existing geothermal power plants in the Upper Rhine already pump roughly 2 billion liters (528 million gallons) of lithium-rich water per year.
"As far as we know, there can be up to 200 milligrams per liter," says Dr. Jens Grimmer, a geoscientist from the Institute of Applied Geosciences at KIT: "If we consistently use this potential, we could cover a considerable part of the demand in Germany."
This rich lithium resource has yet to be tapped due to the lack of a suitable process to pull out the lithium in a cost-effective, environmentally friendly, and sustainable manner.
Using water already being brought to the surface by geothermal plants in the Upper Rhine Trench, the KIT scientists have developed a two-step process for pulling the lithium out of the briny hot waters.
"In a first step, the lithium ions are filtered out of the thermal water and in a second step, they are further concentrated until lithium can be precipitated as a salt," says Grimmer.
Known as the Grimmer-Saravia process, this lithium extraction method does not require the large land usage of classic lithium mining methods.
The current method of extracting lithium from South American salt lakes involves pumping lithium-rich brine water into large ponds and letting natures forces evaporate off the water. This takes up a lot of space and is highly weather-dependent – heavy rainfall can set back production there by weeks or even months.
The KIT researchers say the Grimmer-Saravia process can begin continuously to extract lithium from the brines passing through geothermal plants in a matter of hours and pumps the water, minus the lithium and other minerals extracted back down into the reservoir where the water originated.
Since the process can use the technical and energetic infrastructure of a geothermal plant, its carbon dioxide balance also stands out very positively when compared to the traditional lithium mining methods
"We export many environmental problems to third countries in order to maintain and improve our living standards. With this process, we can assume our responsibility and extract important raw materials for modern technologies in an environmentally friendly way right on our own doorstep," says Florencia Saravia, Grimmer's research colleague and co-founder of the process. "We can also build up regional value chains, create jobs, and reduce geopolitical dependencies at the same time."
Utilizing an existing geothermal plant in the Upper Rhine Trench, the two scientists are now ready to put their process to the test with a prototype facility that will extract several kilograms of lithium carbonate or lithium hydroxide.
If the initial tests are a success, the construction of a large-scale plant is planned. It would then be possible to produce several hundred tons of lithium hydroxide per year at each geothermal plant.
According to current data, the potential in the Upper Rhine Trench on the German and French sides amounts to several thousand tons of recoverable lithium per year.
"If we consistently use this potential, we could cover a considerable part of the demand in Germany," said Grimmer.
This demand is growing rapidly due to the ambitious electrification goals of German automakers.
Mercedes-Benz aims to have a carbon-neutral new passenger car fleet by 2039, with an intermediate goal of having plug-in hybrids or all-electric vehicles to make up more than 50% of its car sales by 2030.
More information on Mercedes-Benz's "Ambition 2039" goals can be read at Mercedes-Benz buys into EV batteries in the July 9 edition of Metal Tech News.
By 2023, BMW Group aims to have 25 electrified models in its line-up – more than half of them fully-electric.
Further details on BMW's EV plans and its efforts to source battery metals can be read at BMW sources sustainable Moroccan cobalt in the current edition of Metal Tech News.
Germany currently gets most of its lithium from Chile, Argentina, and Australia, which account for more than 80% of global production.