A Swiss Army knife platform for critical materials recovery: Why we invested in SiTration
By Eshel Lipman
Founded as a spinoff from research conducted at MIT, SiTration is working to address the demand for critical materials needed to manufacture technologies that are key to the clean energy transition, including electric motors, wind turbines, and batteries. We are excited to join the latest funding round, led by 2150.
Problem: We need sustainably sourced raw materials for the energy transition. A lot of them.
Raw materials are essential for the energy transition because they are the foundation for constructing critical technologies. To build wind turbines, photovoltaic (PV) modules, batteries, electrolysers, electric vehicles (EVs), and the cables that connect them, we need a significant supply of materials such as copper, nickel, lithium, platinum group metals and rare earth metals.
The demand for these materials will increase dramatically as we shift to renewable energy sources and sustainable infrastructure. For example, copper, which is only 0.0068% abundant in the earth’s crust, is a component commonly found in many of the enablers of the energy transition. The annual demand for copper is expected to rise to 36.6 million tonnes by 2031, up from the current demand of about 25 million tonnes. According to McKinsey, the forecast for the supply of copper is only 30.1 million tonnes, resulting in a shortfall of 6.5 million tonnes by the beginning of the next decade, creating a supply crunch. Another example is lithium. To meet the anticipated demand in 2030, 1.42 Mt LCE will be required on top of the 0.75 Mt LCE of existing annual supply and 0.89 Mt LCE from planned and probable projects. This is a substantial growth in lithium demand — more than 3x by 2030 and more than 40x by 2040.
And where will we get all raw materials and critical minerals to meet the world’s seemingly insatiable appetite? As climate-first investors, we are mainly looking in two directions: sustainable mining and metals recycling.
For the mining industry, there is a need for more mines and a more developed supply chain to generate more metals. Mining is a carbon-intensive sector, accounting for 4–7% of the total GHG emissions, so improving the industry’s operations is critical to reducing emissions and its environmental impact. Among recent innovations in the mining industry, we are monitoring soft solutions such as autonomous robots, advanced data analysis for mine operations and tools to trace the origin and carbon footprint of specific materials, and deep-tech solutions addressing directly the primary business (i.e. upgrading the mining process itself). For example, there are unique enzymes that can biologically break down the crystal structure of ores and have the potential to disrupt this industry.
Apart from extracting minerals through optimised mining and refining processes, we also need to utilise the resources that we already have. Recycling represents an alternative pathway to extract valuable materials from end-of-life lithium-ion batteries and manufacturing scrap, with significant importance, especially for countries and geographies lacking resources or established extraction projects (e.g. Europe). From an environmental point of view, battery recycling saves huge amounts of CO2 (among other great benefits of reducing pollution and new mines to be developed).
Recycled raw materials have a CO2 footprint of 8 kg CO2e/kWh relative to 29 kg CO2e/kWh for virgin raw materials, which represents a 72% reduction. Recycling is expected to be profitable, too. By 2025, recycling could yield approximately €550 per tonne of battery material. However, the current recycling process is not as efficient as possible. Current technologies — the most common is hydrometallurgy (see our lithium article that explains more about the sector, and specifically the material recovery techniques) — show significant losses in the process itself. It is inferior due to poor recovery rates, the unnecessary use of toxic solvents, and the poor energy efficiency of the incumbent recycling process. All of this results in uneconomical ways to recover materials from the black mass.
Solution: A technology that efficiently recovers essential raw materials with high energy savings and profits.
This is exactly where SiTration comes into the picture. SiTration’s patented porous silicon membrane technology provides chemical-free, energy-efficient extraction and recycling, reducing greenhouse gas emissions. With their novel technology, developed by Dr Brendan Smith and Prof. Jeffrey Grossman at MIT throughout the last decade, they have crafted a low-cost platform to recover many of the critical metals needed for the energy transition. To be more specific, for each tonne of metal generated with SiTration technology, at least 0.9 tonnes of CO2 in the primary metal process and up to 5 tonnes of CO2 in the tailing valorisation can be saved by reducing the energy required. This can result in a cost reduction of between 20% — 60% in primary metal sourcing and significantly improve the economics of both battery recycling and tailings valorisation.
How does it work? SiTration combines two powerful capabilities: electro-filtration and electro-extraction, to separate and purify target critical materials from harsh and complex feed streams. Electro-filtration utilises a voltage applied to the membrane to amplify filtration performance, enabling both enhanced rejection and selectivity to concentrate target materials in the stream. This can then be recovered in their pure form by the company’s electro-extraction approach. The unique intersection of selectivity and durability offered by the technology allows for little to no pretreatment and minimal resource intensity, thereby slashing environmental impact and cost.
This platform can collect and separate many different metals by simply changing the voltage applied to the membranes. The membrane itself is extremely robust and durable even in the harsh conditions that exist in the leachates and tailing pools of mines around the world.
Those innovative membranes have many use cases in the mining industry. For example, they could work as a replacement for key components used in the primary metal extraction process — heap leaching* — from ores. The same system can also be used for remediation and valorisation of mine tailings (yes, SiTration can turn the waste that can cause so much environmental damage into a profitable business years after the mine is abandoned). Combined, these two market applications — the use of SiTration’s membrane to replace key components in the primary process and mining tailings — represent a market opportunity of over $1 trillion.
Another market application for their technology is the battery recycling industry. Their technology brings a unique approach. If commercialised, they can disrupt existing recycling processes with a unique electro-filtering capability that enables the recycling of lithium from black mass, in addition to cobalt and nickel which is also recovered via SiTration’s process.
SiTration is EPIC: How the carbon maths adds up
Every company which is improving the extraction of metals, either primary or recycled, has the potential to significantly reduce the high emissions of the mining industry. In the case of SiTration, the impact is two-fold: the potential reduction of greenhouse gas emissions and support for the energy transition. Firstly, the expected deployment of their energy-efficient technology in mining and recycling operations can drastically cut millions of tonnes of greenhouse gas (GHG) emissions. This is achieved by enhancing the energy efficiency of both primary metal extraction and the recovery of metals from wastewater streams. Secondly, as critical materials like copper and nickel become scarcer, the metals sourced through improved extraction methods will play a crucial role in advancing technologies that support the energy transition. Each tonne of these metals can contribute to the production of electric vehicles, solar panels, and high-voltage transmission lines, thereby enabling further GHG savings.
We are excited about SiTration as they have a Swiss army knife approach which can address many of the current mining and recycling industry problems, save energy, solve operational burdens and more. We also see a market pull, as several stakeholders in the mining industry are partnering today with the company, and the SiTration team is looking to build an on-site pilot plant soon. Their team has shown strong execution power as they have met all of their milestones ahead of time. In addition to a stellar team, we believe their technology can be used for other applications that haven’t been found yet such as filtration and manufacturing process equipment.
We are excited to be part of the extremely strong syndicate crafted to support SiTration onwards: our friends from 2150, existing pre-seed investors, Azolla Ventures & E14, and two strategic mining-oriented partners from BHP and Orion Industrial Ventures. Altogether, SiTration is well suited now to start the ‘slimy, yet satisfying’ task of making both the mining industry and the battery recycling industry better and greener.
*Side note for curious readers wanting to know a bit more about heap leaching. The heap leaching process is a key step in many metal sourcing processes. SiTration’s system can economically replace the incumbent method, based on SX/EW (Solvent Exchange & Electrowinning).