Cleantech startup develops platform technology for environmentally friendly, resource-saving metal production.
Das Cleantech-Startup Boston Metal develops a clean technology for the production of steel. If the global steel industry were one country, Steel Republic would be the third largest emitter of greenhouse gases behind China and the US. The company, which was spun off from MIT, replaces coal or coke with electricity – and intends to use it to produce steel in an electrolysis process analogous to aluminum production.
The global demand for steel is breathtaking. needed the world in 1950 still 189 million tons, this increased demand to date to more than 1.8 billion tons, i.e. around Factor 10. If Steel Republic were a country, it would be the third largest emitter of greenhouse gases to China and the USA – today industry is responsible for eight to nine percent of global CO2 emissions.
But this is by no means the end of the development: by 2040, a further doubling to 3.7 billion tons is expected.
For decades, the steel industry in Europe was convinced of a technology path that is extremely complex and quite energy-intensive. The biggest snag here: In the process, coal or coke is heated in order to “steal” the oxygen from the iron ore with the resulting carbon monoxide. The graphic above clearly shows the complex manufacturing process of steel.
But this docking of an oxygen molecule with carbon monoxide produces large amounts of the greenhouse gas carbon dioxide, most of which is released into the atmosphere. One option that ThyssenKrupp is pursuing, for example, would be to filter out and bind or store the carbon dioxide before it is released into the atmosphere. But that doesn’t make a process that is already difficult to do economically any more economical.
Alternative: hydrogen instead of carbon
The European steel industry in particular is therefore looking for alternatives: Salzgitter Flachstahl, for example, has described a process with the SALCOS project in which carbon is replaced by hydrogen. Supple regarding it: Instead of carbon dioxide, water is produced as a by-product.
The problem: Salzgitter alone needs electrolysers with an output of 960 megawatts – and green electricity from wind turbines that goes with it. If you think regarding it further, the steel industry alone needs several thousand wind turbines at sea that deliver continuous output and can thus supply electrolysers accordingly. The project is conceivable, but costly and energy-intensive.
Another difficulty is that electrolysers today require a relatively continuous supply of energy – which makes it more realistic today to set up such electrolysers on the coast or directly docked at offshore wind farms than distributed in a decentralized manner near a steel mill. Ultimately, this requirement does not make the overall project any easier.
Boston Metal relies on iron oxide electrolysis
Cleantech startup Boston Metal believes it can find a different way to produce steel. The technology developed by Boston Metal is a type of electrolysis – they call it Molten Oxide Electrolysis. The core technology was developed at the Massachusetts Institute of Technology. Specifically, in Professor Donald Sadoway’s lab.
The communicative scientist and his students proved that a variety of metals, including steel, can be produced in molten oxide electrolysis (on a laboratory scale). This is how the co-founders Prof. Antoine Allanore and Dr. Jim Yurko founded the cleantech company Boston Metal in 2012.
Since then, the team has managed to scale the lab-proven process by a factor of 1,000. The company is now managed by Tadeo Carneiro, the former CEO of the world’s largest niobium manufacturer CBMM. The team is working on extending its own platform technology to different areas – and, for example, also producing metals from the rare earth category.
Technology in detail: from iron oxide to steel
The idea of producing liquid metal using an electrolysis process came regarding by chance. Because Sadoway was originally commissioned by NASA to develop a process with which oxygen can be produced on the moon. The tests with the molten oxide electrolysis turned out that liquid metal is produced as a by-product – on earth, of course, much more valuable than oxygen.
The graphic shows how the technology works: There is an anode at the top. The cathode forms a thin layer of metal at the bottom. The positive and negative electrodes work together—similar to a pump driving electrodes through the electrolyte into the chamber. The electrolyte is a mixture of metallic minerals and other oxides.
If electrical voltage heats up the mixture, oxygen freed from the iron rises in small bubbles. The resulting metal collects on the ground. If you open the flap on the front of the reactor, molten metal flows out of the cell.
A very similar process is also used in aluminum production – but at significantly lower temperatures. 1,550 degrees Celsius are required to obtain pig iron – a temperature that is far too high for many conventional materials.
Shortly before forming Boston Metal, the Sadoway team made a breakthrough when they found a suitable material for the reactor’s anode: an inexpensive alloy of chromium and iron that might withstand these temperatures. “That was the breakthrough that really fueled Boston Metal,” says Sadoway in retrospect.
Boston Metal: Revolutionizing Steelmaking?
And that breakthrough might lead to a steelmaking revolution in five to 10 years. The graphic from a Sadoway presentation explains why the process is cheaper than previous production methods:
According to Boston Metal, the electrolysis technology is modular, ie no investments in the billions associated with classic steel production are required in order to be able to start production. And the energy consumption is also an advantage: The company expects 25 percent lower costs – very different from the alternative route with hydrogen.
Boston Metal is now funded by high profile investors such as Breakthrough Energy Ventures, OGCI Climate Investments, Prelude Ventures and The Engine (MIT). However, the team still has a long way to go before it is ready for commercial use: CEO Tadeo Carneiro expects a large demonstration plant in five years. The first technology for the production of ferroalloys should be ready for the market much earlier.
Steel production is one of the largest industrial emitters of greenhouse gases worldwide, causing around eight percent of total GHG emissions. With its unique fused oxide electrolysis technology, Boston Metal has the potential to decarbonize the massive steel fabrication industry and economically deliver a range of high quality products on a global scale.
Carmichael Roberts von Breakthrough Energy Ventures
While Boston Metal hardly draws attention to itself in a blatant manner, but seriously promotes its own platform technology, awards cannot be dismissed out of hand. At the beginning of the year, the company was included in the Cleantech Group’s Cleantech 100 list for the first time – and just a few days ago it was recognized as a Tech Pioneer by Bloomberg New Energy Finance.
