How to Make Emissions-Free Iron at Temperatures Colder Than Coffee

(Bloomberg) — Sandeep Nijhawan, in his March 2020 meeting with an investor from Breakthrough Energy Ventures, founded by Bill Gates, brought up four business ideas, each addressing rising global temperatures. Fresh from founding two startups – one on hydrogen, one on batteries – Nijhawan only had seven slides to show. The first punch in his deck was making iron with no coal, intense heat, or emissions, powered only by renewable electricity.

“Let me stop you right here,” BEV investor Dave Danielson told him. “If you could do it, I would do it. I don’t want to hear the next three ideas.”

Iron, of course, makes up 98% of the substance of steel, the ubiquitous material that makes up the modern world. In furnaces heated to over 1400°C (2500°F) with coal, the carbon in the coal combines with the oxygen in the iron ore to separate out impurities and unwanted oxygen atoms, releasing large amounts of carbon dioxide.

The iron later goes through a series of steps to be turned into steel, but the iron making step accounts for 90% of the greenhouse gas produced. Steel production is responsible for 7% of the greenhouse gas emissions released into the air each year – more than the climate impact of shipping and aviation combined. Producing iron at lukewarm temperatures and without coal would skip the most emissions-intensive step without resorting to expensive technologies.

That’s why Nijhawan’s idea caught Danielson’s attention: Affordable green steel is a big deal and could disrupt an industry that generates more than $870 billion in revenue every year. With the green light and $2.25 million from BEV and other investors, Nijhawan launched Electra — in stealth mode — to do just that.

You can listen to Nijhawan on Bloomberg Green’s Zero podcast and read the full transcript here. Subscribe to Zero Apple, Spotify, Google and Stitcher.

make electrons work

Stereotypically for a startup, Electra began its experiments in a garage. Nijhawan’s former colleague Quoc Pham joined as chief technology officer. His first task was to find out if it was possible to dissolve iron ore in acidified water.

The outage came within weeks. “I have bad news for you,” Pham said to Nijhawan. “This could be the shortest startup of my life.”

To understand what went wrong, let’s look at three well-known ways you can reduce emissions in steelmaking.

First, capture the emissions generated by the process and bury them deep underground. The first such plant was built in the United Arab Emirates in 2016, but none have been built since then thanks to the upfront cost of carbon capture technology.

Second, use hydrogen as a substitute for coal. The first shipment of steel made with hydrogen was produced last year, but commercial quantities won’t be available until 2026. And since hydrogen from renewable electricity is still more expensive than coal, companies are being forced to use high-quality iron ore, which there isn’t as much of.

“The world is running out of high-quality ores that are available to make steel,” says Nijhawan.

Third, use electricity. Metals like aluminium, copper and zinc are made with electricity – admittedly in much smaller quantities than iron. Until electricity became cheap it was not economical to think of using it for iron production.

However, they cannot conduct electricity through solid iron ore. One solution is to melt it. That’s what Boston Metal Co., a startup founded in 2012, did. Over the last 10 years it has perfected and scaled the technology that works by heating iron ore to 1400°C, using enough electricity to power thousands of homes and concentrating it in a metal box not much larger than a dumpster.

In order to concentrate so much electricity in such a small space, special materials have to be used. Boston Metal can achieve this by using carbon as an electrode – a device that allows energy to flow through it without melting itself – but that too produces carbon dioxide, defeating the purpose of using green electricity. Boston Metal has found an alternative material made from iron and chromium, but so far it has only worked on a pilot scale.

Nijhawan didn’t want to melt anything. Once a process runs at molten metal temperatures, it has to run 24 hours and 365 days. When it stops, the ore solidifies and new casks have to be lined up, causing months of delay. So the process had to be “harmless from a temperature standpoint,” he says — nothing hotter than the temperature at which “coffee is brewed.” That would allow for easy starting and stopping and allow reliance on intermittent renewable energy. But for the process to work at such a low temperature, Pham had to dissolve iron ore in acidified water.

“My pitch to everyone [the investors] was: “Look, I don’t know if that’s possible. I thought the problem through and asked the experts. I think there is a viable way,” says Nijhawan. “All I need is less than 10 people and maybe a year or a year and a half to level this thing.”

He didn’t have to wait that long. Pham returned to the drawing board, reading scientific literature and consulting with experts including Dan Steingart, professor of chemical metallurgy at Columbia University. After weeks of trying new experiments, he found a successful workaround.

Electra now exits stealth mode and refuses to publicly reveal his exact process. However, Nijhawan and Pham shared enough details for independent experts to confirm that what the company claims is technologically feasible.

“Electra was able to perform a difficult conversion of iron oxide to iron using only electricity at such low temperatures,” says Venkat Viswanathan, associate professor at Carnegie Mellon University. “The steps they take trick to be in just the right state.”

A tour of the company’s Colorado facility also shows its progress. There is no coal furnace or molten metal, and laboratory demonstrations show how iron ore might be dissolved. After the electrical process is done, Electra produces office paper sized boards with a thick layer of ferrous metal on top – silvery gray in appearance and surprisingly heavy.

The success of those experiments has helped Electra raise a total of $85 million from BEV, mining giant BHP Group, Singapore-based fund Temasek Holdings, Amazon Inc., and a few other investors. Now all that remains is to scale the technology.

Iron Age, continued

Electra promises to build a facility next year that will have several commercial-size iron plates; a few years later thousands of records are to be produced in a larger factory. With Swedish steel giant SSAB aiming to produce commercial quantities of carbon-free steel by 2026 and Boston Metal pledging to produce zero-emission iron by 2026, the race is officially on.

A full-size commercial Electra plant would be much smaller than conventional steel mills, which can produce 2 million tons of steel per year, cost more than $1 billion, and are so large that entire cities spring up around them. Electra will seek to build facilities that make just 300,000 tons of steel per year, a size that would allow the startup to place itself close to existing electric arc furnaces. These furnaces take scrap steel and recycle it and can also use the iron produced by Electra and tweak the process to add more pig iron than scrap steel.

Another benefit could be locating Electra plants near iron ore mines, which are typically far from urban centers and close to land on which renewable energy can be built. Electra plants could then process ore into iron on-site while removing all impurities, dramatically reducing the volume of material that needs to be transported to a steel mill and further reducing costs.

It may even be Electra’s first commercial application. Using a process for dissolving iron ore, the company has also managed to remove contaminants much more easily than in traditional steelmaking: at lower temperatures, the contaminants do not chemically react like they do in a 1600°C furnace. The world is sitting on billions of tons of low-grade iron ore. It may be possible for Electra to build factories near these mines and make existing operations commercially viable.

“Do or die in a startup is real,” says Nijhawan. “You don’t have 10 years to develop new science. To be honest, instead of having infinite time and resources to see what can be done in other ways, you need to be in that pressure cooker.”

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