Helios: Here's how creating oxygen on the Moon forged a recipe for iron – without CO2

"If a renewable energy source is used, the whole process is 100 percent carbon emissions-free."
Sade Agard
An experiment setup for green iron making
An experiment setup for green iron making

Courtesy of Elad Geffen  

  • The iron and steel industry is responsible for about 7 percent of global energy-related carbon emissions.
  • Whilst in pursuit of lunar oxygen, a company stumbled upon a recipe for net-zero iron manufacturing.
  • An interview reveals plans for a pilot plant in collaboration with steel manufacturers that will produce tons of green steel per day.

Imagine a world where iron production no longer contributes to carbon emissions. It might seem like a distant dream, considering that the iron and steel industry was responsible for 2.8 gigatons (Gt) of CO2 emissions in 2019, representing around 7 percent of global energy-related carbon emissions. 

What's more, the demand for iron, predominantly in the form of steel, will only keep growing with the world's population and economic development. That said, the reality is that steelmakers must reduce their emissions by 30 percent by 2030 to align the industry toward the net-zero Paris Agreement. 

And positively speaking, where there's a challenge, there's also an opportunity – which is where a company called Helios enters the picture. Using their innovative method called "The Helios Cycle," the scientists behind it claim to be making net-zero iron manufacturing possible. What's also intriguing is that their discovery was stumbled upon in the quest for oxygen on the Moon. 

Interesting Engineering (IE) interviewed Heliosdesign lead, Elad Geffen, to take a closer look at this development and its potential future uses. 

The Helios Cycle: From lunar soil to green iron manufacturing

"In order to extract the oxygen out of the lunar soil, we used a method called 'molten regolith electrolysis,' Geffen told IE. "This method separates the oxygen from the metals in the soil." 

Helios: Here's how creating oxygen on the Moon forged a recipe for iron – without CO2
Helios' setup for molten regolith electrolysis

He explained that after running the experiments, his team noticed they got significantly purer iron than expected. 

After a closer inspection, they then realized that one of the crucibles used was made of (in part) alkali metals. "It was these metals that caused the excess iron to be produced," he stated. 

"From there came the idea to use these alkali metals to create a novel process to reduce iron ore (separate the oxygen from the ore) without carbon."

Geffen explained the new approach is all made possible thanks to basic chemistry and thermal energy (heat). "I think that thinking outside the box to create space technologies is what really aided us in finding this solution," he added. 

Producing iron, which is naturally present in the Earth in the form of iron oxides, is the first step in manufacturing steel. Conventionally, coal and iron oxides are combined in scorching blast furnaces to bond oxygen molecules with carbon molecules. During this process, which requires a tremendous amount of energy, one of the byproducts is carbon dioxide (CO2), which we all know to be a significant greenhouse gas.

Helios' technology – dubbed the Helios Cycle – essentially replaces coal with sodium as the reducing agent. "[It's] a two-step process in which sodium is used to reduce first-row transition metals (like iron)," he revealed. 

"In the second step, the byproduct sodium oxides are dissociated to reclaim the sodium in metal form and keep it in a closed loop within the system."

Helios: Here's how creating oxygen on the Moon forged a recipe for iron – without CO2
Diagram of Helios' 2-step process

In other words, sodium oxide is created when sodium molecules interact with the oxygen molecules in iron ore. The oxygen, the only byproduct, is then released into the atmosphere after being split again into sodium and oxygen. After that, the sodium can be reused.

But just how truly "emission-free" is Helios' method?

It's worth noting here that in addition to carbon dioxide emissions, iron manufacturing also produces other greenhouse gases, such as methane and nitrous oxide, which actually have a more potent warming effect than carbon dioxide. Whether Helios' technology can alleviate these emissions has yet to be discovered. 

"Iron making today is responsible for 8-10 percent of the world's total carbon emissions," highlighted Geffen. "Using the Helios cycle, we can reduce all direct carbon emissions. If a renewable energy source is used, the whole process is 100 percent carbon emissions-free," he said. 

Additionally, unlike the conventional blast furnace approach, which requires heating the mixture to more than 2,192 Fahrenheit (1,200 degrees Celsius), Helios' sodium method only requires temperatures of around 750-1,290 Fahrenheit (400-700 degrees Celsius).

Helios: Here's how creating oxygen on the Moon forged a recipe for iron – without CO2
Pouring newly made green iron

"Because the process uses less energy than traditional methods and can process low-grade ores, we anticipate it will lower the final cost of iron making by at least 20 percent," Geffen explained.

The company's site states the tech spares steelmakers the need to modify their energy infrastructure; its carbon-free iron-manufacturing cycle can be integrated into existing infrastructure. This lowers costs and promotes quicker adoption. The specifics, however, were not discussed during this interview. 

If the process works as planned and is widely adopted, its advantages could remove the need for such "green" energy sources in iron production, like hydrogen, which necessitates constructing expensive infrastructure near the plant. Electrolysis may also be unnecessary with Helios' use of solely thermal energy. The company claims that using such electrochemical procedures will require more energy than current methods to create iron.  

Limitations, challenges, and next steps: Will The Helios Cycle make it to scale?

Helios disclosed—in an earlier IE article – that it already has a benchtop setup in its lab. Additionally, the company intends to build a prototype to replace the traditional blast furnace in at least one overseas steel manufacturing site before the end of the year.

"We're talking to big steelmakers and will be setting up small demonstration models within their production chains that will use their existing energy infrastructure," stated Helios' CEO, Jonathan Geifman, at the time.

Although research on the technology is still in its early stages, Geifman is optimistic about Helios' strategy.

Even better, Helios claims that its method can be used beyond iron, for the extraction of materials such as silicon, copper, nickel, and lithium, in a way that is much less detrimental to the environment than those currently used.

"Scaling up is always a challenge. Our R&D team, with its chemists and engineers, is tackling these challenges by building a mid-scale experiment that will produce 10's of kilos of iron per day in a continuous manner," Geffen told IE.

"Next year, we will begin building a pilot plant in collaboration with steel manufacturers that will produce tons of green steel per day," he revealed. 

A more resilient and sustainable future economy

As highlighted earlier, lowering emissions from the production of iron is essential for achieving global climate targets. By reducing these emissions, the rate of climate change, as well as air pollution and the accompanying health hazards (just to name a few negative impacts), may be limited. A 'green' method for iron production would also encourage the growth of a more resilient and sustainable economy, which is also critical for the future.

Thankfully, innovations like Helios' sodium method represent the efforts being made to lessen the carbon footprint of the metals industry, with the possibility of producing no additional carbon at all. Given the advantages, such as improved energy efficiency, it could also be argued that such technologies can become more cost-effective over time. 

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