Here’s the deal: steel needs energy and the energy transition needs steel.
However, as one of the most hard-to-abate sectors, steelmaking has not changed in the nearly 4,000 years it’s been produced, with iron ore at its core. However, with rock-eating microbes, Boston-based biotechnology startup Allonnia is teaming up with the world’s biggest miner, BHP Group Ltd. to finally bring innovation — and fewer emissions — to the millennia-old process.
Steel is one of the most used materials in the world, vital for the construction of homes, schools, hospitals, bridges, cars, and trucks, as well as technologies like solar panels, wind turbines, dams, and electric vehicles crucial for the transition to clean energy.
Reducing the carbon intensity of steelmaking is one of the most mystifying puzzles in the decarbonization jigsaw because, unlike other sectors like oil and gas, which has an alternative in renewables, or aviation which can turn to more sustainable fuels or a variety of potential electric or hybrid options, decarbonizing steel making requires overhauling the process which is reliant on coal.
This is because steel needs iron which is garnered from reducing mined iron ore. The Pilbara region in Western Australia accounts for nearly 40% of the world’s global iron ore supply, making it the largest supplier in the world. Here, mining giant BHP rules the down-under iron ore turf.
But as the world needs every sector, especially heavy industry, to decarbonize in order to mitigate the worst effects of the climate crisis, there’s one problem: like much of the world’s iron ore, the iron ore here contains too much phosphorus, alumina, and other impurities to be refined using anything but coal.
And coal — a member of the gang of fossil fuels the world is desperately attempting to ween itself off of — is bad for emissions.
As a 2021 report by the Brookings Institute explains, “Steelmaking uses coal both as a source of heat and as part of the chemical process of converting iron ore to elemental iron. Both of these uses produce carbon dioxide.”
“Eliminating CO₂ emissions from steelmaking requires a change in process,” the report says, pointing to using hydrogen as both a heat source and the chemical reducing agent as a potential means of slashing emissions.
Right now, hydrogen steel mills are slowly beginning to pop up around the world. Back in February, startup H2 Green Steel announced it would open Europe’s first commercial green steel plant in Sweden by 2025, where it will produce green steel using hydrogen.
The iron ore is refined by a hydrogen reaction, which according to H2 Green Steel, cuts emissions by 95% when compared with traditional steelmaking, which is responsible for 8% of the world’s emissions.
However, to be scaled to the tall order the world needs, this process needs to be able to use where the world’s biggest mining and steel companies get their iron ore, which is held by just seven countries, with Australia as the top dog. And in order for the iron ore to be refined with hydrogen, it can’t have what’s known as “gangue,” aka gunk covering it that makes it unacceptable for most of the world’s prototype hydrogen steel mills currently under development.
But, if we can get this gunk off, allowing the steel to be made using hydrogen mills, and the mills use renewable energy instead of electricity from fossil fuels, as most do today, then the code of steel decarbonization will finally be cracked.
That’s where Allonnia comes in.
As the startup describes itself on its LinkedIn, “We like to think of ourselves as nature's detectives, sifting through billions of biological clues to discover and deploy elegant solutions only nature itself can yield.”
Now Detective Allonnia has uncovered a potentially game-changing discovery that could help solve the steel mystery: BHP’s iron ore contains phosphorus-consuming organisms that can jumpstart the refining process naturally, and according to Paul Perry, vice president of innovation at BHP via Bloomberg, “All living things eat phosphorus.”
Even better, this particular microbe also coincidentally shakes loose alumina from the ore, increasing the purity of the iron ore from 62% to at least 65%, a big deal in the iron industry. If Allonnia is able to scale this process enough to unleash these tiny microbes on giant mounds of iron ore, it would be a major step in the journey to make the steel process carbon-free.
Allonnia’s business is microbes, and they’ve leveraged specialized organisms for all sorts of environmental uses from using specially crafted microbes to cleaning up dangerous chemicals that can linger forever in wastewater and soil to using others to speed up the natural biodegradation process of polyurethane, a widely used plastic material, thus decreasing its pollution.
The Bill Gates-backed startup is also using the microbes to biomine rare earth metals (REE), essential to electronics and much of clean energy technology. They’ve engineered the microbes to bind to target REEs found in discarded electronics, manufacturing waste, or mining trailings, even working with the Department of Defense as they try to scale REE recycling and mining in the U.S. for a more secure supply chain.
Allonnia is employing microbes across several sectors as the world strives for net zero, and with a potentially game-changing organism for the steel and iron industry, it may be inching us closer to the reality of green steel.
According to Simon Nicholas, a Sydney-based steel sector analyst at the Institute of Energy Economics and Financial Analysis via Bloomberg, the grade of iron ore most green steel tech relies on makes up less than 5% of today’s global supply of steelmaking material. But if Allonnia is able to purify the ore, the door opens for that other 95% to be refined without coal.
The process of scaling and getting the centuries-old industry to catch on may be a long one, but at least it’s clear that steel decarbonization may no longer be a long shot.