Blast furnaces have been making iron for centuries. They're also a big reason iron and steel production is so hard to decarbonize: the process relies on carbon, it produces lots of carbon dioxide, and it depends on heavy equipment that can stay in service for decades. Swapping that equipment isn't a quick, software-style upgrade. It's a capital decision that affects production, costs, and daily plant operations for years.
Helix Carbon is trying a different tack. Instead of asking ironmakers to abandon the blast furnace, the startup wants to take some of the carbon dioxide coming out of the process, convert it into carbon monoxide, and feed that gas back into the furnace. The company says this could reduce coke use, lower emissions, and cut costs. That's worth looking at - but the figures here are still projections. They're not yet proof that the approach works at industrial scale.
This article explains how the process is supposed to work, why Helix starts with only a partial coke replacement, and what ironmakers would need to verify before adopting it. The key question isn't just whether the chemistry works in principle. It's whether the full setup can run reliably and make economic sense in a real plant.
How Helix Carbon's process works
Why blast furnaces use coke
A blast furnace turns iron ore into metallic iron. The ore has iron bound to oxygen, so producing iron means removing that oxygen. In the conventional process described by Helix Carbon co-founder and CEO David Brown, coke - a processed coal product - does two jobs. It provides heat, and it generates carbon monoxide that reacts with the ore to strip away oxygen.
That basic chemistry is effective - and deeply built into how iron is made. It also produces carbon dioxide. In a standard operation, much of that carbon dioxide leaves the process as exhaust rather than being used again. That's a major emissions source tied to a system steelmakers can't just "turn off" without changing the furnace and the wider production setup.
Helix's proposal starts with that exhaust stream. Its electrolyzer uses electricity and a catalyst to remove an oxygen atom from carbon dioxide, producing carbon monoxide. Helix then plans to send that carbon monoxide back into the blast furnace, where it can help reduce the ore. In simple terms, the loop is: capture carbon dioxide from the exhaust, convert it into carbon monoxide, and reuse the carbon monoxide in iron production.
The important distinction: recycling carbon is not eliminating it
This is a carbon-recycling approach. Instead of releasing the carbon dioxide immediately as carbon dioxide, the carbon gets put into another step of the production process. That's not the same as permanently storing carbon underground. And it doesn't mean the furnace becomes carbon-free.
This distinction matters when you evaluate emissions claims. If recycled carbon monoxide lets a plant use less coke, the plant may emit less carbon dioxide from coke. But the real outcome depends on the full system: how much coke is actually displaced, how much electricity the electrolyzer uses, and where that electricity comes from. Those are the same kinds of questions you'd ask for any industrial process. They aren't, by themselves, evidence that Helix's approach has already delivered a specific emissions reduction.
A practical way to look at the proposal is to separate three outcomes:
- Carbon reuse: How much blast furnace carbon dioxide can the system convert into usable carbon monoxide?
- Coke displacement: How much coke can the plant avoid using while keeping production and iron quality steady?
- Net emissions impact: After you account for electricity and other parts of the process, how much greenhouse gas does the plant avoid emitting?
A win on one of those measures doesn't automatically mean the other two will also look good. For buyers, the system-level result is what matters.
What Helix says is different about its electrolyzer
Electrolyzers aren't new. What Helix is claiming is more specific: its design can work with the full exhaust stream from a blast furnace. Brown told TechCrunch that many existing electrolyzers need purified, concentrated carbon dioxide, which means the exhaust has to be processed before it can be used.
If Helix can handle a less-prepared exhaust stream, it could simplify the overall setup. Fewer - or smaller - pre-treatment steps might reduce equipment needs, operating complexity, and costs. In industry, avoiding an extra processing stage can matter as much as improving the core chemistry, because every extra unit adds equipment, controls, maintenance, and another possible failure point.
That said, "able to process raw exhaust" is exactly the kind of claim that needs to be tested in real operation. A plant operator will want to know how the electrolyzer responds when the exhaust composition changes, how often it needs maintenance, how long its components last, and whether performance stays stable over time. The published material doesn't provide those results, so these are open questions - not assumptions.
The business case - and the questions behind it
Why a partial coke replacement may be the practical first step
How much coke could be displaced is still unclear. Brown pointed to scientific papers with estimates ranging from as high as 90% to roughly 30%-40%. That range is wide enough to be a warning sign: an estimate at the process level doesn't automatically translate into what a commercial plant can deliver.
Helix's starting point is replacing 33% of the coke. It's a narrower target than "remove coke entirely," and that matters. A partial substitution can let ironmakers test the technology while keeping the existing furnace and much of the operating model intact. It also makes the economics easier to evaluate: does it work at that substitution level, and do the benefits outweigh what it costs to install and run?
Helix also says the approach could save producers $14 per ton of iron. In an industry with tight margins, savings can be meaningful - if they hold across real production volumes and if the calculation includes the right costs. The source doesn't include a detailed cost breakdown, so $14 should be treated as Helix's stated estimate until it's verified with independently reported operating data.
What an ironmaker would need to put in the spreadsheet
A plant that's deciding whether to adopt this would need to compare the total cost of the system with (1) the cost of the coke it displaces and (2) the value of any emissions reductions. The core questions would look like this:
- How much coke is avoided per ton of iron at the intended operating rate?
- What does the electrolyzer system cost to install, connect, and maintain?
- How much electricity does it use, and what does that electricity cost at the plant's rates?
- Can the system operate consistently alongside the existing furnace?
- Does it require additional exhaust treatment or plant modifications?
- What happens to the savings when energy prices and input costs change?
These aren't "figure it out later" items. They determine whether the business case actually works. $14 per ton sounds good, but the real test is what's included in the calculation and how sensitive it is to electricity and equipment availability.
There's also a difference between a demo that works in a controlled setting and a system that works over a plant's operating life. Industrial buyers care about uptime, predictable maintenance, integration risk, and what happens if the retrofit disrupts production. If it can't meet those requirements, it isn't a useful retrofit even if the chemistry performs well in testing.
Why the market moves slowly
The iron and steel industries are huge, but that doesn't make adoption easy. Blast furnaces are long-lived assets. Brown told TechCrunch that some have operated for more than 100 years. That longevity creates a hurdle that lab results can't solve on their own: any new technology has to fit into existing facilities and business plans, not just beat an alternative in a controlled trial.
A plant operator isn't going to replace critical equipment based solely on a promising emissions projection. The decision involves capital planning, technical integration, operating risk, and the cost of changing a process that already produces at scale. That's why a retrofit-focused approach may be easier to consider than a full replacement - though it still has to prove itself in the plant.
For Helix, that means the opportunity is both technical and commercial. The company needs to show the equipment can handle the exhaust, the carbon monoxide can be returned and used effectively, and the savings justify installation and operating costs. Industrial buyers don't reward pitches nearly as much as repeatable performance.
What would make this approach succeed or fail
The technology has to work as a system
The electrolyzer is only one part of the loop. The installation has to connect exhaust handling, carbon dioxide conversion, carbon monoxide delivery, and furnace operations. Each piece affects the others. For example, an electrolyzer that performs well on paper may not help much if it requires heavy exhaust preparation - meaning it wouldn't deliver the simpler integration Helix is aiming for.
So any credible assessment needs to go beyond a single efficiency number. It should look at whether the full setup can deliver the required gas consistently, how it behaves when the plant runs under normal variation, and what maintenance is required. If the approach depends on tightly stable conditions that a real plant can't guarantee, it will be hard to operate economically.
Safety and operational requirements matter too. Carbon monoxide isn't just a chemistry output; it has to be handled within an industrial setting, with the right controls and procedures. That doesn't make the idea unrealistic. It just means the evaluation needs to include the engineering and operational work around the core reaction - not just the reaction itself.
Electricity and emissions accounting matter
Because the process uses electricity, you can't evaluate climate impact by only looking at the carbon dioxide leaving the blast furnace. You have to include the electricity input, too. If the electrolyzer uses a lot of power, then the emissions from generating that electricity can substantially affect the net benefit.
That's why emissions-reduction claims need a clear boundary. Is the comparison limited to coke use at the furnace, or does it also include electricity, upstream inputs, and the equipment needed to run the system? Different definitions can produce different numbers. For buyers and policymakers, transparent accounting is far more useful than a headline percentage without an explanation of what it measures.
The same goes for economics. Electricity prices change. A process that looks cost-effective under one set of assumptions might not work under another. The business case needs to be tested against the plant's actual energy supply, not a generic average.
Starting in specialty chemicals could shorten the route to revenue
Helix says it plans to pursue specialty chemicals first. Brown's argument is that carbon dioxide from waste streams might be usable to make chemicals on-site without having to capture and concentrate the CO2 the way some other processes require.
This fits a common startup reality: the long-term market could be large, but selling into an established sector can take time. A nearer-term application can bring revenue and operating experience while the company works toward iron applications. Whether that strategy pans out depends on the specific chemicals, the quality of the waste stream, and the economics at each site - all of which aren't settled in the current source material.
It's also risky to treat the chemicals path as proof that the blast furnace use is ready. Even if the underlying technology overlaps, different customers, requirements, and operating conditions can mean different outcomes. Success in chemicals would be a good sign, but it wouldn't automatically validate every part of the blast furnace retrofit.
The evidence that would change the assessment
For an industrial technology company, the next meaningful evidence isn't a broader claim about market potential. It's performance data. Useful proof points would include:
- Demonstrated operation on actual blast furnace exhaust, with exhaust conditions clearly described.
- Measured coke reduction at a stated iron production rate.
- Electricity consumption and maintenance requirements over a meaningful period of operation.
- A transparent calculation of cost per ton, including installation and operating costs.
- A lifecycle emissions comparison that states its system boundary and electricity assumptions.
- Evidence that integration won't undermine production reliability.
With those results, customers could separate a promising chemical concept from a system that can be deployed. Until then, Helix's proposal is best understood as an industrial decarbonization strategy with a potentially attractive cost angle - but one that still needs practical validation.
Conclusion: a retrofit, not a free pass
Helix Carbon's idea targets a real industrial constraint: blast furnaces are long-lived, tightly integrated assets, and replacing them isn't a simple transition. Recycling carbon dioxide into carbon monoxide could reduce coke use without asking ironmakers to throw away the furnace entirely. If the savings hold up, the concept is commercially interesting - especially in a sector where margins are thin.
But it's still important to separate a promising process from a proven plant solution. The technology needs to demonstrate reliable operation on real exhaust, measurable coke displacement, credible net emissions benefits, and savings that include electricity use and system costs. A partial retrofit may be more practical than a full replacement, but "practical" doesn't mean "risk-free."
If you're evaluating industrial decarbonization technologies, start with operating data and full system economics - not the headline claim. For Helix, the next milestone is evidence that the loop can run reliably at the scale and cost ironmakers need. Read the TechCrunch report on Helix Carbon for the company's announcement, and then look for independently verifiable performance results before treating the projected benefits as settled.