Helix Carbon wants to make blast furnaces cleaner, not replace them

The iron and steel industries are among the world’s biggest polluters, and most startups trying to cut their emissions have focused on new ways to make the metals. Helix Carbon is taking a different approach: rather than replace the blast furnace — the giant furnace that turns iron ore into the iron used to make steel — it wants to clean up the one already running. “Any attempt to decarbonize the steel industry without dealing with the blast furnace is not going to work,” co-founder and CEO David Brown told TechCrunch.

Blast furnaces have made iron for centuries by burning coke, a processed form of coal, to supply heat for the reaction; carbon monoxide produced by that combustion does the actual work of stripping oxygen from raw iron ore. The process releases large amounts of CO2, normally vented straight into the atmosphere. Helix Carbon’s system instead runs that waste CO2 through an electrolyzer — a device that uses electricity and a catalyst to strip an oxygen atom from the CO2 — turning it back into carbon monoxide and feeding it back into the blast furnace. Electrolyzers aren’t new, but Brown said Helix’s design can handle a blast furnace’s entire exhaust stream, where most electrolyzers are too delicate for anything but purified, concentrated CO2.

Injecting that carbon monoxide lets iron producers use less coke, though how much less is still debated: some research suggests as much as 90% of the coke could be eliminated, while other studies put the figure closer to 30% to 40%. Helix Carbon is proposing that producers start by replacing a third of their coke, which the company says would save $14 per ton of iron — a meaningful number, Brown said, given how thin margins run in an industry that is a combined $2 trillion market, according to Grand View Research. The business also moves slowly, he noted, in part because its equipment lasts so long; some blast furnaces have been running for more than a century.

To bring in revenue sooner than a slow-moving steel industry allows, Helix Carbon plans to court the specialty-chemicals industry first, since it can sell the utilized CO2 without first having to capture and store it. The startup presented onstage Tuesday in the Startup Battlefield pitch competition at TechCrunch Disrupt 2026 in San Francisco, running October 13-15.

Why it matters

A low-capex add-on that turns a blast furnace’s own waste gas into feedstock is the kind of upgrade a slow, capital-intensive industry can adopt without a full infrastructure rebuild — a more plausible path to lower emissions than waiting for new furnace technology.