Helix Carbon Pitches Full-Exhaust Recycling to Cut Iron Costs
Helix Carbon co-founder and CEO David Brown took the Startup Battlefield stage on Oct. 13 to pitch a retrofit for blast furnaces that captures waste carbon dioxide and converts it back to carbon monoxide for reuse in the furnace. TechCrunch
The core hardware is an electrolyzer, which uses electricity and a catalyst to strip one oxygen atom from CO2, leaving CO. That CO can return to the furnace as a reductant, the agent that removes oxygen from iron ore, and as fuel gas. The company says its stack can process the full exhaust stream, not just a small diverted sample called a slipstream, like handling the whole river rather than a bucket drawn from it.
The practical test for that full-stream claim is durability, throughput and power demand. Handling the entire exhaust avoids a separate concentration and bypass loop, but it keeps the cells under continuous load.
Helix Carbon is not proposing full coke displacement at the start. It proposes iron producers begin by replacing 33% of coke, the coal-based furnace fuel, with recycled carbon monoxide.
At that 33% level, the company says producers would save $14 per ton of iron. TechCrunch The company pitches cost reduction first, with emissions reduction as a linked result.
The broader economics here depend on local prices, since coke and electricity pricing differ between sites.
The pitch took place at TechCrunch Disrupt 2026, held Oct. 13-15 at Moscone West in San Francisco. TechCrunch Helix Carbon, based in Massachusetts, was selected for the 2026 Startup Battlefield Top 20. TechCrunch
For go-to-market, Helix Carbon plans to sell first to the specialty chemicals industry to earn revenue earlier. Steel retrofits follow capital spending cycles and qualification timelines. Specialty chemicals can use CO in smaller volumes with shorter sales cycles.
The broader context here is familiar to anyone who has tracked industrial electrolysis. Lab results often fade with real off-gas and continuous operation. Contaminant tolerance, cell lifetime under load, and downstream gas conditioning usually decide commercial viability more than peak efficiency.
In my view, the 33% figure is the most telling technical detail. It suggests Helix Carbon has modeled furnace mass and energy limits, not only electrolyzer performance. Partial replacement lowers process risk while still creating a large, continuous sink for CO. Worth flagging are three variables not yet public: power needed per ton of CO, stack replacement interval, and gas purity at the injection point.
Looking further out, if those variables hold, the upside is clear. Blast furnaces are long-lived assets. A drop-in loop that cuts coke use without a rebuild gives operators a cost reason to keep existing furnaces while cutting direct CO2. That sequencing is pragmatic, and starting with chemicals lets the company refine manufacturing before steel-scale deployment.
