Helix Carbon’s plan is to convert blast-furnace exhaust into carbon monoxide and send it back into the furnace. The company says this could lower coke consumption and costs. Rather than replace existing furnaces, it aims to make them cleaner.
Iron and steel production is among the world’s biggest sources of pollution. Many startups have pursued emissions cuts by finding new ways to produce the metals. Helix Carbon is focusing on the blast furnace instead. “Any attempt to decarbonize the steel industry without dealing with the blast furnace is not going to work,” David Brown, the company’s co-founder and CEO, told TechCrunch.
Blast furnaces have made iron for centuries, producing the iron used to make steel from iron ore. They’ve used coke, a processed form of coal. Iron ore contains iron bound to oxygen; producing metallic iron means removing those oxygen atoms. Coke provides heat as it burns, but it doesn’t directly drive the reaction. Carbon monoxide created during combustion does that by stripping oxygen from the iron.
That process generates tremendous amounts of carbon dioxide, or CO2, which is usually released into the atmosphere. Helix Carbon’s system uses electricity and a catalyst in an electrolyzer to remove an oxygen atom from CO2. This produces carbon monoxide, which can then be fed back into the furnace.
Brown said Helix’s electrolyzer can handle the blast furnace’s full exhaust stream. Most electrolyzers are too delicate to process raw exhaust. They require purified, concentrated CO2, so the gas generally has to be treated before it can be used.
Adding carbon monoxide to the furnace could reduce the amount of coke iron producers need, though the scale of the reduction remains disputed, Brown said. Some scientific papers estimate that up to 90% of the coke could be eliminated; other studies put the figure at 30% to 40%. Helix proposes replacing 33% of the coke to start. The company says this would save producers $14 per ton of iron. “That may not seem like a lot, but margins in the iron industry are famously thin,” Brown said.
These are projections rather than reported results, and the studies’ different estimates mean the eventual coke savings are uncertain. Helix says its system promises to reduce the steel industry’s carbon emissions while increasing iron producers’ profit margins, a rare win-win for a dirty industrial process.
The iron and steel market has a combined value of $2 trillion, according to Grand View Research, making it an appealing target for a young startup. Still, the industry changes slowly, partly because its equipment can remain in service for a long time. “There are blast furnaces that have lived for over 100 years,” Brown said.
Helix plans to pursue the specialty chemicals industry first to generate revenue sooner. Brown said the company could use CO2 without capturing it first: “We don’t need to capture the CO2 first,” he said. “We just utilize it, and that opens up the door of making chemicals on-site right out of waste streams.”
Helix Carbon gave its live, onstage presentation Tuesday in the Startup Battlefield pitch competition at TechCrunch Disrupt in San Francisco, taking place that week from October 13-15.
