{"id":80980,"date":"2026-09-11T16:22:30","date_gmt":"2026-09-11T20:22:30","guid":{"rendered":"https:\/\/overcentral.com\/en\/?p=80980"},"modified":"2026-09-11T16:22:30","modified_gmt":"2026-09-11T20:22:30","slug":"hertha-metals-steel-furnace-80980","status":"publish","type":"post","link":"https:\/\/overcentral.com\/en\/hertha-metals-steel-furnace-80980\/","title":{"rendered":"Hertha Metals slashes steel emissions and costs with new furnace"},"content":{"rendered":"

The steel industry has changed remarkably little since the mid-nineteenth century, when the Bessemer process first made mass production possible. For more than 170 years, the fundamental recipe for turning iron ore into steel has relied on the same basic ingredients: iron ore, coal (converted into coke), and enormous blast furnaces that run at extreme temperatures. That enduring formula is now facing its most serious challenge yet, and it is coming not from a legacy steelmaker or a government mandate, but from a startup called Hertha Metals and its founder, Laureen Meroueh. Hertha Metals has developed a new furnace that can transform iron ore directly into refined liquid steel in a single step, replacing coal with natural gas<\/a>. The result is a process that cuts greenhouse gas emissions by at least half and reduces production costs by 25 percent compared with conventional steelmaking. If Meroueh\u2019s technology scales, it could rewrite the economics of one of the world\u2019s dirtiest industries while finally giving steel buyers a truly cheaper, cleaner alternative.<\/p>\n

Why the steel industry\u2019s carbon problem is so hard to solve<\/h2>\n

Steel production accounts for roughly 7 percent of global carbon dioxide emissions, more than the entire aviation and shipping sectors combined. The bulk of those emissions come from the chemical reaction that occurs inside a blast furnace. Iron ore is primarily iron oxide. To extract the metallic iron, a reducing agent\u2014almost always coke made from coal\u2014must strip away the oxygen atoms. That reaction produces carbon dioxide as a byproduct, and it is intrinsic to the chemistry of traditional steelmaking, not just an energy efficiency issue. Even if a steel plant were powered entirely by renewable electricity, the blast furnace itself would still release massive amounts of CO\u2082.<\/p>\n

Over the past decade, the industry has explored several routes to decarbonization. One approach uses green hydrogen to reduce iron ore, producing water vapor instead of CO\u2082. Another relies on carbon capture and storage to trap emissions from existing blast furnaces. A third method, electric arc furnace recycling, already produces lower emissions, but it is limited by the supply of scrap steel and cannot produce the highest grades of virgin steel. Each of these alternatives carries a significant cost premium. Hydrogen-based direct reduced iron (DRI) is still far more expensive than the blast furnace route, and carbon capture adds billions of dollars in capital expenditure. The steel industry\u2019s core dilemma has been that the cheapest way to make steel is also the dirtiest, and the cleanest ways are too expensive for mass-market adoption. Hertha Metals aims to break that tradeoff.<\/p>\n

Hertha Metals: a single-step furnace that reimagines the process<\/h2>\n

Laureen Meroueh, the founder of Hertha Metals, recognized that the fundamental inefficiency in steelmaking is not just the fuel but the process architecture. Traditional steelmaking requires multiple distinct steps: iron ore must first be reduced to solid sponge iron or molten pig iron in a blast furnace, then that intermediate product must be transferred to a basic oxygen furnace to be refined into steel. Each step involves energy losses, material handling, and additional emissions. Hertha Metals\u2019 furnace collapses these stages into a single continuous operation. Iron ore and natural gas are fed into the furnace, and out comes liquid steel of the desired composition.<\/p>\n

The innovation hinges on the furnace\u2019s design, which allows the reduction and refining reactions to occur simultaneously in a controlled environment. By using natural gas instead of coke, the process eliminates the need for coking plants\u2014themselves significant sources of pollution\u2014and directly cuts the CO\u2082 emitted during reduction. Natural gas, being primarily methane, produces roughly half the CO\u2082 per unit of energy as coal, and when used as a reducing agent, it also avoids the additional carbon that would come from the coke\u2019s own combustion. Meroueh states that the emissions savings are at least 50 percent<\/a> compared with the conventional blast furnace route. Moreover, because the process is simpler and requires less energy per ton of steel, the operating costs drop by about a quarter.<\/p>\n

That cost reduction is what makes Hertha Metals stand out from other green steel initiatives. Most low-emission steel technologies add a premium of 20 to 50 percent to the price of steel, making them unattractive for construction, automotive, and appliance manufacturers that operate on thin margins. By delivering a 25 percent cost advantage, Hertha Metals flips the economic calculus: steelmakers can adopt a cleaner process while actually improving their bottom line.<\/p>\n

How the Hertha Metals furnace works: a technical primer<\/h2>\n

To understand what makes the Hertha furnace different, it helps to compare it with the two dominant steelmaking methods in use today. The blast furnace\u2013basic oxygen furnace (BF-BOF) route starts with iron ore, coke, and limestone fed into a blast furnace, where coke both provides heat and acts as a reducing agent. The resulting molten iron, called pig iron, contains about 4 percent carbon and must be further refined in a basic oxygen furnace by blowing oxygen through it to burn off excess carbon and impurities. The second method, direct reduced iron (DRI) combined with an electric arc furnace (EAF), uses natural gas or hydrogen to reduce iron ore to solid sponge iron, which is then melted in an electric arc furnace. DRI-EAF can be lower in emissions than BF-BOF if powered by clean electricity, but it is typically more expensive and requires high-quality iron ore pellets.<\/p>\n

Hertha Metals\u2019 furnace operates on a different principle, often referred to as smelting reduction. Instead of separating reduction and melting into two vessels, the Hertha furnace integrates them in a single reactor. Iron ore fines\u2014a lower-grade, cheaper form of ore that conventional blast furnaces cannot use directly\u2014are injected along with natural gas and oxygen into a hot bath of molten metal and slag. The natural gas reforms into hydrogen and carbon monoxide, which reduce the iron oxide. The intense heat from the exothermic reactions keeps the metal molten, and the slag absorbs impurities. The result is liquid steel that can be tapped directly, without needing a separate refining step.<\/p>\n

This integration eliminates the need for coke ovens, sinter plants, and the energy-intensive pelletizing of iron ore. It also allows the furnace to operate flexibly, ramping up or down more easily than a blast furnace, which typically runs continuously for years. The natural gas can be replaced with green hydrogen as that technology becomes more economical, potentially bringing emissions down to near zero. For now, the furnace achieves its emissions reduction through fuel switching and process efficiency alone.<\/p>\n

What are the main advantages of Hertha Metals\u2019 new furnace?<\/h2>\n

The Hertha Metals furnace offers three distinct advantages over conventional steelmaking. First, it reduces direct carbon dioxide emissions by at least half because natural gas emits less CO\u2082 than coal and because the integrated process eliminates intermediate steps that each generate their own emissions. Second, it lowers production costs by 25 percent, driven by lower energy consumption, cheaper iron ore feedstock (fines rather than pellets), and the elimination of coking and sintering infrastructure. Third, it simplifies the steel plant layout and reduces capital expenditure, since a single furnace replaces multiple large vessels. These combined advantages make it the first clean steel technology that is also economically compelling on its own terms, without requiring carbon taxes or subsidies to be competitive.<\/p>\n

From a practical standpoint, the furnace also addresses a major bottleneck in the green steel transition: the availability of high-grade iron ore. Traditional DRI processes require iron ore with at least 67 percent iron content, which is becoming scarcer and more expensive. Hertha\u2019s furnace can use lower-grade fines, which are abundant and cheap, widening the resource base for clean steel production.<\/p>\n

The market implications for steel buyers and producers<\/h2>\n

Steel is the backbone of modern infrastructure, used in buildings, bridges, cars, ships, and appliances. Global demand continues to grow, especially in developing economies. Yet steel producers have been reluctant to invest in cleaner technologies because of the high capital costs and uncertain returns. Hertha Metals\u2019 cost advantage could change that calculus. If the furnace performs at commercial scale as claimed, it would give producers a way to differentiate their product on both price and environmental performance, something the market has rarely seen.<\/p>\n

Automakers, for example, face increasing pressure to reduce the carbon footprint of their supply chains. Many have committed to using green steel, but the volumes available are limited and the prices are high. A cleaner steel that is also cheaper would allow them to meet sustainability targets without raising vehicle prices. Similarly, construction companies and appliance manufacturers could source steel with a lower carbon intensity at no extra cost. That could accelerate the adoption of low-carbon steel far faster than regulatory mandates alone.<\/p>\n

The potential disruption is not lost on the incumbent steel industry. Major producers like ArcelorMittal, Nucor, and SSAB have announced their own decarbonization plans, but most rely on hydrogen or carbon capture, which are still expensive and unproven at scale. Hertha Metals\u2019 furnace represents a different path\u2014one that may be more commercially viable in the near term. If the technology is licensed or adopted by existing mills, it could reshape the competitive landscape.<\/p>\n

Laureen Meroueh: the innovator behind the furnace<\/h2>\n

Laureen Meroueh is not a career steel executive. She is a young engineer and entrepreneur recognized in MIT Technology Review\u2019s 2026 Innovators Under 35 list in the climate and energy category. Her background combines materials science, chemical engineering, and a drive to tackle heavy industry\u2019s hardest problems. She founded Hertha Metals to address what she saw as a glaring gap: while billions of dollars were flowing into solar, wind, and batteries, the industrial sector\u2014particularly steel\u2014had been left behind. Her approach is pragmatic, focusing on incremental but transformative improvements to existing processes rather than waiting for a breakthrough in hydrogen production or carbon capture.<\/p>\n

Meroueh\u2019s work exemplifies a broader trend in climate technology: the shift from purely renewable energy solutions to industrial decarbonization. Startups are now targeting cement, steel, chemicals, and aviation, sectors that collectively account for more than a third of global emissions. Hertha Metals is among the most promising because it addresses both emissions and cost, the twin barriers that have kept industrial decarbonization stalled for decades.<\/p>\n

What makes Hertha Metals\u2019 furnace different from traditional steelmaking?<\/h2>\n

Hertha Metals\u2019 furnace differs from traditional steelmaking in three key ways: it combines iron ore reduction and steel refining into a single continuous step, it uses natural gas instead of coke as both fuel and reducing agent, and it can process lower-grade iron ore fines that are cheaper and more abundant. This integrated design cuts direct carbon dioxide emissions by at least half and reduces production costs by 25 percent compared with the conventional blast furnace route. The result is a cleaner steelmaking process that is also more economical, breaking the historic tradeoff between environmental performance and cost.<\/p>\n

Challenges and the road to commercial scale<\/h2>\n

As promising as the Hertha Metals furnace sounds, it has not yet been proven at commercial scale. Most details about the exact design, operating temperatures, and refractory materials are proprietary. Scaling from a pilot or demonstration plant to a full-size furnace capable of producing a million tons of steel per year is a significant engineering challenge. The steel industry is notoriously conservative, and new technologies often take decades to penetrate because of the high capital costs and long asset lifetimes. Existing blast furnaces, once built, can operate for 20 to 30 years. Steelmakers will not shut them down early unless the new technology offers a clear and rapid return on investment.<\/p>\n

Another challenge is the availability and price of natural gas. In regions like Europe and parts of Asia, natural gas is significantly more expensive than coal, which could erode the cost advantage of the Hertha process. However, in North America and the Middle East, where natural gas is abundant and cheap, the economics look much more favorable. Meroueh has indicated that the furnace can eventually be adapted to use green hydrogen, which would eliminate emissions entirely, but that transition depends on the cost of hydrogen falling to competitive levels, which is not expected until the 2030s at the earliest.<\/p>\n

Regulatory and policy factors will also play a role. Carbon pricing, border adjustment mechanisms (like the European Union\u2019s CBAM), and government subsidies for clean industrial technologies could accelerate adoption. If the cost advantage holds even without subsidies, Hertha Metals could be well positioned to capture market share in regions with strong climate policies.<\/p>\n

Broader context: the future of green steel<\/h2>\n

Hertha Metals is entering a crowded but still nascent field. Competitors include established players like SSAB\u2019s HYBRIT project, which uses hydrogen to produce fossil-free steel, and newer entrants like Boston Metal, which uses electrolysis to produce steel from iron ore. Both of those approaches are more capital-intensive and currently more expensive than conventional steel. Hertha\u2019s claim of a 25 percent cost reduction sets it apart, but it remains to be seen whether the technology can deliver that at scale.<\/p>\n

The steel industry\u2019s path to net zero will likely involve a mix of technologies: recycling more scrap, using hydrogen for direct reduction, applying carbon capture to existing plants, and adopting smelting reduction processes like Hertha\u2019s. No single solution will fit every region or market. But the emergence of a technology that can simultaneously lower emissions and costs is a milestone. It suggests that industrial decarbonization does not<\/a> have to be a burden on the economy; it can be an opportunity for innovation and efficiency.<\/p>\n

For the climate, the stakes could hardly be higher. Steel production is a hard-to-abate sector, and even modest reductions in its emissions would have a significant global impact. If Hertha Metals can scale its furnace and license it to steelmakers around the world, it could displace hundreds of millions of tons of CO\u2082 annually, while also making steel cheaper\u2014a rare win-win in the fight against climate change. The next few years will be critical as the company moves from the lab and pilot stage to a demonstration plant that can convince the industry that a 170-year-old recipe is finally ready for a rewrite.<\/p>\n","protected":false},"excerpt":{"rendered":"

The steel industry has changed remarkably little since the mid-nineteenth century, when the Bessemer process first made mass production possible. For more than 170 years, the fundamental recipe for turning iron ore into steel has relied on the same basic ingredients: iron ore, coal (converted into coke), and enormous blast furnaces that run at extreme […]<\/p>\n","protected":false},"author":7,"featured_media":83236,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/cards.overcentral.com\/cards\/en\/80980.png","fifu_image_alt":"Hertha Metals slashes steel emissions and costs with new furnace","footnotes":""},"categories":[31],"tags":[],"class_list":["post-80980","post","type-post","status-publish","format-standard","has-post-thumbnail","category-technology"],"fifu_image_url":"https:\/\/cards.overcentral.com\/cards\/en\/80980.png","fifu_image_alt":"Hertha Metals slashes steel emissions and costs with new furnace","_links":{"self":[{"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/posts\/80980","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/comments?post=80980"}],"version-history":[{"count":0,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/posts\/80980\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/media\/83236"}],"wp:attachment":[{"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/media?parent=80980"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/categories?post=80980"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/overcentral.com\/en\/wp-json\/wp\/v2\/tags?post=80980"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}