[Report] Steel Mill Carbon Emissions '0'... POSCO Steel Envisions Future with Hydrogen

Pohang Steelworks 3 Finex Plant
Making Steel Using 25% Hydrogen
Hydrogen Reduction Steelmaking Commercialization by 2030

"Hydrogen reduction steelmaking technology will determine the future fate of the company." (Jinchan Bae, Executive Director, Head of POSCO HyREX Promotion Team)

On the 24th at POSCO Pohang Steelworks FINEX Plant 3 in Gyeongbuk, the blast furnace emitting molten iron at 1500 degrees Celsius was so hot that it made faces feel warm even from a distance. However, it was not a typical blast furnace. POSCO’s self-developed FINEX fluidized reduction furnace was applied. In a typical steelmaking process, coal is used to remove oxygen attached to iron ore (Fe2O3) to produce pure iron, but the FINEX fluidized reduction furnace uses 25% hydrogen and 75% carbon monoxide as the iron ore reducing agents. It is a testing ground for carbon-free steel.

A panoramic view of the 3FINEX (FINEX) plant at Pohang Steelworks, Gyeongbuk. POSCO is developing the hydrogen reduction steelmaking process HyREX based on the FINEX fluidized reduction furnace technology.
[Photo by POSCO]

POSCO is going further by aiming to increase the hydrogen ratio, currently at 25%, to 100% to make carbon emissions 'zero (0)'. This is called hydrogen reduction steelmaking. In the existing process, coal (C) is used as the reducing agent, producing carbon monoxide (CO), but in the reduction reaction using hydrogen (H), water (H2O) is produced, drastically reducing carbon emissions.

The final hydrogen reduction steelmaking technology POSCO envisions, called 'HyREX', uses the FINEX fluidized reduction furnace and the ESF electric melting furnace together. In a blast furnace, the reduction reaction and the melting of reduced iron occur simultaneously, but hydrogen reduction steelmaking technology separates these into two facilities: the 'reduction furnace' and the 'electric furnace'. HyREX sequentially reacts iron ore with hydrogen in four fluidized reduction furnaces to produce direct reduced iron (DRI), then melts it in the ESF electric melting furnace to produce products.

The Core of Hydrogen Reduction Steelmaking: ESF Electric Melting Furnace

The commonly used electric melting furnace is the electric arc furnace (EAF) type. However, the EAF electric furnace has limitations in simultaneously achieving raw material diversity and energy efficiency. Especially, since the DRI production process focuses on the reduction reaction of iron ore, impurity separation is not well performed. Therefore, the electric furnace melting process must achieve higher temperatures to separate and remove slag, and because a large amount of iron is removed in this process, steelmaking efficiency can decrease.

Molten steel is being tapped from the electric arc furnace test facility at POSCO ESF.
[Photo by POSCO]

Accordingly, POSCO chose the ESF electric melting furnace as an alternative to EAF, which can handle raw materials of various grades. Unlike EAF, the ESF furnace contains some carbon inside, maintaining a reducing environment, and is designed to control slag components like a traditional blast furnace, allowing it to handle relatively low-quality DRI. Jaehun Park, Head of the Electric Furnace Research Group, said, "The EAF electric furnace form has limitations in controlling DRI components with a large amount of impurities, so only high-quality raw materials must be used, but ESF can use low-quality DRI, making it more versatile."

The POSCO ESF electric melting furnace pilot facility, unveiled for the first time this time, was completed earlier this year and completed its first tapping in April. At the site where the pilot facility was installed, there was a huge crane transporting the raw material DRI. Park explained, "The crane mixes DRI in the desired ratio and uniformly feeds it into the facility. After molten iron is generated and fills the inside of the facility, the tapping hole, where molten iron comes out, is opened to drain it." He added, "This is also a point that differentiates it from EAF, which requires tilting the furnace to drain molten iron about every 50 minutes."

The pilot facility is not very large, but it will be expanded much larger after commercialization. Park said, "The pilot facility is only about 1/30 to 1/10 the size of the actual facility. Currently, one of the largest ESF electric furnaces in the world, SNNC’s rectangular electric furnace, has an inner diameter length of 40 to 42 meters, which is the size we are targeting for the electric furnace."

Commercialization Targeted by 2030... A Step Toward Carbon Neutrality by 2050

POSCO has set a goal to accelerate the development of ESF electric melting furnace technology, introduce a 300,000-ton scale HyREX pilot facility, and complete commercialization technology by 2030. This is part of fulfilling the declaration to achieve carbon neutrality by 2050.

By 2030, POSCO plans to improve the efficiency of existing facilities based on the blast furnace process producing conventional molten iron, introduce electric furnaces to produce low-carbon products, and gradually reduce carbon emissions using bridging technologies until low-carbon technologies are commercialized. Then, by 2050, the company plans to fully transition to HyREX facilities.

Meanwhile, since Chairman Jang Inhwa took office in March, POSCO Group announced seven future innovation tasks to strengthen the competitiveness of core businesses and innovate the overall management system to prepare a turning point for becoming a top-tier company. Among the seven future innovation tasks, the group’s policy is that to rebuild steel competitiveness, it must lead in green transformation (eco-friendly transition).

At his inauguration ceremony in March, Chairman Jang presented specific directions to restore the steel business’s super-gap competitive advantage, including realizing an economically viable low-carbon supply system and building an 'intelligent factory' that applies artificial intelligence (AI) and robotics technology throughout all processes.