KIER's electrified annealing system revolutionises steelmaking with near-zero emissions

The Korea Institute of Energy Research (KIER) has demonstrated an electrified annealing system for galvanised steel strip that promises deep cuts in process emissions while preserving product quality and throughput, offering a pragmatic pathway for steelmakers facing tightening decarbonisation requirements.

According to a paper published in Applied Thermal Engineering in September 2025, the KIER team led by Dr Hookyung Lee replaced conventional gas burners in continuous galvanizing line (CGL) annealing furnaces with upper‑ and lower‑mounted electric heating elements. The retrofit retains existing refractory structures and strip conveyance, but delivers rapid, uniform radiant heating by controlling the element‑to‑strip distance. Trials at the facilities of Samwoo Eco Co., Ltd., supported by Korea’s Ministry of Trade, Industry and Energy, processed 0.49 mm strip at 750°C and produced material whose colour, microstructure and mechanical properties were indistinguishable from that produced in combustion furnaces. The researchers reported reductions of more than 98 percent in both CO2 and nitrogen oxide exhaust concentrations. The results were also summarised by EurekAlert.

For industrial stakeholders, the practical advantages are significant. The research team estimates capital and installation footprints could be roughly 40 percent smaller than for conventional combustion systems because fuel supply, burner and large exhaust arrangements are no longer required. Crucially for operations managers, productivity was maintained at levels comparable with existing furnaces, addressing a common industry concern that electrification might compromise throughput.

Policy drivers and market signals increase the urgency for such solutions. South Korea’s government has set an ambitious industrial decarbonisation agenda, tasking the sector with cuts of up to 31 percent against 2018 emissions and promoting transitions to electric arc furnaces and other low‑carbon routes, according to reporting by S&P Global. Internationally, mechanisms such as the European Union’s Carbon Border Adjustment Mechanism raise the commercial stakes for exporters by internalising embedded carbon costs in traded goods.

The KIER approach reflects a broader trend in steel and metals processing: targeted electrification that couples modest equipment change with operational optimisation. Industry research published in the journal Processes describes work at Hyundai Steel’s Incheon works to modify side‑wall injectors in electric arc furnaces (EAFs), introducing a water‑cooled copper jacket and redesigned nozzle, which cut electrical energy consumption by about 5 kWh per tonne and raised productivity by roughly 3.1 t/h, producing substantial annual cost savings. That study illustrates how incremental engineering changes in electric systems can deliver measurable efficiency and throughput gains across heavy industry.

KIER’s team positions their demonstration as a platform for further innovation. “This demonstration is the world’s first case to show that carbon free heating can be achieved simply by replacing burners with electric heating elements,” Dr Lee said. He added: “Moving forward, we plan to expand the technology into an AI based design and operation system that automatically recommends optimal heating element configurations based on steel strip width, thickness, and conveying speed, ultimately developing it into an export ready carbon free heating solution linked to commercial scale demonstrations with domestic steelmakers and overseas markets.”

The path from demonstration to decarbonised production depends on power sourcing as much as process design. When the electric annealing system is fed with renewable electricity, it can deliver near‑zero direct process emissions and reduce exposure to carbon levies on embedded emissions. For manufacturers and procurement professionals seeking low carbon feedstocks, that transforms an operational change into a market differentiator that aligns with corporate net‑zero commitments and supply‑chain decarbonisation goals.

Commercial adoption will hinge on further piloting with industry partners, comparisons of lifecycle emissions and costs against alternative low‑carbon options such as hydrogen‑fuelled processes or expanded EAF capacity, and the availability of competitively priced renewable power. Nonetheless, the KIER work demonstrates a low‑risk retrofit route that preserves established CGL architectures while delivering substantial emissions and space‑and‑cost advantages, a proposition likely to attract interest from steelmakers and their customers as regulatory and market pressures mount.