A pilot carbon capture unit at ArcelorMittal's integrated steelworks in Gent, Belgium, has removed more than 90% of the carbon dioxide from a portion of the site's blast furnace off-gas, closing the first phase of a four-company trial.
The test applied Mitsubishi Heavy Industries' Advanced KM CDR Process to the dusty, sulfur-bearing off-gas stream across more than 4,500 hours of operation, according to the companies. The partners described the campaign as demonstrating technical feasibility at pilot scale and as producing the operational and engineering data needed to weigh a full-scale installation at the Gent blast furnace.
Participating in the project are ArcelorMittal S.A. of Luxembourg City, MHI of Tokyo, BHP Group Ltd. of Melbourne and Mitsubishi Development Pty Ltd of Brisbane. ArcelorMittal is hosting the trial, MHI supplies the proprietary capture process and leads process engineering and technical evaluation, and BHP and MDP — suppliers of steelmaking raw materials to ArcelorMittal's European operations — are providing funding.
Site-level potential
Assessments drawing on the phase 1 results indicate that applying the technology at full scale to pre-combustion blast furnace off-gas could lower CO2 intensity at the Gent site by as much as 24%. Extending capture to several emission points around the plant could, in the partners' view, support progress toward near-zero emissions intensity.
Blast furnace off-gas carries substantial concentrations of both CO2 and carbon monoxide. Only the CO2 was captured in this phase; the remaining carbon, in the form of CO, can still be burned for power and heat elsewhere on the site, releasing CO2 at combustion.
Second phase turns to the reheating furnace
Phase 2 will widen the scope to other emission points, beginning with gases from the hot strip mill reheating furnace, which is gas-fired and brings thick steel slabs to the temperature required for rolling into thin sheet. That furnace runs on a blend of by-product gases — coke oven gas, blast furnace off-gas and basic oxygen furnace gas — together with natural gas, making it a separate post-combustion capture target.
The next campaign will test MHI's process against a different and more variable flue-gas profile, adding data on how capture performs when integrated across several processes within one steelworks. Those findings are intended to inform updated engineering and deployment studies for commercial-scale applications.
Frederik Van De Velde, chief executive of ArcelorMittal Belgium, said the partners set out to understand how capture could fit into existing steel plants and called the first-stage outcome pleasing, adding that scaling the technologies needed for decarbonization is the next step and that he looks forward to early results from the reheating furnace work.
Tatsuto Nagayasu, senior vice president and head of CCUS at MHI, said the length of the run and the capture rates mark a milestone for applying the company's technology in steel, showing it can operate with dust, sulfur-containing compounds and other impurities present while generating data for design assessments.
Dr. Ben Ellis, BHP's vice president of marketing sustainability, said the results point to abatement potential in the blast furnace and integrated steelmaking route, noting that roughly 70% of global steel production still comes from blast furnace steelmaking and is expected to remain a key process for decades.
Tadashi Mizuno, managing director and chief executive of MDP, said the phase 1 outcome strengthened confidence that capture applied to blast furnace gas could be a viable emissions-reduction pathway, working alongside energy efficiency improvements and high-quality raw materials in the industry's longer-term decarbonization.