ArcelorMittal Ghent pilot captures over 90% of blast furnace CO2

A pilot carbon capture unit at ArcelorMittal Belgium's integrated steelworks in Ghent captured more than 90 percent of the carbon dioxide in blast furnace off-gas, the company has announced. The trial, run with Mitsubishi Heavy Industries (MHI), BHP and Mitsubishi Development Pty Ltd (MDP), logged over 4,500 hours of operational testing before closing its first phase.

The number matters because of the gas it came from. Blast furnace off-gas carries dust, sulfur compounds and other contaminants that complicate capture. The pilot used MHI's Advanced KM CDR Process and demonstrated, in ArcelorMittal's assessment, the technical feasibility of applying that technology to a gas stream most capture chemistry would rather avoid.

There is a design elegance in the arrangement. The first phase captured only the carbon dioxide from the off-gas; the carbon monoxide stayed in the stream and remained available for power and heat generation elsewhere on the site. The steelmaker keeps its fuel value and loses its liability. Takeaway: capture does not have to mean waste of the remaining gas chemistry.

What could full scale deliver?

ArcelorMittal's assessment of the trial results puts the upper bound at a 24 percent reduction in the carbon emissions intensity of the Ghent facility, if the technology is applied at full scale to pre-combustion blast furnace off-gas.

The company also flagged the wider prize. Extending capture to multiple emission sources across the integrated steelworks, it stated, could support further reductions and progress toward near-zero-emissions-intensity steelmaking. That is a pledge with a measurable horizon, and it now has pilot data behind it.

The distinction is worth keeping straight. What exists today is a pilot: 4,500 hours, over 90 percent capture, one gas stream. What exists on paper is a full-scale deployment concept, uncosted in the announcement, with a 24 percent ceiling. Separating the two is the discipline that will decide whether this becomes capacity or commentary.

What comes next: the reheating furnace

The second trial phase will move downstream. It will test MHI's capture technology on flue gases from the hot strip mill reheating furnace, a unit that burns a mixture of by-product gases — coke oven gas, blast furnace off-gas and basic oxygen furnace gas — together with natural gas to heat steel slabs before rolling.

The technical step up is real. Phase one addressed pre-combustion blast furnace gas. Phase two will examine post-combustion capture under more variable flue-gas conditions, a harder service for any solvent system. According to ArcelorMittal, the results will add information on integrating capture across different steelmaking processes and will feed updated engineering and deployment studies for potential full-scale applications.

Takeaway: phase one proved the chemistry works on dirty gas; phase two tests whether it survives the messier realities of mixed-fuel combustion.

Why the consortium shape matters

The partner list reads as a supply-chain alignment rather than a research curiosity. MHI brings the Advanced KM CDR Process, already deployed in industrial capture service elsewhere. BHP and MDP, as coal suppliers to steelmaking, have a direct interest in blast furnace routes remaining viable under tightening carbon constraints. Capture at the furnace mouth is, among other things, a bid to extend the life of the incumbent process.

That is the quiet wager in Ghent: that the integrated blast furnace can be retrofitted toward near-zero intensity rather than replaced. The 24 percent figure suggests how far retrofit alone can travel, and how much of the distance must be covered by other means.

The milestone to watch is the phase two dataset. Its variability results, and the deployment studies they feed, will determine whether Ghent's 90 percent pilot rate becomes a full-scale specification or a well-documented demonstration.