The steel industry is one of the largest sources of CO₂ emissions, contributing up to 9% of global output, posing a major challenge in the fight against climate change. Among emerging solutions for carbon capture, Metal-Organic Frameworks (MOFs) have gained significant attention for their ability to selectively capture CO₂ thanks to their high surface area and tunable properties. Unlike conventional methods, MOFs offer a more efficient and potentially scalable approach to reducing emissions from high-temperature industrial processes. This article explores the growing relevance of MOF-based CO₂ capture for the steel industry, highlighting its potential to support deep decarbonization and enable more sustainable steel production.

The Carbon Capture Challenge for the Steel Industry 

Many of the CO₂ emissions in steel production are process-inherent, meaning they cannot be eliminated through electrification or fuel switching alone. For instance, CO₂ is released during the chemical transformation of calcium carbonate (CaCO₃) into lime (CaO) in kilns and from the reduction of iron ore (Fe₂O₃) to iron in blast furnaces. These unavoidable emissions make carbon capture essential. Compounding this challenge, CO₂ emissions now have direct financial consequences under regulatory frameworks. These carbon-related policies place a price on emissions, making it increasingly costly for steel producers to operate without effective carbon management solutions.

Why the Steel Industry Is an Ideal Target for Carbon Capture?

One of the most compelling technical reasons for targeting the steel sector is the nature of its flue gases. In particular, blast furnace gas (BFG) — a by-product of the reduction of iron ore with coke — exits at moderate temperatures (typically 100°C to 400°C) and contains a relatively high concentration of CO₂ (20–25%) along with large amounts of CO, N₂, and smaller fractions of H₂ and water vapor. Such conditions make it highly suitable for post-combustion or pre-combustion CO₂ capture.

Several key pieces of equipment in steel plants are responsible for the bulk of CO₂ emissions. The blast furnace is the most significant contributor, due to the direct combustion of coke and the reduction reactions that release CO₂. The sintering plant and lime kiln also emit large volumes of CO₂, both from fossil fuel combustion and the decomposition of carbonates. The basic oxygen furnace (BOF) generates moderate emissions during the conversion of hot metal to steel. If used, the electric arc furnace (EAF), used primarily for recycling scrap, emits less, mainly depending on the carbon content of the input and the source of electricity. Coke ovens, direct reduced iron (DRI) units, and on-site power generation systems round out the major emission sources, varying in their output but collectively contributing to the sector’s substantial carbon footprint.

This concentration of emissions from identifiable and centralized sources makes the steel industry not only a significant challenge for decarbonization but also a strategic opportunity for deploying scalable carbon capture technologies. 

Complying with Climate Regulations and Industry Commitments