As part of a PhD project within the EPSRC Centre for Doctoral Training (CDT) in Resilient Decarbonised Fuel Energy Systems, supported by the IFRF, researcher Jack Wells at the University of Sheffield is investigating the Optimisation of Chemical Absorption for the Decarbonisation of the Iron and Steel Industry. Now that he is completing his studies, I asked Jack to give us an update, which he has kindly provided below:

“The decarbonisation of hard-to-abate industrial sectors, such as the iron and steel industry, is critical for achieving the Net Zero climate change target. As a foundational sector of the global economy, annual global crude steel production has increased from 1.56 Gtonnes in 2012 to 1.89 Gtonnes in 2023. In 2023, over 71% of this production came from the Blast Furnace-Basic Oxygen Furnace (BF-BOF) route. This method is inherently carbon-intensive, relying on coking coal both as a reducing agent and a source of thermal energy in the blast furnace, and is the source of around 70% of process CO2 emissions. Approximately 1.9 tonnes of CO2 are emitted per tonne of crude steel cast, giving the steel industry an estimated 7% of global greenhouse gas emissions. Meaningful decarbonisation should therefore focus on the BF-BOF production route, beginning with the blast furnace.

“The long-term vision for decarbonised steel production is primarily to eliminate blast furnaces, replacing them with hydrogen-based direct reduced iron (DRI) reactors to produce liquid iron. In this pathway, green hydrogen would be produced through electrolysis powered by renewable energy, avoiding CO2 emissions. However, the global hydrogen economy faces challenges in scaling production and deploying supporting infrastructure. Furthermore, many existing blast furnaces have operational lifetimes of several decades and are unlikely to be retired early, particularly in China.

“An intermediate solution is therefore required to decarbonise conventional blast furnaces, providing a transitional step between current processes and anticipated green manufacturing methods. Carbon capture and storage (CCS) has been identified as a key enabler in this transition through to 2050 and beyond, with chemical absorption emerging as the most readily applicable interim technology for treating process emissions from steel manufacturing.

“However, the deployment of chemical absorption carbon capture in the iron and steel industry, and other hard-to-abate industrial sectors, is hindered by a significant knowledge gap: the absence of publicly available and transparent performance benchmarks from conventional capture plants operating under the elevated CO2 conditions typical of industrial process emissions.

“To address this gap, an experimental campaign was carried out on the chemical absorption pilot plant at the Energy Innovation Centre (EIC) in Sheffield, UK, shown in Figure 1. Novel performance benchmarks were established for a flue gas flow with its CO2 concentration ranging from 10 to 25 mol.% in 5% increments, using a 35 wt.% MEA solvent in a conventional packed-bed capture system.

“The investigation generated extensive and detailed operating data, including liquid-to-gas (L/G) and solvent/CO2 ratios, solvent loadings and cyclic capacities, reboiler duties, and column temperature profiles, in addition to system energy balances and a component-level breakdown of the solvent regeneration energy. The findings provide practical guidance for tuning industrial-scale capture plants and offer a straightforward and accessible reference point for future pilot plant studies, essential for benchmarking, process validation, and technology development for heavy industry process emissions treatment. These findings are being prepared for publication and will be available at a future date.

“The initial test conditions were informed by a process simulation model of the capture plant, detailed in the following publication earlier this year:

Wells J, Heeley A, Akram M, Hughes KJ, Ingham DB, Pourkashanian M. Simulation and modelling study of a chemical absorption plant to evaluate capture effectiveness when treating high CO2 content iron and steel industry emissions. Fuel; 380; 133189 (Jan 2025) https://doi.org/10.1016/j.fuel.2024.133189.

Experimental data from the campaign was then used to further calibrate the simulation model, forming the basis for a predictive digital twin of the pilot plant. This digital twin will be refined as additional data becomes available.”

I look forward to seeing the findings of this study in more detail when published, and wish Jack every success with his future career.