Global steel giant ArcelorMittal and SEKISUI CHEMICAL have been working together on a project to capture and reuse CO2 emitted during steelmaking.
The two companies have been supported by the New Energy and Industrial Technology Development Organization (NEDO), Japan’s national research and development agency, and have launched an 'International collaboration on CCU for circular carbon in Steelmaking' (hereafter, the NEDO project), scheduled for three years from 2021.
One of the research topics is to develop a fundamental technology for Synthesis Gas (carbon monoxide and hydrogen) production using Sekisui Chemical’s chemical looping technology.
Through tests using actual blast furnace gas at ArcelorMittal's plant in Asturias, Spain, a CO2 conversion rate of 90% and a hydrogen conversion rate of 75% has been achieved, higher than the project target of a CO2 conversion rate of 85% or higher and a hydrogen conversion rate of 60% or higher using this technology.*1 . To obtain these results, it was important to carry out a CO2 capture process reaching 90% of CO2 purity.
The two companies now plan to further optimise the conditions, replacing the catalyst with a high-performance one, and conducting a long-term test with a higher reaction yield by the end of 2023. They will also consider new projects to demonstrate the ability to scale-up the new technology.
According to ArcelorMittal, steelmaking accounts for 7-9 % of global CO2 emissions. The blast furnace process in particular, which produces pig iron from iron ore, accounts for about 70% of CO2 emissions in the steel industry and, therefore, reducing these emissions is a major challenge for the steel industry. In the NEDO project, CO2 separated and captured from blast furnace gas is converted to Synthesis Gas (a mixture of CO and H2) through a chemical process. The converted 'syngas' is introduced into the blast furnace as a reduction agent to replace coke (CCU for carbon circulation in steelmaking). Through the project, both companies will demonstrate technologies that contribute to the effective use of CO2 and CO2 reduction.
In addition to completing the NEDO project, ArcelorMittal and Sekisui Chemical aim to launch a new project to demonstrate their ability to scale-up for commercialization.
*1 This achievement is a result of NEDO's international joint research and development project in the field of clean energy.