“…To date, the Ca-Cu looping process has been experimentally validated in packed-bed reactors up to TRL5 for the production of virtually pure H 2 from natural gas [2]. However, the use of this promising pre-combustion technology has also been proposed to decarbonise blast furnace gas (BFG), called for this particularly application Calcium Assisted Steel-mill Off-gas Hydrogen (CASOH) [3]. In this context, the H2020 C 4 U project aims to scale the Ca-Cu looping technology up to TRL7 and design the process for optimal integration in the steel industry [4].…”