Decarbonization of Blast Furnace Gases Using a Packed Bed of Ca-Cu Solids in a New TRL7 Pilot
José Ramón Fernández, Mónica Alonso, Alberto Méndez, Miriam Díaz, R. García, Marcos M. Chávez, Irene Alzueta, J.C. Abánades
Abstract
This work outlines the commissioning and initial experiments from a new pilot plant at Arcelor Mittal Gas Lab (Asturias, Spain) designed to decarbonize up to 300 Nm3/h of blast furnace gas (BFG). This investigation intends to demonstrate for the first time at TRL7 the calcium-assisted steel-mill off-gas hydrogen (CASOH) process to decarbonize blast furnace gases. The CASOH process is carried out in packed-bed reactors operating through three main reaction stages: (1) H2 production via the water–gas shift (WGS) of the CO present in the BFG assisted by the simultaneous carbonation of CaO; (2) oxidation of the Cu-based catalyst with air, and (3) reduction of CuO with a fuel gas to regenerate CaO and produce a concentrated CO2 stream. The first experimental campaign used 200 kg of commercial Ca- and Cu-based solids mixed to create a 1 m reactive bed, which is sufficient to validate operations and confirm the process’s effectiveness. A product gas with 40% of H2 is obtained with CO2 capture efficiency above 95%. Demonstrating at TRL7 the ability to convert BFG into H2-enriched gas with minimal CO/CO2 enables remarkable decarbonization in steel production while utilizing existing blast furnaces, eliminating the need for less commercially developed production processes.