Dynamic pressure-swing chemical looping process for the recovery of CO from blast furnace gas

• Published in: Energy conversion and management 2022-04, Vol.258, p.115515, Article 115515
• Main Authors: Flores-Granobles, Marian, Saeys, Mark
• Format: Article
• Language: English
• Subjects: Aspen Adsorption; BFG; Blast furnace chemistry; Blast furnace gas; Blast furnace iron mixers; Carbon dioxide; Chemical energy; CO separation; Dynamic pressure; Gas mixtures; Intermediates; Iron and steel plants; Pressure; Pressure-swing; Recovery; Residual energy; RWGS; Sorbents; Water gas
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2022.115515

[Display omitted] •Design of a dynamic process for blast furnace gas separation and upgrading.•58% CO recovery from a steel gas via a sorption enhanced pressure-swing process.•Production of a 62 mol% CO and 38 mol% CO2 gas mixture from blast furnace gas.•Higher H2 and lower N2 contents in the steel gas improve the CO recovery. Blast furnace gas (BFG) contains residual chemical energy (CO and H2) that is currently burned to provide heat and electricity in the steel plant. Considering BFG’s large production volume and CO content, part of this CO could be recovered to avoid conventional CO production. We develop and optimize a pressure-swing reverse water gas shift (PS-RWGS) chemical looping process to produce a CO-rich stream from BFG. An iron-based oxygen storage material (OSM) and a calcium-based CO2 sorbent are used as solid intermediates to circumvent the thermodynamic limitations of the RWGS. In an optimized PS-RWGS cycle, the pressure swings between 1.05 bar and 18.7 bar to recover 58%CO from BFG (0.13 mol CO per mol BFG) as a 62 mol% CO and 38 mol% CO2 gas mixture. CO recovery can be further increased if the BFG feed is enriched with H2 or less diluted with N2.