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

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 H-2 or less diluted with N-2.

Automated summary

The study develops a pressure-swing reverse water gas shift (PS-RWGS) chemical looping process to recover CO from blast furnace gas, reducing conventional CO emissions.