Energy and economic performance of three amine technologies for carbon capture in integrated iron and steel production plants

• Compared MEA, PZ/AMP and CAL008 amines for carbon capture in integrated steelmaking. • CAL008 and PZ/AMP outperformed MEA with comparable energy performance. • PZ/AMP had the lowest levelised cost of capture for blast furnace gas. • CAL008 had lower absorbent management costs than PZ/AMP due to its recoverability. • CAL008 had the lowest levelised cost for sintering and basic oxygen furnace gases. This study presents a techno-economic comparison of three amine technologies for CO 2 capture from three major CO 2 -rich flue gases in integrated iron and steelmaking processes. The amine technologies were based on aqueous solutions of 30 wt% MEA, a 13 wt% PZ and 27 wt% AMP blend (PZ/AMP), and CSIRO’s proprietary CAL008 absorbent. The flue gases considered, in order of decreasing CO 2 intensity, were blast furnace gas (BFG), sintering gas (SG), and basic oxygen furnace gas (BOFG). Carbon capture systems utilised amine solutions in standard absorber-stripper and modified cold rich-split process configurations. The processes were simulated using ProTreat®, employing a rate-based approach to design and simulate absorber and stripper columns, targeting 90 % capture. Using the standard design, CAL008 achieved minimum regeneration duties of 2.82–2.97 MJ/kg CO 2 , comparable to PZ/AMP (2.56–2.76 MJ/kg CO 2 ) and significantly lower than MEA (3.20–3.30 MJ/kg CO 2 ). The cold rich-split modification further reduced the minimum regeneration duty, particulalry for BFG, with reductions of 14.3 % for CAL008, 12 % for PZ/AMP, and 6.2 % for MEA. The levelised cost of carbon capture (LCCC) was lowest for PZ/AMP among the amine technologies when applied to BFG, primarily due to its lower regeneration energy requirement. However, when considering absorbent management costs—including those associated with thermal and oxidative degradation, thermal reclaiming, and waste disposal—CAL008 had a lower LCCC than PZ/AMP and MEA for SG and BOFG. This advantage primarily stemmed from CAL008’s ability to be recovered from a degradation product, in contrast to MEA and PZ/AMP, which required replacement with fresh absorbent.