Conversion of biomass to blast furnace injection fuel via high-temperature and high-pressure steam upgrading: An experimental and DFT calculation study

This study proposes a novel high-temperature, high-pressure steam upgrading technology to convert biomass into a clean fuel for blast furnace injection, aiming to reduce the steel industry’s reliance on fossil fuels. Experimental results on reed, pine needles, and bamboo husk demonstrated that the process significantly enhances fuel properties. A 90-min treatment increased the fixed carbon content of reed-derived biochar from 15.75 % to 31.68 % and its higher heating value from 17.65 to 21.76 MJ/kg. Crucially, the technology effectively removed alkali metals, reducing K₂O content in bamboo husk biochar from 34.47 % to 9.51 %, thereby mitigating key operational risks. The spectroscopic analyses (FTIR, Raman) confirmed the mechanistic pathway: FTIR revealed the efficient removal of oxygenated functional groups (e.g., –OH, C O), while Raman indicated a subsequent increase in structural order and aromaticity. Density functional theory calculations corroborated these findings, revealing the preferential cleavage of low bond order C–O bonds as the fundamental driver of this deoxygenation and aromatization process. This technology presents a viable and innovative pathway for producing sustainable blast furnace fuel, contributing to the green and low-carbon transition of the steel industry. © 2025 Elsevier Ltd.