Sustainable metallurgical-grade biocoke production by bio-oil and 2,5-furandicarboxylicacid from biomass residues cleavage at low temperature: a key pathway for carbon neutrality in steel industry

The steel industry accounts for 30 % of global industrial greenhouse gas emissions, which is primarily attributed to the utilization of metallurgical coke. While carbon-neutral biochar is a material that rivals conventional coke, the inferior mechanical properties and higher preparation temperature limit biochar as an ideal alternative for metallurgical coke. Herein, ammonium octamolybdate is employed to transform birch residues into metallurgical-grade biocoke at low temperature. AOM affords advanced catalytic capacity during pyrolysis under a nitrogen-oxygen mixture, inducing the formation of superoxide free radicals on birch residues to produce 2,5-furandicarboxylic acid. The resulting 2,5-furandicarboxylic acid serves as a polymerization agent to facilitate the cross-polymerization between biochar and bio-oil for preparing biocoke. The produced biocoke displays superior 6.2 MPa of compressive strength, 59.2 % of coke strength after reaction, 92.28 % of mechanical durability, and 38.79 MJ/kg of higher heating value, close to first-grade metallurgical coke. Carbon emission analysis shows replacing 30 % of metallurgical coke by biocoke for 1 t of iron production reduces 419.43 kg of CO 2 emissions. This study presents a mild pyrolysis-polymerization strategy to produce densified metallurgical-grade biocoke for metallurgical coke alternative and underscores biocoke's potential for low-carbon production of the steel industry.