Feasibility analysis and environmental impact evaluation of biochar derived from mango pit for blast furnace injection

Abstract

Biochar, produced by the pyrolysis of carbon–neutral biomass, has great potential to replace pulverized coal (PC) injection in blast furnace (BF) ironmaking. Herein, this study aimed to develop a low-ash and low-alkali metal biochar from mango pit (MP) and evaluate its environmental impact as an alternative fuel for BF ironmaking. This paper first studied the feasibility of mango pit biochar (MPB) as an alternative fuel. Compared with other preparation conditions, MPB prepared at 600 °C for 60 min (MPB-600–60) had the most similar fuel performance to PC, which was confirmed by principal component analysis (PCA). Moreover, MPB-600–60 exhibited lower ash and alkali metal content compared to PC. The co-combustion experiment demonstrated that MPB-600–60 could promote the combustion of mixed fuel, and the optimal combustibility was achieved when the addition ratio of MPB-600–60 was 80%. Comprehensive life cycle assessment (LCA) revealed that the reduction of global warming potential (GWP) amounted to 220 kg CO2 eq/tHM if MPB 100% replaced PC. These results indicated that MPB could significantly reduce the greenhouse gas emissions and the environmental impact of BF ironmaking. This study provides a novel and promising approach for developing low-carbon and clean alternative fuels in BF ironmaking.