Evaluating the Use of Pyrolyzed Agricultural Residue in Coal Blend for Cokemaking

The steel sector faces a significant challenge in decarbonizing its processes. It is not an easy task since 70% of steel production comes from the Blast Furnace/BOF route using coke as the main reducer, fuel from a fossil and non-renewable source. One of the short-term highlighted alternatives is the use of biomass, but inserting this material in the production of coke is not trivial. Numerous studies involving sawdust, charcoal, and wood residues demonstrate that any introduction of biomass to the coal blend leads to a decrease in coke quality. Nevertheless, the majority indicate that a 2% biomass addition does not significantly impact in coke quality. Despite its promise, biomass utilization is constrained by limited availability, particularly for extensively researched biomass sources. This article aims to comprehensively characterize agribusiness residues as alternative biomass materials for metallurgical coke production, thereby enhancing biomass supply to the steel industry. The characterization includes coke samples produced with varying proportions of sugarcane bagasse, maize residues, coffee husks, and eucalyptus husks following the pyrolysis process. It is observed that pyrolysis is essential for optimizing biomass compatibility with the coking process by reducing volatile content and reactivity. Additionally, microstructural analysis reveals increased coke porosity upon biomass addition, attributed to the inherent porosity of the biomass, subsequently elevating the coke reactivity index (CRI). Despite this, the use of some agriculture residues, in amounts of 2%, there is the drop in DI (Drum Index) of 2% and an increase in CRI of 3%.