Performance evaluation of biomass chemical looping gasification in a fluidized bed reactor using industrial waste as oxygen carrier

The study investigates biomass chemical looping gasification (BCLG) using nickel smelter slag as an oxygen carrier (OC). Key operating parameters, including reactor temperatures (800-900 °C), OC-to-biomass ratio (OCBR, 4:1-15:1), and steam as a gasification medium, were evaluated in a 5kW_th fluidized bed reactor using pine forest residue. Performance metrics including gas composition and process efficiencies were assessed. OCs were characterized using XRD, BET and SEM-EDS analyses. Optimal performance was achieved at 850 °C, an OCBR (10:1) and a steam-to-biomass ratio (1.4). The gas composition was 38.87 vol% H₂, 19.65 vol% CO, 34.48 vol% CO₂, and 6.61 vol% CH₄, with a product gas yield of 1.24Nm³/kg-biomass. Carbon conversion efficiency was 77.85 %, cold gas efficiency 58.70 %, and levelized cost of fuel was 0.15 €/Nm³ for product gas and 4.55 €/kg for H₂.The results suggest that steam addition significantly enhanced char conversion, improving overall BCLG efficiency. Moreover, nickel smelter slag demonstrated stability, consistent reactivity, and limited sintering behavior.