Oxy-blown bubbling fluidized bed gasification of high-ash Indian coal: A pilot – Scale demonstration

India's vast coal reserves offer a strategic pathway for clean energy via gasification; however, the high-ash content of indigenous coal renders most global gasifier designs techno-economically unviable. To address this gap, the CSIR-Central Institute of Mining and Fuel Research (CSIR-CIMFR) developed an indigenous Oxy-blown Bubbling Fluidized Bed Gasification (BFBG) pilot plant (TRL-6). The present findings evaluate the gasification performance of high-ash Indian coal at a thermal capacity of 107–150 kWth, utilizing a steam-oxygen mixture at atmospheric pressure and temperatures between ∼936 and 987 °C. The research systematically investigates the effects of the equivalence ratio (ER) and steam-to-coal (S/C) ratio on key gasification performance indicators, including Syngas composition and yield, H2/CO ratio, Carbon Conversion Efficiency (CCE), Cold Gas Efficiency (CGE), and Lower Heating Value (LHV) of the syngas. Under optimized conditions (ER: 0.40; S/C: 0.82), the process achieved a syngas composition of H2:CO:CH4:CO2 in the ratio of 38.45%:23.99%:7.34%:30.22%, yielding an H2/CO ratio of 1.60. Performance indicators achieved a CCE of 97.23%, CGE of 87.57%, and LHV of 9.03 MJ/Nm3 syngas. These results demonstrate the feasibility of producing hydrogen-rich syngas suitable for methanol synthesis, Direct Reduced Iron (DRI) production, and chemical feedstock. The findings provide the foundational data necessary for scaling up to pithead demonstration facilities in India.