Regeneration of iron fuel in fluidized beds, Part I: Defluidization experiments and theoretical prediction model

Hydrogen-based direct reduction of iron oxide powder in gas-fluidized beds has become an emerging technology. Agglomeration fine at elevated temperatures is however one key issue hindering the technological development. To obtain better knowledge high-temperature agglomeration mechanism, (de-)fluidization behavior micron-sized combusted particles experimentally studied this Part I. Effects various operating and material variables (temperature, gas flow rate, particle size) on fluidization are investigated. Different regimes (e.g. stable fluidization, agglomerating fast defluidization) categorized based experimental results. A theoretical model force balance developed to predict regime boundaries fluidization. The obtained applied for design hydrogen-based process II.