Effects of Biomass Properties on Hematite Flash Reduction-Biomass Steam Gasification Coupling Process

摘要

The flash reduction-biomass gasification coupling process integrates an exothermic gasification process and endothermic reduction process in the same reactor without repeated conversions of material and energy. A three-dimensional computational fluid dynamics (CFD) model of the hematite flash reduction-biomass steam gasification (FR-BSG) coupling process was conducted using the Eulerian-Lagrangian method to study effects of biomass properties, including particle size, type, and moisture, on the coupling performance. To explore the influence mechanism, the effect of biomass properties on the BSG process was first studied in terms of the species production, mole fraction, and carbon conversion of biomass particles; then, the effect of biomass properties on the FR-BSG process was investigated based on the reduction degree and residence time of hematite particles. Results show that an increase in particle size leads to decreases of CO and H-2 mole fractions in the produced gas of the BSG process, which leads to a decrease of hematite reduction degree in the FR-BSG process. Variations in the gas product for the biomasses studied are insignificant because the compositions were similar; hence, one type can be replaced by another. Last, reducing the moisture content in the biomass can increase the reduction degree of the hematite.