Two dimensional numerical computation of a circulating fluidized bed biomass gasifier

A two dimensional model for an atmospheric CFB biomass gasifier has been developed which uses the particle based approach and integrates and simultaneously predicts the hydrodynamic and gasification aspects. Tar conversion is taken into account in the model. The model calculates the axial and radial distribution of syngas mole fraction and temperature both for bottom and upper zones. The proposed model addresses both hydrodynamic parameters and reaction kinetic modeling. Results are compared with and validated against experimental data from a pilot scale air blown CFB gasifier which uses different types of biomass fuels given in the literature. Developed model efficiently simulates the radial and axial profiles of the bed temperature and H₂, CO, CO₂ and CH₄ volumetric fractions and tar concentration versus gasifier temperature. The minimum error of comparisons is about 1% and the maximum error is less than 25%.