CFD Modelling of Biomass Gasification in Fluidized-Bed Reactor Using the Eulerian-Eulerian Approach

摘要

A comprehensive two dimensional numerical model has been developed to simulate the biomass gasification in a fluidised bed reactor. Gas-solid flows as well as the chemical reactions are considered. Euler-Euler model is adopted to describe the multiphase flow regime inside the reactor. The standard k-ε model is used to model the turbulence for each phase. The particle motion inside the reactor is modelled using various drag laws derived from Kinetic Theory of Granular Flow. Biomass fuel after pyrolysis is fed as char and volatile matter. The reaction rates of homogeneous reactions and heterogeneous reactions are determined by Eddy-Dissipation rate and Arrhenius- Diffusion reaction rate respectively. Gas velocities, flow patterns, composition of gas product and distribution of reaction rates are obtained. Results are compared with experimental data and found to be in agreement.