Abstract
A three-dimensional Eulerian multiphase based computational model was developed to simulate the black liquor gasification processes in a fluidized bed gasifier (FBG) at low temperature. The standard k-e model and kinetic theory of granular model were used to simulate the gas phase and solid phase, respectively. Black liquor pyrolysis, homogeneous reactions and heterogeneous reactions were taken into account in chemical model. The reaction rates of homogeneous and heterogeneous reaction were determined by Arrhenius–Eddy dissipation reaction rate and kinetic reaction rate. Simulations were carried out at four different operating conditions, i.e. reactor temperature was kept at 550 degree centigrade or 600 degree centigrade, and nitrogen or air was used as fluidizing medium. The calculated results were in well agreement with the experiment used as calibration. Base on the simulation, gas-sold flow patterns and gas species molar fraction distributions were obtained, the relationship of gas composition profiles with the temperature and the fluidizing media were discussed.
©2012 Walter de Gruyter GmbH & Co. KG, Berlin/Boston
