Author(s)

K. Kleiva, R. K. Thapa & B. M. Halvorsen

Abstract

Study of a fluidized bed reactor for gasification of biomass K. Kleiva, R. K. Thapa & B. M. Halvorsen Department of Process, Energy and Environmental Technology, Telemark University College, Norway Abstract Experimental studies have been performed on a cold fluidized bed with glass and plastic particles emulating the properties of wood and olivine particles. The purpose of the experimental studies was to find the fluidization properties of the particles. These experimental studies have founded the background for conducting computational studies of multiphase flows of particles with the same properties. The computational studies are performed in ANSYS Fluent 12.0. The mathematical model has been verified with an experimental study to validate the simulations. A combination of steam, olivine particles and wood chips has then been simulated based on the results from the experimental and computational studies. The results from the computational studies show that the minimum fluidization velocity in the Fluent-simulations is higher than in the physical experiments, which is expected to a certain degree because of the wider distribution of particle sizes in the physical experiment. The pressures in the simulations scale well with the experimental results with increasing superficial velocity; more than one solid phase in the simulation gives a higher difference in pressure between the simulated and experimental values. Keywords: fluidized bed, CFD, multi-phase Eulerian model, multiple density simulations, biomass, CHP. 1 Introduction The behavior of biomass particles inside a fluidized bed is an essential part of the efficiency of a gasification combined heat and power-plant (CHP-plant), and for simulations of the behavior to be accurate, physical experiments are vital. The computational model used in fluent is based on already published models [1].

Keywords

fluidized bed, CFD, multi-phase Eulerian model, multiple density simulations, biomass, CHP.