INFLUENCE OF SIZE AND SIZE DISTRIBUTION OF BIOMASS AND BED MATERIAL ON PERFORMANCE OF A DUAL FLUIDIZED BED GASIFICATION REACTOR

摘要

A computational fluid dynamic (CFD) model has been developed for the investigation of fluid dynamics and reaction kinetics in a dual fluidized bed biomass gasification reactor.Gas-solid flow and reaction kinetics are solved using Eulerian-Langrangian computational approach.Devolatilization of wood particles and chemical reactions: steam gasification, CO2 gasification, methanation, water-gas shift and methane reforming are involved in the model.The effect of biomass and bed material size and size distribution on the performance of the reactor has been investigated.The efficiencies of the reactor as a result of different size distributions of fuel particles and bed materials are compared.The process parameters such as reaction temperature, steam/fuel ratio and fluidizing velocity are kept constant for all cases.It is observed that the efficiency of the reactor is higher with reduced particle size of biomass as well as of the bed material.