Research On Characteristics Of Flow And Gasification For Biomass In Gasification Reactor

In order to solve the energy crisis and environmental crisis,the development and utilization of the renewable energy has become a trend for the future energy structure.As an important component of renewable energy,biomass is of great significance to the rational utilization,and biomass gasification technology has broad prospects for development.The gasification reactor is the core component of biomass gasification process.The research on the internal structure and reaction of reactor is helpful to improve the technical level of biomass gasification.This paper is mainly divided into two parts:the numerical simulation of gas flow and the numerical simulation of gasification reaction in the gasification reactor.The numerical study on the cold flow focuses on the effects of different air distribution board,pressure drop,solid particle concentration and bed pressure drop.By comparison and theoretical analysis,the best opening rate of 3.4%was determined.Based on the optimal aperture ratio,the influence of different drag models on the fluidization state of particles in the gasification unit is explored.The Syamlal-O'Brien model was selected for calculation of the drag force.The effects of different velocities on the fluidization state were also studied.It was found that the bed height and the pressure drop increased with the increase of velocity.In the numerical simulation of gasification reaction,the pine sawdust and cotton straw were used as the biomass material aiming to study the effects of different air equivalence ratios(0.19?0.27)on the CO formation.The variation of CO production did not change due to the change of raw materials.The effect of temperature change on the formation of CO was equally studied.It was found that the increase of initial temperature of 700K,was favorable for the formation of CO,while less change had been seen with the case of temperature of more than 700K.The most favorable temperature for CO formation was 1500K.At last,the traditional gasification agent was changed by adding different proportions of CO2.It was found that,the addition of CO2 is conducive to the formation of CO,and the amount of production increases with the increase of temperature.