Application Abstract: Biomass slow pyrolysis is an important thermochemical conversion technology for the production of value-added bio-char.Screw reactor is a promising reactor for biomass slow pyrolysis.The exothermic behavior of biomass slow pyrolysis tends to trigger temperature runaway in the area where particles tend to cluster together in the screw reactor.For handling such temperature runway,the project proposes a method by intensifying the local particle mixing in that area,which is expected to distribute the heat efficiently and uniformly in the reactor bed and to remove the heat out of the bed quickly.Based on the combined Computational Fluid Dynamics and Discrete Element Method(CFD-DEM),accurate flow model and comprehensive transport-reaction mathematic model will be separately developed for revealing the particle flow and mixing behavior in the reactor,and for revealing the coupled mechanism between the transport phenomena and the biomass pyrolysis reactions in the screw reactor,respectively.Based on the above information,the mechanism of triggering temperature runaway in the reactor bed is expected to be explained.Method is to be explored for intensifying the local particle mixing in the area where particles clustering tends to happen in order to achieve the efficient regulation on the temperature runaway in the screw reactor.The study in the project will provide helpful theoretical information for the engineering implement and regulating of the new technology—the technology of biomass slow pyrolysis in the screw reactor with local intensification of particle mixing.
