CFD Analysis of Gasification Process (Downdraft Gasifier)

Abstract

Gasification converts carbonaceous pulverized fuels into synthesis gas, a mixture of CO and H2 that is a raw material for chemicals as well as a fuel for producing elec- tricity. Gasi cation has the best fuel exibility of any of the advanced technologies for power production, and current technology has already operated well with biomass and other low-value feed stocks, and with high-ash residues.Gasi cation produces a much higher concentration of carbon dioxide than direct combustion of coal in air. The higher concentrations of carbon dioxide make carbon capture and storage more economical than it otherwise would be. In view of these, gasi cation energy combined with Computational Fluid Dynamics (CFD) software has been described in some de- tail in the following study. The aspect of gasi cation processes have been investigated with regard to the existing (down-draft) gasi er using simulation in FLUENT soft- ware. The project is about the modeling of uid ow of fuel inside biomass down-draft gasi er using FLUENT software. Using the typical design of down-draft gasi er, the model is produced in 2-Dimension for easier iterations and simulations. The forma- tion of ow pattern, temperature, turbulence, product gas composition, and radiation heat transfer will be investigated.To anticipate the solid's behavior, particle concen- tration and particle size change due to pyrolysis and surface reactions will be modeled using an Eulerian-Lagrangian approach.