Determination of gas-solid distribution characterization in a fluidized bed system

Due to increasing energy consumption, energy costs, and environmental pollution worldwide and in Turkey, the efficient use of energy, minimizing environmental impacts, and the development of appropriate systems are becoming increasingly important. In this context, clean and efficient combustion of Turkey's almost 22 billion tons of low-quality lignite reserves, along with newly discovered resources, is crucial for meeting a significant portion of the country's energy needs. Of Turkey's coal, 7.3% is hard coal, while 92.7% is lignite. Turkey has approximately 19.3 billion tons of lignite and 1.5 billion tons of hard coal reserves. Additionally, fuels from organic sources like biomass, whose production has increased in Turkey in recent years, are also being used.Fluidized beds are systems in which solid particles exhibit fluid-like behavior. In these systems, solid particles move within a gas or liquid, leading to behavior similar to that of a fluid. This technology is particularly effective for burning low-quality fossil or non-fossil fuels under complete combustion conditions. By maintaining bed temperatures at 800-900°C for coal or 400-500°C for non-fossil fuels like biomass, the formation of NOx is reduced, and SO₂ can be captured with the addition of suitable adsorbents. Consequently, the need for flue gas treatment facilities is often eliminated In fluidized beds, combustion and emission behaviors are primarily determined by bed hydrodynamics. Fluidized bed hydrodynamics is a mechanism that explains the interactions and dynamics of gas-solid two-phase flow. In this study, the hydrodynamics of two-phase flow within a fluidized bed were analyzed using the Ansys Fluent computational fluid dynamics program. The model was based on my design, using simpler, more classic fluidized bed designs for various analyses, and the system was examined. The flow cycle created by the gas and solid phases was visualized, and the flow characteristics were analyzed by creating pressure contours, gas velocity distributions within the column, solid velocity distributions, and velocity and pressure profiles at the system inlet.