This paper presents a case study for the selection of an optimum CFD technique from various techniques which are used to study and understand the flow in a Gas-Solid fluidized bed. Fluidization is an operation through which fine solid particles are transformed into a fluid like state through contact with either a gas, liquid or both and behave like a fluid through suspension in a liquid or gas. Fluidization is the preferred method of operation due to its many advantages over other configurations, like good solid mixing leading to uniform temperature and maintaining it throughout the bed, high mass and heat transfer rates, significantly lower pressure drops which reduce pumping costs and lower pollutant emissions, among many others. That is why, the Gas–Solid fluidized bed reactors have various advantages that make them attractive for a number of industrial processes. There is a need to improve the designs and reduce the emissions of these Gas-Solid fluidized bed reactors due to the increasing applications of the same. The fluidization and heat transfer behaviors of a fluidized bed are studied using various Computational Fluid Dynamics (CFD) techniques and flow models used for gas-fluidization.