The multi zone fluidized bed reactor instantaneously creates several chemical/physical environments in a single reactor vessel. Effective solid circulation across zones can be achieved by tuning the reactor geometries, solid properties, and operating conditions. However, there is limited research for this innovative reactor concept beyond the laboratory scale, among which a better understanding of the complex fluid dynamics, dominating the solid circulation in different zones, is a basis. This work aims to propose a new method to capture the fluid dynamics of a pilot MZFBR by laboratory measurements with validation from theoretical analysis and simulation. Toward this goal, we first performed particle characterizations, and fluidization testing experiments in a laboratory scale fluidized bed reactor and a pilot scale multi zone fluidized bed reactor at ambient conditions to study the development of fluidization regimes. Then we compared the minimum fluidization velocity with argon and air between the experimental measurements and theoretical calculation results and proposed a modified Ergun equation, which better fits our system. Finally, we conducted computational particle fluid dynamics simulations for the pilot multi zone fluidized bed reactor with the Ergun equation and our modified equation and compared the results against previous experimental observations. Simulations display that the prediction of pressure drop in the pilot scale multi zone fluidized bed reactor with the proposed Ergun equation is similar to that of the original equation, with a relative deviation of around 3%. However, the modified equation captured the bubbling fluidization behavior as the experiment, while the Ergun equation predicted a smooth fluidization without any bubbles. The better agreements validated both our workflow of estimating the fluidization behavior in a pilot multi zone fluidized bed reactor from laboratory measurements and the simulation strategy.