Design and scale-up of fluidized beds are significantly impacted by their hydrodynamic features. Cold flow experimentation complemented by CFD simulations are powerful tools for understanding different phases behavior and optimize the design for real operation conditions. This presentation provides instances of hydrodynamic studies utilized for design of processes for thermochemical conversion of Biomass and Petcoke through Chemical Looping Combustion and Pyrolysis. The features of the key elements such as fluidized bed reactors, L-valves and solid fuel injection line are presented through an experimental and numerical approach.