HYDRODYNAMICS CHARACTERISTICS OF NANOPARTICLE AGGLOMERATES HAVE BEEN INVESTIGATED IN A FLUIDIZED BED. THE EXPERIMENTAL MEASURMENTS WERE PERFORMED IN A BED CONTAINING SILVER OXIDE DRY POWDER BELONGING TO GROUP B OF GELDART’S CLASSIFICATION WITH AN INITIAL PARTICLE SIZE OF 30 NM. PRESSURE MEASUREMENTS AND AN OPTICAL FIBER TECHNIQUE ALLOWED DETERMINING THE EFFECT OF INITIAL PARTICLES LOADINGS ON THE FLUIDIZATION CHARACTERISTICS AND SOLID VOLUME FRACTION OF PARTICLES. INTERPARTICLE ADHESION FORCES BETWEEN SILVER OXIDE NANOPARTICLES GIVE RISE TO THE FORMATION OF NANOPARTICLE AGGLOMERATES WITH A WIDE PARTICLE SIZE DISTRIBUTION. NUMERICAL SIMULATIONS WERE ALSO PERFORMED TO EVALUATE THE SENSITIVITY OF GAS-SOLID DRAG MODELS. IN ALL SIMULATIONS, AN EULERIAN-EULERIAN TWO FLUID MODEL AND AN AVERAGE PARTICLE SIZE OF 200 MM WAS USED WITH DIFFERENT DRAG MODELS. THE AXIAL PROFILE OF SOLID VOLUME FRACTION HAVE BEEN DETERMINED TO EVALUATE THE SENSITIVITY OF DIFFERENT DRAG MODELS, INCLUDING WEN-YU., GIDASPOW, AND MODIFIED SYAMLAL-O, BRIEN FUNCTIONS. THE SIMULATION RESULTS OBTAINED FOR THE BED EXPANSION RATIO AND MINIMUM FLUIDIZATION VELOCITY SHOW THAT THE MODIFIED SYAMLAL-O’BRIEN DRAG MODEL PROVIDES THE CLOSEST FIT TO THE EXPERIMENTAL DATA.