To analyse the behaviour of gas-solid flow, the experimental, nonintrusive technique of particle image velocimetry (PIV) was applied. This technique enables the acquisition of information regarding the microscopic velocity field in a bidimensional plane. The physical experiments were conducted in the vertical and horizontal sections of a test facility. The operating conditions at the inlet were 140 m(3)/h of air and a 40 g/m(3) mass load ratio, which are typical conditions for dilute flows. Solid-phase catalyst particles with a Sauter mean diameter of 56.7 mu m, similar to those applied in the petroleum industry for FCC systems, were used. Experimental radial profiles for the axial velocity data of the solid phase were compared with the respective numerical results obtained by the CFD code in FLUENT 13. Turbulence in the gas phase was modelled with a k - epsilon model, and second-order versions of this model were used for turbulence in the solid phase. Turbulence was induced by the drag force with direct numerical simulation (inviscid model) and was modelled using the kinetic theory for granular material with the equilibrium model (KTGF equilibrium). The results showed that both the inviscid and KTGF models produced good agreement with the experimental data for dilute gas-solid flow in ducts, particularly in regions of developed flow.