Spherical nano-sized zinc oxide (ZnO) particles were produced by a spray pyrolysis method using the aerosol technique described in this study. The effects of reaction temperatures of 600, 800 and 1000 degrees C and collection locations of the particles, such as the flask collector and the tube exit, on the morphology and crystal structure of the ZnO particles were investigated. X-ray diffraction (XRD) studies showed that the crystallinity of the particles was increased by increasing the reaction temperature from 600 degrees C to 1000 degrees C. Fourier transform infrared spectroscopy (FIR) measurements revealed that the particles were pure and similar to each other. Scanning electron microscopy (SEM) revealed that the synthesized nanoparticles had sizes between 200 nm and 400 nm, with uniform morphologies. A computational fluid dynamics (CFD) model of the horizontally positioned tube reactor was developed. Simulation results provided information about the residence time and the temperature distribution along the tube, which were found to be correlated to the particle morphology. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.