This work presents the design and experimental evaluation of a cold-flow model, built to simulate a 100 kW chemical-looping combustor for solid fuel. A theoretical background is provided, as well as some initial results using air as fluidization medium. The cold-flow model has been operated for about 10 h and shows no indication of imbalances in the bed inventories. In the fuel and air reactors, the mass fluxes were found to be linear in the riser pressure drop and the corresponding measured mass flows were approximately proportional to the mass flows calculated from the riser pressure drop. From the study of mass flows, residence times in both the fuel and air reactor were obtained. From pressure profile investigations, it was found that the system remained stable to changes in the fluidization velocity. Thus, both the internal circulation in the fuel reactor, and the circulation between air and fuel reactor, could be varied in a large range with only minor impact on the solids inventories of the air and fuel reactors. (C) 2012 Elsevier B.V. All rights reserved.