The new version of a comprehensive simulation program of moving and fluidized-beds (CSFB or CSFMB) has been tested against data generated from a gasification unit at the University of California at Davis (UCD), Department of Biological and Agricultural Engineering. The pilot operated at atmospheric pressure under bubbling fluidized-bed and consumed various biomasses as well residues. Air was used as gasifying agent and electrical resistances around the reactor helped heating the reactor during start-up and were kept under low energy discharge during experiments. CSFMB was adapted to allow simulation of such cases as well to several other possibilities of additional heating systems to reactors. The present paper presents the results from cases of almond shells and walnut pruning gasification. Good to reasonable agreement between simulation and operational data have been obtained. (c) 2008 Elsevier Ltd. All rights reserved.