A comprehensive simulation program for fluidised bed equipment (CSFB) has been improved and is now able to predict operational conditions of bubbling and circulating fluidised bed equipment such as boilers, gasifiers, dryers, shale-retorting reactors, and pyrolysers with various designs and consuming a wide range of feedstock. This paper concentrates on the improvements on the original bubbling model. Comparisons between simulation results and real equipment operational conditions under bubbling fluidised bed techniques are presented. Since those comparisons showed relatively low deviations, it is believed that CSFB is useful for improving operational conditions of existing industrial units and as auxiliary tool for designing of new equipment. (c) 2007 Elsevier Ltd. All rights reserved.