Combustion performances and emission characteristics of olive cake and coal are investigated in a bubbling fluidized bed. Flue gas concentrations of O-2, CO, SO2, NOx, and total hydrocarbons (CmHn) were measured during combustion experiments. Operational parameters (excess air ratio (lambda), secondary air injection) were changed and variation of pollutant concentrations and combustion efficiency with these operational parameters were studied. The temperature profiles measured along the combustor column was found higher in the freeboard for olive cake than coal due to combustion of hydrocarbons mostly in the freeboard. Combustion efficiencies in the range of 83.6-90.1% were obtained for olive cake with lambda of 1.12-2.30. For the setup used in this study, the optimum operating conditions with respect to NOx and SO2 emissions were found as 1.2 for lambda and 50 L/min for secondary air flowrate for the combustion of olive cake. (c) 2006 Elsevier Ltd. All rights reserved.