Abstract: A method of starting up a fluidized bed combustor in which a gas containing oxygen is passed from an outlet beneath the level of the slumped bed to cause a spouting action above the level of the slumped bed. Liquid fuel is supplied from a nozzle adjacent to or located within the spout, and an ignition source applied to the bed. The liquid fuel and gas containing oxygen supply are regulated so as to fluidize at least part of the bed adjacent to the liquid fuel outlet and to obtain a controlled rise in the temperature of the bed until the hot fluidized condition is reached.

Abstract: The invention is directed to improving the quality of fluidization of fluidized solids and comprises the addition of fluidization promoters in particle form that have a smaller density and particle size than the neat solids. In a preferred embodiment of the invention the catalyst is a Fischer-Tropsch catalyst and the fluidization promoter comprises carbon particles.