include a cylindrical chamber into which the gas solid mixture is tangentially directed causing a vortex flow whereby the inertia of the solid particlesdirects them to the walls of the chamber by centrifugal acceleration upon contact with the wall the solids drop to the bottom of the cyclone by gravity in the preferred embodiment the cyclone separator is lined with ceramic material to improve its abrasion resistance a valve at the bottomof the cyclone separators is used to maintain a level of solid particles and to control flow of solids while a single cyclone separator is described it is clear that multiple separators may be used to improve the gas solid separation if multiple separators are used they can be arranged in series parallel or some combination of the two the process gas 82 from the fluidized bed oxidizer exits the top of the cyclone separators and can be vented to the atmosphere however if significant levels of pollutants are present in the process gas it can befurther treated such as by gas scrubbing or selective catalytic reduction in process gas treater 90 treated process gas 92 can be vented to the atmosphere it is also possible to recover waste heat from the discharge of process gas by using a heat exchanger to.