Thermal regeneration of bentonite sorbent with application of the reburning, as a method of reduction of NOx emission, has been presented. It has been proved that in the freebooard above fluidised bed, it can be achieved significant decrease of NOx concentration in the flue gases, related to contractual conditions. In the freeboard of the reactor besides reburning it has been conduced separation of the raw material from regenerated material and pneumatic transport of solid material achieved from regeneration. It has been revealed that transport processes have no negative influence on NOx reduction conditions. Heat evolved above the fluidised bed is partly transferred to the fluidised bed and that facilitates obtaining the thermal equilibrium in the bed.