Method of and a plant for combusting carbonaceous fuel by using a solid oxygen carrier

A method of combusting carbonaceous fuel in a combustion plant, the method comprising the steps of:

• (a) introducing particulate oxygen selective sorbent into an adsorption reactor of the combustion plant to form a first particle bed in the adsorption reactor;
• (b) fluidizing the first particle bed by an oxygen-containing first fluidizing gas to provide a first partial pressure of oxygen p1 in the adsorption reactor to adsorb oxygen from the fluidizing gas to the sorbent, so as to produce oxygen-rich sorbent and oxygen-depleted exhaust gas;
• (c) discharging oxygen-depleted exhaust gas from the adsorption reactor along a first exhaust gas channel;
• (d) conveying oxygen-rich sorbent from the adsorption reactor to a combustion reactor of the combustion plant along a sorbent conveying channel to form a second particle bed in the combustion reactor;
• (e) fluidizing the second particle bed by an oxygen-deficient second fluidizing gas to provide a second partial pressure of oxygen p2 in the combustion reactor, where p2 is less than p1, to desorb oxygen from the sorbent, so as to produce free oxygen gas and oxygen-depleted sorbent;
• (f) introducing carbonaceous fuel into the combustion reactor to oxidize the fuel with the free oxygen gas, and to produce carbon dioxide containing exhaust gas, and to maintain a low partial pressure of oxygen p2′ in the combustion reactor, where p2′ is less than p1, to continue desorbing oxygen from the sorbent;
• and
• (g) discharging carbon dioxide containing exhaust gas from the combustion reactor along a second exhaust gas channel.