Patent ID: 7946843

Claim:
A method of combusting solid 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 fludizing gas to provide a first partial pressure of oxygen p 1 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 consisting mainly of carbon dioxide, to provide a second partial pressure of oxygen p 2 in the combustion reactor, where p 2 is less than p 1 , to desorb oxygen from the sorbent in the combustion reactor, so as to produce free oxygen gas and oxygen-depleted sorbent; (f) introducing solid carbonaceous fuel into the combustion reactor to oxidize the fuel with the free oxygen gas, and to produce exhaust gas consisting mainly of carbon dioxide and water, and to maintain a low partial pressure of oxygen p 2 ′ in the combustion reactor, where p 2 ′ is less than p 1 , to continue desorbing oxygen from the sorbent; (g) discharging exhaust gas from the combustion reactor along a second exhaust gas channel; and (h) obtaining at least a portion of the second fluidizing gas as a side stream of the exhaust gas discharged from the combustion reactor.