Oxycombustion Circulating Fluidized Bed Reactor, Method of Operating Such a Reactor and Method of Upgrading a Circulating Fluidized Bed Reactor

Abstract

An oxycombustion circulating fluidized bed reactor includes a reactor chamber, and a gas distribution arrangement provided in the bottom section of the reactor chamber for introducing gas into the reactor chamber. A windbox chamber having gas introduction nozzles introduces gas from the windbox chamber into the reactor chamber and an has an inlet that opens into the windbox chamber. A first gas feeding system introduces gas into the windbox chamber, and a second gas feeding system introduces gas into the wind box chamber in the vicinity of at least one nozzle inlet.

1 . An oxycombustion circulating fluidized bed reactor comprising:
 a reactor chamber; and   a gas distribution arrangement provided in the bottom section of the reactor chamber for introducing gas into the reactor chamber, the gas distributor arrangement comprising (i) a windbox chamber having gas introduction nozzles, the gas introduction nozzles being arranged for introducing gas from the windbox chamber into the reactor chamber and having respective inlets that open into the windbox chamber, (ii) a first gas feeding system for introducing gas into the windbox chamber, and (iii) a second gas feeding system for introducing gas into the wind box chamber in the vicinity of at least one nozzle inlet.   
     
     
         2 . An oxycombustion circulating fluidized bed reactor according to  claim 1 , wherein the second gas feeding system comprises a number of outlets, each of the outlets being arranged to direct the gas to be fed towards a nozzle inlet. 
     
     
         3 . An oxycombustion circulating fluidized bed reactor according to  claim 2 , wherein the outlets are arranged to direct the gas into the nozzle inlet. 
     
     
         4 . An oxycombustion circulating fluidized bed reactor according to  claim 2 , wherein the outlets are arranged at a distance below the nozzle inlet. 
     
     
         5 . An oxycombustion circulating fluidized bed reactor according to  claim 2 , wherein the outlet and the inlet provide an ejector effect. 
     
     
         6 . An oxycombustion circulating fluidized bed reactor according to  claim 1 , wherein the reactor chamber includes a particle separator for separating fluidized particles which are entrained with gases that result from the reactions taking place in the reaction chamber. 
     
     
         7 - 16 . (canceled) 
     
     
         17 . An oxycombustion circulating fluidized bed reactor according to  claim 6 , wherein the particle separator is provided with a gas outlet and an outlet for separated particles. 
     
     
         18 . An oxycombustion circulating fluidized bed reactor according to  claim 17 , wherein the gas outlet is arranged in flow communication with the first gas feeding system via a recycling conduit. 
     
     
         19 . An oxycombustion circulating fluidized bed reactor according to  claim 18 , wherein the recycling conduit includes a gas mixing unit. 
     
     
         20 . An oxycombustion circulating fluidized bed reactor according to  claim 19 , wherein the gas mixing unit is in flow communication with a source of oxygen-rich gas. 
     
     
         21 . An oxycombustion circulating fluidized bed reactor according to  claim 1 , wherein the second gas feeding system is in flow communication with a source of oxygen-rich gas. 
     
     
         22 . A method of operating an oxycombustion circulating fluidized bed reactor that has a reactor chamber and a gas distribution arrangement provided in the bottom section of the reactor chamber, the method comprising:
 introducing gas into a windbox chamber, having gas introduction nozzles with respective inlets, through a first gas feeding system;   introducing gas into the reaction chamber through the windbox chamber; and   introducing a stream of oxygen-rich gas through a second gas feeding system into the vicinity of the inlet of at least one nozzle in the windbox chamber.   
     
     
         23 . A method of operating an oxycombustion circulating fluidized bed reactor according to  claim 22 , further comprising introducing the stream of oxygen-rich gas from a distance towards the inlet of at least one nozzle through an outlet in the second gas feeding system. 
     
     
         24 . A method of operating an oxycombustion circulating fluidized bed reactor according to  claim 22 , further comprising introducing gas containing more than 90% of oxygen into the vicinity of the inlet of at least one nozzle through the second gas feeding system. 
     
     
         25 . A method of operating an oxycombustion circulating fluidized bed reactor according to  claim 22 , further comprising introducing a mixture of recycled exhaust gas and oxygen through the first gas feeding system to the windbox chamber. 
     
     
         26 . A method of operating an oxycombustion circulating fluidized bed reactor according to  claim 25 , further comprising mixing the stream of oxygen-rich gas with the gas introduced through the first gas feeding system to the windbox chamber at the inlet of the nozzle. 
     
     
         27 . A method of operating an oxycombustion circulating fluidized bed reactor according to  claim 22 , wherein the stream of oxygen-rich gas induces an ejector effect to the gas in the windbox chamber. 
     
     
         28 . A method of upgrading an existing circulating fluidized bed reactor having a windbox chamber provided with nozzles and a first gas feeding system for feeding gas to the windbox chamber, the method comprising steps of:
 arranging a second gas feeding system having a plurality of feed pipes below inlets of the nozzles into the windbox chamber of the existing circulating fluidized bed reactor; and   arranging a source of oxygen-rich gas in connection with the second gas feeding system.   
     
     
         29 . A method of upgrading an existing circulating fluidized bed reactor according to  claim 28 , further comprising providing the existing circulating fluidized bed reactor with an exhaust gas recycling conduit that connects the exhaust gas conduit to the windbox chamber of the reactor. 
     
     
         30 . A method of upgrading an existing circulating fluidized bed reactor according to  claim 29 , further comprising feeding the source of oxygen-rich gas to the first gas feeding system.