The invention relates to a method and to a device for chemical looping combustion CLC of a solid hydrocarbon feed wherein it is proposed to inject the solid hydrocarbon feed so as to limit any occurrence of sticking of the feed to the walls of the injection device. The solid feed is fed into a conveying zone operating under fluidized bed conditions and opening into a combustion reactor. A fluidization gas is injected into this conveying zone while controlling the flow of gas in such a way that the superficial velocity of the gas in the conveying zone is higher than the terminal velocity of the solid hydrocarbon feed particles and the terminal velocity of solid particles present in the combustion reactor, and while controlling the fluidization gas temperature in such a way that the temperature in the conveying zone is less than or equal to 500 C.

Systems and methods for generating electrical power combine pressurized fluidized bed combustors (PFBC) and molten carbonate fuel cells (MCFC) to provide a low cost solution for electricity generation with CO.sub.2 capture. A solid fuel is introduced fuel into a pressurized fluidized bed combustor to produce steam, a first quantity of electrical power, and a flue gas including CO.sub.2. Air, natural gas, at least a portion of the steam and at least a portion of the flue gas including CO.sub.2 are introduced to a molten carbonate fuel cell to produce a second quantity of electrical power and an output stream comprising primarily CO.sub.2. The pressurized fluidized bed combustor can desirably be air-fired and the solid fuel introduced there into can desirably be in a finely pulverized form.

Methods and devices for combusting a carbonaceous fuel in an oxy-combustion fluidized bed reactor involving controlling the local oxygen content within the oxy-combustion reactor to specified levels. The carbonaceous fuel and an oxygen-containing gas are introduced into a fluidized bed reactor and eluted through a fluidized bed of an inert material, dolomite or a combination thereof to combust the fuel and oxygen to produce at least CO.sub.2 and steam. The oxygen-containing gas is a mixture of oxygen, recycled CO.sub.2 and steam and has sufficient oxygen added to the recycled CO.sub.2 and steam that the mixture contains 7-20 mole % oxygen. The carbonaceous fuel and the oxygen-containing gas are introduced into the fluidized bed at a location in sufficiently close proximity to each other to avoid producing a reducing atmosphere at the location. At least a portion of the produced CO.sub.2 and steam are recycled to the reactor.

A method for efficiently conveying impurities in a pressurized fluidized incinerator system is provided. Cleaning gas is supplied to an upper valve, and thereafter, the upper valve is driven so as to communicate an upper discharge device and a tank. The upper discharge device is driven so as to convey the impurities from the dust collector to the tank, and thereafter, the upper discharge device is stopped and the upper valve is driven so as not to communicate the upper discharge device and the tank. Thereafter, the supply of the cleaning gas to the upper valve is stopped.

Methods and devices for combusting a carbonaceous fuel in an oxy-combustion fluidized bed reactor involving controlling the local oxygen content within the oxy-combustion reactor to specified levels. The carbonaceous fuel and an oxygen-containing gas are introduced into a fluidized bed reactor and eluted through a fluidized bed of an inert material, dolomite or a combination thereof to combust the fuel and oxygen to produce at least CO.sub.2 and steam. The oxygen-containing gas is a mixture of oxygen, recycled CO.sub.2 and steam and has sufficient oxygen added to the recycled CO.sub.2 and steam that the mixture contains 7-20 mole % oxygen. The carbonaceous fuel and the oxygen-containing gas are introduced into the fluidized bed at a location in sufficiently close proximity to each other to avoid producing a reducing atmosphere at the location. At least a portion of the produced CO.sub.2 and steam are recycled to the reactor.

A method of operating an oxycombustion circulating fluidized bed (CFB) boiler that includes a furnace having a grid at its bottom section, a solid material separator connected to an upper part of the furnace, and an external solid material handling system. Oxidant gas is introduced into the CFB boiler through the grid as fluidizing gas, the fluidizing gas including recirculating flue gas. Fuel material is introduced into the circulating fluidized bed. A sulfur reducing agent including CaCO.sub.3 is introduced into the circulating fluidized bed. Solid material is circulated out of the furnace and provides an external circulation of solid material via the external solid material handling system. The solid material is fluidized in the external solid material handling system by introducing a fluidizing medium including recirculating flue gas into the handling system. A predetermined amount of steam is introduced into the handling system as a component of the fluidizing medium.

Sulfurous fuel and CaCO.sub.3-containing sorbent are combusted in a furnace of a circulating fluidized bed boiler. A dry circulating fluidized bed scrubber includes a reactor with water and Ca(OH).sub.2 feeds for converting SO.sub.2 in the exhaust gas to CaSO.sub.3 and CaSO.sub.4 and a dust separator in gas flow connection with the reactor. A discharge removes CaO-containing bottom ash from the furnace. A classifier classifies a portion of the removed CaO-containing bottom ash into coarse and finer portions. A fine ash channel conveys some of the finer bottom ash portion from the classifier to a grinder. A ground ash channel conveys some of the ground bottom ash portion from the grinder to a hydrator to hydrate CaO in the ash to Ca(OH).sub.2. A hydrated ash channel conveys some of the Ca(OH).sub.2 from the hydrator to the dry circulating fluidized bed scrubber as a sorbent.