An air nozzle arrangement for a fluidized bed boiler, comprising an air feed pipe and an air nozzle which limit an air feed duct configured to supply air to the furnace of the fluidized bed boiler. The air nozzle arrangement comprises a surface configured to guide coarse material along said surface. At least part of said surface is thermally insulated from the air nozzle and/or the air feed pipe. Furthermore, at least part of said surface is configured to protect at least part of said air nozzle and/or air feed pipe. Thus, the temperature of said surface is configured to be high when the fluidized bed boiler is in operation, whereby the solidification of molten material of the fluidized bed in the air nozzle arrangement is reduced.

An air nozzle arrangement for a fluidized bed boiler, comprising an air feed pipe and an air nozzle which limit an air feed duct configured to supply air to the furnace of the fluidized bed boiler. The air nozzle arrangement comprises a surface configured to guide coarse material along said surface. At least part of said surface is thermally insulated from the air nozzle and/or the air feed pipe. Furthermore, at least part of said surface is configured to protect at least part of said air nozzle and/or air feed pipe. Thus, the temperature of said surface is configured to be high when the fluidized bed boiler is in operation, whereby the solidification of molten material of the fluidized bed in the air nozzle arrangement is reduced.

A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.

A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.

The invention relates to a method for chemical-looping combustion of a hydrocarbon-containing feedstock, comprising: contacting oxygen-carrying material particles coming from a reduction zone R0 with an oxidizing gas stream in a reactive oxidation zone R1, separating the fly ashes, the fines and the oxygen-carrying material particles within a mixture coming from zone R1 in a dilute phase separation zone S2, the driving force required for dilute phase elutriation in S2 being provided by the oxidizing gas stream from reactive oxidation zone R1. Optionally, partitioning is carried out in a dedusting zone S4, then possibly in a dense phase elutriation separation zone S5. The invention also relates to a chemical-looping combustion plant allowing said method to be implemented.

The invention relates to a method for chemical-looping combustion of a hydrocarbon-containing feedstock, comprising: contacting oxygen-carrying material particles coming from a reduction zone R0 with an oxidizing gas stream in a reactive oxidation zone R1, separating the fly ashes, the fines and the oxygen-carrying material particles within a mixture coming from zone R1 in a dilute phase separation zone S2, the driving force required for dilute phase elutriation in S2 being provided by the oxidizing gas stream from reactive oxidation zone R1. Optionally, partitioning is carried out in a dedusting zone S4, then possibly in a dense phase elutriation separation zone S5. The invention also relates to a chemical-looping combustion plant allowing said method to be implemented.

A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.

A carbonaceous feed pyrolysis apparatus is provided including two or more hot particle fluidized beds, and one or more positive displacement apparatus for the transfer of hot particles between two or more of the beds, wherein one or more of the fluidized beds contains a combustion zone. A bio-oil production process is also provided, including pyrolysis of a carbonaceous bio-mass using two or more fluidized beds, including a first combustion zone carried out in one or more combustion fluidized beds in which a particulate material is fluidized and heated, and a second pyrolysis zone carried out in one or more pyrolysis fluidized beds in which the hot particles heated in the combustion zone are used for pyrolysis of the bio-mass.

A carbonaceous feed pyrolysis apparatus is provided including two or more hot particle fluidized beds, and one or more positive displacement apparatus for the transfer of hot particles between two or more of the beds, wherein one or more of the fluidized beds contains a combustion zone. A bio-oil production process is also provided, including pyrolysis of a carbonaceous bio-mass using two or more fluidized beds, including a first combustion zone carried out in one or more combustion fluidized beds in which a particulate material is fluidized and heated, and a second pyrolysis zone carried out in one or more pyrolysis fluidized beds in which the hot particles heated in the combustion zone are used for pyrolysis of the bio-mass.

A method of preventing blockage of circulating bed material in a circulating fluidized bed reactor includes collecting a continuously flowing bed of solid particles in a gas lock in a return leg of a reactor, measuring gas lock bed pressure values within the bed of the particles, generating a gas lock bed height indication signal on the basis of measured gas lock bed pressure values. A definition stage includes defining and storing to a control system a range of normal gas lock bed height indication signals, formed in normal circulation flow conditions, as a function of the reactor load, and defining and storing to the digital control system a reactor load dependent alarm criterion. The method includes comparing a current gas lock bed height indication signal with the reactor load dependent alarm criterion, and decreasing the reactor load if the current indication signal fulfils the reactor load dependent alarm criterion.