The invention relates to abed management cycle for a fluidized bed boiler, comprising the steps of: a) providing fresh ilmenite particles as bed material to the fluidized bed boiler; b) carrying out a fluidized bed combustion process; c) removing at least one ash stream comprising ilmenite particles from the fluidized bed boiler; d) separating ilmenite particles from the at least one ash stream; e) recirculating separated ilmenite particles into the bed of the fluidized bed boiler. The invention also relates to a corresponding arrangement for carrying out fluidized bed combustion, comprising a fluidized bed boiler comprising ilmenite particles as bed material; and a system for removing ash from the fluidized bed boiler; wherein the arrangement further comprises a separator for separating ilmenite particles from the re-moved ash; and means for recirculating separated ilmenite particles into the bed of the fluidized bed boiler.

A rapid thermal processing system includes an inorganic heat carrier particles reheater coupled to an inorganic particle cooler. For example. inorganic heat carrier particles may be cooled in a shell and tube inorganic particle cooler by indirect heat exchange with a cooling medium. The cooled inorganic heat carrier particles may then be supplied to a reactor to transfer heat to carbonaceous material.

A fluidized bed system includes a first nozzle group that is provided inside a fluidized bed furnace, a second nozzle group that is provided inside the fluidized bed furnace, a first supply section that supplies a gas into the fluidized bed furnace through the first nozzle group, a second supply section that supplies the gas into the fluidized bed furnace through both the first and second nozzle groups, and a control section that controls the second supply section during a start-up operation to supply the gas into the fluidized bed furnace to form a fluidized bed of a fluid medium inside the fluidized bed furnace, and stops the supply of the gas by the second supply section and controls the first supply section during a normal operation to supply the gas into the fluidized bed furnace to form the fluidized bed of the fluid medium inside the fluidized bed furnace.

A particle separator module and a heat exchange chamber module connectable to a circulating fluidized bed boiler. The particle separator module includes 2N vertically aligned steam tubes, N being an integer greater than one. Each of the vertically aligned steam tubes is attached to a boiler upper portion and extends downwards to a predetermined level. Each of the 2N vertically aligned steam tubes is attached to one of N first beams. Each of the N first beams is suspended to hang in a horizontal position at the predetermined level by two adjacent steam tubes of the 2N vertically aligned steam tubes. N second beams are attached in a horizontal position to the top surface of the heat exchange chamber module, which is arranged to be suspended from the particle separator module by having each of the N second beams suspended by two adjacent beams of the N first beams.

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.

In a method for operating a steam generator, a transport reactor is provided. Only a substantially pure oxygen feed stream is introduced into the transport reactor in an amount sufficient to maintain the transport reactor at or above a specific system load. The specific load is the system load when only the substantially pure oxygen feed stream is provided to the transport reactor at a minimum flow velocity for operating the transport reactor. A fuel is combusted in the presence of the substantially pure oxygen feed stream to produce a flue gas, which contains solid material. The solid material is separated from the flue gas and passed to a heat exchanger. The heat exchange may be one of a moving bed heat exchanger or a fluidized bed heat exchanger. The solid material is directed to the transport reactor to contribute to the combustion process.

A fluidized bed heat exchanger with a chamber (24) comprises a solid particles inlet port (22), a solid particles outlet port (30), arranged at a distance to the inlet port (22), means (46) for introducing a fluidizing gas from a bottom area into the chamber (24). The heat exchanger further comprises at least two heat transfer means (28) within the one chamber (24), each being provided with a heat transfer medium inlet port (42) and a heat transfer medium outlet port (44), wherein a first heat transfer means (28) is designed as a reheater and second heat transfer means (28) is designed as a superheater to achieve a heat transfer medium temperature and a heat transfer medium pressure above that of the reheater. At least one of the reheater or superheater is made of a multiplicity of heat transfer tubes arranged in a meandering fashion for conveying a heat transfer medium.

The present invention relates to an iron fuel boiler process for iron fuel combustion, comprising the steps of combusting an iron fuel suspension medium comprising iron fuel and oxygen in an iron fuel burner arrangement to obtain an iron oxide containing medium; receiving the iron oxide containing medium into an iron fuel boiler arrangement for transferring the iron oxide containing medium towards a separation unit disposed at the end of said iron fuel boiler arrangement; exchanging heat between the iron oxide containing medium and a boiler of the iron fuel boiler arrangement with a heat-exchange medium during the transfer of the iron oxide containing medium through said iron fuel boiler arrangement; and separating iron oxide from the oxide containing medium to obtain solid iron oxide particles and a gas flow. The process further comprising the step of cooling said iron oxide containing medium with a cooling medium during said transfer of the iron oxide containing medium through the iron fuel boiler arrangement such that a temperature of the iron oxide is achieved of below the sintering temperature of the particles at said separation unit.

A method of monitoring circulation of solid material in a circulating fluidized bed reactor including a reaction chamber, at least one solid material separator, and a return path between the separator and the chamber. The method includes selecting process variables of the process of circulating of solid material in the return path, and selecting performance indicators of the process of circulation of solid material amongst the selected process variables for each performance indicator of the process of circulation of material, creating a multivariate model for each performance indicator, using history data of the process variables and the performance indicators, determining a modelled value of the performance indicators, by applying current measured values of the process variables to the multivariate model, and comparing the modelled value of each performance indicator to a respective measured value and inspecting a presence of an anomaly between the modelled value and the respective measured value.