Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

A water-cooled column (4) used in a circulating fluidized bed boiler furnace is disclosed, wherein the water-cooled column is formed by connecting membrane water-cooled walls (41). The water-cooled column (4) includes a lower section (A), an upper section and a transition section. The lower section (A) is a single column and is provided with inner secondary air ports (400) on a side wall thereof. The upper section includes a plurality of sub-columns (B, C). The membrane water-cooled walls at the lower section (A) extend to the upper section through the transition section. Each of the sub-columns (B, C) is formed by connecting extension portions extending upward from respective membrane water-cooled walls (41) in the membrane water-cooled walls (41), which are connected to form the lower section (A), and the plurality of sub-columns (B, C) are separated from each other.

A water-cooled column (4) used in a circulating fluidized bed boiler furnace is disclosed, wherein the water-cooled column is formed by connecting membrane water-cooled walls (41). The water-cooled column (4) includes a lower section (A), an upper section and a transition section. The lower section (A) is a single column and is provided with inner secondary air ports (400) on a side wall thereof. The upper section includes a plurality of sub-columns (B, C). The membrane water-cooled walls at the lower section (A) extend to the upper section through the transition section. Each of the sub-columns (B, C) is formed by connecting extension portions extending upward from respective membrane water-cooled walls (41) in the membrane water-cooled walls (41), which are connected to form the lower section (A), and the plurality of sub-columns (B, C) are separated from each other.

Processes for producing polycrystalline silicon by thermal decomposition of silane are disclosed. The processes generally involve thermal decomposition of silane in a fluidized bed reactor operated at reaction conditions that result in a high rate of productivity relative to conventional production processes.

Processes for producing polycrystalline silicon by thermal decomposition of silane are disclosed. The processes generally involve thermal decomposition of silane in a fluidized bed reactor operated at reaction conditions that result in a high rate of productivity relative to conventional production processes.

A circulating fluidized bed apparatus, comprising a circulating fluidized bed furnace 10 with an outer furnace wall 10r and at least one heat exchange chamber 20, which is friction-locked to a section of the outer furnace wall 10r, as well as a platform PL which extends horizontally and at a distance to an upper ceiling 10c of said heat exchange chamber 20, wherein the heat exchange chamber 20 is further supported by at least one leverage 50, which is arranged onto said platform PL and extends from a first end 50f, pivotally mounted to the outer furnace wall 10r, away from said furnace wall 10r to a second end 50s, and a fastener 60 extending downwardly from said second end 50s of said leverage 50 to a part of the heat exchange chamber 20 offset the outer furnace wall 10r.

A circulating fluidized bed apparatus, comprising a circulating fluidized bed furnace 10 with an outer furnace wall 10r and at least one heat exchange chamber 20, which is friction-locked to a section of the outer furnace wall 10r, as well as a platform PL which extends horizontally and at a distance to an upper ceiling 10c of said heat exchange chamber 20, wherein the heat exchange chamber 20 is further supported by at least one leverage 50, which is arranged onto said platform PL and extends from a first end 50f, pivotally mounted to the outer furnace wall 10r, away from said furnace wall 10r to a second end 50s, and a fastener 60 extending downwardly from said second end 50s of said leverage 50 to a part of the heat exchange chamber 20 offset the outer furnace wall 10r.