A plugging resistant, highly stable free-jet burner and method which provide Ultra-Low NO.sub.x emissions using (a) large free-jet ejection ports, (b) a wide tip-to-tip spacing, and (c) auxiliary stabilization tips in the throat of the burner which are highly resistant to plugging and also produce very low levels of NO.sub.x emissions.

A plugging resistant, highly stable free-jet burner and method which provide Ultra-Low NO.sub.x emissions using (a) large free-jet ejection ports, (b) a wide tip-to-tip spacing, and (c) auxiliary stabilization tips in the throat of the burner which are highly resistant to plugging and also produce very low levels of NO.sub.x emissions.

A burner and methods of using the burner. The burner produces a flame from combustion air and fuel gas. Flue gas, also produced, can be withdrawn and recycled to the burner. A cooling or condition gas, such as ambient air, may be mixed with the flue gas to reduce its temperature. The burner may also utilize a stage injection so that a portion of the produced flue gas is recycled internally.

A burner and methods of using the burner. The burner produces a flame from combustion air and fuel gas. Flue gas, also produced, can be withdrawn and recycled to the burner. A cooling or condition gas, such as ambient air, may be mixed with the flue gas to reduce its temperature. The burner may also utilize a stage injection so that a portion of the produced flue gas is recycled internally.

A pressurized fluidized bed combustor (PFBC) and method of operation. A heated diluent is used alone or in combination with adjustments to a combustor gas velocity, to manage the bed temperature and keep it within allowable ranges. The diluent can be taken from the combustor flue gas, and recycled and reheated through the fluidized bed.

A pressurized fluidized bed combustor (PFBC) and method of operation. A heated diluent is used alone or in combination with adjustments to a combustor gas velocity, to manage the bed temperature and keep it within allowable ranges. The diluent can be taken from the combustor flue gas, and recycled and reheated through the fluidized bed.

A carbon sequestration system includes a furnace having an oxy-combustion burner, a mill configured to receive a fuel and to provide the fuel to the oxy-combustion burner, a waste heat recovery exchanger configured to receive a flue gas from the furnace, the flue gas ultimately supplied to one or more of an overfire air port of the furnace, the oxy-combustion burner, the mill, and a CO.sub.2 purification unit, the CO.sub.2 purification unit configured to produce a purified CO.sub.2 stream.

A boiler system comprises a housing with a generally cylindrical shape extends between first and second walls to provide a generally cylindrical space. A fire tube is positioned near a bottom of the generally cylindrical housing and extends longitudinally from a first wall of the cylindrical housing to a fire tube end wall. The boiler system also includes a burner with a generally cylindrical housing which defines a generally cylindrical chamber and an end plate. The burner extends into the fire tube, and the fire tube provides a combustion chamber where combustion of an air-fuel mixture is accomplished using the burner. The end plate of the burner is adjustable so as to adjust the flame that extends from within the burner housing into the fire tube.

A boiler system comprises a housing with a generally cylindrical shape extends between first and second walls to provide a generally cylindrical space. A fire tube is positioned near a bottom of the generally cylindrical housing and extends longitudinally from a first wall of the cylindrical housing to a fire tube end wall. The boiler system also includes a burner with a generally cylindrical housing which defines a generally cylindrical chamber and an end plate. The burner extends into the fire tube, and the fire tube provides a combustion chamber where combustion of an air-fuel mixture is accomplished using the burner. The end plate of the burner is adjustable so as to adjust the flame that extends from within the burner housing into the fire tube.

A method for isolating substantially pure carbon dioxide from flue gas is provided. The method can include combusting carbon based fuel to form flue gas; cooling the flue gas to provide substantially dry flue gas; removing N.sub.2 from the dry flue gas to provide substantially N.sub.2 free flue gas CO.sub.2; and liquifying the substantially N.sub.2 free flue gas CO.sub.2 to form substantially pure carbon dioxide.