Oxy-fuel combustion in circulating fluidized bed boilers

• The conditions for CO2 reduction in a circulating fluidized bed (CFB) oxy-boiler are studied, that is, operationwith pure oxygen, diluted by recirculated flue gases to moderate the combustion process. Two casesare analyzed: the ready-to-convert case, a normal air-fired CFB boiler, only slightly modified to be operatedwith oxygen instead of air for CO2 capture, and a more general option, an entirely new design,employing high oxygen concentration in the input to the oxy-fuel CFB boiler. It is found that at a givenfuel load, the relevant parameters for maintaining the CFB performance (bed temperature and fluidizationvelocity) in the ready-to-convert case cannot be kept entirely equal to those in the air-fired case,and some compromise has to be found. The new-design case results in a smaller boiler than that ofthe comparable air-fired case, depending on the oxygen concentration and the corresponding flue-gasrecirculation. This case is expected to contribute favorably to reduction of the cost of CO2 removal.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Nyckelord

Oxycombustion

Circulating fluidized bed

Coal

Carbon capture.

Boiler

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)