A summary is given on the development of fluidized bed conversion (combustion
and gasification) of solid fuels. First, gasification is mentioned,
following the line of development from the Winkler gasifier to recent
designs. The combustors were initially bubbling beds, which were found
unsuitable for combustion of coal because of various drawbacks, but they
proved more useful for biomass where these drawbacks were absent. Instead,
circulating fluidized bed boilers became the most important coal converters,
whose design now is quite mature, and presently the increments in size and
efficiency are the most important development tasks. The new modifications
of these conversion devices are related to CO2 capture. Proposed methods
with this purpose, involving fluidized bed, are single-reactor systems like
oxy-fuel combustion, and dual-reactor systems, including also indirect
biomass gasifiers.
Change of existing circulating fluidized bed boilers to oxy-firing conditions for CO2 capture
