Milestones in Fluidized Bed Reactor Technology

Fuel conversion in a fluidized bed was first introduced by Winkler who 

The high turbulence created in the fluid-solid mixture leads to much higher heat transfer coefficients than those which can be obtained in fixed beds. The resulting uniformity of the fluidized bed makes it applicable for effecting catalytic reactions, especially highly exothermic and temperature sensitive reactions. However, the fluidization technology is much more complicated than that associated with fixed bed reactors. 

For the low activity FCC catalysts then available, the bubbling bed design was a decided improvement over the first CFB reactor. Until the mid-1970s, virtually all FCC units maintained a dense phase bubbling or turbulent bed in the reactor vessel. A few of the second generation bubbling bed FCC reactors are still in operation [97]. 

The contemporary commercial reactors used for sulphide ore roasting, Ficher-Tropsch synthesis and acrylonitrile manufacture were routinely operated in the bubbling and turbulent fluidization regimes [56, 112]. 

With the introduction of zeolites in the early 1960s, the FCC catalyst activity began to increase steadily [97]. By 1980 many units were again operating in a CFB mode to reduce the residence time of the gas reactants in the reactor. Today, by far the greatest use of CFB reactors is for the FCC process in petroleum refining. 

Fuel conversion in a fluidized bed was first inffoduced by Winkler who patented a gasifier in 1922 [80]. The first large-scale use of fluidized beds, the Winkler gas generator, was thus established for the process of gasification of coal in 1926 [27, 48]. These units were 13 (m) high, 12 (m ) in cross section and fed by powered 

SO that the reaction vessel caused over-cracking into undesired light gases and coke. In recent versions of the catalytic cracker, the catalyst is completely entrained in the riser-reactor to reduce the contact time. 

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