Bubbling bed regenerators

Stacked unit configuration with the regenerator above the reactor Ultra low contact time achieved via feed injection perpendicular to a shaped falling curtain of catalyst Reaction products pass to external cyclones while the spent catalyst falls into a stripper and air lifted into a bubbling bed regenerator ... 

The overall benefits of this high efficiency combustor over a conventional bubbling- or turbulent-bed regenerator are enhanced and controlled carbon-bum kinetics (carbon on regenerated catalyst at less than 0.05 wt %) ease of start-up and routiae operabiUty uniform radial carbon and temperature profiles limited afterbum ia the upper regenerator section and uniform cyclone temperatures and reduced catalyst iaventory and air-blower horsepower. By 1990, this design was well estabUshed. More than 30 units are ia commercial operation. 

The second reaction vessel in a catalytic cracker is called the regenerator. The solid catalyst from the reactor is combined with a compressed air stream from an air blower, and the solid and gas phases flow upward into a bed of fluidized solid catalyst. The early designs used a bubbling bed reactor in which the velocity in the bed is slightly above the minimum fluidization velocity. More recent designs use a transport fluidized-bed reactor. A typical air-to-oil weight ratio is 0.54. 

Maleic anhydride/phthalic anhydride Regenerator bubbling bed/turbulent fluidized bed regime Turbulent fluidized bed regime... 

Orthoflow B Stacked configuration Positions of reactor/regenerator reversed for reduced utility consumption Bubbling bed cracking... 

The regenerator dense bed is modeled as a bubbling bed with heterogeneous coke bum and CO conversion to CO2. Bulk density is modeled as a function of bed height and pressure. Promoters are modeled by updating selected coke-bum parameters. Combustion air composition is determined... 

Regenerator Combust coke present on catalyst Bubbling bed reactor with two phases Kinetic models for coke combustion with air and enriching oxygen [41]... 

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