Fluidized bed process for making activated carbon including heating by

Abstract

There is disclosed an improved process for activating carbon in a fluidized bed which includes continuous activation at a temperature between 1,000.degree.F. and 2,200.degree.F., preferably 1,700.degree.F. to 1,950.degree.F. in the bed. The activation step includes heat transfer by conduction through a distributor plate to the bed and means to achieve a high degree of particle agitation, thus allowing a continuous activation of carbon without the formation of sintered coal ash. The prevention of coal ash sintering allows the process to continue over long periods of time without frequent shutdowns. Carbonaceous material is fed into an initial compartment and a bed is formed on the floor of the compartment. The floor is a gas permeable distributor plate. Fluidizing gases are introduced through the plate into this compartment. As the carbonaceous material is added, some carbonaceous material overflows the initial compartment and forms a bed in another compartment. The second compartment is like the first compartment. By overflowing, the carbonaceous material moves through a plurality of similar compartments until it exits the activator as activated carbon. The thermal energy required to activate the carbonaceous material and to maintain the bed temperature is generated by combustion of fuel in a combustion chamber located beneath the plate. It is the purpose of this invention to provide a process whereby a substantial part of the thermal energy is transferred to the bed by conduction through the distributor plate.