Westvaco Corporation

Homer R Johnson

Albert J Repik

Charles E Miller

There is disclosed an improved process for activating carbon in a fluidized bed system which includes continuous activation at a temperature between 1,000.degree. F. and 2,200.degree. F. using a specific composition of fluidizing gases. The thermal energy required to activate the carbon and to maintain the bed temperatures is transferred only in part by the sensible heat of the fluidizing gases. The fluidizing gases contain excess oxygen, which reacts exothermically with the products of the activation reaction and contributes heat necessary to maintain the bed temperatures. The improved process may also entail introducing secondary excess air above the bed to react exothermically with products evolved from the reactions occurring within the bed to provide additional heat to drive the activation reaction.

Process for activating carbonaceous material

An improved two-step fluid bed process for conditioning sized, agglomerative, high volatile bituminous coal is disclosed. The agglomerative bituminous coal is first crushed and sized for fluidization. A first treatment is conducted under oxidizing conditions at below the fusion temperature of the coal, preferably at about 600.degree. F., followed immediately by a second treatment under a non-oxidizing or inert atmosphere at preferably 800.degree. F. .+-.50.degree. F. The resulting oxidized and heat treated coal particles have a volatile content of at least 15% and are thereby rendered non-agglomerative when thereafter subjected to even higher temperatures, e.g., when making activated carbon and/or synthesis gas.

Two-step process for conditioning sized coal and resulting product

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.

Fluidized bed process for making activated carbon including heating by

Fluidized bed technique for oxidizing normally agglomerative bituminous coal is disclosed. One high rank bituminous coal is prepared for activation by grinding, briquetting and crushing to the 3/4 inch to 4 mesh size. Thereafter, the coal particles are fluidized in an oxygen containing atmosphere at from about 400.degree.F. to 700.degree.F. Water is preferably added during oxidation, controlling the oxidation temperature. In this manner, coal particles are rendered non-agglomerative which, when thereafter subjected to carbonization and activation, yields superior activated carbon.

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Charleston, SC, United States of America

Homer R Johnson