Patent ID: 8501142

Claim:
A process for carbonizing and activating carbonaceous material selected from the group consisting of coconut-derived material and like material of vegetable origin and resin materials to produce activated carbon, said process comprising: providing an externally fired rotary kiln having: inlet and discharge ends, a downward slope towards its discharge end, annular weirs at intervals along the kiln for controlling progress of the material and lift bars between the weirs for agitating the material, lifting portions of the material, and causing lifted material to cascade to the bottom of the rotary body, each annular weir retaining behind it a body of material to be treated, and progress of the material being primarily overflow as additional material is supplied; the process comprising: supplying the material to the inlet end of the kiln; supplying to the kiln an atmosphere comprising steam or carbon dioxide substantially free of oxygen; maintaining a first region of the kiln having an independently controllable supply of heat at a temperature sufficient for drying or removing solvent from the material without carbonization; maintaining a second region of the kiln having an independently controllable supply of heat downstream from the first region at a temperature sufficient for carbonization of the material without activation; maintaining a third region of the kiln having an independently controllable supply of heat downstream from the second region at a temperature sufficient for activation of the carbonized material; and collecting activated carbon from the discharge end of the kiln.