GB965709A - An improved process for producing activated carbon - Google Patents

Abstract

Activated carbon is produced by heating a bed of granular carbonaceous material, e.g. anthracite, semi-anthracite, dry steam coal and precarbonized coconut shell, to a temperature of 800-950 DEG C. and subjecting the bed to a stream of hot activating gas, e.g. steam, preheated before it enters the bed to a temperature of at least 800 DEG C. and about that of the bed, the gas being arranged to flow upwards through the bed with a velocity sufficient to form a fluidized bed. In the drawing, the reactor consists of a ong lagged metal tube 1 made, for example, of stainless steel which forms a tubular furnace within which a bed of carbonaceous material 2 is supported by gauze 3 above steam generator 4, fresh carbonaceous material being fed into the <PICT:0965709/C1/1> furnace from hopper 5 through valve 6 and the bed being maintained at a constant height by means of an over-flow tube 7 which descends through the centre of the tube 1. Tube 7 has a controlling outlet valve 8 and outlet tube 9 is provided to remove the hot spent activating gases and is coiled below the bed to form a heat exchanger 10. The bed 2 is heated to 800-950 DEG C. by the surrounding furnace heater 11 and steam is produced from the water 12 by heat from the heat tube 9 and the heated lagged main tube 1. To facilitate the transfer of heat to the gas stream an auxiliary fluidized bed containing, for example, alumina granules may be positioned below the bed of carbonaceous material. The Provisional Specification refers to effecting the activation of the carbon at 700-1000 DEG C.