GB208555A - Improvements in the process of producing decolorizing carbon - Google Patents

Abstract

208,555. Algemeene Norit Maatschappij. Nov. 19, 1921, [Convention date]. Charcoal. - Decolorizing carbon is produced from predistilled carbonaceous material of vegetable, animal or mineral origin, such as charcoal or coked peat, by a two-stage continuous process in a vertical or inclined retort comprising a first stage in which the charge, descending by gravity, is scoured by the upward passage through it of the reaction gases from the second stage, and a second stage in which the charge is activated by heat and gases. Suitable activating gases are steam, carbon dioxide or monoxide, retort gases, water-gas coke-oven gas, producer gas, combustible gases, air, hydrogen or chlorine or mixtures of these gases and they may be introduced into the bottom of the retort in a comparatively cool state, so as finally to cool the charge. In addition solid activators, such as calcium or magnesium carbonate or chloride, or slaked or quick lime, may be added to the charge. On entering the first zone, the reaction gases may be mixed with hot substantially inert gases, and the whole, together with any distillation products, is preferably withdrawn at a short distance from the top of the retort to obviate the choking of the conduit. The heating of the retort may be external, such as by means of the retort gases, internal, such as by injection of hot combustion or combustible or burning gases, or both internal and external. Zones of different temperatures may be maintained in the retort and into each zone the gas having the optimum activating effect at that temperature may be injected. An example shows the treatment of wood charcoal using steam as activating gas in a vertical retort having serially connected heating chambers and a sluice discharging the treated material into a detachable water-sealed vessel. Specification 167,195 is referred to. The Specification as open to inspection under Sect. 91 (3) (a), is not limited to gravity-feeding of the charge. Volatile chlorides are also specified as activating gases, and ammonium and sodium chlorides as solid activators. This subject-matter does not appear in the Specification as accepted.