Patent ID: 6316378
Filing Date: 2001-11-13
Classification: C01B

Abstract:
Process for the production of shaped activated carbon from spherically preformed raw materials which contain at least 3% volatile components and at most 4% ash, expressed in terms of solids content, by steam activation in an inert-gas flow in an indirectly heated, continuously operating rotary tunnel kiln, characterised in that the spherically preformed raw material is delivered to a rotary tunnel dryer pre-heated to from 880 to 900.degree. C. up to a filling volume of from 10 to 20%, a product temperature of from 250 to 300.degree. C. is set up in the dryer in the 50 to 80% kiln length range, calculated from the product input, and the material is dried continuously with 6-fold product turnover per kiln rotation and a residence time of from 30 to 60 minutes by means of a hot gas in countercurrent to a residual moisture content of at least 10%, then the dried product is transferred up to a filling volume of from 5 to 10% to an indirectly heated rotary tunnel kiln, which is subdivided into a carbonising zone and activating zone, and is carbonised and activated continuously in an inert-gas flow with 8-fold product turnover per kiln rotation and with a product temperature profile in the carbonising zone of from 850 to 900.degree. C. and a residence time of from 120 to 180 minutes, and with a product temperature profile in the activating zone of from 910 to 920.degree. C. and a residence time of from 480 to 720 minutes with the addition of from 3 to 5 kg/h.kg of steam in the activating zone.