ON THE SUITABILITY OF AGRICULTURAL BY-PRODUCTS FOR THE MANUFACTURE OFGRANULAR ACTIVATED CARBON

An investigation of several agricultural by-products revealed that the ir suitability for activated carbon production is not determined by ge neral material-specific features (elemental composition) but by type-s pecific features. A coarse-cellular structure (as in wood). which is i ndicated by porosities of the raw materials higher than similar to 35% is disadvantageous. A specific change in the properties of cokes (por osity, density, hardness) is possible by varying the conditions of pyr olysis. By rapid heating in the pyrolysis step, for instance, macropor ous residues are produced. Temperature and burnoff have the greatest i nfluence on the quality of the activated carbon during the activation step. Of the investigated materials, coconut shells yield granular act ivated carbon of the highest quality. The following order of suitabili ty of raw materials for activated carbon production was established: c oconut shells > peach stones > plum stones > hazelnut shells > walnut shells > cherry stones.