Abstract: Extruded pellets comprising a majority of activated carbon particles and an inorganic binder are disclosed to provide improved performance when processed through tumbling equipment while the pellets are in their "green" state (i.e., pellets which are fresh off the extruder and contain activated carbon), binder material, and water and have not been subjected to any thermal processing (drying or calcining). The tumbling action both smooths and densifies (i.e., reduces interparticle voids within) the pellet, thereby closing any cracks and greatly improving appearance. Improved performance results from an ability to increase the weight of carbon pellets which can be packed into a fixed volume and thereby increase the volumetric working capacity of the bed for adsorbing/desorbing vapors. Another benefit is to greatly reduce the levels of dust associated with the carbon, both the initial dust and the dust attrition.

Abstract: A method and apparatus for determining the phosphorus content which can be volatilized in a solid carbon sample. The sample is heated in the presence of steam to produce a vaporous steam containing volatile phosphorus. Next, the vaporous stream is passed through a zinc oxide layer whereby the voliatle phosphorus is retained. A colored solution is formed upon adding to the zinc oxide layer a vanadate-molybdate reagent. Finnally, the intensity of the colored solution is determined by a spectrophotometer; and the phosphorus content is determined by comparison with a standard intensity graph.