The content of ash, another characteristics parameter, depends on the raw material used. Generally, its value increases with the number of regeneration cycles, with a percentage increase of 0.5–1.0% for each cycle. This involves a consequent limitation of the number of possible regenerations.For activated carbons, the content of ash is b15%. The Iodine number is an index of the ability of the sorbent to adsorb small molecules,expressed in mg of iodine adsorbed per gram of carbon. For activated carbons, the Iodine number varies in the range 500–1200 mg/g. Finally,another important parameter is the specific surface area expressed in m2/g. Generally, adsorption capacitates increase with the growth of this parameter. In the case of activated carbons, the specific surface area varies in the range 500–1500 m2/g