PREPARATION AND CHARACTERIZATION OF HIGH SURFACE AREA ACTIVATED CARBONS FROM PALM SHELLS SUITABLE FOR ADSORPTION OF HIGHER MOLECULAR WEIGHT COMPOUNDS

摘要

Utilization of biomass for production of porous carbons is well established industrially, as the demand is abundant due to varied industrial application. Activated carbons with highly developed surface area are widely used in a variety of industries for applications which include separation/purification of liquids and gases, removal of toxic substances, as catalysts and catalyst support. Activated carbons have been traditionally produced by the partial gasification of the char either with steam or CO2 or a combination of both. Usually the physical activation is a two-step process which involves carbonization of a carbonaceous material followed by the activation of the resulting char at elevated temperature in the presence of suitable oxidizing gases such as carbon dioxide, steam, or their mixtures. In chemical activation process the precursors are impregnated with dehydrating chemicals such as H3PO4, ZnCl2, K2CO3, NaOH or KOH and carbonized at desired conditions in a single step. Chemical activation offers several advantages which include single step activation, low activation temperatures, low activation time, higher yields and better porous structure.