Recently, they are subject of study in many fields related to the abatement of air pollutants such as VOC because they are very harmful to both human and environment. The problem of their abetment increases because many of streams where VOCs are present are much diluted. One of the most promising technologies for this application can be adsorption using activated carbons. Nonpolar surface of activated carbon is suitable for adsorption of VOCs. Zeolites and polymeric resins usually are used in conditions that selectivity is key factor.

In this research, activated carbon was synthesized from walnut shell by chemical-activation using different activating agents like ZnCl2, H3PO4 and K2CO3. Impregnation ratio of activating agent to precursor is varied from 0.5 to 2. To address the adsorbents properties, different analysis like BET, XRD, SEM and FTIR carried out over the course of research. For evaluation of adsorption performance of synthesized activated carbons, a bench scale pilot has been designed. The pilot was designed to create stable concentration of volatile organic compounds as well as flow rates. The desigened unit was used to carry out adsorption experiments on synthesized activated carbons.

Optimum ratios of activating agent to precursor of ZnCl2, H3PO4 and K2CO3 were 2/1, 1.5/1 and 1/1 regarding to specific surface area, respectively. The BET surface area for these samples was 2643, 1246 and 1210 m2/g and amount of toluene adsorbed was 2643, 1246 and 1210 m2/g, respectively. Surface characteristic has been shown different for different activating agent due to reaction between activating agent and precursor. It was shown that adsorption capacity of impregnated activated carbon prepared using H3PO4 was suitable for adsorption of organic compounds.

The synthesis of activated carbon has done in the Reactor and Catalysis Research Center. The adsorption experimental has been done in HSEQ of Tabriz Petrochemical using their analytical instruments and SUT pilot.