Thermal treatment of sawdust and coal-tar pitch mixture to produce porous carbon materials by chemical activation

In this work, different activated carbons were prepared from composites based on birch sawdust and coal-tar pitch by chemical activation with zinc chloride, phosphoric acid, and potassium hydroxide followed by carbonization. The influence of different chemical agents (ZnCl₂, KOH, and H₃PO₄), final temperature of carbonization and media on yield and structural properties of the carbonic product was studied. It was shown that chemical agents allow increasing yield of carbonic residue. Composite modification by H₃PO₄ or ZnCl₂ facilitates the formation of molded porous carbonic residue during the carbonization process. However, addition of KOH to the composite leads to formation of powder-like carbonic residue having a specific surface area of 1,600 m² g^?1 at 800 °C. It was established that all samples aged in air medium at 800 °C have higher values of specific surface area in comparison with the same samples aged in argon medium at similar conditions.