Preparation of activated carbon from phenolic resin by KOH chemical activation under microwave heating

Microwave irradiation was used as a heat source in the preparation of activated carbon (AC) from phenolic resin by potassium hydroxide chemical activation. The input microwave power was varied from 0.26 to 0.52 kW, while weight ratios of KOH to phenolic resin, R, were changed from 2 to 6. For a comparison, phenolic resin was also activated at R = 4 using electric furnace heating. During microwave irradiation of KOH and KOH/phenolic resin mixtures, the sample temperatures increased rapidly, which proved that activated carbon was prepared from the mixture under microwave irradiation. The most developed porosity of AC was obtained at R = 4 with a microwave power of 0.39 kW, and the activated carbon was characterized by high mesopore ratio. The development of mesopores under microwave heating was attributed to the rapid heating of the sample in contrast to slow electric furnace heating. The possibility of using the AC as a desiccant humidity conditioner was confirmed in terms of its effective water adsorptivity.