ACTIVATED CARBON FROM LIGNITE COAL BY CHEMICAL ACTIVATION WITH POTASSIUM HYDROXIDE
Keywords:
Activated carbon, adsorption, chemical activation, lignite coalAbstract
This work focussed on the preparation and characterization of activated carbon from indigenous lignite using the chemical activation technique by impregnation with potassium hydroxide solution. The variables studied included temperature, time and chemical-precursor ratio. The prepared activated carbon products were analyzed for their composition (proximate analysis) and the porous structure such as surface area and pore volume distribution. Among the variables studied, temperature and chemical ratio appeared to have the largest effect on the adsorption and porous properties of the carbons. The maximum BET surface area of 2,236 m²/g of carbon was obtained for activated carbon prepared at the activation temperature of 900°C, activation time of 60 min and chemical-precursor weight ratio of 1.0 : 1.0, but with product yield of only about 20%. Activated carbon obtained from lignite by chemical activation showed better adsorption capacity as compared to that prepared by physical activation, due principally to much higher specific surface area and larger pore volume.
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