Effect of temperature and time of carbonization on coal-based activated carbon adsorption

Abstract Coal from Bangko, South Sumatra is a low rank coal which has the potential to be used as activated carbon material. The result of proximate analysis and calorific value of coal shows that Bangko coal is included in the lignite category, with fixed carbon 43.58%, volatile matter 41.1% and calorific value 4915 Cal/g. Synthesis of activated carbon from lignite coal was carried out through the carbonization and activation. Carbonization was carried out at several temperature variations, between 400°C-900°C for 2 hours using airtight steel box under non-oxidizing conditions. While the activation has taken place at 900°C for 60, 90 and 120 minutes using water vapour as an activator. The activated carbon iodine number was determined as an indicator of the coal absorption capacity and its porosity. Synthesized activated carbon at 900oC and 120 minutes shows the highest iodine number, 1274.8 mg / g. This activated carbon has 76.78% fixed carbon, 10.65% volatile matter, 5.91% moisture content and 6.66% ash content. Based on the result, we were concluded that low rank coal like lignite was the potential material to produce coal based activated carbon with high capacity adsorption.