PREPARATION OF NANOPOROUS ADSORBENTS FROM BROWN COAL USING ALKALI ACTIVATION AND THERMAL SHOCK

Thermal-shock KOH activation has been used to produce nanoporous activated carbon from brown coal. The specific surface area, total pore volume, volumes of micropores and subnanometer pores were determined for activated carbons prepared at a varied alkali/coal ratio. Thermal shock was demonstrated to be more efficient for the development of surface area with SBET equaling up to 1700 m 2 /g in comparison to 1000 m 2 /g for thermally-programmed heating. Increasing the KOH/coal ratio in the activated mixture increases the total pore volume, the micropore volume, and also the volume of subnanometer pores. Thermal shock produces nanoporosity at lower KOH/coal ratios than respective low-rate heating processes of KOH activation.