ENVIRONMENTAL SCANNING ELECTRON-MICROSCOPY OF ACTIVATED CARBON PRODUCTION FROM ANTHRACITE BY ONE-STEP PYROLYSIS-ACTIVATION

Experiments were carried out to produce activated carbons from anthrac ite using one-step steam pyrolysis-activation. Environmental scanning electron microscopy (ESEM) was used to observe the porosity developmen t in real time. The anthracite samples were heated in different gas at mospheres before steam activation. The ESEM observations showed that t he activation agent had a significant effect on the porosity of activa ted carbon produced from anthracite. The activated carbon produced by steam activation at 850 degrees C for 6 h had the highest surface area and a well-developed porous structure. Substantial activation of anth racite surfaces and formation of extensive porosity occurred under the same conditions but with steam at 270 Pa instead of atmospheric press ure. Air treatment at 300 degrees C for 3 h before steam activation al so led to production of activated carbon with well-developed porosity. An important advantage of the activated anthracites produced in this study is their microporous structure with a considerable fraction of p ores of molecular dimensions. This indicates that molecular sieve mate rials can be producted from Pennsylvania anthracite by one-step pyroly sis-activation under appropriate conditions.