Quantitative evaluation of structural transformations in raw coals on heat-treatment using HRTEM technique

✍ Scribed by A Sharma; T Kyotani; A Tomita

• Book ID: 104135703
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 961 KB
• Volume: 80
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/s0016-2361(01)00018-7

✦ Synopsis

The structural transformations in Beulah-Zap (BZ), Illinois (IL) no. 6, Upper Freeport (UF) and Pocahontas (POC) no. 3 coals on heattreatment at 427, 800 and 12008C were examined by high-resolution transmission electron microscopy (HRTEM) technique. The stacking number and layer sizes of heat-treated coals were evaluated. The structural change in coal strongly depends on whether a coal undergoes plastic stage or not. BZ coal does not show plasticity and accordingly no signi®cant change was observed even at 12008C heat-treatment temperature. IL, UF and POC coals showed increase in ordering of layers when heat-treated depending upon their degree of plasticity. UF coal with highest plasticity developed highly ordered structures similar to graphitizable carbon. For IL and POC coals with very little plasticity, the change in structure at high temperature was also found to depend on the stacking orders present in the initial raw coals. The HRTEM technique can successfully quantify the structural change in coal on heat-treatment.