| Autor: |
Frank Derbyshire, Marit Jagtoyen, Susan M. Rimmer, M W Thwaites, B. McEnaney, John M. Stencel |
| Rok vydání: |
1991 |
| Předmět: |
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| DOI: |
10.1016/b978-0-7506-0387-4.50122-4 |
| Popis: |
Publisher Summary This chapter describes the adsorbent carbons from coals by chemical activation. The preparation of adsorbent carbons by chemical activation involves the reaction of a carbon precursor with an ionic reagent at elevated temperatures, followed by leaching to recover the remaining soluble reagent and its products. The volatile matter content of the acid-treated carbons is lower than that of the thermal products, although the difference decreases with heat treatment temperature (HTT). Acid treatment appears to accelerate the carbonization process at low HTT, and a more highly cross-linked structure is developed that is less prone to volatile loss. Evidence for accelerated carbonization is also provided by reflectance measurements on the subbituminous coal. Below 550°C, the reflectance of the altered huminite is higher for the acid-treated coals, indicating the onset of more extensive structural change at lower HTT than for the thermal products. These observations are consistent with the acid-effecting partial digestion of the coal followed by the development of a more anisotropic carbon. Below about 450°C, the textures of the acid-treated carbons are more homogeneous than those of the thermal products. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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