| Autor: |
Duprez, D., Fadili, K., Barbier, J. |
| Zdroj: |
Industrial & Engineering Chemistry Research; August 4, 1997, Vol. 36 Issue: 8 p3180-3187, 8p |
| Abstrakt: |
Unpromoted and K-promoted Ni/Al2O3 catalysts were prepared, calcined at 400 or 700 °C, and subsequently reduced at 500 or 800 °C. Cyclopentane hydrogenolysis was carried out within the 370−500 °C temperature range to obtain a carbon deposit. After coking, the catalysts were regenerated by carbon gasification in H2 at 800 °C. TPO of the carbon deposits was carried out, and the filaments were examined by SEM and TEM. The structural parameters (particle size, degree of nickel reduction, promotion by K) as well as the hydrogen flow rate showed marked effects on both the coking and the regeneration. The catalysts coked at high temperature (≈480 °C) form very stable carbon filaments whose gasification requires both a high temperature (800 °C) and a high H2 flow rate. On the contrary, those which are coked at a lower temperature (420−460 °C) form filaments much more readily gasified by H2. |
| Databáze: |
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