New sulfur adsorbents derived from layered double hydroxides
| Autor: | Erin Morris, S. Adam Tackett, Mark Crocker, Dennis E. Sparks, Patricia M. Patterson, Tonya Morgan |
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| Rok vydání: | 2008 |
| Předmět: |
Hydrotalcite
Magnesium Process Chemistry and Technology Thermal decomposition Inorganic chemistry Layered double hydroxides chemistry.chemical_element engineering.material Heterogeneous catalysis Catalysis chemistry.chemical_compound Adsorption chemistry Transition metal engineering General Environmental Science Carbonyl sulfide |
| Zdroj: | Applied Catalysis B: Environmental. 82:190-198 |
| ISSN: | 0926-3373 |
| DOI: | 10.1016/j.apcatb.2008.01.012 |
| Popis: | Mixed oxides, prepared via the thermal decomposition of layered double hydroxides (LDHs), were screened gravimetrically for their ability to adsorb carbonyl sulfide (COS). Based on promising results obtained for Ni/Mg/Al, Ni/Mg/Fe and Co/Mg/Al mixed oxides, a study was undertaken to optimize the composition of these materials for COS adsorption. To investigate the effect of the M(II):M(III) ratio, LDHs of the type [MzMgyAlx(OH)2](CO3)x/2·0.5H2O (where M = Ni or Co, and x + y + z = 1) were prepared at values of x corresponding to 0.33 and 0.20. Simultaneously, the elemental ratio of transition metal to magnesium (z/y) was varied. Mixed oxides obtained from the resulting LDHs were tested in fixed bed mode with a feed of 100 ppm COS in N2 to determine breakthrough capacity. In general Ni/Mg/Al mixed oxides showed the best performance, a composition with Ni/Mg/Al = 0.32/0.48/0.20 showing the best adsorption capacity. Treatment of the spent adsorbent under an atmosphere of 5% H2 in N2 at 450 °C was found to provide an effective means of restoring the adsorption capacity over two cycles of adsorption and regeneration, although after three such cycles, adsorption capacity decreased. |
| Databáze: | OpenAIRE |
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