Oxidation of sulfur dioxide to sulfur trioxide over honeycomb DeNoxing catalysts
| Autor: | L. J. Alemany, Pio Forzatti, Natale Ferlazzo, F. Bregani, Jiri Svachula, Enrico Tronconi |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Industrial & Engineering Chemistry Research. 32:826-834 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie00017a009 |
| Popis: | A systematic study addressing the effects of the operating conditions (contact time, temperature), of feed composition (O[sub 2], SO[sub 2], H[sub 2]O, NH[sub 3], NO[sub x], NH[sub 3] + NO[sub x] concentrations), and of catalyst design parameters (wall thickness, V content) in the oxidation of SO[sub 2] to SO[sub 3] over honeycomb commercial-type DeNoxing catalysts is described. Data are presented which refer to transient behavior of the catalysts, indicating that long conditioning times are required associated with the buildup of surface sulfate species. The steady-state reaction rate is of variable order in SO[sub 2], the order increasing with SO[sub 2] concentration as long as this is below 200 ppm and then decreasing; it is asymptotically independent of oxygen, depressed by water, strongly inhibited by ammonia, and slightly enhanced by NO[sub x]. The apparent activation energy changes from [approximately]50 to [approximately]20 kcal/mol on increasing the reaction temperature. A redox steady-state kinetic model is presented which accommodates qualitatively all of the observed effects. Once properly modified the same model has the potential to explain also transient effects during conditioning of the catalyst. |
| Databáze: | OpenAIRE |
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