Deactivation Pattern of a 'Model' Ni/MgO Catalyst in the Pre-Reforming of n-Hexane
| Autor: | Giuseppe Trunfio, Francesco Arena |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
sintering
genetic structures Hydrogen Chemistry Inorganic chemistry pre-reforming chemistry.chemical_element Sintering lcsh:Chemical technology Catalyst poisoning Catalysis poisoning lcsh:Chemistry Hexane chemistry.chemical_compound lcsh:QD1-999 Phase (matter) activity decay Thiophene lcsh:TP1-1185 Physical and Theoretical Chemistry Exponential decay |
| Zdroj: | Catalysts, Vol 4, Iss 2, Pp 196-214 (2014) Catalysts 4 (2014): 196–214. doi:10.3390/catal4020196 info:cnr-pdr/source/autori:Trunfio G.; Arena F./titolo:Deactivation pattern of a "Model" Ni%2FMgO catalyst in the pre-reforming of n-hexane/doi:10.3390%2Fcatal4020196/rivista:Catalysts/anno:2014/pagina_da:196/pagina_a:214/intervallo_pagine:196–214/volume:4 |
| ISSN: | 2073-4344 |
| DOI: | 10.3390/catal4020196 |
| Popis: | The deactivation pattern of a “model” Ni/MgO catalyst in the prereforming of - n -hexane with steam ( T , 450 °C; P , 5–15 bar) is reviewed. The influence of the steam-to-carbon ratio (S/C, 1.5–3.5) on the rate of catalyst fouling by cokingis ascertained. Catalyst fouling leads to an exponential decay in activity, denoting 1 st -order dependence of the coking process on active sites availability. Hydrogen hinders the coking process, though slight activity decay is due to sintering of the active Ni phase. Deactivation by thiophene causes a sharp, almost lineardrop to nearly zero activity within only 6 h; this deactivation is likely , due to dissociative adsorption of thiophene with subsequent strong, irreversible chemical adsorption of -atoms on active Ni siteS i.e. , s,irreversible poisoning. Modeling of activity decay curves (α, a t /a 0 ) by proper kinetic equations allows assess the effects of ingtemperature, pressure, S/C, H 2 and thiophene feed on the deactivation pattern of the model Ni/MgO catalyst by coking, sintering, and poisoning phenomena. |
| Databáze: | OpenAIRE |
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