Inhibition and Deactivation of Hydrodenitrogenation (HDN) Catalysts by Narrow-Boiling Fractions of Athabasca Coker Gas Oil
详细信息 查看全文
- 作者：Will Kanda ; Iva Siu ; John Adjaye ; Alan E. Nelson ; and Murray R. Gray
- 刊名：Energy & Fuels
- 出版年：2004
- 出版时间：March 2004
- 年：2004
- 卷：18
- 期：2
- 页码：539 - 546
- 全文大小：92K
- 年卷期：v.18,no.2(March 2004)
- ISSN：1520-5029
文摘
The hydrodenitrogenation (HDN) of quinoline in the presence of narrow-boiling fractions ofAthabasca bitumen coker gas oil was studied over a commercial NiMo/
-Al2O3 hydrotreatmentcatalyst. The study was conducted to determine whether trends in HDN activity with increasingboiling point were the result of the increased molecular weight of the Athabasca coker gas oil(i.e., changes in hydrocarbon structure) or due to the nitrogen species contained in the feedstocks.In each boiling-point range, the components in the gas oils demonstrated, to a varying degree,both reversible inhibition and deactivation of catalyst activity. The low-boiling gas oil fraction(bp. 343-393 
C) was more inhibitory and deactivated the catalyst to a greater degree thanintermediate- (bp. 433-483 C) or high-boiling (bp. 524 C+) fractions for the HDN of quinoline.Nitrogen speciation analysis suggested that alkyl-carbazoles and tetrahydrobenzocarbazoles werethe primary species responsible for the higher inhibition and deactivation observed in the lightestfraction. In addition, the HDN activity of the narrow-boiling fractions varied with hydrogen partialpressure and sulfur concentration, although these effects were independent of molecular weight.This study suggests that, although Athabasca coker gas oils have higher concentrations ofpolyaromatics, compared to conventional distillates, non-nitrogen-containing species are insignificant in inhibiting catalyst activity, in comparison to the organonitrogen compounds.Consequently, the resistance of the Athabasca coker gas oils to HDN can be attributed to theorganonitrogen compounds-particularly, alkyl-carbazoles and tetrahydrobenzocarbazoles-ratherthan the aromaticity of the gas oils.
-Al2O3 hydrotreatmentcatalyst. The study was conducted to determine whether trends in HDN activity with increasingboiling point were the result of the increased molecular weight of the Athabasca coker gas oil(i.e., changes in hydrocarbon structure) or due to the nitrogen species contained in the feedstocks.In each boiling-point range, the components in the gas oils demonstrated, to a varying degree,both reversible inhibition and deactivation of catalyst activity. The low-boiling gas oil fraction(bp. 343-393 C) was more inhibitory and deactivated the catalyst to a greater degree thanintermediate- (bp. 433-483 C) or high-boiling (bp. 524 C+) fractions for the HDN of quinoline.Nitrogen speciation analysis suggested that alkyl-carbazoles and tetrahydrobenzocarbazoles werethe primary species responsible for the higher inhibition and deactivation observed in the lightestfraction. In addition, the HDN activity of the narrow-boiling fractions varied with hydrogen partialpressure and sulfur concentration, although these effects were independent of molecular weight.This study suggests that, although Athabasca coker gas oils have higher concentrations ofpolyaromatics, compared to conventional distillates, non-nitrogen-containing species are insignificant in inhibiting catalyst activity, in comparison to the organonitrogen compounds.Consequently, the resistance of the Athabasca coker gas oils to HDN can be attributed to theorganonitrogen compounds-particularly, alkyl-carbazoles and tetrahydrobenzocarbazoles-ratherthan the aromaticity of the gas oils.