Hydrodenitrogenation

Besides the thermodynamic limitations of HDN, reactivity of N-compounds is strongly influenced by their molecular structure, which interferes with the absorption of the N-atom on the active site (Ho, 1988). Basic N-compounds are also the strongest inhibitors of hydrogenation sites and consequently of all reactions that may follow this pathway (e.g., HDS). Therefore, removing N-inhibitors is an essential strategy to achieve deep desulfurization of diesel fuels. 

FIGURE 7.9 Examples of reaction pathways of hydrotreating reactions. 

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The primary determinant of catalyst surface area is the support surface area, except in the case of certain catalysts where extremely fine dispersions of active material are obtained. As a rule, catalysts intended for catalytic conversions utilizing hydrogen, eg, hydrogenation, hydrodesulfurization, and hydrodenitrogenation, can utilize high surface area supports, whereas those intended for selective oxidation, eg, olefin epoxidation, require low surface area supports to avoid troublesome side reactions. 

Reactions occurring in hydrotreatment units are mainly hydrodesulfurization and hydrodenitrogenation of sulfur and nitrogen compounds. In... 

Examples of hydrodenitrogenation of two types of nitrogen compounds normally present in some light and middle crude distillates are shown as follows ... 

T. Kabe, A. Ishiara, W. Qian (Eds.), Hydrodesulfurization and Hydrodenitrogenation, Wiley-VCH, Weinheim, 1999. 

Reaction Kinetics of the Hydrodenitrogenation of Decahydroquinoline over NiMo(P)/Al203 Catalysts... 

Hydrodenitrogenation (HDN) is an important process in petroleum refining. It removes nitrogen from oil distillates, so that less NOx pollutes the air when oil is burned and poisoning of the subsequent refining catalysts is reduced when the oil is processed further. Although HDN has been studied intensively and different reaction mechanisms, catalytic active sites, and functions of the catalytic components have been proposed, there are stiU many questions to be answered in order to better mderstand the reaction and the catalyst (1-4). 

In the case of hydrodenitrogenation, the study of the reaction kinetics on model compounds has shown the lack of the steric inhibiting effect observed in case of the... 

The effect of hydrogen pressure in the reaction network and kinetics of quinoline hydrodenitrogenation has been matter of debate. Some controversial results and explanation were raised by the proposal of light hydrocarbons formation [78], The lack of observation of these hydrocarbons in previous experiments was explained by the low pressure employed and the deviations observed of the mass balances in these experiments were an evidence for the formation of lights HCs. The controversy is not clear yet and might be the subject for further investigations. 

Bhinde, M. V., Ph.D.Catalytic hydrodenitrogenation. Thesis. University of Delaware, 1979. 

Mathur, K. N. Schrenk, M. D. Kwart, H., and Katzer, J. R., Development of Unique Catalysts for Hydrodenitrogenation of Coal-Derived Liquids. DOE, Office of Fossil Energy. 1982. 

Gopalan, U., Hydrodenitrogenation of Pyridine over Alumina Supported Platinum Catalyst. Master of Applied Science Thesis. University of Otawa, Chemical Engineering. 1998, p. 69. 

Moreau, C. Bekakra, L. Olive, J. L., and Geneste, P., Hydrodenitrogenation of Quinoline and Phenanthridine in the Presence of 2, 6-Diethylaniline and Hydrogen-Sulfide Over Molybdenum and Nickel-Molybdenum Sulfides Supported on Zirconia, Titania, Nickel-Aluminates and Magnesium-Aluminates. Bulletin Des Societes Chimiques Beiges, 1991. 100(11-12) pp. 841-847. 

Zhao, Y. Czyzniewska, J., and Prins, R., Mechanism of the direct hydrodenitrogenation of naphtylamine on sulfided NiMo/A1203. Catal. Lett, 2003. 88 p. 155. 

Satterfield, C. N., and Yang, S. H., Catalytic Hydrodenitrogenation of Quinoline in A Trickle-Bed Reactor. Comparison With Vapor Phase Reaction. Ind. Eng. Chem. Process Des. Dev, 1984. 23 pp. 11-19. 

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