Quinoline, hydrodenitrogenation

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. 

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. 

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. 

Scheme 1. Known reaction network for hydrodenitrogenation of quinoline...

The general hydrodenitrogenation reaction mechanism often presented for compounds like quinoline which boils ca. 260°C (500°F) at 760 mm Hg is as follows (2,4) ... 

FIGURE 8.19 Reaction network and rate constants at 375°C for quinoline HDN. Source C. N. Satterfield and S. H. Yang, Catalytic Hydrodenitrogenation of Quinoline in a Trickle-Bed Reactor. Comparison with Vapor Phase Reaction, Industrial and Engineering Chemistry Product Research and Development 23 11-19 (1984). With permission. 

C. W. Curtis, D.R. Cahela. Hydrodenitrogenation of Quinoline and Coal using Precipitated Transition Metal Sulfides. Energy Fuels 3 168-174,1989. 

Transition metal sulfides of the 3" row show high activity in hydrotreating reactions and some of them are studied as potential promoters of conventional catalysts in order to improve their performance. Carbon supported Pt sulfide was highly active in hydrodesulfurization (HDS) of thiophene and hydrodenitrogenation (HDN) of quinoline and pyridine [1,2]. The Pt/silica-alumina sulfide catalyst has been investigated as the promising candidate for deep HDS [3]. 

Interest in new compositions and new synthetic routes in the context of catalysis is growing, and recent examples of the synthesis and use of non-oxidic, ceramic compositions in catalysis include SiC as a support for Ni or Pt in CO hydrogenation (2), SiC as a support for Co and Mo for thiophene hydrodesulphurisation (3), transition metal (Ti, Ta, Mo or W) carbides for methanol decomposition (4), early transition metal carbides, nitrides or borides for hydrodenitrogenation of quinoline (5), and the synthesis of high surface area molybdenum carbide (6). 

Hydrodenitrogenation. Heterocyclic compounds containing nitrogen in coal liquids are either basic (pyridines, quinolines and acridines) or non-basic (pyrroles, indoles and carbazoles). Attempts have been made to study these model compounds to highlight the mechanism involved in hydrodenitrogenation process. 

Gioia F, Lee V. Effect of hydrogen partial pressure on catalytic hydrodenitrogenation of quinoline. Ind. Eng. Chem. Process. Des. Dev. 1986 5 918-925. 

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