How Does an Acidic Support Affect the Hydrotreatment of a Gas Oil with High Nitrogen Content?

Abstract

Two NiMo sulfide catalysts, supported on Al 2 O 3 and silica-alumina, respectively, were compared in the hydrotreating of a mixture of straight-run and coker gasoil. Experiments were conducted in a continuous fixed bed reactor, at 623-643K and 5 MPa. The Al 2 O 3 -supported catalyst proved to be slightly more active in HDN and significantly more active in HDS than its silica-alumina analogue. The activity trend was attributed to the inhibition provoked by the strong adsorption of basic nitrogen species. Earlier work had shown that the adsorption (and thus the inhibition) was significantly stronger on an acidic support. Our data further showed that the reactivity of neutral (pyrrole benzologues) and basic nitrogen compounds was

Molecular-Level Insights into Coker/Straight-Run Gas Oil Hydrodenitrogenation by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…The behaviors of basic and neutral nitrogen compounds as a function of HDN conversion were very different (Table ). Basic nitrogen species were very gradually converted, whereas the neutral species disappeared very quickly at low conversion but subsequently their concentration remained constant . This behavior applies not only to N1, but also to the N2 class.…”

“…Basic nitrogen species were very gradually converted, whereas the neutral species disappeared very quickly at low conversion but subsequently their concentration remained constant. 45 This behavior applies not only to N1, but also to the N2 class. Our results confirm the paradigm that carbazole species are the most refractory nitrogen compounds 59 but the refractory character only appears at rather high conversions.…”

“…In this work, which is based on the Ph.D. thesis of Nguyen, 44 hydrotreated effluents of gas oil mixture with high nitrogen content were analyzed by FT-ICR/MS. A macroscopic analysis of the corresponding catalytic tests was presented elsewhere; 45 we analyzed the global evolution of neutral and basic nitrogen species (similar to the previous work of Wei et al 46 ) but could not provide molecular details. In this work, we interpret the HDN reaction pathways on a molecular level, which becomes possible by analyzing the evolution of DBE families and carbon number distribution as a function of global HDN conversion.…”

“…In this work, which is based on the Ph.D. thesis of Nguyen, hydrotreated effluents of gas oil mixture with high nitrogen content were analyzed by FT-ICR/MS. A macroscopic analysis of the corresponding catalytic tests was presented elsewhere; we analyzed the global evolution of neutral and basic nitrogen species (similar to the previous work of Wei et al …”

Recent advances in the catalytic deoxygenation of plant oils and prototypical fatty acid models compounds: Catalysis, process, and kinetics

“…Among the oxide supports reported in the literature, silica (SiO 2 ) and alumina (Al 2 O 3 ) are two conventional materials that have been widely used by many material scientists for the CDO of fatty acid, mainly due to their excellent thermal and chemical resistance characteristics under severe operating conditions. Polymorphic crystalline aluminium oxides (γ-Al 2 O 3 ) or commonly referred with the generic name of alumina has been used extensively as a catalyst support in the hydrotreatment of petroleum fraction for the removal of heteroatoms such as sulphur (HDS), nitrogen (HDN), and oxygen (HDO) [66]. It is a popular choice for many catalytic applications due to its high specific surface area, good physical strength, and excellent resistance to thermal degradation [67].…”