Jump to main content
Jump to site search


Structural analysis of heavy oil fractions after hydrodenitrogenation by high-resolution tandem mass spectrometry and ion mobility spectrometry

Abstract

Heavy petroleum fractions such as vacuum gas oils (VGOs) are structurally and compositionally highly complex mixtures. Nitrogen species which have a significant impact on the subsequent refining processes are generally removed by the hydrodenitrogenation (HDN) catalytic process. The purpose of this study was to identify and characterize compounds that are refractory to the HDN process. This may allow examining the effectiveness of a vacuum distillate hydrotreatment catalytic bed in removing nitrogen-containing compounds before the cracking step. . Three different VGO fractions of the same oil before and after HDN processes were analysed in ESI(+) by FTICR mass spectrometry and ion mobility spectrometry - mass spectrometry (IMS-MS); in particular compounds containing basic nitrogen, such as quinoline and isoquinoline. Ultra-high resolution FTICR mass spectrometry provides a sufficiently high mass resolution power to resolve different compounds and attribute to each ion a unique molecular formula. Information on the isomeric content was obtained by use of tandem mass spectrometry (MS/MS) and IMS-MS. The evolution of the fragmentation of the N1 class compounds as a function of collision energy allowed the identification of the molecular nucleus raw formula, showing their ‘island’ type structure (a central polycyclic core with branched alkyl chains). From the IMS-MS experiments, it appeared clearly that based on IMS peak width, lower isomeric dispersity was obtained after the HDN process and based on drift time and collision cross section determination, species presenting longer alkyl branches are the molecules most refractory to the HDN process.

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Dec 2018, accepted on 11 Jan 2019 and first published on 11 Jan 2019


Article type: Paper
DOI: 10.1039/C8FD00239H
Citation: Faraday Discuss., 2019, Accepted Manuscript
  •   Request permissions

    Structural analysis of heavy oil fractions after hydrodenitrogenation by high-resolution tandem mass spectrometry and ion mobility spectrometry

    J. Le Maître, M. Hubert-Roux, B. Paupy, S. Marceau, C. Rüger, C. Afonso and P. Giusti, Faraday Discuss., 2019, Accepted Manuscript , DOI: 10.1039/C8FD00239H

Search articles by author

Spotlight

Advertisements