As a result of the deterioration in the quality of crude oils and the tightening up of environmental standards, refiners are modifying their processes in order to meet the growing demand for light cuts and middle distillates. They must also meet eco-efficiency criteria, all of which requires a detailed chemical characterization of these various cuts.

Oil products contain hundreds of thousands of compounds, including nitrogen-, oxygen and sulfur-type heteroatoms. Their characterization requires cutting-edge, sensitive and robust analytical methods _ methods that have been the focus of increasing research at IFPEN _, based on high-resolution mass spectrometry (FT-ICR/MSa).

This analysis technique was deployed, via three different ionization modes, for several Vacuum Gas Oils (VGO) derived from various refining processes(1). It was used to identify differences in composition between the samples from these diverse origins and monitor the evolution of nitrogen(2) and sulfur(3) species during hydrotreatment steps.

Since FT-ICR/MS analyses generate considerable and complex data spectra, their exploration was conducted using chemometric approaches, making it possible to categorize samples from the identification of the various chemical species.

Figure 3
Analytical methodology for the characterization of sulfur compounds in Vacuum Gas Oils.

Data were also merged via PARAFACb analysis, making it possible to evaluate the combined impact of nitrogen and sulfur compounds on different refining processes(1). This original approach (figure) provides access to molecular descriptors essential for modeling and optimizing conversion processes.

a - Fourier-transform ion cyclotron resonance mass spectrometry
b - Parallel Factor Analysis

(1) L. Pereira de Oliveira, M. Lacoue-Nègre, J.-F. Joly, L. Duponchel. Analytical Chemistry, vol. 92, n° 3, (2020).
DOI : 10.1021/acs.analchem.9b05263

(2) J. Guillemant, F. Albrieux, L. Pereira de Oliveira, M. Lacoue-Nègre, L. Duponchel, J.-F. Joly. Analytical Chemistry, vol. 91, n° 20, (2019).
DOI : 10.1021/acs.analchem.9b01702

(3) J. Guillemant, F. Albrieux, M. Lacoue-Nègre, L. Pereira de Oliveira, J.-F. Joly, L. Duponchel. Analytical Chemistry, vol. 91, n° 18, (2019).
DOI : 10.1021/acs.analchem.9b02409

Scientific contact: alexandra.berlioz-barbier@ifpen.fr