Extraction-Coupled Oxidative Desulfurization (ECODS) and Denitrogenation (ECODN) of Real Fuels under Mild Conditions Using a Polyoxometalate Catalyst and Molecular Oxygen

Title data

Tochtermann, Jens ; Tietze, Florian ; Huber, Michael ; Korth, Wolfgang ; Albert, Jakob ; Jess, Andreas:
Extraction-Coupled Oxidative Desulfurization (ECODS) and Denitrogenation (ECODN) of Real Fuels under Mild Conditions Using a Polyoxometalate Catalyst and Molecular Oxygen.
In: Energy & Fuels. Vol. 39 (2025) Issue 1 . - pp. 781-797.
ISSN 1520-5029
DOI: https://doi.org/10.1021/acs.energyfuels.4c04387

Official URL:

Abstract in another language

In this contribution, the difficulties of removing sulfur from actual refinery products, i.e., kerosene and diesel fuel, using an aqueous solution of H8PV5Mo7O40 (HPA-5) catalyst and molecular oxygen as an oxidizing agent (ECODS) are examined. Regarding oxidation of the S-containing aromatics, the reactivity in the distillation cuts proceeded in the following order: thiophenes > benzothiophenes > dibenzothiophenes. Kerosene consists primarily of easily removable thiophenes and benzothiophenes, whereas diesel contains benzothiophenes and mostly refractory dibenzothiophenes that are hard to remove. Hence, desulfurization of kerosene is significantly easier compared to diesel. Furthermore, the existence of aromatic hydrocarbons in the organic matrices of the real fuels poses challenges to the desulfurization process described in this work. They prevent the formation of the active catalyst by inhibiting the partial reduction of HPA-5 from VV to VIV. The inhibition of aromatic hydrocarbons in ECODS increases in the following order: dibenzothiophenes > benzothiophenes > thiophenes. Moreover, the level of inhibition rises in proportion to the quantity of condensed aromatic rings: tri+-aromatics > diaromatics > monoaromatics. To address this issue, oxalic acid as a sacrificial agent mitigates the inhibition of aromatic compounds. This acid partially reduces the HPA-5 from VV to VIV, yielding the active catalyst species. Vanadyl sulfate, which acts as a source of VIV, is also capable of dealing with aromatic inhibition. Moreover, the process of removing sulfur is expedited as the length of the n-alkane chain increases.In this contribution, the difficulties of removing sulfur from actual refinery products, i.e., kerosene and diesel fuel, using an aqueous solution of H8PV5Mo7O40 (HPA-5) catalyst and molecular oxygen as an oxidizing agent (ECODS) are examined. Regarding oxidation of the S-containing aromatics, the reactivity in the distillation cuts proceeded in the following order: thiophenes > benzothiophenes > dibenzothiophenes. Kerosene consists primarily of easily removable thiophenes and benzothiophenes, whereas diesel contains benzothiophenes and mostly refractory dibenzothiophenes that are hard to remove. Hence, desulfurization of kerosene is significantly easier compared to diesel. Furthermore, the existence of aromatic hydrocarbons in the organic matrices of the real fuels poses challenges to the desulfurization process described in this work. They prevent the formation of the active catalyst by inhibiting the partial reduction of HPA-5 from VV to VIV. The inhibition of aromatic hydrocarbons in ECODS increases in the following order: dibenzothiophenes > benzothiophenes > thiophenes. Moreover, the level of inhibition rises in proportion to the quantity of condensed aromatic rings: tri+-aromatics > diaromatics > monoaromatics. To address this issue, oxalic acid as a sacrificial agent mitigates the inhibition of aromatic compounds. This acid partially reduces the HPA-5 from VV to VIV, yielding the active catalyst species. Vanadyl sulfate, which acts as a source of VIV, is also capable of dealing with aromatic inhibition. Moreover, the process of removing sulfur is expedited as the length of the n-alkane chain increases.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Additional notes:	Institute of Technical and Macromolecular Chemistry, University of Hamburg
Institutions of the University:	Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Chemical Engineering Faculties > Faculty of Engineering Science > Chair Chemical Engineering > Chair Chemical Engineering - Univ.-Prof. Dr.-Ing. Andreas Jess Research Institutions > Research Units > Zentrum für Energietechnik - ZET
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 540 Chemistry 600 Technology, medicine, applied sciences > 600 Technology 600 Technology, medicine, applied sciences > 620 Engineering 600 Technology, medicine, applied sciences > 660 Chemical engineering
Date Deposited:	11 Feb 2025 09:11
Last Modified:	11 Feb 2025 09:11
URI:	https://eref.uni-bayreuth.de/id/eprint/92346