M. Vrinat

Comprehensive 2D chromatography with mass spectrometry: a powerful tool for following the hydrotreatment of a Straight Run Gas Oil

Comprehensive two-dimensional gas chromatography (GC × GC) is a technique which is rapidly gaining importance for the analysis of complex samples, especially within petrochemical matrixes. Until recently GC × GC has been a technique used within analytical laboratories to characterize complex multi-component mixtures such as fuels, perfumes and organic aerosol extracts, which are difficult to analyze using conventional GC or GC-MS techniques. In the present study we will illustrate how GC × GC-qMS can be used as an effective tool to accurately monitor the conversion of a Straight Run Gas Oil (SRGO) on a Cobalt Molybdenum (CoMo) supported on an alumina sulfide catalyst. A SRGO was hydrotreated at various temperatures and liquid hourly space velocities (LHSV). The products were analyzed and attention was paid to the transformation of sulfur and aromatic compounds. Quantitative analyses using GC × GC-qMS were performed and compared to the “Simulated Distillation” and total sulfur analysis illustrating that this technique can provide a comprehensive view of the entire matrix, family of products and their distribution as well as single molecule evolution upon catalytic conversion.

Deep Hydrodesulfurization of Dibenzothiophenes Over NiW Sulfide Catalysts Supported on Sol–Gel Titania–Alumina

This work showed that the use of Al2O3–TiO2 as carriers has a positive effect on the activity of supported NiW catalysts in the hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene carried out in a batch reactor at 320xa0°C and total H2 pressure of 5.5xa0MPa. Two Al2O3–TiO2 mixed oxides with Al/Ti atomic ratios of 10 and 2 were synthesized by sol–gel method together with the pure Al2O3 synthesized as reference support. For NiW/Al2O3–TiO2 and NiW/Al2O3 catalysts, a metal load of 17 and 5.5 wt% of W and Ni were considered respectively. It was found that both Al2O3–TiO2-supported catalysts exhibited higher activity than alumina-supported one. The catalyst with a largest TiO2 content (NiW/AT2) demonstrated to be 23xa0% more active with respect to NiW/Al2O3. Solids were characterized by temperature-programmed reduction (TPR), high resolution transmission electronic microscopy and X-ray photoelectronic spectroscopy (XPS) techniques. A decrease in support–metal interaction (from TPR) was observed when Ti content increased, which could lead to a higher amount of NiWS phase (from XPS). Besides, a slight increase in the slabs length in WS2 was observed for titania-containing catalyst with respect to NiW/Al2O3, indicating that the dispersion can still be optimized. The atomic ratio Al/Tixa0=xa02 of the NiW/Al2O3–TiO2 catalyst proved to be a potential substitute for current catalysts for sulfur reduction in ultra-clean diesel.