Sulfur compounds characterization using FT-ICR MS: Towards a better comprehension of vacuum gas oils hydrodesulfurization process

Some aromatic sulfur compounds contained in vacuum gas oils are known to be very refractory to hydrotreatment. Thus, a better knowledge of these molecules would help to improve hydrodesulfurization efficiency by designing targeted catalysts or choosing adequate operating conditions for hydrotreatment process. The characterization of such compounds using advanced analytical techniques such as Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) can give more information about the aromaticity and the number of carbon atoms of these refractory molecules. One vacuum gas oil feed and six hydrotreated samples obtained from pilot plant tests at several temperatures or using different catalysts have been analyzed using APPI (+)-FT-ICR MS. The differences of the aromaticity and number of carbon atoms among the several hydrotreated samples have been investigated to identify the effects of catalysts and temperatures over hydrotreatment process. Principal Component Analysis was used to explore the obtained data and put forward the variables explaining most of the variance between the hydrotreated samples.