10 research outputs found
Speciation of Basic Nitrogen Compounds in Gas Oils and Vacuum Gas Oils by Derivatization with BF<sub>3</sub> prior to NMR Analysis
Nitrogen-containing
compounds, present in gas oils (GO) or vacuum
gas oils (VGO) cuts, affect many of the important petroleum processes
such as hydrocracking and hydrotreating due to their nucleophilic
character. Basic nitrogen compounds, which can inhibit the acidic
sites of the catalysts, are mainly pyridine derivatives (6-membered-ring
nitrogen compounds), and despite the use of highly resolutive methods,
their characterization, especially in VGO, is still limited. Herein,
we propose a new promising methodology, coupling the derivatization
with BF<sub>3</sub> of nonprotogenic nitrogen species and the use
of NMR analysis. By crossing information from <sup>19</sup>F, <sup>1</sup>H, <sup>1</sup>H–<sup>19</sup>F HMBC and <sup>19</sup>F DOSY, it is possible to determine the close environment of the
nitrogen atom of the most nucleophilic nitrogen impurities in GO or
in VGO cuts, independently of the sizes of the molecules. This approach
allows the characterization and comparison of fingerprints of basic
nitrogen impurities in charges or effluents