Separation And Quantification Of Nitrogen Compounds In Vacuum Residues

In this paper, nitrogen compounds were separated from Liaohe, Venezuela viscous oil vacuum residue by ion exchange resin in order to determine the final separating effect. The effects of types of resin, ion exchange resin,s treatments, composition of the eluant on desorption were studied. Ion exchange resin and silica gel/basic alumina finally separated vacuum residue into saturates, aromatics, neutral nitrogen fraction, acid fraction and basic fraction. The utilization of IR spectroscopy, Aqueous potentiometric titration, FTICR-MS helps us to qualitatively analysis nitrogen compounds in each component.The results show that the macroporous resin D001-cc, D201 are chosen as the adsorbent; in further processing condition, acetone extraction after macro-porous anion exchange resin modified by 2.0 mol/L NaOH solution while macro-porous cation exchange resin modified by 30% H₂SO₄ solution is the best, 2.0 mol/L KOH solution and 30% HCLO4 solution take second place; the eluants on desorption are cyclohexane, benzene-ethanol, ethanol; elution method is that anion exchange resin separates acid fraction and non-acid fraction by chromatography column, cation exchange resin separates non-basic fraction by chromatography column while basic fraction by extraction.The results show that basic nitrogen is mainly consisted in basic fraction, which contains more than 70%, then in the neutral nitrogen fraction contains 10～12%, in the acid fraction contains 5～8%; non-basic nitrogen is mainly consisted in acid fraction, which contains more than 65%, then in the neutral nitrogen fraction contains 10～15%, in the basic fraction belows 10%; while nitrogen is very low in the saturates and aromatics. In Venezuela oil vacuum, the basic fraction and neutral nitrogen fraction mainly contains quinoline, pyridine, the acid fraction is mainly consisted of amine. In Liaohe oil vacuum, the acid fraction is mainly consisted of amine, the basic fraction mainly contains amine and pyridine. Application of FTICR-MS in quantification of nitrogen compounds in vacuum residua fractions.