Characterization of Nitrogen Compounds in Coker Heavy Gas Oil and Its Subfractions by Liquid Chromatographic Separation Followed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

A coker heavy gas oil (CHGO) was separated into saturates, aromatics, resins, and asphaltenes (SARA) fractions. The resin fraction was separated into six subfractions by high-performance liquid chromatography (HPLC). The CHGO and its subfractions were characterized by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The mass spectra showed that the mass range of basic and neutral nitrogen compounds was 200−450 and 160−400 Da, respectively. Five nitrogen class species, N1, N2, N1O1, N1O2, and N1S1, were assigned in the positive-ion spectrum. Six nitrogen class species, N1, N2, N1O1, N1O2, N2O1, and N1S1, were assigned in the negative-ion spectrum. Among the identified nitrogen compounds, the N1 class species was dominant. The N1 class species were enriched in the resin fraction. The N2 class species are likely amphoteric molecules and were enriched in the asphaltene fraction. The composition of nitrogen compounds in the resin subfractions varied significantly in double-bond equivalence (DBE) and carbon number. As the polarity of the resin subfraction increased, the average molecular weights of the nitrogen compounds decreased, DBE values for each heteroatom class species increased, and the N2 class species became the dominant nitrogen compounds at the expense of the N1 class species.

Characterization of Basic Nitrogen-Containing Compounds in the Products of Lube Base Oil Processing by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…Sample preparation method by positive-ion ESI FT-ICR MS has been previously reported. 2,5 The sample solution was infused via an Apollo II electrospray source at 180 L/h by a syringe pump. The operating conditions for positive-ion formation were 4.0 kV emitter voltage, 4.5 kV capillary column front end voltage, and 320 V capillary column end voltage.…”

“…However, GC-MS is not capable of analyzing samples that contain higher molecular-mass nitrogen compounds because of their low volatility. 2,5 Recently, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with an ultrahigh mass resolution and mass accuracy has been successfully used to analyze trace polar compounds found in petroleum systems at the molecular level. Positive-ion ESI can selectively ionize heteroatom species, such as basic nitrogen compounds, and negative-ion ESI can be used for acids and neutral nitrogen compounds.…”

“…Positive-ion ESI can selectively ionize heteroatom species, such as basic nitrogen compounds, and negative-ion ESI can be used for acids and neutral nitrogen compounds. 2,6,7 Smith et al 8 analyzed the polar heteroatom species including basic and neutral nitrogen compounds in eight heavy vacuum gas oil (HVGO) distillation fractions with different boiling ranges of Athabasca bitumen by positive-and negative-mode ESI FT-ICR MS. Liu et al 4 has characterized the composition of basic nitrogen compounds in the products of Liaohe atmospheric residue hydrocracking including VGOs by positiveion ESI coupled with FT-ICR MS.…”

Identification of organonitrogen and organooxygen compounds in the extraction residue from Buliangou subbituminous coal by FTICRMS

“…Organooxygen compounds 30 X-ray photoelectron spectrometer 31 Fourier transform ion cyclotron resonance 32 mass spectrometer 33 3 4 a b s t r a c t 35 Organonitrogen and organooxygen compounds (ONCs and OOCs) in the extraction residue (ER) from 36 Buliangou subbituminous coal were characterized by electrospray ionization Fourier transform ion cyclo- 37 tron resonance mass spectrometry (ESI FTICRMS) analysis. Pyrrolic and hydroxy are the most abundant 38 nitrogen and oxygen function groups on the ER surface according to analysis with an X-ray photoelectron 39 spectrometer.…”

“…All the solvents used in the experi-119 ment are commercially purchased analytical reagents, which were 120 purified by distillation with a rotary evaporator prior to use. [35,39]. In detail, the sample solution was infused via ESI at a flow 134 rate of 300 L/h with a syringe pump.…”