Compositional Analysis of Oil Residues by Ultrahigh-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry was used for compositional analysis of polar and asphaltene fractions of complex oil residues. The samples were collected before and after the processing of oil in a residue hydrocracking unit, in which the feed oil was the vacuum distillation residue of the crude oil, and the product sample was the residue collected after the processing. From the asphaltene fraction, as many as ∼26 000 peaks were detected by atmospheric pressure photoionization and more than ∼33 000 peaks by positive-ion electrospray ionization (ESI), with up to 18 distinct heteroatom classes identified. Negative-ion ESI provided complementary information through selective ionization of acidic compounds. The detected species were sorted based on heteroatom class, carbon number and aromaticity (double bond equivalence, i.e. number of rings + double bonds to carbon). The N 1 class compounds were predominant in both fractions of the feed and product oils. The sulfur-containing compounds were mainly degraded or removed during the processing as expected. Vanadyl porphyrins (heteroatom class N 4 O 1 V 1 ), detected in the asphaltene fraction of the feed oil, were not observed in the product oil fractions that is consistent with their efficient removal. Increase in the aromaticity for the most heteroatom classes was generally noticed in both polar and asphaltene fractions.

Recent developments in atmospheric pressure photoionization‐mass spectrometry

“…Rather than targeted analysis, the aim in petroleomics is often to characterize different compound classes and their proportions. The characterization is typically done based on exact masses from ultra‐high resolution FTICR‐MS, which can derive double‐bond equivalences, and identities and numbers of heteroatoms (McKenna et al, 2010a, b, 2013a; Kekäläinen et al, ; McKenna, Marshall, & Rodgers, ; Podgorski et al, ). Promising results for structural elucidation of crude‐oil components have also been achieved with ion‐mobility spectrometry (IMS) and theoretical collision cross‐section calculations (Ahmed et al, ).…”

“…Due to oil sample complexity, the most‐comprehensive characterization of petroleum compounds is achieved when several ionization techniques (and sometimes both polarities) are combined (Barrow et al, ; Kekäläinen et al, ; Chiaberge et al, ; Headley et al, ; Lababidi & Schrader, 2014; Ruddy et al, ). For example, NPLC‐FTICR‐MS was used to characterize de‐asphalted crude oil with ESI, APCI, APPI, and APLI as ionization techniques (Lababidi & Schrader, 2014).…”

Ultrahigh-Resolution Magnetic Resonance Mass Spectrometry Characterization of Crude Oil Fractions Obtained Using n-Pentane

“…In this work, fractions obtained by flowing n -pentane throughout a column packed with sand and crude oil were analyzed using high-resolution mass spectrometry. This technique has been successfully used in characterizing changes in compositional distributions in crude oils and fractions as a result of chemical − and physical , processes. Although quantification is not possible and results are influenced by the ionization technique used, there is a treasure trove of compositional information that can be obtained on the basis of the careful comparison of materials undergoing significant changes.…”

In-Depth Analysis of Raw Bio-Oil and Its Hydrodeoxygenated Products for a Comprehensive Catalyst Performance Evaluation

“…15,16 More advanced techniques like nuclear magnetic resonance (NMR), high-performance liquid chromatography (HPLC), or Fourier transformed infrared (FTIR) spectroscopy are known to provide valuable information on the quantification of specific functional groups in bio-oil. 17 Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) has the capability of making a great impact in the analysis of highly complex and heavy feedstocks like heavy-crude-oil-derived mixtures 18,19 or oxygenated streams. 13,20 Through this technique, the analysis of highly polar species (like those in bio-oil) is plausible using electrospray ionization (ESI), while the nonpolar hydrocarbons and neutral phenolics are preferentially ionized through atmospheric pressure photoionization ((+)APPI).…”

“…Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) has the capability of making a great impact in the analysis of highly complex and heavy feedstocks like heavy-crude-oil-derived mixtures , or oxygenated streams. , Through this technique, the analysis of highly polar species (like those in bio-oil) is plausible using electrospray ionization (ESI), while the nonpolar hydrocarbons and neutral phenolics are preferentially ionized through atmospheric pressure photoionization ((+)­APPI). Palos et al have applied (+)­APPI FT-ICR/MS for elucidating the activity of a series of hydrotreatment catalysts on the upgrading of a light cycle oil and scrap tire oil (LCO/STO) blend.…”