ESI-MS Analysis of Thiol-yne Click Reaction in Petroleum Medium

Petroleum contains a large number of heteroatomic compounds, but today, most of them are not efficiently utilized. The constant development of the sustainability concept recalls for rethinking the usage of fossil resources with improved chemical utility. In order to initiate research aimed at involving active petroleum compounds in chemical transformations, a new analytical method for product detection is needed. Here, we study the click reaction of thiols with alkynes, leading to the formation of α-vinyl sulfides directly in the petroleum environment. The reaction was carried out using an (IMes)Pd(acac)Cl catalyst, which demonstrated tolerance to petroleum components. In this study, the concentration of thiols ranged from 1 M to 0.01 M (from 8% to 0.1%). To detect products at low concentrations, a special alkyne labeled with an imidazole moiety was used. This approach made it possible to observe the formation of vinyl sulfides by electrospray ionization mass spectrometry (ESI-MS), which provides an opportunity for further optimization of the reaction conditions and future developments for the direct involvement of oil components in chemical reactions.

Characterization of Severely Biodegraded Crude Oils Using Negative-Ion ESI Orbitrap MS, GC-NCD and GC-SCD: Insights into Heteroatomic Compounds Biodegradation

A slightly and two severely biodegraded crude oils with the same origin were analysed using negative-ion electrospray ionization Orbitrap mass spectrometry (ESI Orbitrap MS), gas chromatography-nitrogen chemiluminescence detector (GC-NCD), and GC-sulfur chemiluminescence detector (GC-SCD) to investigate the composition of heteroatomic compounds and their fate during severe biodegradation and to provide insights into biodegradation pathway of hopanes, nitrogen- and sulfur-containing compounds. Twelve heteroatomic compound classes, including O1–O5, N1, N2, N1O1–N1O3, N1S1 and O3S1, were detected and assigned unambiguous molecular formulae. The O1 species are likely phenols with additional naphthenic and/or aromatic rings. Carboxylic acids (O2 species) are originated from oxidation of hydrocarbons, and the tricyclic naphthenic acids are the most resistant, followed by bicyclics. Hopanes could be biodegraded by demethylation or by unstable hopanoic acids as intermediates to yield 25-norhopanes. The N1 species are pyrrolic compounds with naphthenic and/or aromatic rings and are dominated by carbazole analogues. Carbazoles with more aromatic rings are more resistant to biodegradation. The N1 species could be converted to N1O1 and N1O2 compounds via ring-opening and hydroxylation pathways. The N1S1 species contain a pyrrolic and cyclic sulfide structure, which are highly recalcitrant to biodegradation. Benzothiophenes and dibenzothiophenes might be biodegraded via the complete pathway or the sulfur-specific pathway rather than by other pathways to yield acidic oxygenated sulfur compounds.

EXTRACTION OF ARENES AND HETEROATOMIC COMPOUNDS FROM n-UNDECAN BY BIEXTRAGENT N-METHYLPYRROLIDONE-ETHYLENE GLYCOL

The results of the extraction of thiophene, dibenzothiophene, diphenylamine, indole, carbazole, fluoranthene and pyrene from model mixtures with n-undecane, as well as thiophene from a mixture with n-heptane at a content of the extractable component in the binary system of 10% wt. are presented. A mixed solvent N-methylpyrrolidone - ethylene glycol with the composition of 90/10% wt. at 25 °C was used for the extraction. The experimental data obtained were compared with the results of the extraction of the same components from model mixtures with n-undecane by pure N-methylpyrrolidone

Distribution of nitrogen and oxygen compounds in shale oil distillates and their catalytic cracking performance

The positive- and negative-ion electrospray ionization (ESI) coupled with Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to identify the chemical composition of heteroatomic compounds in four distillates of Fushun shale oil, and their catalytic cracking performance was investigated. There are nine classes of basic nitrogen compounds (BNCs) and eleven classes of non-basic heteroatomic compounds (NBHCs) in the different distillates. The dominant BNCs are mainly basic N1 class species. The dominant NBHCs are mainly acidic O2 and O1 class species in the 300–350 °C, 350–400 °C, and 400–450 °C distillates, while the neutral N1, N1O1 and N2 compounds become relatively abundant in the > 450 °C fraction. The basic N1 compounds and acidic O1 and O2 compounds are separated into different distillates by the degree of alkylation (different carbon number) but not by aromaticity (different double-bond equivalent values). The basic N1O1 and N2 class species and neutral N1 and N2 class species are separated into different distillates by the degrees of both alkylation and aromaticity. After the catalytic cracking of Fushun shale oil, the classes of BNCs in the liquid products remain unchanged, while the classes and relative abundances of NBHCs vary significantly.