Resolution and Identification of Petroleum Sulfonate by Electrospray

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Resolution and Identification of Petroleum sulfonate by Electrospray ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Shengke Li, Bo Peng, Dan Liu, and Chi Sun Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.5b03015 • Publication Date (Web): 29 Mar 2016 Downloaded from http://pubs.acs.org on April 1, 2016

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Resolution and Identification of Petroleum sulfonate by Electrospray ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Shengke Li, a, b Bo Peng, a,* Dan Liu, a Chi Sun a a

Research Institute of EOR, China University of Petroleum (Beijing), Beijing 102249, PR China

b

College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Fushun 113001, PR China

*

To whom correspondence should be addressed

ABSTRACT: In this study, a petroleum sulfonate (PS) and its sulfonating raw oil were directly detected without pre-separation by using negative ion electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), in order to resolve and identify polar heteroatomic compounds in complex PS as well as to study the changes of various compounds from raw oil to PS before and after sulfonation. There were roughly 8500 and 6100 peaks positively resolved by mass spectrometry in PS and raw oil, respectively. Thirteen heteroatom classes in raw oil were identified as follows: N1, N1O1, N1O2, N1O3, N1O4, N1O5, O1, O2, O3, O3S1, O4, O5, and O5S1. As for those in PS, there are nineteen classes, including N1, N1O1, N1O1S1, N1O2, N1O2S1, N1O3, N1O3S1, N1O4, N1S1, O1, O1S1, O2, O2S1, O3, O3S1, O4, O4S1, O5, and O5S1. Dominated O3S1, O2, O3, O4, N1O2, O4S1 classes were classified and discussed in terms of double-bond equivalent (DBE) and carbon numbers. Significant O3S1 class species were centered at a DBE value of 4-10 with a carbon number of 23-34, corresponding to various alkyl aryl sulfonate

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such as alkyl benzene and alkyl indane sulfonate. In summary, this paper introduced ESI FT ICR-MS to comprehensively characterize PS at the molecular level.

INTRODUCTION

Petroleum sulfonate (PS) is a sort of anionic surfactant，which has been extensively used for enhancing oil displacement efficiency in tertiary oil recovery due to the ability of reducing interfacial tension (IFT).1-3 PS is commonly synthesized by sulfonation of crude oils or distillates with various sulfonating agents, such as concentrated sulfuric acid, oleum, sulfur trioxide and chlorosulfonic acid.4 The sulfonation products are complicated mixtures containing the effective active components (sulfonate), unsulfonated oil and inorganic salts.5 Desirable products are surfactant species with good interfacial activity, such as O3S1-, O4S1-, and N1O3S1-containing class species. Excellent sulfonate could reduce IFT of crude oil/surfactant system reaching to ultra-low value (10-3mN/m), less adsorbed by rock in oil reservoir, and have good temperature/brine compatibility.6 PS is generally evaluated by properties closely related to their composition and structure,7-9 including IFT behavior, adsorption behavior, temperature/brine compatibility, and oil recovery characteristics.2,

10, 11

However, PS derived from crude or distillate is complicated mixtures

containing large amounts of active components and unsulfonated oil, both of which are of various structural hydrophobic groups，as it is hard to separate PS into single component. More attention recently has been paid to quantitative analysis of active species,5, average structure,12,

13

6

elemental composition and

average molecular weight and molecular weight distribution, and simple

qualitative analysis between mono-sulfonate and di-sulfonate in PS characterization.14 Feng15 et al.


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characterized PS by ESI TOF MS after separating PS into different components. However, they only determined the relative molecular mass distribution of the PS components by using MS. The advent of ultrahigh-resolution FT-ICR MS makes it possible to resolve and identify up to thousands of chemically distinct components in the extreme complex. During the past decades, FT-ICR MS has been extensively applied to petroleomics due to its ultrahigh resolution power and mass accuracy measurement.16-19 Marshall and co-workers20-22 demonstrated that a single ESI FT-ICR MS could accurately resolve and identify heteroatom-containing (N, O, and S) organic compounds in different crude oil. Moreover, Stanford23 introduced FT-ICR MS into oilfield chemistry. They identified nonvolatile polar acidic and basis emulsion stabilizers in various geographically distinct crude oils by means of ESI FT-ICR MS. The widespread use of FT-ICR MS could be partly attributed to advances in ion-source technology. Electrospray ionization (ESI) selectively ionizes polar species in crude oil, distillates and their derivatives, generating quasi-molecular ions [e.g., (M+H)+ or (M-H)-]. ESI is characterized by little fragmentation generated during ionization, so that one ionic species is basically produced for each neutral analyte originally present.24 Because negative ion ESI can selectively ionize acidic polar heteroatomic molecules within the predominately hydrocarbon matrix of petroleum samples without fragmentation, 25 it is chosen as the ionization method for the PS. In addition, it avoids the need for pre-separation.26 In this work, the combination of FT-ICR MS with negative-ion ESI developed a unique way to analyze complex PS. In this condition, ultra-high resolution MS was utilized to obtain accurate masses and further identify


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molecule formula. Thus, the possible structures of sulfonate can be inferred based on analysis of double-bond equivalent (DBE, namely, number of ring plus double bond) and the carbon number. Therefore, an innovative approach for detailed characterization of petroleum sulfonate used in EOR was introduced in this study.

EXPERIMENTAL

Materials

The petroleum sulfonate required for EOR was synthesized with the raw oil obtained from Daqing Refining & Chemical Company (China). The raw oil was furfural extract oil from Daqing vacuum gas oil (boiling range 370~490℃). The sulfonation reacted in a home-built single tube film sulfonation reactor by sulfur trioxide sulfonating agent under ambient pressure. The reactor is a glass tube with inner diameter of Φ8 and length of 2.2 m. The SO3/dried air mixture was pumped into the sulfonation reactor by a flow control pump.4 Meanwhile, the heated raw oil was transported to the top of the sulfonation reactor, then formed even oil film on the inner wall. The raw oil parallel flowed down as well as reacted with SO3/air mixture within the reactor. Sulfonating product mainly contained petroleum sulfonic acid and unsulfonated oil after separating acid sludge. 20% NaOH solution was added into continuously stirred sulfonating product to neutralize the petroleum sulfonic acid until a pH value of 8~10. Subsequent product was subjected to extract by 50% ethanol solution to roughly remove unsulfonated oil and inorganic. Finally, petroleum sulfonate was obtained by evaporating the solvent of extract liquor. Sulfonating conditions and composition for PS and raw oil are listed in table 1. The reactions that are likely to occur during sulfonation as follows:


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Primary reaction: R

R

+

SO3

SO3H

Secondary reaction: R

R

+ SO3 SO3H

SO2OSO3H R R

R

SO2OSO3H

R-OH + SO3

SO2

+

sulfate

+ H2SO4 R

R-OSO3H

Neutralization: R

R

SO3H

+ NaOH

R-OSO3H + NaOH

SO3Na

+ H2 O

R-OSO3Na + H2O

ESI FT-ICR MS Analysis and data processing

Test samples were analyzed at State Key Laboratory of Heavy Oil Processing (China University of Petroleum, Beijing) with a Bruker apex-ultra FT-ICR mass spectrometer equipped with a 9.4 T superconducting magnet coupled to ESI ionization source in the negative ion mode. Shi et al.27 introduced sample preparation and MS analysis procedure for negative-ion ESI FT-ICR MS in details. Specific information should be highlighted that the PS and its raw oil were dissolved in toluene at 10 mg/mL, respectively. And then a total of 20 µL of each toluene solution was further diluted with 1mL of methanol/toluene (3:1, v/v) mixed solution. Final solutions were spiked with 30% NH4OH and then injected into an Apollo II ESI source at a rate of 3 µL/min with a syringe


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pump. Typical analysis conditions of negative-ion mode for electrospray source were 4.0 KV of emitter voltage, 4.5 KV of capillary column introduce voltage, and﹣320 V of capillary end voltage.28, 29 Mass calibration and data processing were performed as described in previous works.27 In brief, mass spectrometer was internally calibrated using class homologous series with a high relative abundance of negative-ion ESI MS peaks. Then, mass spectrum peaks with signal-to-noise ratio greater than six were exported to a spreadsheet to assign elemental compositions by a software named Broker Daltonics DataAnalysis of version 3.4. Each MS peak was identified for elemental components, Figure S-1 shows expansion of odd- and even-mass peaks of the PS. Subsequently, FT-ICR MS sorts elemental compositions into three typical molecular characteristics, namely “class”, “type” and carbon distribution, according to numbers of heteroatom, rings plus double bonds (DBE) values, carbon numbers, respectively.30 For a molecule formula, CcHhNnOoSs, DBE can also be calculated according to the following formula. DBE = c – h/2 + n/2 + 1.31 The iso-abundance plots were made by normalizing response intensity according to the following formula. The normalized parameter is named point size. Point size = 39(Ii – Imin) / (Imax – Imin) + 1 Where, Ii — intensity of a peak; Imin — intensity minimum in all of peaks; Imax — intensity maximum in all of peaks.


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RESULTS AND DISCUSSION

Negative Ion ESI FT-ICR Mass Spectra

In this study, we aimed to apply ESI FT-ICR MS into direct resolution and identification of polar heteroatomic compounds, especially O3S1 class and carboxyl-containing species. We sought to firstly find out and summarize various heteroatomic classes (e.g., N1, O3S1, O2, O3, N1O2, etc.), and then identify different types (i.e., molecules with different DBE) for each class, and finally clarify the carbon number distribution (i.e., different alkyl carbon number) for each type. Figure 1 displays the same mass distribution (250﹤m/z﹤700) of wide-band negative ESI FT-ICR mass spectra of the PS and its raw oil. Peaks of raw oil were concentrated at 400 Da, whereas it is clear that the mass distribution for the PS is bimodal. The lower mass “hump” matches the raw oil and the higher mass “hump” possible due to the newly formed sulfur-containing species, as evidenced by the increased number of species in the PS sample. It is suggested that sulfonation enlarged average molecular weight of compounds in the raw oil，which is consistent with the process that hydrogen atoms were replaced by sulfonic acid groups. There are nearly 6100 resolved peaks in the raw oil, whereas approximate 8500 resolved peaks are found in the PS. The highest intensity peaks at m/z 255 and 283 in the PS should be C16 and C18 fatty acids acting as contaminants in the negative-ion ESI analysis of samples.28, 32 In the sulfonation, aromatic and naphthenic compounds are mainly sulfonated to produce the PS. FT-ICR MS provided accurate masses make assigning molecular formula possible under lower mass error.


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Heteroatomic Compound Class

For a molecule formula, CcHhNnOoSs, NnOoSs is defined as class. All the heteroatom classes with various types in both samples were sorted and presented in Figure 2. Number of heteroatom classes from raw oil summed to 13, in which the N1, N1O2, O1, O2 and O3 class species were dominantly abundant. By contrast, number of heteroatom classes in PS increased up to 19. Apart from O3S1 and N1O3S1 class, 5 additional species (O2S1, N1O2S1, N1S1, O1S1 and N1O1S1) were found in the PS after sulfonation, suggesting that sulfonation yielded undesirable sulfur-containing by-products. In the sulfonating reaction, sulfonic acid group substituted for a hydrogen atom attached with aromatic ring resulting in target sulfonates (O3S1) and organic sulphones (R1SO2R2, R1 and R2 refer to different alkyl substituents) by-products. Therefore, O3S1, N1O3S1, O2S1, N1O2S1 class species could appear in mass spectrum of the PS. The types and content of N1O1S1，N1S1 and O1S1 species much less than that of O3S1 and O2 species. Hence, they have little influence on interfacial properties, so they are not discussed here.33 The histogram clearly indicated that O3S1 class species were abundant in the PS, demonstrating excellent sulfonating effects. Figure 3 shows approximately the same compounds at the same nominal mass (403 Da) of both samples excluding O3S1 and O4S1 appeared in the PS, suggesting that sulfonic acid groups may be generated by sulfonation. The infrared spectra of raw oil and PS were shown in Figure S-2 and S-3. Meanwhile, the IR spectra showed that the sulfonic acid group was not detected by using IR spectroscopy but detected in the PS. The statistical and structural information of O3S1 homologues is listed in Table 2.


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It should be noted that sulfonation is generally accompanied by oxidation due to the strong oxidizing property of sulfur trioxide.6, 34 The alkyl side chain of hydrocarbon matrix compounds were liable to be oxidized along with hydrogen transfer, chain breaking and cyclization. Black substances that were difficult to be bleached were generated as a result of the reactions mentioned above, especially sulfates (R1-O-SO2-O-R2) from chain paraffin with tertiary carbon atom.35

DBE versus Carbon Number for various Classes

Negative ion ESI FT-ICR MS selectively ionizes polar compounds such as phenols, alcohols, carboxylic acids, and pyrroles. For raw oil, the N1 class species that are of highest abundance are neutral nitrogen-containing compounds such as carbazole (DBE = 9) and benzocarbazloe (DBE = 12), while the O1 class species are phenols or alcohols. However, we highlight the class species easily adsorbed at air/water and (or) liquid/liquid interface leading to interfacial tension reduction, including well-known sulfonate (O3S1) and carboxyl-contained compounds (O2, O3, O4, etc.).36, 37 In combination with elemental composition, DBE and carbon number can generally help infer possible molecular structures. O2, O3 and O4 class species. Figure 4 shows iso-abundance plots of DBE versus carbon number for O2, O3 and O4 class species before and after sulfonation. It is shown that sulfonation appears to increase the diversity of oxygenated compounds. All the three oxygen-containing classes have a more widely DBE and carbon number distribution in the PS than that of in the raw oil. The carbon numbers of O2 species change from range of 16-38 to 8-50 after sulfonation. And DBE values of O2 species change from range of 1-15 to 1-18 after sulfonation. The distribution change of carbon numbers and DBE values for O2 species may be attributed to oxidation by sulfur trioxide.34 The


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bigger DBE value is, the higher condensation degree of compounds are. Relative abundance of O2 class species increases with decrease of DBE values. High abundance O2 species mainly concentrate on DBE of 1 and 2. The O2 class species with a DBE value of 1 are fatty acids, while species with a DBE value of 2-6 are commonly considered as naphthenic acids with 1-5 naphthenic rings. Meanwhile, those of DBE value higher than 4 may be aromatic acids. For example, species with DBE values of 5 and 6 are likely to be secohopanoic acid and hopanoid acid homologue, respectively. Furthermore, the species with high DBE values and lower carbon number are more likely to be aromatic acids.28 The C16 and C18 with a DBE value of 1 should be contaminants introduced by the sample preparation process.32 The high abundant O3 species in raw oil are centered at carbon numbers of 26-35 and DBE values of 4-7, while those in PS have a relatively uniform distribution. DBE values of O3 species in PS vary from 1 to 22 and carbon numbers range from 14 to 50. The blank area in the plot indicates that O3 species were not detected there. The most abundant O3 species with DBE values of 4, 5 and 6 likely correspond to aromatic acids with 0-2 naphthenic rings and 1 hydroxyl. The similar carbon number distribution and DBE for O2 and O4 in both samples suggest that O4 class species are not the dimer of O2 species. The O4 species with a DBE value of 2 are dicarboxylic acids. The O4 species with DBE values of 3-5 are dibasic carboxyl acids with 1-3 naphthenic rings. The species with DBE values higher than 6 likely contain an aromatic ring and two carboxyls. The O4 species with a DBE value of 1 are chain hydrocarbons including a carboxyl and two hydroxyls. O3S1 class species. Figure 5 shows the iso-abundance plot of DBE as a function of the carbon number for O3S1 class species in the PS. However, O3S1 species in raw oil is not provided because of


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limited types and low abundance. Moreover, those O3S1 species in raw oil should not be sulfonate as evidence from absence of sulfonic acid groups in the IR spectrum (Figure S-2). Figure 5 also indicates that O3S1 species spreads over a wide range of DBE values from 1 to 16 with carbon numbers of 18-40. As for the O3S1 species with high abundance, DBE values range from 4 to 10 and carbon numbers vary from 25 to 33. DBE calculated formula (DBE = c – h/2 + n/2 + 1) indicates that DBE value is only related to C, H and N atom numbers, so SO3 group does not affect the DBEs. The O3S1 species with low DBE values of 1-3 suggest that the sulfonic acid group was added to cycloalkanes with 1-3 naphthenic rings. And that group should append to naphthenic rings, demonstrated by the absence of O3S1 class species with a DBE value of zero. Meanwhile, the abundance decreases as naphthenic ring increases within the range of DBE values from 1 to 3. For petroleum sulfonate, O3S1 species with DBE values greater than or equal to 4 should contain a benzene ring, because the sulfonic acid group is liable to replace hydrogen atoms on the aromatic ring in the process of sulfonation. When the DBE value equals to 4, the compounds should be alkyl benzene sulfonate with one benzene ring. The O3S1 Species with a DBE value of 5 are likely alkyl indane/tetrahydronaphthalene sulfonate with a benzene ring and a five- /six-membered naphthenic ring. Therefore, the number of possible structural formulas increases with the DBE value. Each abundant O3S1 species was identified by means of matching with the usual alkylaryl sulfonate and the most possible chemical structural formulas were listed in Table 2.38 Relative abundance of various O3S1 types demonstrated that sulfonation prefers to occur on aromatic rings instead of naphthenic rings and scarcely acts on alkyl chains.


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O4S1 class species. The O4S1 class species are likely sulfonates with a hydroxyl group. These hydroxyl sulfonates should be generated by sulfonation on the base of O1 class species. The O4S1 species with DBE values greater than or equal to 4 may be obtained from sulfonation of phenols by sulfur trioxide, whereas those with DBE values of 1-3 are likely generated by sulfonation of alcohols. The inference above can be supported by distribution of O1 species in the raw oil, Figure 6 (right). The O1 species with DBE a value of 1-3 should be alcohols with 1-3 naphthenic rings, but they have not been detected due to the much lower response factor of an alcoholic hydroxyl group compared to strong polarity species in the raw oil (such as carboxylic acids). The O1 species with a DBE value greater than 3 should be detected as phenols due to their greater polarity than alcohols. However, the O4S1 species are also likely sulfates (sulfuric acid monoesters) obtained from reaction of high-carbon fatty alcohols with sulfur trioxide. Sodium sulfuric acid monoester (R-OSO3Na) is an important anionic surfactant. They could be synthesized by fatty alcohols reacting with sulfur trioxide and then neutralizing by NaOH solution. The reaction mechanism consists of three steps as follows: sulfate

R-OH + 2SO3

R-O-SO2-O-SO3H

fast

(1)

ageing R-O-SO2-O-SO3H + R-OH R-OSO3H + NaOH

slower

neutralize

2R-OSO3H

R-OSO3Na + H2O

(2) (3)

Except hydroxyl sulfonates, the O4S1 species with DBE of 1-12 are also likely sulfates. But, the O4S1 species with DBE of zero should not be hydroxyl sulfonates but sulfates. Because sulfonation difficultly occurs on alkyl chains just as O3S1 species mentioned above.


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N1O2 class species. The structure of N1O2 should be taken into account because of the high relative abundance and possibility for existence of carboxyl groups. It should encompass a pyrrole/pyridine ring and a carboxyl group when the N1O2 class is acidic. Figure 7 shows the same distribution of DBE values and carbon numbers for N1O2 and N1, suggesting that N1O2 was generated by biodegradation of N1. Previous literature31 indicated that N1O2 class resulted from attacking the pyrrolic core or aromatic core adjacent to the pyrrolic ring by carbazole degrading enzyme, during which a hydroxyl or a carboxyl group was generated. With the exception of plausible acidic N1O2 class, the degradation of N1 may also introduce a nitrogen-containing species with two hydroxyls. Therefore, further structural determination for N1O2 is recommended to combine with other analytical techniques (e.g., FTIR and NMR).

CONCLUSIONS

Detailed molecular composition of interfacial active components in Daqing petroleum sulfonate was comprehensively characterized by FT-ICR MS coupled to ESI. The structural information of O3S species were determined matching with common sulfonate such as alkyl benzene and alkyl naphthalene sulfonate. Meanwhile, the O4S1 species should be hydroxyl sulfonates and sulphates, both are beneficial for interfacial activity. The O2, O3, O4 and N1O2 species all likely contain carboxylic acids, which could be potential active species after reaction with alkalis such as sodium hydroxide in alkali/surfactant/polymer (ASP) flooding. FT-ICR MS coupled to negative ion ESI furnishes a powerful and promising tool for the comprehensive characterization of active components in complicated petroleum sulfonate which are synthesized by crude oil, distillates, and even vacuum residuum.


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AUTHOR INFORMATION

Corresponding Authors:

Bo Peng; Telephone: +8610-8973-4903. E-mail: [email protected]

Notes

The authors declare no competing financial interest.

ACKNOWLEDGEMENTS

This work was supported by the National High Technology Research and Development Program of China (863 program) (2008AA06Z207) and China national Ministry of Education (107019).

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(14) Wang, S.; Liu, X.; Jiang, S. Determination of Petroleum Mono and Disulfonates by Ion Chromatography Coupled with Weighted Least Squares Linear Regression. Energy Sources, Part A

2011, 33 (20), 1883-1888. (15) Feng, Ziyan; Cui, Mingwei; Liu, Jingjing; Song, Yuhe; etc. Separation and Characterization of Petroleum Sulfonate Components. Asian Journal of Chemistry 2014, 26 (20), 6722-6726. (16) Lo, C. C.; Brownlee, B. G.; Bunce, N. J. Electrospray-mass spectrometric analysis of reference carboxylic acids and Athabasca oil sands naphthenic acids. Analytical Chemistry 2003, 75 (23), 6394-6400. (17) Hemmingsen, P. V.; Kim, S.; Pettersen, H. E.; Rodgers, R. P.; etc. Structural characterization and interfacial behavior of acidic compounds extracted from a North Sea oil. Energy & Fuels 2006, 20 (5), 1980-1987. (18) Smith, D. F.; Klein, G. C.; Yen, A. T.; etc. Crude oil polar chemical composition derived from FT-ICR mass spectrometry accounts for asphaltene inhibitor specificity. Energy & Fuels 2008, 22 (5), 3112-3117. (19) Zhang, L.; Hou, Z.; Horton, S. R.; etc. Molecular Representation of Petroleum Vacuum Resid.

Energy & Fuels 2013, 28 (3), 1736-1749. (20) Marshall, A. G.; Rodgers, R. P. Petroleomics: The Next Grand Challenge for Chemical Analysis.

Accounts of Chemical Research 2004, 37 (1), 53-59. (21) Marshall, A. G.; Rodgers, R. P. Petroleomics: Chemistry of the underworld. PROCEEDINGS

OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2008, 105 (47), 18090-18095.


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(22) Qian, K.; Robbins, W. K.; Hughey, C. A.; Cooper, H. J.; etc. Resolution and Identification of Elemental Compositions for More than 3000 Crude Acids in Heavy Petroleum by Negative-Ion Microelectrospray High-Field Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Energy & Fuels 2001, 15 (6), 1505-1511. (23) Stanford, L. A.; Rodgers, R. P.; Marshall, A. G.; Czarnecki, J.; etc. Detailed Elemental Compositions of Emulsion Interfacial Material versus Parent Oil for Nine Geographically Distinct Light, Medium, and Heavy Crude Oils, Detected by Negative- and Positive-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Energy & Fuels 2007, 21 (2), 973-981. (24) Rodgers, R.; Schaub, T.; Marshall, A. G. Petroleomics: MS Returns to Its Roots. Analytical

Chemistry 2005, 77 (1), 20A-27A. (25) Hughey, C. A.; Rodgers, R. P.; Marshall, A. G.; etc. Identification of acidic NSO compounds in crude oils of different geochemical origins by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry. Organic Geochemistry 2002, 33 (7), 743-759. (26) Hughey, C. A.; Rodgers, R. P.; Marshall, A. G.; etc. Acidic and neutral polar NSO compounds in Smackover oils of different thermal maturity revealed by electrospray high field Fourier transform ion cyclotron resonance mass spectrometry. Organic Geochemistry 2004, 35 (7), 863-880. (27) Shi, Q.; Hou, D.; Chung, K. H.; etc. Characterization of Heteroatom Compounds in a Crude Oil and its Saturates, Aromatics, Resins, and Asphaltenes (SARA) and Non-basic Nitrogen Fractions Analyzed by Negative-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Energy & Fuels 2010, 24 (4), 2545-2553.


Energy & Fuels

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(28) Shi, Q.; Zhao, S.; Xu, Z.; etc. Distribution of Acids and Neutral Nitrogen Compounds in a Chinese Crude Oil and Its Fractions: Characterized by Negative-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Energy & Fuels 2010, 24 (7), 4005-4011. (29) Wang, L.; He, C.; Zhang, Y.; Zhao, S.; etc. Characterization of Acidic Compounds in Heavy Petroleum Resid by Fractionation and Negative-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Analysis. Energy & Fuels 2013, 27 (8), 4555-4563. (30) Smith, D. F.; Schaub, T. M.; Kim, S.; etc. Characterization of acidic species in Athabasca bitumen and bitumen heavy vacuum gas oil by negative-ion ESI FT-ICR MS with and without acid-ion exchange resin prefractionation. Energy & Fuels 2008, 22 (4), 2372-2378. (31) Pan, Y.; Liao, Y.; Shi, Q.; etc. Acidic and Neutral Polar NSO Compounds in Heavily Biodegraded Oils Characterized by Negative-Ion ESI FT-ICR MS. Energy & Fuels 2013, 27 (6), 2960-2973. (32) Teräväinen, M. J.; Pakarinen, J. M. H.; Wickstrom, K.; etc. Comparison of the composition of Russian and North Sea crude oils and their eight distillation fractions studied by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry: The effect of suppression. Energy & Fuels 2007, 21 (1), 266-273. (33) Sandvik, E. I.; Gale, W. W. Characterization of Petroleum Sulfonates. Soc. Pet. Eng. 1977, 17 (3), 184-192. (34) Wang, F. Q.; Wang, Y. D.; Wu, Y. X.; Gao, M. Synthesis and performance assessment of petroleum sulfonate for oil displacement. Journal of China University of Petroleum 2008, 32 (2), 138-141.


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Energy & Fuels

(35) Niu, R. Study on the synthesis of Petroleum Sulfonate for oil recovery. Daqing Petroleum

Institute 2004, P6-P10. (36) Chen, T.; Zhang, G.; Ge, J. Dynamic Interfacial Tension Between Gudao Heavy Oil and Petroleum Sulfonate/HPAM Complex Systems. Petroleum Science and Technology 2012, 30 (14), 1417-1423. (37) Gong, H.; Xin, X.; Xu, G.; Wang, Y. The dynamic interfacial tension between HPAM/C17H33COONa mixed solution and crude oil in the presence of sodium halide. Colloids and

Surfaces A: Physicochemical and Engineering Aspects 2008, 317 (1-3), 522-527. (38) Wang, S.; Li, Z.; Zhang, J.; etc. Correlation between the Structure and Interfacial Activity of Petroleum Sulfonates and Their Quality Evaluation. Petrochemical Technology (China) 2012, 41 (5), 573-577.


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Tables caption Table 1. Composition of the raw oil and petroleum sulfonate

Table 2. Identification of O3S1 species in petroleum sulfonate


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Energy & Fuels

Table 1. Composition of the raw oil and petroleum sulfonate Raw oil furfural extract oil from vacuum gas oil (boiling range 370~490℃) composition (wt %) saturate

23.78

aromatic

68.22

resin

7.73

asphaltene

0.26 Petroleum sulfonate

component (wt %) active

43.69

unsulfonated oil

38.95

inorganic salt

11.50

volatiles and water

3.87

synthesis conditions sulfonating agent, SO3 SO3-to-aromatics ratio, 1.26 temperature, 35 ℃ reaction time, 30 min


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 41

Table 2. Identification of O3S1 species in the petroleum sulfonate DBE

Type

Chemical formula

Structure

n

4

Alkyl benzene

CnH2n+1-(C6H4)-SO3-

R

5

Alkyl indane

CnH2n+1-(C9H8)-SO3-

R

SO3-

11～33

Alkyl tetrahydronaphthalene

CnH2n+1-(C10H10)-SO3-

R

SO3-

10~32

6

Alkyl acenaphthylene

CnH2n+1-(C12H12)-SO3-

R

SO3-

7

Alkyl naphthalene

CnH2n+1-(C10H6)-SO3-

R

8

Alkyl biphenyl


R

9

Alkyl fluorene


R

10

Alkyl phenanthrene


R

SO3-

12～33

7~32

SO3-

SO3-

SO3-

SO3-

9～30

6～29

6～29

3～26

Note: combination of chemical formula and DBE is unable to distinguish between alkyl indane and alkyl tetrahydronaphthalene.


Page 23 of 41

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Energy & Fuels

Figures caption Figure 1. Broadband negative-ion ESI FT-ICR mass spectra of PS (bottom) and its raw oil (top). The PS has approximately the same peaks distribution as raw oil at range of 250~700 m/z. The average resolving powers (m/∆m50%) of the PS and the raw oil are ~400,000 and ~450,000, respectively.

Figure 2. The histograms of heteroatom “classes” and “types” (corresponding to DBE) derived from negative ESI ICR mass spectra of the PS and its raw oil. It is worth noting that the bar graph data refer to the summed mass spectrometric intensities but do not quantitatively reflect the species.

Figure 3. Expansion of mass segment of the PS (bottom) and raw oil (top). Red dashed lines indicate the presence of peaks in the PS as well as in the raw oil.

Figure 4. Iso-abundance plots of DBE versus carbon number for O2, O3, and O4 class in the PS and its raw oil.

Figure 5. Iso-abundance plot of DBE versus carbon number for O3S1 class species in the petroleum sulfonate.

Figure 6. Iso-abundance plots of DBE versus carbon number for O4S1 class in PS and O1 class in raw oil.

Figure 7. Iso-abundance plots of DBE versus carbon number for N1O2 and N1 class species in the raw oil and PS.

23


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 41

Raw oil

200

300

400

500

600

700

m/z

300

400

500

600

700

m/z

PS

200

Figure 1. Broadband negative-ion ESI FT-ICR mass spectra of PS (bottom) and its raw oil (top). The PS has approximately the same peaks distribution as raw oil at range of 250~700 m/z. The average resolving powers (m/∆m50%) of the PS and the raw oil are ~400,000 and ~450,000, respectively.

24


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Energy & Fuels


25


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 26 of 41


26


Page 27 of 41

25

25

PS O2

20

20

15

15

DBE

DBE

Raw oil O2

10

5

10

5

0

0 10

20

30

40

50

10

20

Carbon number

40

50

40

50

40

50

25

Raw oil O3

PS O3

20

20

15

15

DBE

DBE

30

Carbon number

25

10

5

10

5

0

0

10

20

30

40

50

10

20

Carbon number

30

Carbon number

25

25

PS O4

Raw oil O4 20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

10

5

10

5

0

0 10

20

30

40

50

10

20

30

Carbon number

Carbon number


27


Energy & Fuels

25

PS O3S1 20

15

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 28 of 41

10

5

0 10

20

30

40

50

Carbon number


28


Page 29 of 41

25

25

PS O4S1

Raw oil O1

20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

10

10

5

5

0

0 10

20

30

40

10

50

20

Carbon number

30

40

Carbon number

Figure 6. Iso-abundance plots of DBE versus carbon number for O4S1 class in PS and O1 class in raw raw.

29


50

Energy & Fuels

25

25

Raw oil N1

20

20

15

15

DBE

DBE

Raw oil N1O2

10

5

10

5

0

0 10

20

30

40

50

10

20

Carbon number

30

40

50

40

50

Carbon number

25

25

PS N1

PS N1O2 20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 30 of 41

10

5

10

5

0

0 10

20

30

40

50

10

20

Carbon number

30

Carbon number


30


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Energy & Fuels

Tables caption Table 1. Composition of the raw oil and petroleum sulfonate

Table 2. Identification of O3S1 species in petroleum sulfonate


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table 1. Composition of the raw oil and petroleum sulfonate Raw oil furfural extract oil from vacuum gas oil (boiling range 370~490℃) composition (wt %) saturate

23.78

aromatic

68.22

resin

7.73

asphaltene

0.26 Petroleum sulfonate

component (wt %) active

43.69

unsulfonated oil

38.95

inorganic salt

11.50

volatiles and water

3.87

synthesis conditions sulfonating agent, SO3 SO3-to-aromatics ratio, 1.26 temperature, 35 ℃ reaction time, 30 min


Page 32 of 41

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Energy & Fuels

Table 2. Identification of O3S1 species in the petroleum sulfonate DBE

Type

Chemical formula

Structure

n

4

Alkyl benzene

CnH2n+1-(C6H4)-SO3-

R

5

Alkyl indane

CnH2n+1-(C9H8)-SO3-

R

SO3-

11～33

Alkyl tetrahydronaphthalene

CnH2n+1-(C10H10)-SO3-

R

SO3-

10~32

6

Alkyl acenaphthylene

CnH2n+1-(C12H12)-SO3-

R

SO3-

7~32

7

Alkyl naphthalene


R

8

Alkyl biphenyl


R

9

Alkyl fluorene


R

10

Alkyl phenanthrene


R

SO3-

12～33

SO3-

SO3-

SO3-

SO3-

9～30

6～29

6～29

3～26

Note: combination of chemical formula and DBE is unable to distinguish between alkyl indane and alkyl tetrahydronaphthalene.


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 34 of 41

Figures caption Figure 1. Broadband negative-ion ESI FT-ICR mass spectra of PS (bottom) and its raw oil (top). The PS has approximately the same peaks distribution as raw oil at range of 250~700 m/z. The average resolving powers (m/Δm50%) of the PS and the raw oil are ~400,000 and ~450,000, respectively.





Figure 6. Iso-abundance plots of DBE versus carbon number for O4S1 class in PS and O1 class in raw oil.



Page 35 of 41

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Energy & Fuels

Raw oil

200

300

400

500

600

700

m/z

300

400

500

600

700

m/z

PS

200

Figure 1. Broadband negative-ion ESI FT-ICR mass spectra of PS (bottom) and its raw oil (top). The PS has approximately the same peaks distribution as raw oil at range of 250~700 m/z. The average resolving powers (m/Δm50%) of the PS and the raw oil are ~400,000 and ~450,000, respectively.


Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 36 of 41



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Energy & Fuels



Energy & Fuels

25

25

PS O2

20

20

15

15

DBE

DBE

Raw oil O2

10

5

10

5

0

0 10

20

30

40

50

10

20

25

40

50

40

50

40

50

25

Raw oil O3

PS O3

20

20

15

15

DBE

DBE

30

Carbon number

Carbon number

10

5

10

5

0

0

10

20

30

40

50

10

20

Carbon number

30

Carbon number

25

25

PS O4

Raw oil O4 20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 38 of 41

10

5

10

5

0

0

10

20

30

40

50

10

20

Carbon number

30

Carbon number



Page 39 of 41

Energy & Fuels 25

PS O3S1 20

15

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

10

5

0 10

20

30

40

50

Carbon number



Energy & Fuels 25

25

Raw oil O1

PS O4S1 20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 40 of 41

10

10

5

5

0

0 10

20

30

40

50

10

20

30

40

Carbon number

Carbon number

Figure 6. Iso-abundance plots of DBE versus carbon number for O4S1 class in PS and O1 class in raw raw.


50

Page 41 of 41

Energy & Fuels

25

25

Raw oil N1

20

20

15

15

DBE

DBE

Raw oil N1O2

10

5

10

5

0

0 10

20

30

40

50

10

20

Carbon number

30

40

50

40

50

Carbon number

25

25

PS N1

PS N1O2 20

20

15

15

DBE

DBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

10

5

10

5

0

0 10

20

30

40

50

10

20

30

Carbon number

Carbon number



Resolution and Identification of Petroleum Sulfonate by Electrospray

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