JP7379256B2 - Analysis method for petroleum heavy fractions - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act 1. Publication name FY2018 Research and development project related to structural analysis and reaction analysis of petroleum, which forms the basis of highly efficient petroleum refining technology Business report 2. Date of issue: March 29, 2019 3. Publisher Petroleum Energy Technology Center (General Incorporated Foundation) [Publications, etc.] 1. Meeting name 3rd Petroliomics Technical Seminar in 2019 2. Date: July 19, 2019 3. Publisher: Keita Katano [Publications, etc.] 1. Meeting Name The 20th International Conference Petroleum Phase Behavior & Fouling (PetroPhase2019) 2. Date: June 4, 2019 3. Publisher: Keita Katano [Publications, etc.] 1. Meeting name: Japan Petroleum Institute Yamagata Conference (49th Petroleum and Petrochemical Symposium) 2. Date: November 1, 2019 3. Publisher: Keita Katano [Publications, etc.] 1. Publication name Petroleum Institute of Japan Yamagata Conference (Invited lecture, 49th Petroleum and Petrochemical Symposium) (Speech abstract) 88 pages, Petroleum Institute of Japan 2. Date of issue: October 31, 2019 3. Publisher: Keita Katano [Publications, etc.] 1. Publication address https://www. jstage. jst. go. jp/browse/sekiyu/-char/ja 2. Date of publication: December 31, 2019 3. Publisher Keita Katano

The present invention relates to a method for analyzing petroleum heavy fractions, and more particularly, in compositional analysis of petroleum heavy fraction samples using FT-ICR MS, APPI method and ESI in the presence of silver ions are used. The present invention relates to a method for analyzing heavy fractions of petroleum, which is applied in combination with a method for analyzing petroleum heavy fractions, an apparatus, system, computer, and method for using the same, and a computer program for causing a computer to execute the apparatus, and a recording medium thereof.

In recent years, from the perspective of diversifying petroleum processing, the production of unconventional crude oil and heavy distillates containing a variety of complex components has attracted attention. Among them, sulfur components are generally almost always included in crude oil components. The amount varies depending on the region of crude oil production, but is approximately 0.1 to 4% by weight. Therefore, sulfur components are present in each fraction separated from crude oil by distillation, and generally the heavier the fraction, the higher the sulfur component. The sulfur components contained in petroleum include hydrogen sulfide, mercaptans, sulfides, disulfides, and thiophenes, and in addition to these, it also contains a considerable number of compounds with unknown structures, and the higher the boiling point, the more complex the structure. It has become. The presence of sulfur components in petroleum not only causes bad odors and catalyst poisoning, but also causes sulfur dioxide gas, which is a combustion product of sulfur components, to be an air pollutant. Accurately analyzing the composition of petroleum containing harmful sulfur contained in raw materials and products is a major mission of the petroleum refining industry.

On the other hand, petroleum heavy fractions contain aromatic molecules as a main component. For this reason, when performing comprehensive component analysis using a mass spectrometer on fractions excluding saturated components, it is an important technical matter to be able to efficiently ionize aromatic components. The current ionization method that most closely meets this purpose is the APPI method (Atmospheric Pressure Photoionization), which uses a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) Since its introduction into the component analysis of oil, it has contributed to the characterization of many heavy oils (Non-Patent Document 1). In the APPI method, a toluene solution in which a sample is dissolved is sprayed onto a heater, and the vaporized solution is ionized by being irradiated with ultraviolet light by a Kr lamp in the subsequent stage.

Additionally, Patent Document 1 reports the use of the APPI method in combination with the ionization method of other petroleum components when determining the composition model of a petroleum residue sample using FT-ICR MS. ing.

Jeremiah M. Purcell et al. , Energy Fuels, 2010, 24, 2257-2265

Patent No. 6166661

However, as a result of measuring petroleum heavy fraction samples using the APPI method, the applicant's study revealed that the sulfur content was still underestimated. Therefore, as a result of further investigation, the present applicant determined that the APPI method and the ESI method (electrospray ionization: We have discovered that the composition of heavy petroleum fractions, including the amount of sulfur, can be analyzed with high precision when applied in combination with electrospray ionization (electrospray ionization method).

An object of the present invention is to provide a new technical means for analyzing the composition of petroleum heavy fractions containing sulfur with high precision.

In order to achieve the above object, the present inventors created the following invention. That is, the gist of the present invention is as follows.
A method for analyzing petroleum heavy fractions of the present invention, comprising:
(a) preparing a plurality of fractions separated from a petroleum heavy fraction, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) a step of forming molecular ions or quasi-molecular ions of components constituting each fraction in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS),
Electrospray ionization (ESI) method was applied to the aromatic fraction with three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction with three or more rings and the polar resin fraction were A step of applying atmospheric pressure photoionization (APPI) method to some or all of the fractions of and (d) estimating the composition of the petroleum heavy fraction based on each fraction composition information.

In another embodiment of the present invention, an apparatus and system for estimating the desulfurization rate of target oil, a method for operating the same, a computer program for executing the same, a recording medium thereof, and a computer storing the same are also provided.

According to the present invention, the composition of a petroleum heavy fraction containing sulfur can be analyzed with high accuracy.

1 is a flowchart of a method for analyzing petroleum heavy fractions in one embodiment of the present invention. FIG. 1 is a block diagram of a petroleum heavy fraction analyzer according to an embodiment of the present invention. It is a graph showing the heteroclass distribution of atmospheric residue (AR)_tricyclic or higher aromatic content (3A+) of ultra-heavy crude oil observed by the APPI method and the Ag-ESI method. It is a graph showing the heteroclass distribution of ultra-heavy crude oil AR_polar resin (Po) observed by the APPI method and the Ag-ESI method. FIG. 5A is a DBE plot of ultra-heavy crude oil AR_3A+ observed by the APPI method. FIG. 5B is a DBE plot of ultra-heavy crude oil AR_3A+ observed using the Ag-ESI method. FIG. 5C is a DBE plot of ultra-heavy crude oil AR_3A+ that integrates the results of the APPI method and the Ag-ESI method. It is a graph showing that the heteroclass of integrated data is classified into each category as a correction target. It is a graph showing heteroclass candidates that can be used as correction factors.

<Analysis method of petroleum heavy fraction>
According to one embodiment of the present invention, a method for analyzing petroleum heavy fractions comprises:
(a) preparing a plurality of fractions separated from a petroleum heavy fraction, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) a step of forming molecular ions or quasi-molecular ions of components constituting each fraction in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS),
Electrospray ionization (ESI) method was applied to the aromatic fraction with three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction with three or more rings and the polar resin fraction were A step of applying atmospheric pressure photoionization (APPI) method to some or all of the fractions of (d) estimating the composition of the petroleum heavy fraction based on each fraction composition information; (e) optionally using the elemental analysis information of the petroleum heavy fraction as a correction factor; The method is characterized by comprising the step of adjusting an estimated value of the composition of the heavy fraction.
Hereinafter, one embodiment of the present invention will be described step by step according to the flowchart of FIG.

Step (a): Separation of multiple fractions including the tricyclic or higher aromatic fraction and the polar resin fraction (S1 in Figure 1)
According to one embodiment of the present invention, first, a plurality of fractions separated from a heavy petroleum fraction and including at least a tricyclic or higher aromatic fraction and a polar resin fraction are prepared.

The petroleum heavy fraction is also simply referred to as heavy oil, and is not particularly limited as long as it is heavy and sticky crude oil, residual oil from crude oil, or petroleum fraction. The petroleum heavy fraction used in step (a) includes, for example, atmospheric distillation residue (AR) obtained from crude oil with an API degree of 25 or less, preferably an API degree of 20 or less, vacuum distillation residue (VR), and dense petroleum fractions such as catalytic cracking residues, visbreaking oils and bitumen. These heavy oils usually contain 1% by mass or more of asphaltenes, and asphaltenes extracted from these petroleum heavy fractions can also be used as petroleum heavy fractions. These may be used alone or in combination of two or more. Note that the API degree is a unit indicating the specific gravity of crude oil products as determined by the American Petroleum Institute.
In addition, coker oil, synthetic crude oil, naphtha cut crude oil, heavy gas oil, vacuum gas oil, LCO, GTL (Gas To Liquid) oil, wax, etc. are mixed with atmospheric distillation residue oil etc. to produce petroleum heavy fractions. It can also be used.
Note that the above-mentioned asphaltene refers to a portion of heavy oil that is insoluble in n-heptane. When the content of asphaltene in the heavy oil is 1% by mass or more, the asphaltene agglomeration moderating effect of the asphaltene aggregation moderator can be sufficiently exerted.

As described above, the plurality of fractions separated from the petroleum heavy fraction include at least the tricyclic or more aromatic fraction and the polar resin fraction. The plurality of fractions is preferably 3 or more fractions, more preferably 7 fractions. Such fractions include asphaltene (As), saturated content (Sa), 1-ring aromatic content (1A), 2-ring aromatic content (2A), aromatic content with 3 or more rings (3A+), and polar resin (Po). and polycyclic aromatic resins (PA).

In separating each fraction, there are no particular restrictions on the criteria used to define the boundaries between the fractions or the method used for fractionation, but in the case of heavy oil, it is preferable to perform "pretreatment for separation by type." The method of "pretreatment for separation by type" is not particularly limited and may be separated into several components according to arbitrary standards, such as column chromatography fractionation, Soxhlet extraction, high-speed solvent extraction Known methods such as extraction methods can be used. In the case of heavy oil, it is preferable to use a column chromatography fractionation method, such as the method described in JP-A No. 2011-133363. The number of components to be fractionated may be appropriately selected depending on the purpose.
Specifically, the separation of each fraction from the heavy petroleum fraction can be carried out by a method including the following first to fourth steps.

(1st step)
Heavy oil is separated into asphaltene (As), maltene (Ma) soluble in n-paraffin, and other insoluble components by Soxhlet extraction.
(Second step)
The maltene fraction separated in the above (first step) was analyzed using column chromatography to determine the saturated fraction (Sa), the 1-ring aromatic fraction (1A), the 2-ring aromatic fraction (2A), and the 3- or more-ring aromatic fraction (Sa). 3A+), polar resin (Po) and polycyclic aromatic resin (PA).
(3rd step)
More preferably, the 3 or more ring aromatic fraction (3A+) obtained in the second step is further separated into a Peri type 4 ring aromatic fraction and a Cat type 4 ring aromatic fraction using preparative liquid chromatography. It may be separated into an aromatic fraction and, in some cases, an aromatic fraction with five or more rings (5A+).
(4th step)
In addition, the insoluble matter separated in the above (first step) is separated into a toluene-soluble matter (asphaltene (As)) that is soluble in toluene, and other toluene-insoluble matter, and the toluene-insoluble matter is further divided into THF-soluble matter. Separate into THF-soluble components and other THF-insoluble components.

Step (b-1): Implementation of ESI method in the presence of silver ions for the aromatic fraction with three or more rings and the polar resin fraction in FT-ICR MS (S2 in Figure 1)
According to one embodiment of the present invention, the aromatic fraction with three or more rings (3A+) and the polar resin fraction (Po) are subjected to electrospray ionization in the presence of a silver ion additive in FT-ICR MS. (ESI) method is applied at least to form molecular ions or pseudomolecular ions.

Applying the electrospray ionization method (hereinafter also referred to as Ag-ESI method) to 3A+ and Po in the presence of silver ions is effective in reducing sulfur and silver in 3A+ and Po, which contain relatively high concentrations of sulfur components. It is advantageous in detecting a wide range of sulfur components with high precision by utilizing complex formation with ions.

Silver ions are preferably applied in the form of silver salts for 3A+ and Po. A preferred example of the silver salt is silver triflate.

Since the Ag-ESI method is a very soft ionization method that does not involve heating during the ionization process, it is possible to detect a distribution in which petroleum molecules are associated, not only in sulfur components but also in fractions containing many hetero elements such as polar resins. can be observed on the high molecular weight side. As a specific method of the Ag-ESI method, for example, Ag triflate is added to a methanol/toluene mixed solvent containing 3A+ and Po as a sample. , 28, 557-452.

In one embodiment of the present invention, ionic molecules or quasi-ionic molecules obtained from a sample are measured by FT-ICR MS (mass spectrometry using Fourier transform ion cyclotron resonance method). The spectrum obtained by FT-ICR MS is also referred to as "FT-ICR mass spectrometry spectrum." In FT-ICR MS, the value of m/z can be determined to the fourth decimal place. Therefore, by performing accurate mass calculations that also take into account the presence of atomic isotopes, it is possible to determine the molecular formula of the molecule that belongs to that peak.

Further, according to a preferred embodiment of the present invention, in addition to the ESI method, an atmospheric pressure photoionization (APPI) method is further applied for 3A+ and Po in FT-ICR MS to form molecular ions or pseudomolecular ions. The information obtained by the APPI method and the Ag-ESI method may be integrated. While the APPI method ionizes mainly aromatic components with low polarity, in the ESI method, the ionizable components are not limited to aromatic molecules. Therefore, the range of compounds suitable for both detections is different, and integrating both types of data is advantageous in performing highly accurate analysis. Therefore, according to a more preferred embodiment of the present invention, information on molecular ions or quasi-molecular ions regarding the aromatic fraction having three or more rings and the polar resin fraction identified based on the APPI method and the ESI method is integrated.

In the APPI method, for example, a sample is dissolved in a toluene solution, the sprayed liquid sample is heated and vaporized at about 300 to 400° C., and then applied to FT-ICR MS. The APPI method may be carried out according to the method described in Non-Patent Document 1. The APPI method can be advantageously used to ionize nonpolar aromatic molecules.

Further, according to an embodiment of the present invention, when the APPI method is used in combination, it is preferable to apply collision induced dissociation (CID) to the measurement target. When applying CID, it is preferable to loosen the associated molecules in the measurement target and observe the molecular weight distribution of a single molecule. Using CID in combination allows us to directly observe the associated molecules and investigate their composition combinations, thereby obtaining information on what kind of heteroclasses are involved in the association and obtaining more accurate analysis results. It can be used to advantage.

Step (b-2): Implementation of the APPI method on fractions other than the tricyclic or higher aromatic fraction and the polar resin fraction in FT-ICR MS (S3 in Figure 1)
Further, according to an embodiment of the present invention, the APPI method is applied to a part or all of each fraction other than the tricyclic or higher aromatic fraction and the polar resin fraction to constitute each of the fractions. Form molecular ions or quasi-molecular ions of the components.

Fractions other than tricyclic or higher aromatic components (3A+) and polar resin (Po) to which the APPI method is applied include, for example, saturated components (Sa), asphaltene (As), 1-ring aromatic components (1A), Examples include a two-ring aromatic component (2A) and a polycyclic aromatic resin (PA), but preferably a one-ring aromatic component (1A) and a two-ring aromatic component (2A). The APPI method is advantageous in detecting nonpolar aromatic molecules present in high concentrations in 1A, 2A, etc. with high precision.

Note that, as explained in step S2 above, when the APPI method and the ESI method are used together, the APPI method may be applied to 3A+ and Po, and the present invention also includes such an aspect.

Further, according to a preferred embodiment of the present invention, for saturation (Sa), asphaltene (As), and polycyclic aromatic resin (PA), Matrix-Assisted Laser Desorption Ionization (MALDI) method, Molecular ions or quasi-molecular ions can be obtained by applying a direct laser ionization (LDI) method, but it is more preferable to apply the LDI method. LDI can be advantageously utilized to ionize high molecular weight and high boiling point molecules (eg, 704° C.+).

According to a more preferred embodiment of the present invention, from the viewpoint of efficient ionization, it is preferable to apply the Ag-LDI method to the saturated component (Sa) to obtain molecular ions or quasi-molecular ions.

The LDI method and the Ag-LDI method can be carried out, for example, according to the description in Energy Fuel 2013, 27, 7348-7383.

Step (c): Identification of the structure and concentration corresponding to molecular ions or pseudomolecular ions by FT-ICR MS (S4 in Figure 1)
By FT-ICR MS, each fraction composition information including the structure and concentration corresponding to the molecular ion or pseudomolecular ion obtained in S3 is specified.

According to one embodiment of the invention, FT-ICR MS can typically provide three chemical information layers for petroleum systems. The first level is the heteroatom class (or compound class), e.g., hydrocarbon (HC), monosulfur molecule (1S), mononitrogen molecule (1N), dioxygen molecule (2O), mononitrogen-oxygen molecule ( 1N1O), etc. The second level is the Z number distribution (or homolog distribution). Z is defined as the hydrogen deficiency in the general chemical formula CcH2c+ZNnSsOo. The more negative the Z number, the more unsaturated the molecule. Another commonly used term is called double bond equivalent (DBE). In a typical petroleum system, DBE=1-(Z-n)/2, where n is the number of nitrogen atoms. The third level of information is the total carbon number or molecular weight distribution of each congener. If the nuclear structure of a compound is known, total alkyl side chain information can be derived by subtracting the number of carbon atoms in the nucleus. Based on such information, according to FT-ICR MS, it is possible to specify information on the composition of each fraction, including the structure and concentration of ions and pseudoion molecules obtained from the measurement sample.

Specific details such as structures and concentrations corresponding to molecular ions or quasi-molecular ions in FT-ICR MS can be carried out based on Japanese Patent Application Publication No. 2014-218643 and Japanese Patent Application Publication No. 2020-502495 by the present applicant. It is possible.

Step (d): Estimate the composition of petroleum heavy fraction (S5 in Figure 1)
According to one embodiment of the present invention, the composition of the petroleum heavy fraction is estimated based on each fraction composition information obtained in step (c). In this step, the estimated value of the total composition of the petroleum heavy fraction can be calculated by integrating the composition information of each fraction and using a known calculation program.

Step (e): Estimate the composition of petroleum heavy fraction (S6 in Figure 1)
According to one embodiment of the invention, elemental analysis information of the petroleum heavy fraction is used as a correction factor to adjust the estimate of the composition of the petroleum heavy fraction.

The elemental composition of each fraction is particularly useful as a correction factor in estimating the total composition of the petroleum heavy fraction with high accuracy when optimizing the estimate of the composition of the petroleum heavy fraction in step (d). It can be used to advantage. The elemental composition used as a correction factor is preferably that of sulfur, nitrogen and oxygen. Further, from the viewpoint of correcting the estimated value with higher accuracy, the correction factor is preferably the amount of a plurality of components that contain sulfur atoms and do not contain nitrogen atoms. Optimizing the estimated composition of the petroleum heavy fraction by providing a correction factor based on the elemental analysis results can be performed, for example, based on a known search algorithm (MATLAB, etc.) used in the examples described below. I can do it.

<Petroleum heavy fraction analysis equipment and system>
Next, with reference to FIG. 2, one embodiment of the petroleum heavy fraction analysis apparatus of the present invention will be described. FIG. 2 is a functional block diagram of the petroleum desulfurization rate estimation device according to the embodiment.
Note that in FIG. 2, illustration of an interface for inputting and outputting information is omitted.

The analyzer 1 includes a fraction providing section 10, a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) 20, a composition estimating section 30, and a composition correcting section 40.

I. Fraction Providing Unit The fraction providing unit 10 separates a plurality of fractions including at least a tricyclic or higher aromatic fraction and a polar resin fraction from the petroleum heavy fraction. The fraction providing unit can be configured with a known column chromatography device such as HPLC, which can perform separation according to the properties of each fraction.

II. FT-ICR MS
The FT-ICR MS 20 can be composed of an ionization section 21 and a fraction composition information analysis section 22. The ionization unit 21 may be equipped with one or more ionization devices such as APPI method, Ag-ESI method, LDI method, Ag-LDI method, etc., and the ionization device may include a syringe, a nebulizer ( The FT-ICR MS21 may be equipped with a vaporizer, vaporizer, lamp (UV lamp, etc.), and connected to a mass spectrometer in the main body of the FT-ICR MS21 via a capillary or the like.

Further, each fraction composition information analysis section 22 can be composed of a Fourier transform ion cyclotron resonance mass spectrometer, a storage section in which information about petroleum components is stored as a database, and a calculation section. Based on the information on each component acquired by the method and the information stored in the storage section, the calculation section analyzes the composition information of each component. The calculation unit and the storage unit include, for example, the database and program (Multi-Component Aggregation Model: MCAM) described in Japanese Patent Application Laid-Open No. 2014-218643 and Japanese Patent Application Publication No. 2020-502495 by the present applicant, JACD (Juxtaposed Attributes for Chemical-Structure Description), etc.) is stored, and the composition information of each fraction is analyzed.

III. Composition Estimation Unit The total composition estimation unit 30 estimates the total composition of the petroleum heavy fraction based on each fraction composition information obtained from each fraction composition information analysis unit 22. The composition estimating section can be configured by a known arithmetic device.

IV. Composition Estimating Unit The composition estimating unit 40 optimizes the estimated value of the total composition of the petroleum heavy fraction obtained by the total composition estimating unit 30 using the elemental analysis information of the petroleum heavy fraction as a correction factor. The composition estimating section 40 may include a storage section that stores elemental analysis information, and can be configured by a known arithmetic device. The total composition estimating section and the composition correcting section may be integrally configured by one arithmetic device.

Further, according to one embodiment of the present invention, each part of the petroleum heavy fraction analysis apparatus may be constructed integrally, but each part may be constructed separately as desired. When analyzing a petroleum heavy fraction using such independent parts, the analyzer can be provided as a system for estimating the total composition of the petroleum heavy fraction. In this specification, a system is a logical collective configuration of a plurality of devices, and the devices of each configuration are not limited to being in the same housing.

Therefore, according to another aspect of the invention, there is provided a system for analyzing petroleum heavy fractions, comprising:
(a) a fraction providing unit that prepares a plurality of fractions separated from petroleum heavy fractions, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), an ionization part that forms molecular ions or quasi-molecular ions of components constituting each fraction,
Electrospray ionization (ESI) method was applied to the aromatic fraction with three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction with three or more rings and the polar resin fraction were an ionization section that applies an atmospheric pressure photoionization (APPI) method to some or all of the fractions;
(c) Each fraction composition information analysis section that uses FT-ICR MS to identify the composition information of each fraction, including the structure and concentration of molecular ions or pseudomolecular ions, and (d) Based on the composition information of each fraction, An analysis system is provided that includes a composition estimator that estimates the composition of a heavy fraction.

<Computer program for estimating escape rate>
In the present invention, a series of processes of the petroleum heavy fraction analysis system can be executed by hardware, software, or a combination of these. When executing processing using software, a program that records the processing sequence can be installed and executed in the memory of a computer built into dedicated hardware, or the program can be installed on a general-purpose computer that can execute various types of processing. and execute it.

For example, the program can be recorded in advance on a hard disk or ROM as a recording medium. Further, the program can be stored (recorded) temporarily or permanently in a removable recording medium such as a flexible disk, CD-ROM, MO disk, DVD, magnetic disk, or semiconductor memory.

In addition to installing programs on a computer from a removable recording medium as described above, programs can also be transferred wirelessly to a computer from a download site, or transferred to a computer by wire via a network such as a LAN or the Internet. Now, you can receive the program transferred in this way and install it on a recording medium such as an internal hard disk.

The method of the present invention can be suitably implemented by a computer that stores the computer program described above in its internal storage device.

Furthermore, the various processes described in this specification are not only executed in chronological order according to the description, but also may be executed in parallel or individually depending on the processing capacity of the device that executes the process and as necessary. .

EXAMPLES The present invention will be explained below with reference to examples, but the present invention is not limited to these examples.

Samples and reagents
Ag-ESI measurement Ultra-heavy crude oil (AR) was fractionated into 7 fractions (Sa, 1A, 2A, 3A+, Po, PA, As), and 3A+ and Po were selected as target samples. Methanol and toluene were commercially available products (both HPLC grade manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.). A commercially available silver triflate (AgOTf, purity 99% or higher, manufactured by Sigma-Aldrich Japan LLC) was used. The heavy crude oil AR fraction sample (3A+, Po) was dissolved in a toluene/methanol mixed solvent (volume ratio 1:1) to a final concentration of 500 μg/mL, and AgOTf was added at a concentration of 50 μg/mL to prepare the measurement solvent. And so.
APPI method
In the APPI measurement, ultra-heavy crude oil AR 3A+, Po was used as a target sample and dissolved in toluene (HPLC grade) to a final concentration of 100 μg/mL.

The prepared sample was measured using an FT-ICR MS (solariX 12T, manufactured by Bruker Japan Co., Ltd.) equipped with a 12 Tesla superconducting magnet using a combination of an attached APPI source and an ESI source. The range of the measured mass-to-charge ratio (m/z) was 200 to 3000, and the S/N was improved by integrating the time domain data of 4M words in the range of 100 to 400 times. Both APPI and ESI measurements were performed in positive ion mode. In each case, calibration using an external standard reagent (APCI, ESI Low Concentration Tuning Mix, manufactured by Agilent Technologies, Inc.) was performed before the measurement. The sample solution was delivered using a syringe pump, and the delivery rate was 180 μL/h for ESI and 400 μL/h for APPI. In addition, since ESI measurement is an ionization method so soft that the dimer distribution of petroleum molecules is observed, we also conducted measurements using collision-induced dissociation at an energy level that eliminates the observed multimer distribution. is the monomer distribution.

Data analysis peak detection and recalibration were performed using Composer (manufactured by Sierra Analytics). The sample was subjected to elemental analysis for the three elements N, O, and S, and comparisons were made with the amounts detected by FT-ICR MS. Furthermore, in order to create an abundance contour map of DBE vs. carbon number for each heteroatom class, the heteroclass (NnOoSs), type (DBE), and carbon number were aggregated for each elemental composition (CnHhNnOoSs).

Example 1: Comparison of APPI method and Ag-ESI method In FT-ICR MS, a comparison of detection sensitivity was carried out when using the APPI method or the Ag-ESI method.

The heteroclass distributions of 3A+ (3 or more aromatic rings) in the atmospheric residue (AR) of ultra-heavy crude oil observed by the APPI method and the Ag-ESI method were compared according to Table 1 below.

The results were as shown in FIG.
In the APPI method, monovalent radical cations were mainly observed, and a small amount of monovalent positive ions due to proton addition ([H]) were also observed.
On the other hand, in the Ag-ESI method, only the components to which Ag+ was added were subjected to data analysis. In the Ag-ESI method, it was confirmed that the amount of heteroclasses (classes containing S atoms but not containing N atoms) was significantly increased.

Comparing the breakdown of heteroclasses between the APPI method and the Ag-ESI method, it is found that in the APPI method, classes containing only an S atom (S, S2) are mainly observed, while in the Ag-ESI method, in addition to these, O Classes containing both atoms and S atoms (OS, OS2) were included with high abundance. From this, it is thought that the Ag-ESI method supplements information regarding components containing both O atoms and S atoms, which is difficult to access using the APPI method.

The heteroclass distribution of AR Po (polar resin) observed by the APPI method and the Ag-ESI method was compared. The results were as shown in FIG.
As shown in FIG. 4, the ability of the Ag-ESI method to efficiently ionize classes containing both O atoms and S atoms was even more remarkable for Po, which contains many polar components.

In order to confirm the range of detected S compounds in terms of the number of carbon atoms in the molecule and the degree of unsaturation (Double bond equivalent, DBE), we created a DBE plot of the heteroclasses classified into main components in Figure 3 and compared them. Ta. The results were as shown in FIG. FIG. 5A is a DBE plot of ultra-heavy crude oil AR_3A+ observed by the APPI method. FIG. 5B is a DBE plot of ultra-heavy crude oil AR_3A+ observed using the Ag-ESI method. FIG. 5C is a DBE plot of ultra-heavy crude oil AR_3A+ that integrates the results of the APPI method and the Ag-ESI method.

The DBE plot displayed the distribution of S-containing classes based on the color bar of the sum of all observed components. As can be seen from FIG. 5, the number of carbon atoms in the APPI method was in the range of about 15 to 75, and in the Ag-ESI method, it was in the range of about 15 to slightly less than 70, and the molecular weight ranges of both were almost the same. Comparing the DBE ranges, it can be seen that the APPI method can hardly detect components with a DBE of less than 4, but the Ag-ESI method can detect these components with high sensitivity. In the APPI method, since the ultraviolet rays emitted from the Kr lamp are 10 eV, it is theoretically difficult to ionize molecules with a lower degree of unsaturation than one aromatic ring (DBE=4). The Ag-ESI method does not have such restrictions, and even S compounds with a low degree of unsaturation can be accessed. As for the form of the S compound with a low degree of unsaturation, in the case of feedstock oil, it is considered that S atoms are contained in the cycloalkane in the chemical form of sulfide. From this, it is thought that the Ag-ESI method supplements information regarding S compounds containing the sulfide form. In the Ag-ESI method, the distribution center of the DBE range is around DBE=8, whereas in the APPI method, it is around DBE=14, and the upper limit of the DBE range is also about 5 higher. The APPI method observes aromatic components with high DBE more efficiently than the Ag-ESI method. In this way, the APPI method and the Ag-ESI method each contain components that complement each other, and it is thought that the S compound detection range will be expanded by integrating the data of both methods. FIG. 5C shows a DBE plot of the S-containing class created by integrating both data into one. This expanded the detection range of S compounds in 3A+ and Po, and significantly improved detection sensitivity.

Tables 2 and 3 show a comparison of the heteroatom content calculated from the APPI method, Ag-ESI method, and integrated data, respectively, with the elemental analysis results. Looking at this, the underestimation of the amount of S element in the APPI method is more noticeable in Po than in 3A+. The Ag-ESI method detects S compounds even in Po with a sensitivity that exceeds the elemental analysis results. Looking at the amount of N element, in any ionization method, it almost agrees with the elemental analysis results. The elemental analysis results show that 3A+ contains 0.80 wt% of O atoms, and Po contains 3.00 wt%, but the APPI method underestimates this. Therefore, one reason why the amount of S element is underestimated by the APPI method is considered to be that a compound containing both O atoms and S atoms cannot be efficiently ionized. On the other hand, in the Ag-ESI method, ionization occurs by addition of Ag+ to the S atom moiety, so it is presumed that S compounds could be detected with high sensitivity regardless of the presence or absence of O atoms.

If the data from the APPI method and the Ag-ESI method are integrated into one, the heteroclass abundance will not be consistent with the elemental analysis results. In particular, the sensitivity of the amount of S is high, and the amount of O tends to be underestimated. We adjusted the correction factors for these heteroclasses and examined corrections in order to get closer to more consistent results. Specifically, optimization calculations were performed as follows. The heteroclass of the integrated data was classified into each category as shown in FIG. 6 as a correction target. A search algorithm was created using the MATLAB program (MathWorks Inc.) by providing correction factors for these and minimizing the difference from the elemental analysis results.

At this time, in order to eliminate numerical coincidences in which a small amount of observations is used for extremely expanded explanations, the adjustment range of the correction factor is set to 0.5 to 2, and the adjustment target is limited to the top three abundances of each category. And so. The above are the constraints applied to this optimization calculation. A graph showing heteroclass candidates that can be used as correction factors is shown in FIG. In addition, Table 4 shows a comparison of the amounts of each element after the optimization performed with the ultra-heavy crude oil AR_3A+ and Po. In Table 4, especially for 3A+, the results after optimization showed good agreement. It was confirmed that the optimization results tended to be more consistent in Po as well.

Table 5 shows a comparison of the same optimization calculations as above for 3A+ and Po obtained from the desulfurized oil of ultra-heavy crude oil AR. In the case of produced oil, the degree of agreement shows the same tendency as the raw material, and even with the above correction, the heteroclass abundance can be adjusted to an amount that is consistent to some extent with the amount observed in elemental analysis. It has been shown.

In the study of the above ionization method, we achieved a comprehensive detection range for S compounds by combining the APPI method and the Ag-ESI method, and further matched the bulk elemental analysis results by correcting the heteroclass correction factor. The results were calculated. It was found that the APPI method underestimates both S atoms and O atoms, but when measured by the APPI method, classes containing only S atoms (S and S2) decrease in desulfurized oil, while S atoms It is inferred that classes containing both S and O atoms remained in the produced oil because they were more difficult to remove than these, and that the S content (and O content) was underestimated because it was difficult to access using the APPI method. be done. It was found that the Ag-ESI method is an ionization method that can compensate for these heteroclasses.

From the above results, the detection sensitivity of S compounds is improved in aromatic components with 3 or more rings and polar resin fractions, and this method can also access S compounds with low unsaturation (sulfides) that do not have aromatic rings. It turns out it's possible. It was also confirmed that compounds containing both O and S atoms, which cannot be detected efficiently by the APPI method, can be detected with high sensitivity. By combining the results of the APPI method and the Ag-ESI method to expand the detection range of S compounds than before, and then optimizing the heteroclass correction factor, it is possible to perform corrections that are consistent with bulk elemental analysis results. It turned out to be.

Claims (14)

A method for analyzing petroleum heavy fractions, the method comprising:
(a) preparing a plurality of fractions separated from a petroleum heavy fraction, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) a step of forming molecular ions or quasi-molecular ions of components constituting each fraction in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS),
Electrospray ionization (ESI) method is applied to the aromatic fraction having three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction having three or more rings and the polar resin fraction (c) Applying the atmospheric pressure photoionization (APPI) method to some or all of the fractions other than the fractions (c) Using the FT-ICR MS, each fraction containing the structure and concentration of the molecular ion or pseudomolecular ion is A method comprising at least the steps of: identifying composition information; and (d) estimating the composition of a petroleum heavy fraction based on the composition information of each of the fractions. Step (a) provides a saturated fraction, a monocyclic aromatic fraction, a bicyclic aromatic fraction, a tricyclic or higher aromatic fraction, a polar resin fraction, and a polycyclic resin fraction. 2. The method of claim 1, wherein the method is a step. 3. A method according to claim 1 or 2, wherein the silver ions in step (b) are applied in the form of a silver salt. 4. The method of claim 3, wherein the silver salt in step (b) is silver triflate. Any one of claims 1 to 4, wherein step (b) further comprises a step of applying an APPI method to the aromatic fraction having three or more rings and the polar resin fraction in FT-ICR MS. The method described in section. A method according to claims 1 to 5, wherein step (b) comprises performing collision-induced dissociation on each of the fractions. 7. According to any one of claims 1 to 6, further comprising the step of: (e) adjusting the estimated composition of the petroleum heavy fraction using the elemental analysis information of the petroleum heavy fraction as a correction factor. Method described. A petroleum heavy fraction analysis device,
(a) a fraction providing unit that prepares a plurality of fractions separated from petroleum heavy fractions, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), an ionization part that forms molecular ions or quasi-molecular ions of components constituting each fraction,
Electrospray ionization (ESI) method is applied to the aromatic fraction having three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction having three or more rings and the polar resin fraction an analysis section that applies an atmospheric pressure photoionization (APPI) method to some or all of the fractions other than the fractions;
(c) each fraction composition information analysis unit that specifies each fraction composition information including the structure and concentration of the molecular ion or pseudomolecular ion by the FT-ICR MS; and (d) each fraction composition information An analysis device equipped with a composition estimating section that estimates the composition of petroleum heavy fractions based on the above information. The analyzer according to claim 8, further comprising: (e) a total composition correction section that adjusts the estimated value of the composition of the petroleum heavy fraction using elemental analysis information of the petroleum heavy fraction as a correction factor. A petroleum heavy fraction analysis system,
(a) a fraction providing unit that prepares a plurality of fractions separated from petroleum heavy fractions, including at least a tricyclic or higher aromatic fraction and a polar resin fraction;
(b) In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), an ionization part that forms molecular ions or quasi-molecular ions of components constituting each fraction,
Electrospray ionization (ESI) method is applied to the aromatic fraction having three or more rings and the polar resin fraction in the presence of silver ions, and the aromatic fraction having three or more rings and the polar resin fraction An ionization section that applies an atmospheric pressure photoionization (APPI) method to some or all of the fractions other than the fractions;
(c) each fraction composition information analysis unit that specifies each fraction composition information including the structure and concentration of the molecular ion or pseudomolecular ion by the FT-ICR MS; and (d) each fraction composition information An analysis system equipped with a composition estimation section that estimates the composition of petroleum heavy fractions based on The analysis system according to claim 10, further comprising: (e)) a total composition correction section that adjusts the estimated value of the composition of the petroleum heavy fraction by using the elemental analysis information of the petroleum heavy fraction as a correction factor. . A computer program for executing the method according to any one of claims 1 to 7, the apparatus according to claim 8 or 9, or the system according to claim 10 or 11. A recording medium recording the computer program according to claim 12. A computer storing the computer program according to claim 12 in an internal storage device.