JPS6166792A - Rivet braking method - Google Patents

Abstract

Visbreaking of heavy residual oil is carried out at high severity in the presence of an organic sulfur compound containing a thiol group and a highly aromatic hydrogen donor material having HAr and H hydrogen contents each of at least 20% of the total hydrogen content.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for treating residual right-hand feedstock by visbreaking in the presence of highly aromatic hydrogen donor substances.

[Prior Art Problem] Covisbreaking is a well-known technique consisting of pyrolyzing or cracking atmospheric distillation residues under relatively mild conditions to obtain a product with a lower viscosity and pour point. is a petroleum refining process that reduces the amount of lower viscosity and more expensive blended oil required to produce a residue stock useful as a fuel oil. The raw material charged to the visbreaking equipment is atmospheric distillation residue,
The above except for the 6 heavy aromatic oils which are mixtures of two or more refinery streams derived from sources such as vacuum distillation residues, furfural extracts, propane deasphalt tars and catalytic cracking unit residues. Most of the feedstock components behave separately during the visbreaking operation. As a result, the severity of the operation on the charge mixture is very limited by the least desirable component (the component that produces the most coke). Oil charging raw material is approximately 450
It passes through a heater at a pressure of kPa to about 7000 kPa and is heated to about 425°C to about 525°C.

The light gas oil can be recycled to reduce the temperature of the effluent from about 60°C to about 370°C. Equilibrium distillation of the cracking products from the reaction rectifies the vaporous overhead oil to light distillation overhead products, such as gasoline and light gas oil residues, and liquid residues to heavy gas oil distillate and residue oils. Vacuum rectification to tar. An example of the above-mentioned visbreaking method is described in "Thermal Visbreaking of Heavy Residence Use" by Beutber et al.
rmalVisbreakiHof Heavy FL
4 Ends Journal The
Oil and Gas Journal 57:4
6. November 9, 1959, pp. 151-157; Rhoe et al., “Visbreaking Near Flexible Process (Visbreaking: A F
1exible Process) Hydrocarbon 7υ-197
January 9, pp. 131-136; and U.S. Patent No. 4,2
No. 33,138.

Various visbreaking methods have been proposed in which the residual oil is added to the visbreaking step with or without the addition of hydrogen or a hydrogen donor.

For example, U.S. Pat.
A process is described for the production of monocyclic aromatic hydrocarbon necks (70-220°C) by recycling the 2-70°C product fraction and the 220'C+ product fraction for hydrogenolysis and annihilation. This is done in the presence of 1 to 28% by weight of free radical acceptor and in the presence or absence of hydrogen at a temperature of 37
U.S. Pat. No. 4,087 with visbreaking of residual oil (increasing depolymerization of residual oil) at 0°C to 480°C
, 757 specifies 9 to 180 ON per residual oil 1-3.
m' in the presence or absence of hydrogen at a temperature of 400-54
A middle distillate (175-34
5° C.) is described.

U.S. Patent No. 2,953,513 Gi 370
Distillate thermal cracking tar and catalytic cracking tar having a boiling point above ℃ and containing aromatics of at least 40% by weight are partially hydrogenated to obtain an H/C ratio of 0.7/1 to 1.6. /1 hydrogen donors are produced, and then the residual oil charging material is 9 to 8
A process is proposed consisting of mixing with 3% hydrogen donor and pyrolysis at 427-482°C to produce a low-boiling product. US rB Patent No. 4. Q90,947 specifies that residual oil (
425-540"C) to lighter products. The hydrogen donor is premium coker gas oil (premiu+* coker g).
as oil) (345 to 540° C.) It can be produced by hydrotreating the gas oil alone or in a mixture with the gas oil produced in a pyrolysis apparatus. U.S. Pat. No. 4,292,168 M1 discloses that heavy hydrocarbon oils are heated in the absence of a catalyst at a temperature of about 320°C to about 500°C and a pressure of 220°C.
A method is described for improving quality with substantially no carbon production by heating with hydrogen and a hydrogen donor solvent at 0 to 18,000 kPa for about 3 minutes to about 30 minutes.

Examples of hydrogen donor solvents include pyrene, fluoranthene, anthracene and benzanthrone. US Patent No. 4
, 292,686 describes a process consisting of contacting the residual oil with a hydrogen donor at a temperature of 350 DEG to 500 DEG C., a pressure of 2 to 7 MPa and a liquid tin hourly space velocity of 0.5 to 10.

European Patent Application No. 133,774 discloses that coke or A method for producing a V1 fuel oil product is described, which involves the formation of a filterable precipitate. According to the invention described in the patent application specification, a sulfur component, a nitrogen component,
To provide a low molecular weight fuel T4 oil product with improved viscosity and flow properties by visbreaking heavy petroleum charges containing harmful contaminants such as asphaltenes and metals at high severity. I can do it. The method of the invention provides the ability to substantially eliminate and/or reduce the need for cutter stock to meet fuel oil viscosity specifications.

The present invention resides in an improvement to the visbreaking process described in the above-mentioned specification, which comprises introducing an organic sulfur compound to the heavy petroleum residue prior to visbreaking in the presence of a hydrogen donor substance. .

[Means for Solving the Problems] Accordingly, the present invention provides a method for visbreaking heavy petroleum residues, comprising: (a) adding an IJltiE yellow compound having an active thiol component to the residue; and (b) visbreaking in the presence of highly aromatic hydrogen donor molecules each having a H^, hydrogen content and H6 hydrogen content of at least 20% of the total hydrogen donor hydrogen content;
The present invention provides a method for visbreaking heavy petroleum residues, characterized in that a fuel oil product having a viscosity lower than that of the feedstock residue is recovered.

[Operation] The hydrogen donor material used in the process of the invention is a mixture of thermally stable polycyclic aromatic segments or hydroaromatic segments obtained from one or more petroleum refining operations. . Preferably, the hydrogen donor has an average boiling point range of 230 to 510°C and an API gravity of 20°C or less.

An example of a suitable hydrogen donor is a fluid catalytic cracker (F
CC) high aromatic petroleum refinery streams such as main distillation column bottoms, FCC light cycle oils and thermophore contact clubking unit (TCC) syntower bottoms; all of the above refinery streams contain e.g. naphthalene, It contains significant proportions of polycyclic aromatic hydrocarbon components such as dimethylnaphthalene, anthracene, phenanthrene, fluorene, chrysene, pyrene, perylene, diphenyl, benzothiophene, tetralin and dihydronaphthalene. The refractory petroleum materials described above are resistant to conversion to higher grade (lower molecular weight) products by conventional non-hydrogenation operations.Typically, the petroleum residue fractions and recycle fractions described above have an average carbon/hydrogen content. It is a hydrocarbon mixture with a ratio of about 1/1 or more and an average boiling point of 230°C or more.

The FCCC main distillation column bottoms section is a highly suitable hydrogen donor for use in the process of the present invention.

Typically, FCC main distillation column bottoms [or FCC clarified slurry oil (CSO)] contains a mixture of components as described by mass spectrometry:

7-' Alkylbenzene 0.4
0.00 Naphthenebenzenes 1.0
0.03 dinaphthenebenzenes
3.7 0.16 Naphthenes
0.1 0.00 Acenaphthenes (biphenyls) 7.4 0.08 Fluorenes 10.1 0
．． 11 Phenanthrenes 13.1 Naphthenephenanthrenes 11.0 0
．． 18 Pyrenes, fluoranthenes 20.5
0 Chrysenes 10.4
0 Benzofluoranthenes 6.9
0 Perylenes 5.2
0 Benzothiophenes 2.4 Dibenzothiophenes 2.4 Naphthobenzothiophenes 2.4 Total 64.4 35゜6
0.60 A typical FCC main distillation column residue oil or clarified slurry oil has the following analytical values and characteristics - "Amount % C89,93 H' 7.35 N O,44 SL, 09 1 total 99 .80 Pour Point 10°C C0R1% 996 Steam L Initial Boiling Point 254°C 5% 338°C 95% 485°C The preferred hydrogen donor material for the pond is the light cycle oil obtained from the main rectifier in riser type FCC operations.
LCO), and LCO is obtained from the distillation temperature range substantially below 370°C.

Typical FCC light cycle oil (LCO) has the following analysis values and properties. Boiling point distribution, weight % 215°C 48 215-343°C 879 343-427°C 7.3427-538
℃ □ 538℃ □ H, weight% 10.64S, weight%
1. oIN, weight%
o, 24Ni+V, ppm
-COR1wt% □ Paraffins, wt% 12.7 mononaphthenes 11.7 polynaphthenes
12.8 Monoaromatics 24.
7 Diaromatics 21.7 Polyaromatics 14,3 Aromatic Sulfur
21 hydrogen total, weight% 9.0~
95FCC main distillation column bottoms and light cycle oil are obtained by catalytic crabbing of light oil in the presence of a solid porous catalyst. A more complete description of the method for producing the petroleum fractions described above can be found, for example, in U.S. Pat. No. 3,725,240 and U.S. Pat. No. 4,302,323.

Catalytically cracked zero stocks such as clarified slurry oils and light cycle oils are preferred hydrogen donor materials because of their excellent physical properties and chemical composition. Hydrogen Donor A critical aspect of this material is the ratio of aromatic naphthenic and paraffinic components; the type and content of aromatic and naphthenic structures and the high content of alpha hydrogen provide an excellent hydrogen donor material. do.

The hydrogen transfer ability of a hydrogen donor substance can be expressed as a specific type of hydrogen bonding measured by proton nuclear magnetic resonance spectroscopy. Nuclear magnetic resonance properties of heavy carbon and arsenic oils have been extensively developed.

The spectrum 60 (c/s) has the following frequency c Hertz (
Hz)] and chemical shift (δ), four bands (Ha,
Ha, R7 and HAr) divided into: YuHJL Fat Hz O~60 60~100 120
~200 36 (1-560δ 0-1.0
1.0~1.8 2.0~3.3 6.0~9.2H
Ar protons are attached to aromatic rings and are a measure of the aromaticity of a substance. Ha protons are attached to non-aromatic carbon atoms that are directly attached to aromatic ring structures, such as alkyl groups and naphthenic ring structures themselves. The Hβ proton is attached to the carbon atom at the second position farther from the aromatic ring, and the Hr proton is attached to the carbon atom at the third position, or more distant from the aromatic ring structure. are doing. This is explained by the following formula: (7)
The α HAr proton is important because of its strong solvent power. A high content of H protons is particularly important because H6 protons are unstable and are potential hydrogen donors.

It is particularly preferred that the hydrogen donor substances used in the process of the invention have a hydrogen content distribution in which the H static proton content is between 20 and 50% and the Ha proton content is at least 20%, preferably between 20 and 50%. For example, in an H donor stream containing a total hydrogen content of 95% by weight, the α-hydrogen content must be at least 19% by weight (20% of the total hydrogen content), with the remaining hydrogen being non-α-hydrogen. It is.

Hydrogen donors with the desired hydrogen content distribution can be obtained as the residue fraction from the catalytic cracking or hydrocracking of gas oil stocks in moving bed reactor operations or fluidized bed reactor operations.

Typically, depending on conditions such as temperature, pressure, catalyst/oil ratio, space velocity, and nature of the catalyst, high-severity cracking operations increase HAr and Ha proton content and decrease less desirable non-α-hydrogen content. produces a petroleum residue solvent.

The proton distribution of the aromatic hydrocarbon by-product stream is described below: /' No, 2 34.1 (3,18) 38,
8 29.1 9.32No, 3 3
4.3 (3,19) 35,5 30.2
9.30 [The values in parentheses are absolute percentages, and all three LCOs mentioned above are effective H
is a donor] No, 2 30.0 (2,15>
35.0 35.8 7.17No,
3 19.4 (1,39) 65.0
5.0 7.16 No, 2 36.4 (2
,68) 18,8 44.8No,3
18.5 (1,36) 64.3 17
．． 2 No. 4 18.1 (1,33) 67
．． 7 14.2 No, 129.8 (2,78) 2
8.841.4No, 2 18.2 (1,70)
58.8 23. ONo, 3 16
．． 3 (1,52) 68,1 15.6 Lord &
q Length work Z upper plate 27.1 21.6 46.3 work CC Boiseura No. 1 21.5 (2,39> 58.4
20.1No, 2 20 (2,0
7> 58 22No, 3 6.9
(0,89) 85.1 8 All the above values are for non-hydrogenated materials.

From the above data, it can be observed that even among hydrocarbons obtained from similar general operations, some have the desired proton distribution while others do not.For example, FCC/MCB No. 1 and No. 2 and FCC/
C3O No. 1 and No.

2 has a desirable proton distribution, but FCC/MCB No. 3 and No. 4 and FCC/C3O No. 3 do not have a desirable distribution. Furthermore, the higher aromatic hydrogen donor component is derived from petroleum. SRC recycle solvents are preferred, but the SRC recycle solvent is
Note the exact analogy with o,1 and no,2.

tavi introduced into residual oil undergoing visbreaking
Preferably, the yellow compound has an active thiol (-3H) group. Suitable compounds in this respect are thiophenols,
Dibenzothiophene is not a suitable sulfur compound insofar as it includes dodecanethiol and benzothiophene components.

Furthermore, the refined t8! obtained from the extraction of paraffinic oils, for example with furfural, to remove aromatics! The stream and other refinery streams can contain sufficient amounts of sulfur compounds with sufficient 1,000-ol functionality and can be added directly or indirectly to the resid.

Other methods of introducing organic sulfur compounds into heavy residue oils include sulfonating aromatic extracts obtained from extraction of paraffinic oils with phenol or furfural to remove aromatic compounds, e.g. The families are then gently hydrogenated to form organosulfur compounds suitable for addition to heavy residues for visbreaking. Techniques for aromatic extraction, sulfonation and hydrogenation are known in the art.

Other sources of thiol compounds include contacting a thiophenol-containing hydrocarbon stream with a basic solution such as sodium hydroxide in water or alcohol, decanting the basic phase, and then acidifying the solution to release thiol compounds. It is an extract obtained by liberating compounds. The thiol compounds can be separated and mixed with the heavy residue oil. This technique removes sulfur from one section of the refinery stream and provides a means for utilizing the sulfur in other steps of the refinery operation. Hydrocarbon streams that can be used in the process described above include aromatic (furfural) extracts from lubricating oil stocks and cycle oil stocks.

The process of the present invention can be carried out advantageously in a refining process of the type shown schematically in Figure 1. Referring to Figure 1, a viscous hydrocarbon oil charge, typically 496°C + Arab heavy residue oil, is It is supplied to a visbreaking device (visbreaking heating device U) 8 through a conduit 4. Conduit 6 for charging raw material
from 0.1 to 50 fflff1%, preferably 0.1% based on the filtrate donor material and residual oil charge supplied by
~20% by weight (hydrogen donor/residue weight ratio 0.00
1-05, preferably 0.001-0.2).

An amount of organic sulfur compound is added via line 2 such that the sulfur content in the stream flowing through line 2 is between 0.05 and 10% by weight. The amount of organic sulfur compound added is such that the sulfur content is 0.
A suitable amount is 5 to 5%. Mild thermal decomposition of the residual oil under visbreaking conditions occurs in the visbreaking unit, producing a visbreaking unit effluent stream that travels in conduit 10. This effluent is cooled by mixing with the quench stream from conduit 14, and the visbreaking device effluent is subsequently passed through conduit 12 to a distillation column (distillation unit) 22 in which Rectification is carried out at the top of the distillation column through conduit 24 to C1-gases (C3, C4 and lower gases) and c,-13.
Obtain a 5°C naphtha section.

220° C. section and through conduit 16 as a residual oil stream, and this section is recycled as a quench stream through conduit 14 or recovered as heavy fuel oil (HFO) through conduit 18; Alternatively, conduit 20 may be used to mix the cutter stock in a mixing device to meet fuel oil product specifications.

The overhead oil section discharged from the distillation column into conduit 24 is cooled.
It is guided to a separation device 26. This cooling unit separates the liquid introduced through conduit 24 into a CS-offgas stream 28 (predominantly C8 or C4 and below) and a Cs-135°C naphtha section which is discharged by conduit 30. The hydrogen donor is Due to its nature, it can be removed as a heavy oil fraction and used directly as a heavy fuel oil, thereby avoiding the need for separation.

The process of the invention is suitable for improving the quality of various heavy liquid hydrocarbon oils which are mixtures containing at least 75% by weight of six components with boiling points above 370°C. Substances included in this class are residue fractions obtained by catalytic cracking of gas oil 1, solvent extracts obtained during processing of lubricating oil stocks, asphalt precipitates obtained during deasphalting operations, petroleum products and tar sands bitumen. It is a high-boiling residual oil obtained during vacuum distillation of raw materials.

Visbreaking operating conditions can vary widely based on the nature of the heavy oil material, the nature of the hydrogen donor material, and other factors. Typically, the operation is carried out at a temperature range of 350-485°C, preferably 425-455°C, for 1-60 minutes.
This can be carried out preferably within a residence time range of 7 to 20 minutes. The pressure used is usually 1480-7000 kPa, which is sufficient to maintain the liquid state.

An important aspect of the present invention is to improve visbreaking performance by optimizing the operating severity for heavy oil charges.Increasing the severity normally increases the distillate and gaseous The yield of hydrocarbon heads is increased and the amount of cutter oil required for mixing is reduced to obtain a residual fuel oil of specification viscosity. However, at high severity levels, the formation of coke deposits tends to increase, resulting in the production of unstable fuel oils as assessed by blockage of heater tubes and/or the formation of precipitates. The combined use of hydrogen donors and organosulfur compounds in the process suppresses the formation of precipitate components, thereby allowing visbreaking at higher severities with the production of stable fuel oils. As an example, visbreaking of a heavy petroleum charge, which is normally carried out at a mK of 427°C and a residence time of 500 seconds, can be carried out under the conditions of the present invention at a temperature of 427°C and a residence time of 800 seconds to produce a fuel oil free of precipitated components. can get things. Such higher severity significantly reduces the need for the cutter saw 2, which represents a significant financial savings.

[Example] The present invention will be further explained below with reference to Examples.

The hydrogen donor ability of the hydrogen donor solvent and the effect of the thiophenolic compound in increasing it were demonstrated by the following tests.

Four tests were conducted in which the materials listed in column 2 of the table below were added to thick-walled glass tubes as listed in column 311m.

The glass tube was sealed with nitrogen, sealed and incubated at 440°C for 1
The mixtures were then analyzed using vapor pressure chromatography to calculate the hydrogen donating capacity of the individual mixtures.

Slurry oil 0.2311 4.83
0.893 Benzophenone Q, 200 F2 Clarified Slurry Oil 0.2093 0.95
1.16 Penzophenone 0.2026 3 Clarified slurry oil 0.2110 0.95
4.81 Thiophenol 0.0431
3.88 Benzophenone 0.2011 4 Clarified slurry oil 0.2069 0.95
0.876 dibenzothiophene 0.0770
3.88 Benzophenone 0.2019

[Brief explanation of the drawing]

The figure is a schematic diagram of the purification process for carrying out the method of the present invention.
Distillation column (distillation device), 26...cooling separation device.

Claims (1)

[Claims] 1. A method for visbreaking heavy petroleum residues, comprising: (a) adding an organic sulfur compound having an active thiol component to the residue; and (b) reducing the total hydrogen donor hydrogen content. at least 20% H_
visbreaking the resid in the presence of a highly aromatic hydrogen donor having an A_r hydrogen content and an H_α hydrogen content to recover a fuel oil product having a viscosity lower than that of the feed resid. Visbreaking method for heavy petroleum residue. 2. H_A_r hydrogen content is 20 based on total hydrogen content
50% and the H_α hydrogen content is 20-50%. 3. H_A with at least 1.9% by weight hydrogen donor solvent
3. A method according to claim 2, having an H_r content and an H_α content of at least 2.0% by weight. 4. Any one of claims 1 to 3, wherein the hydrogen donor substance is FCC main distillation column residue oil, clarified slurry oil, TCC synthesis column residue oil, SRC recycled oil, or light cycle oil. The method described in. 5. The visbreaking is carried out at a temperature of 350 to 485°C, a residence time of 1 to 60 minutes, and in the presence of a hydrogen donor substance of 0.1 to 50% by weight based on the heavy residual oil. The method described in any one of paragraphs to paragraphs 4 to 4. 6. The method according to any one of claims 1 to 5, wherein the organic sulfur compound is selected from thiophenol, dodecanethiol and benzothiophene. 7. The method according to any one of claims 1 to 6, wherein the visbreaking is carried out in the absence of free hydrogen.