JPH05320672A - Stabilizer for heavy oil storage and heavy oil composition containing the same - Google Patents

Abstract

PURPOSE:To obtain a stabilizer for heavy oil storage which can prevent asphaltene from forming a sludge during storage of heavy oil by incorporating a compound having CH=N bond(s) in the molecule in to heavy oil. CONSTITUTION:This stabilizer contains a compound (a) having at least one CH=N bond in the molecule, or the compound (a) and a polymer having at least one =C=N+< bond in the molecule. Examples of the compound (a) to be used include compounds of formulas I and II, wherein R1 and R2 are each an organic group (except for the case where both of them are an aromatic group having an OH group as the substituent); R3 and R4 are each H or 1-4C alkyl; and (n) is 2 to 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizer for improving the storage stability of heavy oil and a heavy oil composition containing the stabilizer, and more particularly, to asphaltene sludge formation during storage of heavy oil. The present invention relates to a heavy oil storage stabilizer to be suppressed, and a heavy oil composition to which the heavy oil composition has been added to improve storage stability.

[0002]

2. Description of the Related Art Heavy oil is generally commercialized by appropriately mixing petroleum distillation residue oil and petroleum distillate oil in accordance with product specifications. The residual oil is composed of an asphaltene content, a resin content (maltene content), and an oil content. Heavy oil containing this residual oil, if asphaltene precipitates as sludge,
It causes various troubles such as clogging of the fuel strainer and accumulation on the bottom of the fuel tank.

In heavy oil having good storage stability, asphaltene is dispersed in martens by forming micelles to form a kind of colloidal structure. In this case, the aromaticity of the base material also affects the storage stability, and if the aromatic component and resin content are insufficient, asphaltene is likely to precipitate. As described above, the aromatic component and the resin component in the heavy oil have a function of stably dispersing asphaltene in the oil phase.

On the other hand, in recent years, in the petroleum industry, in order to obtain more middle distillates from crude oil, deep drawing of atmospheric distillation, secondary equipment such as fluid catalytic cracking equipment, thermal cracking equipment, hydrocracking equipment, etc. Is commonly used. Along with that, the storage stability of heavy oil has decreased more than before due to the heavy residue oil and the increase in cracked heavy oil.

For example, in order to prevent pollution, it has been practiced in the past to produce a low-sulfur heavy oil by removing the sulfur content in the heavy oil by hydrotreatment, but this is not limited to desulfurization.
Hydrotreating has also come to be used to crack heavy fractions into more valuable low boiling fractions. Then, in order to increase the yield of the kerosene gas oil fraction which is a light oil, the processing conditions are becoming more severe. As a result, aromatic components and resin content in desulfurized heavy oil have decreased, and the tendency of asphaltene to aggregate and separate to form sludge has increased.

Under these circumstances, there is a demand for development of an additive for improving the storage stability of heavy oil containing residual oil obtained by treating heavy oil under severe conditions.
Examples of such additives include, for example, JP-A-2-2923.
The use of Mannich bases is disclosed in Japanese Patent Application Laid-Open No. 2-2.
In Japanese Patent No. 38091, use of various distillation residual oils as a dispersant for sludge, and in Japanese Patent Laid-Open No. 63-117026, a polymer block of acrylate or methacrylate and a polymer of amino group-containing acrylate or methacrylate. The use of block copolymers composed of blocks and the use of benzotriazole compounds have been proposed in JP-A-63-117026. However, sufficient effects cannot be obtained with these conventional additives, and the development of additives that can further improve the storage stability of heavy oil is desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a storage stabilizer for improving the storage stability of heavy oil and a heavy oil composition to which the storage stabilizer is added.
A more specific object of the present invention is to store heavy oil, which prevents the asphaltene component in the distillation residue oil in heavy oil using a cracking base material from being separated into a petroleum distillate oil and agglomerated to form sludge. It is intended to provide a stabilizer and a heavy oil composition containing the storage stabilizer.

The present inventors have conducted extensive studies to solve the above-mentioned problems of the prior art, and as a result, have found that polar groups (-COOH, -COOR, carbonyl groups such as> C = O) contained in the asphaltene component; A compound having a functional group capable of interacting with acidic groups such as OH, —NO ₂ , and —SO ₃ H) or a functional group capable of interacting with the polar group is introduced into the polymer together with the compound. It was found that the storage stability of heavy oil was significantly improved by adding a specific modified polymer to heavy oil, and the present invention was completed based on this finding.

[0009]

Thus, according to the present invention, there is provided a heavy oil storage stabilizer comprising a compound (a) having at least one --CH.dbd.N-- bond in the molecule. Provided. Further, according to the present invention, a compound (a) having at least one —CH═N- bond in the molecule
And a polymer (b) having at least one> C = N ⁺ <bond in the molecule, the storage stabilizer for heavy oil is provided. Further, according to the present invention, there is provided a heavy oil composition containing each of the above storage stabilizers.

The present invention will be described in detail below. (Heavy oil) The heavy oil in the present invention is a mixture of petroleum distillation residue oil and petroleum distillate oil according to the product specifications,
It is conventionally classified into A heavy oil, B heavy oil, and C heavy oil, and includes those corresponding to JIS K-2205 type 1, type 2, and type 3, respectively. Generally, A heavy oil has a residual oil amount of 0.05 to 2%, and B heavy oil has a residual oil amount of 40 to 60%.
%, C heavy oil has an amount of distillate oil of 5 to 40% (both in% with respect to heavy oil). Heavy oil containing cracked oil of heavy oil such as catalytically cracked gas oil, indirect desulfurized gas oil, and hydrocracked gas oil as distillate oil has a remarkable effect of the storage stabilizer of the present invention.

Petroleum Distillation Residual Oil The petroleum distillation residual oil used in the present invention is a generic term for heavy oil withdrawn from the bottom of a distillation column in a petroleum refining process, and is compared with distillate oil. The residual oil can be specifically classified into atmospheric distillation residual oil, vacuum distillation residual oil, cracked residual oil and the like. The atmospheric distillation residue oil is a heavy bottom oil having a boiling point of 400 ° C. or higher that remains at the bottom of the apparatus obtained by distilling crude oil with an atmospheric distillation apparatus, and is commonly called long-residue.

The reduced pressure residual oil is obtained by reducing the atmospheric pressure residual oil under reduced pressure.
For example, it is an ultra-heavy bottom oil remaining at the bottom of the apparatus obtained by distillation with a vacuum distillation apparatus at a pressure of 5 to 50 mmHg, which is commonly called short residue. Direct desulfurization atmospheric pressure residual oil or direct desulfurization vacuum residual oil obtained by reacting atmospheric distillation residue oil or vacuum distillation residual oil with hydrogen in the presence of a catalyst can also be used.

As the cracked residual oil, atmospheric distillation residual oil or vacuum distillation residual oil is used at a reaction temperature of 400 to 500 ° C. and a pressure of 5
Distillation residue oil of pyrolysis oil obtained by pyrolyzing under conditions of ~ 30 kgf / cm ² ; reaction temperature 350-500 ° C, pressure about 60-200 kgf in the presence of a catalyst such as molybdenum, nickel, tungsten, vanadium, cobalt. / Cm
Distillation residue oil of hydrocracked oil obtained by hydrocracking under ² conditions; catalytically cracked oil obtained by catalytic cracking at a reaction temperature of about 400 to 600 ° C in the presence of a catalyst such as activated clay, silica-alumina and zeolite Distillation residual oil; and the like.

In addition, a residual oil extracted from a vacuum distillation residual oil with a solvent such as propane, kerosene, and furfural is also used. You may use these residual oils in combination of 2 or more type. The storage stabilizer of the present invention is particularly effective when added to a mixture of two or more different residual oils.

The residual oil of petroleum distillation residue has an asphaltene content of 1.0% by weight or more, preferably 1.0 to 20% by weight, or a residual carbon content of 4.0% by weight or more, preferably 5.
Those containing 0 to 30% by weight are desirable.

The composition of these residual oils is not constant depending on the type of crude oil and the operating conditions of the distillation column, but when roughly classified, it is composed of asphaltene content, resin content, aromatic content, and oil content. The asphaltene component is usually dispersed in a resin component called resin, and these form a kind of colloid (gel) structure.

Petroleum distillate oil The term " petroleum distillate oil" as used in the present invention means a fraction obtained from an atmospheric distillation apparatus or a vacuum distillation apparatus, or a boiling point obtained by decomposing or reforming the same at atmospheric pressure of 150 to It is a hydrocarbon at 560 ° C. Specifically, for example, straight-run fractions such as kerosene, gas oil, heavy gas oil, catalytic cracking gas oil, indirect desulfurization cracked gas oil, hydrocracked gas oil, etc. , Contact dewaxing heavy gas oil, contact dewaxing vacuum gas oil, and the like.

(Storage Stabilizer) In the present invention, at least one —CH═N in the molecule is used as a storage stabilizer for heavy oil.
A compound (a) having a bond, and the compound (a),
A polymer (b) having at least one bond represented by the general formula> C = N ⁺ <in its molecule is used.

[0019]Compound (a) The compound (a) has at least one —CH═N in the molecule.
-A compound having a bond, having 1 or 2 such bonds
The compound represented by the general formula (I) ₁-CH = NR ₂ (I) (wherein R ₁And R ₂Can be the same or different and are organic
A compound represented by the formula (II)

[0020]

[Chemical 2] [In the formula, R ₁ and R ₂ may be the same or different and each represents an organic residue (except when R ₁ and R ₂ are aromatic groups having an OH group as a substituent). R ₃ and R _{4, which} may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 2-18. ] It is a compound shown by these.

By the way, among the compounds represented by the general formula (II), compounds in which R ₁ and R ₂ are phenyl groups having an OH group as a substituent (for example, N, N'-disalicylidene-1,2- (Propylenediamine) is known as a metal deactivator for jet fuels and gasoline (which chelate metal ions, and it is necessary that the OH group is in the ortho position). Cracking oil corresponding to kerosene or gas oil fraction produced when catalytic cracking or thermal cracking of quality oil, or fuel oil containing these cracking oils (light cycle oil, desulfurized straight distillation gas oil (DS-GO), etc.) It is known to be effective as a coloring preventing agent (Japanese Patent Publication No. 3-44595).

However, as a result of the study by the present inventors,
It was confirmed that this compound does not have a sludge preventing effect on asphaltene in heavy oil. The present inventors have conducted further studies and found that a compound having at least one —CH═N- bond in the molecule other than the compound is effective as a sludge formation inhibitor for heavy oil.

The compound represented by the general formula (I) is
A compound having a —CH═N- bond, wherein R is ₁And R ₂
As specific examples of, for example, phenyl group and substituted phenyl
Group (as a substituent, for example, an alkyl group, an alkoxy group
Group, carboalkoxy group, dialkylamino group, carbo
Aromatic groups such as xyl and cyano groups, etc.
And alicyclic groups such as cyclohexyl and cyclohexyl groups.
It

One -CH = N represented by the general formula (I)
Specific examples of the compound having a bond include, for example, benzylidenemethylamine, benzylidenebutylamine, benzylideneaniline, benzylidenecyclohexylamine, propylidenebutylamine, propylideneaniline, cyclohexylidenebutylamine, cyclohexylideneaniline, ethoxybenzylidenebutylaniline, and
4-Carboxybenzylidene butylaniline, 4-carbomethoxy benzylidene butylamine, benzylidene-4-cyanoaniline, dimethylamino benzylidene aniline, benzylidene-4-carboxy aniline, etc. are mentioned.

The compound represented by the general formula (II) is a compound having two or more --CH.dbd.N-- bonds, and R ₁
Specific examples of R ₂ and R ₂ include a phenyl group and a substituted phenyl group (substituents include, for example, an alkyl group, an alkoxy group, a carboalkoxy group, a dialkylamino group, a carboxyl group and a cyano group). Examples thereof include an alicyclic group such as an aromatic group, an alkyl group and a cyclohexyl group.

Two or more --C represented by the general formula (II)
Specific examples of the compound having an H═N-bond include, for example, N, N′-bis (benzylidene) -1,2-propylenediamine, N, N′-bis (benzylidene) -1,
2-ethylenediamine, N, N'-bis (5-octylbenzylidene) -1,2-propylenediamine, N-benzylidene-N'-propylidene-1,2-propylenediamine, N, N'-bispropylidene-1,2. -Propylenediamine, N-benzylidene-N'-cyclohexylidene-1,2-ethylenediamine, N, N'-bis (benzylidene) -1,2-hexamethylenediamine and the like can be mentioned.

The compound represented by the general formula (II) is usually an oligomer obtained by a condensation reaction of a polyfunctional amine having a diamine or higher and a polyfunctional aldehyde having a dialdehyde or higher. Examples of polyfunctional amines include aliphatic diamines such as ethylenediamine, propylenediamine, tri- or hexa-methylenediamine, aromatic diamines such as phenylenediamine, toluenediamine, and N-methylphenylenediamine. Examples of polyfunctional aldehydes include phthalaldehyde and its isomers, bisterephthalaldehyde, 1,8-diformylnaphthalene, and the like.

Polymer (b) The polymer (b) is> in the molecular chain and / or at the end of the molecular chain.
C = N ⁺ <is a polymer having a bond, and the bond can be introduced by a polymer reaction exemplified below.
It can also be introduced by a copolymerization reaction using a monomer having these bonds.

As the starting polymer of the polymer (b), 1,
3-butadiene, isoprene, 1,3-pentadiene,
Conjugated dienes such as 2,3-dimethyl-1,3-butadiene and 1,3-hexadiene, or homopolymers of olefin-based monomers such as ethylene, propylene and other α-olefins, or olefin-based monomers and styrene thereof. And a copolymer with an aromatic vinyl compound such as vinyltoluene.

Preferred specific examples include, for example, styrene-butadiene copolymers (random copolymers or block copolymers of AB type, ABA type, BAB type, etc .; , A is a polystyrene chain, and B is a polybutadiene chain.), Styrene-isoprene block copolymer (each type similar to the above), styrene-piperylene copolymer, vinylnaphthalene-butadiene copolymer, styrene-isobutylene block. Examples thereof include copolymers, styrene-butadiene graft copolymers (including comb types), acenaphthylene-butadiene copolymers, butadiene-isoprene copolymers, and polyene and diene polymers such as polyisoprene.

For these starting polymers, it is usual to first introduce a> C = N ⁺ <bond at the end of the molecular chain and then a> C = N <bond and / or> C = N in the molecular chain. ⁺ <Introduce a bond. (1) As a method of introducing> C = N ⁺ <bond at the terminal of the molecular chain, the following methods can be mentioned. Polymerization active end, that is, a polymer having an alkali metal or an alkaline earth metal bonded thereto and the general formula (III)

[0032]

[Chemical 3] A compound having a bond (X in the formula is oxygen or sulfur atom), N-substituted amino (thio) aldehyde, N-substituted amino (thio) ketone or the like is reacted to hydrolyze the reaction product. Can be manufactured by the following methods (JP-A-58-162604 and JP-A-60-1).
(See Japanese Patent No. 37913).

The anionic living polymer used in this method is at least one end of a molecular chain obtained by polymerizing a monomer polymerizable with an anionic polymerization catalyst such as an alkali metal and / or alkaline earth metal-based catalyst. A polymer (including an oligomer to a high molecular weight polymer) in which the above metal is bound to. Further, it is also possible to use a polymer to which the metal is added by a post reaction (addition reaction).

The metal-based catalyst used in the polymerization and addition reaction is not particularly limited, and a catalyst conventionally used in anionic polymerization can be used. Examples of the alkali metal-based catalyst include organic lithium compounds having 2 to 20 carbon atoms such as n-butyllithium and sec-butyllithium, and examples of the alkaline-earth metal-based catalyst include barium, strontium and calcium. Examples include, but are not limited to, compound-based catalyst systems.

The polymerization reaction and the alkali metal and / or alkaline earth metal addition reaction are carried out in a hydrocarbon solvent conventionally used in anionic polymerization or in a solvent which does not decompose a metal-based catalyst such as tetrahydrofuran, tetrahydropyran or dioxane. Done in.

The amount of the metal-based catalyst used is usually 1
It is in the range of 0.1 to 200 mmol per 00 g. The amount of the metal-based catalyst used in the addition reaction varies depending on the amount of the metal to be added, but is usually about 0.1 to 10 mmol per 100 g of the polymer.

The polymerization is usually carried out in the presence of a polar compound such as an ether compound, an amine compound or a phosphine compound as a randomizing agent and a vinylating agent. These polar compounds are usually used also in the addition reaction. The conditions of the polymerization and the addition reaction may be according to a conventional method and are not particularly limited.

The organic compounds used to react with the polymer to which the alkali metal or alkaline earth metal is bound are as follows. Examples of the compound having the atomic group represented by the general formula (III) include N-methyl-β-propiolactam, N-methyl-2-pyrrolidone, Nt-butyl-2-piperidone and N-methyl-ε. -Capturactam,
N-Substituted lactams such as N-phenyl-ω-laurylolactam and their corresponding thiolactams; 1,3-
Examples thereof include N-substituted cyclic ureas such as dimethyl-2-imidazolidinone and 1,3-dimethylethyleneurea, and N-substituted cyclic thioureas corresponding thereto (see JP-A-60-137913). ).

Other organic compounds include 4,4 '
N-substituted aminoketones such as bis (dimethylamino) benzophenone, and corresponding N-substituted aminothioketones; N-substituted aminoaldehydes such as 4-dimethylaminobenzaldehyde, and corresponding N-substituted aminoaldehydes Amino thioaldehydes are mentioned (Japanese Patent Laid-Open No. 58-162604).

The amount of these organic compounds used is usually 0.05 to 10 mol per mol of the metal bound to the polymer. The reaction between the living anionic polymer and the like and the organic compound is carried out in a solution of a solvent that dissolves both. Since the reaction takes place rapidly, the reaction temperature and reaction time can be selected within a wide range, but it is generally from room temperature to 100 ° C. and for several seconds to several hours. After the reaction is completed, the reaction product is hydrolyzed,
For example, by adding alcohol such as methanol or isopropyl alcohol to the reaction mixture as a coagulant, or by subjecting the reaction mixture to steam stripping, an atomic group having> C = N ⁺ <bond at the end of the molecular chain is formed. The introduced polymer can be obtained.

(2) As a method of introducing> C = N ⁺ <bond into the molecular chain, the following method can be mentioned. (I) In a polymer having a carbon-carbon unsaturated bond in the molecular chain, in the presence of a Lewis acid, a compound represented by the general formula (IV) R ₁ —CH═N—R ₂ (IV) (where R ₁ and R ₂ represents an organic atomic group), and an organic acid halide is reacted with the organic acid halide (JP-A-61-225202).

Examples of the organic compound represented by the general formula (IV) include benzylideneaniline, benzylidenebutylamine, benzylideneoctylamine and the like. Examples of organic acid halides include acetyl chloride and benzoyl chloride. Also,
As the Lewis acid, for example, BF ₃ , BF ₃ O (C ₂ H ₅ )
₂ , AlCl ₃ , TiCl ₄ , SnCl ₄ , SbCl ₅ , A
Examples thereof include gBF ₄ .

The reaction conditions and the like are not particularly limited, but usually, the reaction is carried out in an inert solvent such as benzene, toluene and cyclohexane at 20 to 80 ° C. for about 1 to 2 hours. The organic compound represented by the general formula (IV) and the organic acid halide are each usually 0.1 to 3 per 100 parts by weight of the polymer.
It is about 0 parts by weight.

(Ii) In a polymer having a carbon-carbon unsaturated bond in the molecular chain in the presence of a Friedel-Crafts catalyst,
There is a method of reacting an N-hydroxymethylamide compound (N-methylol compound) and further reacting with an alkyl halide or methyl p-toluenesulfonate to achieve N-alkylation [eg, C.I. Giordano
Et al. SYNTHESIS, 92 (1971)].

The N-hydroxymethylamide compound is a reaction product of an amide compound and an aldehyde compound. As the aldehyde compound, an aliphatic or aromatic aldehyde such as formalin, butyroaldehyde, valeroaldehyde, benzaldehyde, etc. is used. Examples of the amide compound include acetamide, benzamide, methoxybenzamide, nitrobenzamide, N-methylbenzamide, butyroamide, phthalamic acid and glutaric acid amide. In addition, a copolymer containing N-methylol acrylamide monomer as one component is also used as the N-hydroxymethylamide compound.

Alkyl halides such as benzyl bromide, benzyl chloride, bromohexane, bromopropane and chloropentane, chloromethyl ether, dimethylsulfate and methyl p-toluenesulfonate are mainly used as the alkylating agent.

Examples of Friedel-Crafts catalysts include BF ₃ , BF ₃ O (C ₂ H ₅ ) ₂ , BCl ₃ and AlC.
l ₃ , TiCl ₄ , SnCl ₄ , FeCl ₃ , WCl ₆ , P
A generally known metal halide or metalloid halide such as OCl or (C ₂ H ₅ ) ₂ AlCl can be used.

(Iii) A polymer having a carbon-carbon unsaturated bond in its molecular chain is reacted with a nitrile oxide, nitrile imine, or nitrile ylide known as 1,3-dipole addition reaction with an unsaturated bond. After that, an N-alkylation is carried out by reacting with an alkyl halide or dimethyl sulfate [eg, Huisgen's Ang.
ew. Chem. , 75 , 604 (163)]. Regarding the introduction reaction of the isoxazoline ring by nitrile oxide, the reference by Tada, Numata et al. (Journal of Japan Rubber Association, 43 ,
996 (170)).

(Iv) A polymer having a carbon-carbon unsaturated bond in its molecular chain is reacted with a halohydroxyimino compound such as α-chlorohydroxyiminopropanal in the presence of a dehydrochlorinating agent such as anhydrous carbon sodium. N, by reacting with an alkyl halide or dimethylsulfate.
-There is a method for measuring methylation.

(3)> C = N at the end of the molecular chain and in the molecular chain
⁺ <A method for introducing a bond includes a combination of the above methods (1) and (2).

These modified polymers (b) are polymers which are essentially soluble in petroleum distillate oil, specifically, -10.
It dissolves in petroleum distillate oil in the temperature range of ℃ to 160 ℃. As such a polymer, a straight chain / branched hydrocarbon-based polymer is mainly preferable in a straight-run distillate, and an alicyclic / aromatic hydrocarbon is mainly contained in a cracked distillate since an aromatic component is large. Polymers are preferred.

It is preferable that 1 to 10 of the above-mentioned> C = N ⁺ <bonds are contained in one molecule of the polymer. The molecular weight of the polymer is also not particularly limited and includes oligomers to hundreds of thousands of high molecular weight polymers. Furthermore, if necessary, the modified polymer of the present invention can be used after hydrogenating the carbon-carbon unsaturated bond.

The compound (a), or the compound (a) and the polymer (b), which are the storage stabilizers of the present invention, is usually 50 ppm or more, preferably 100 p
It is contained at a ratio of pm to 5% by weight, more preferably 300 ppm to 2% by weight.

When the compound (a) and the polymer (b) are used in combination, the compound (a): polymer (b) is used in a weight ratio of usually 1 to 99.5: 99 to 0.5. , Preferably 10 to 99:90 to 1, more preferably 50 to 95: 5.
It is 0-5.

The storage stabilizer of the present invention may be added with other additives such as hindered phenols such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butylphenol, or N, N'-diisopropyl-p-phenylenediamine, N, N'-dibutyl-
Amine-based antioxidants such as p-phenylenediamine; combustion improvers such as sulfonates, naphthenates and phenol salts of metals such as calcium, magnesium, barium, chromium, cobalt, manganese and iron; antifog agents Antiknock agents; ash improving agents such as calcium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, alumina; coloring agents such as azo dyes; polybutene, polymethacrylate, potystyrene, polyvinyl acetate, ethylene-vinyl acetate copolymers, etc. Pour point depressant, which can be used in combination with a surfactant type additive such as polyoxyalkylene amine or polyoxyalkylene solmitane.

[0056]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. The parts and% in the examples are by weight unless otherwise specified.

The methods for measuring the physical properties are as follows. <Stability of heavy oil> The stability of heavy oil is FS manufactured by Nippon Oil Co., Ltd. according to the ASTM spot test (D-2781).
-Evaluated using TESTER. That is, after heating the sample oil to 80 ° C., a part of the sample oil is scooped with a glass rod and one drop is dropped on the filter paper at 80 ° C. Hold for 30 minutes,
Then, the stability of the heavy oil is evaluated by comparing the spot on the test paper with the standard spot. The spots (sample spots) of the sample spread on the filter paper are compared with the standard spots, the coincident one is selected, and the spot number is recorded. The smaller the spot number, the better. Table 1 shows the spot number judgment criteria of the spot test.

[0058]

[Table 1]

<Dispersion Stability of Asphaltene> n-Heptane was added dropwise to 10 ml of vacuum distillation residue oil hydrocracked oil (VRDS heavy oil) to which 1000 ppm of additive had been added, until n-heptane was agglomerated. The precipitation potential (P) can be calculated from the dropping amount by Van Kerk.
Voort et al. [J. J. Heithaus, JI
P, 48 (458), 45 (1962)] and the P value is used to evaluate the dispersion stability of asphaltene. The larger the P value, the better the dispersion stability.

[Example] 15 g of VRDS C heavy oil (P value: 1.17) was placed in a sample bottle having an internal volume of 20 cc, and storage stabilizers of 100 ppm and 500 pp were added at room temperature, respectively.
m, and 1000 ppm were added. The container was sealed and left in a gear oven at 100 ° C. to accelerate thermal deterioration. It was taken out every 24 hours, one drop of VRDS heavy oil was dropped on a spot tester, the mixture was developed at 100 ° C., the presence or absence of spots and the ring thickness were visually observed, and the spot number was determined in comparison with a reference table. If the spot number is No. The number of days until reaching 3 was measured. The storage stabilizer used and the evaluation results are shown in Table 2. Table 3 shows the evaluation results of the dispersion stability of asphaltene.

The terminal-modified block copolymer used as the polymer (b) was prepared by the following method. After washing and drying, 500 g of xylene, n-hexane solution of 62.5 mmol of n-butyllithium and 0.5 mmol of tetramethylethylenediamine were added to a stainless steel polymerization reactor having an internal volume of 2 liters, which was replaced with nitrogen. 6
1,3-Butadiene 40 at 0 ° C with stirring contents
0 g was added over 1 hour to polymerize. After the completion of the polymerization reaction, 100 g of styrene was added over 15 minutes for polymerization. After completion of the polymerization reaction, N-methyl-2 was used as a terminal modifier.
-Pyrrolidone (63.6 mmol) was added and reacted for 30 minutes. The weight average molecular weight in terms of standard polystyrene measured by GPC (gel permeation chromatography) of the obtained terminal-modified butadiene-styrene block copolymer was 14,000.

[0062]

[Table 2] (* 1) The usage rate is 8/2. (* 2) Dai-ichi Kogyo Seiyaku Co., Ltd., trade name PRYSURF A-
212E. The usage rate is 9/1.

[0063]

[Table 3] (* 1) The usage rate is 8/2. (* 2) Dai-ichi Kogyo Seiyaku Co., Ltd., trade name PRYSURF A-
212E. The usage rate is 9/1.

The results of Tables 2 and 3 show that the heavy oil storage stabilizer of the present invention imparts excellent storage stability to heavy oil even when the amount added is small.

[0065]

INDUSTRIAL APPLICABILITY The heavy oil storage stabilizer of the present invention improves the storage stability of heavy oil, and particularly prevents sludge formation during storage of asphaltenes in heavy oil using a cracked base material. The heavy oil composition having the action and having the stabilizer added thereto is imparted with excellent storage stability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Shimizu 8th place, Chidori-cho, Naka-ku, Yokohama, Kanagawa Japan Central Oil Research Institute (72) Inventor Tadashi Yamashita 8th place, Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Central Research Institute of Nippon Oil Co., Ltd.

Claims (6)

[Claims] 1. At least one —CH═N— in the molecule.
A storage stabilizer for heavy oil, comprising a compound (a) having a bond. 2. At least one —CH═N— in the molecule.
A storage stabilizer for heavy oil, comprising a compound (a) having a bond and a polymer (b) having at least one> C = N ⁺ <bond in the molecule. 3. The compound (a) has the general formula (I) R ₁-CH = NR ₂ (I) (wherein R ₁And R ₂Can be the same or different and are organic
A compound represented by the formula (1), which represents a residue).
The storage stabilizer described. 4. The compound (a) is represented by the general formula (II): [In the formula, R ₁ and R ₂ may be the same or different and each represents an organic residue (except when R ₁ and R ₂ are aromatic groups having an OH group as a substituent). R ₃ and R _{4, which} may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 2-18. ] The storage stabilizer according to claim 1 or 2, which is a compound represented by the formula: 5. The storage stability stabilizer according to claim 4, wherein the compound (a) is a condensation reaction product of a polyfunctional amine and a polyfunctional aldehyde. 6. A heavy oil composition comprising the storage stabilizer according to claim 1 or 2.