JPH05279675A - Low-temperature stability improver for heavy oil and heavy oil composition containing the same - Google Patents

Abstract

PURPOSE:To provide the subject improver for heavy oil passability and storage stability, comprising a heavy oil-soluble polymer having C=N<+> bond in the molecule and a second polymer soluble in heavy oil and having specific ethylene chains in the molecular chain. CONSTITUTION:The objective improver having the above-mentioned advantages, comprises (A) a polymer soluble in heavy oil and having C=N<+> bond in the molecule prepared by an anionic living polymerization between an aromatic vinyl compound such as styrene and a diene compound such as 1,3-butadiene to form an alkali (alkaline earth metal-terminated block copolymer followed by reacting with e.g. an N-substituted amino(thio)aldehyde and then hydrolyzing and (B) a second polymer also soluble in heavy oil and having at least 5 ethylene chains (e.g. a styrene-butadiene block copolymer) in the molecular chain).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to heavy oil, particularly heavy oil A, B
Regarding the low temperature stability improver of petroleum fuel oil such as heavy oil and C heavy oil, more specifically, cracked base oil such as thermal cracking oil of heavy oil and catalytic cracking oil, and vacuum distillation residual oil such as visbroken residual oil, etc. The present invention relates to a low temperature stability improver for improving the fuel strainer oil permeability and long-term stability of a heavy oil using a base material having poor storage stability at low temperatures. Further, the present invention is
The present invention relates to a heavy oil composition obtained by adding a low temperature stability improver to heavy oil.

[0002]

BACKGROUND OF THE INVENTION Heavy oil is a petroleum oil used as an industrial boiler, a heating furnace, and other fuel oils.
It is produced using heavy residual oil obtained by distilling crude oil as a material source. Heavy oil is produced by appropriately mixing petroleum distillation residual oil and petroleum distillate oil according to the product standard, and is conventionally classified into A heavy oil, B heavy oil, and C heavy oil. It corresponds to 1 type, 2 types and 3 types of standards, respectively (JIS K-2205).

Conventionally, when heavy oil such as heavy oil A is used as a fuel oil for a hot water heating boiler, a hot air heater for a greenhouse, a diesel engine for private generators, a diesel engine for ships such as fishing boats, etc., it cools under natural conditions. The wax precipitates from the heavy oil, which has been cooled to a low temperature, and its crystals grow. When the wax crystal grows, it blocks the boiler, the oil pipe of the engine, the fuel strainer, etc., and interrupts or disables the fuel supply. In particular, such obstruction of oil permeability often occurs in winter cold regions.

It is strongly required in this field to prevent troubles of oil permeability at low temperature, and up to now, many fluidity improvers (flow impul bar) and addition of these fluidity improvers have been added. Fuel composition has been developed,
Used commercially.

At present, as fluidity improvers, alkylnaphthalene polymers, polyalkyl (meth) acrylates, branched polyethylenes, ethylene-vinyl acetate copolymers, alkenylsuccinamides, polyamide compounds of olefins and maleic anhydride copolymers, And mixtures of two or more of these are known.

These fluidity improvers generally adsorb the wax to the wax or form a eutectic with the wax when the heavy oil is exposed to a low temperature, so that the shape and size of the wax crystals are increased. , And has the effect of controlling the surface state,
This is intended to improve the fluidity of heavy oil at low temperatures.

On the other hand, in order to obtain more middle distillates from crude oil with the increase in demand for gasoline, in the petroleum industry in recent years, deep drawing of atmospheric distillation, fluid catalytic cracking equipment, thermal cracking equipment, It has become common to use secondary equipment such as hydrocrackers.

Along with this, heavy oil using residual oil, especially heavy oil A, is deteriorated in storage stability at low temperature and oil permeability of fuel strainer due to heavy residual oil and incorporation of light cycle oil (LCO). Has become a problem more than ever before. The reason for this is that the amount of cracking base material used as a base material for heavy oil increases, and in particular, the asphaltene content of the residual oil contained in heavy oil A increases, while the resin content that increases stability in light oil ( It is considered that asphaltene, which is dispersed by forming micelles in the martens, is precipitated at low temperature. Further, since residual oil having an effect as a fluidity improver is deposited, the wax content also has a large effect of reducing fluidity.

As a measure against these problems, a method of improving the oil permeability of a fuel strainer at a low temperature of heavy oil by combining a mixture of an ethylene / vinyl acetate copolymer and an alkylnaphthalene polymer with petroleum distillation residual oil has been proposed. However, in this method, the effect of improving the precipitation of the residual oil itself by agglomeration at low temperatures is not sufficient.

When preparing heavy oil or as a post-treatment, 1
A method for preventing the generation of asphaltene sludge in residual oil by adding an oil-soluble alkali metal or alkaline earth metal compound at a high temperature of 70 ° C. has been proposed (JP-A-1-279995). The method does not satisfy the effect of improving the stability at low temperatures, and moreover, it causes a lot of energy loss and is not practical.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a low temperature stability improver for improving oil permeability and storage stability of heavy oil. A more specific object of the present invention is to prevent the asphaltene component in the distillation residue oil of heavy oil using a cracking base material from aggregating and precipitating in the petroleum distillate oil, and to practically use a fuel strainer at a low temperature. It is an object of the present invention to provide a low-temperature stability improving agent for heavy oil that improves oil permeability and storage stability (long-term stability), and a heavy oil composition containing the low-temperature stability improving agent and having improved low-temperature stability.

As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors have found that polar groups (-COOH,> C = O, -OH, -NO) contained in the asphaltene component.
₍₂ etc.) When combined with a heavy oil by combining a specific modified polymer having a functional group capable of interacting with ( ₂ etc.) in the polymer chain and a polymer containing an ethylene chain in the molecular chain, excellent low temperature stability is improved. It was found that the effect was exhibited, and the present invention was completed based on this finding.

[0013]

Thus, according to the present invention, a polymer (1) which is soluble in heavy oil and has> C = N ⁺ <bonds in the molecule, and soluble in heavy oil. Thus, there is provided a low temperature stability improver for heavy oil, comprising a polymer (2) having at least 5 ethylene chains in the molecular chain. Further, according to the present invention, there is provided a heavy oil composition obtained by adding the low temperature stability improver to heavy oil.

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 40%.
The amount of distillate oil of 60% and C heavy oil is 5 to 30% (both are% by volume with respect to heavy oil). Heavy oil containing cracked oil of heavy oil such as catalytically cracked gas oil, indirect desulfurized cracked gas oil and hydrocracked gas oil as distillate oil has a remarkable effect of the low temperature fluidity improver 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 residue oil or direct desulfurization vacuum residue oil obtained by reacting atmospheric distillation residue oil or vacuum distillation residue 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
~30kgf / cm ² of the distillation residue of the thermally cracked oil obtained by thermally decomposing under渣油; molybdenum, nickel, tungsten, vanadium, the presence of a catalyst such as cobalt, reaction temperature 400 to 500 ° C., a pressure of about 60 200 kgf / c
Distillation residue oil of hydrocracked oil obtained by hydrocracking under the condition of m ² ; 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 residue oil of catalytically cracked oil; and the like.

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

The residual oil from petroleum distillation residue has an asphaltene content of usually 1.0% by weight or more, preferably 1.0 to 20% by weight, or a residual carbon content of usually 4.0% by weight or more, preferably 5.0 to Those containing 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 (maltene content), and oil content. The asphaltene component is usually dispersed in a resin component called a marten layer, and these form a kind of colloidal (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 150 to atmospheric pressure. It is a hydrocarbon at 450 ° 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.

(Low temperature fluidity improver) In the present invention, as a fluidity improver,> C = N ^{+ in the} molecule, both soluble in heavy oil.
<The polymer (1) having a bond and the polymer (2) having at least 5 ethylene chains in the molecular chain are used in combination.

These polymers (1) and (2) are polymers which are essentially soluble in petroleum distillate oil, and specifically,
It dissolves in petroleum distillate oil in the temperature range of -30 ° C to 160 ° C. 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 polymer (1) of the present invention can also be used after hydrogenating the carbon-carbon unsaturated bond.

The polymer (1) which is one of the components of the low temperature stability improver of the present invention comprises a polar group (-COOH, -COOR, carbonyl group such as> C = O) contained in the asphaltene component of the residual oil. An acidic group such as —OH, —NO ₂ , and —SO ₃ H)).

The other component, the polymer (2), preferably has a molecular skeleton of a block copolymer such as an AB type or an ABA type, and has in the molecular chain. It is a polymerization having 5 or more chains of ethylene (—CH ₂ CH ₂ —). Although it seems that this is due to such a skeleton, the polymer (2) acts like the residual oil, martens, to help the colloidal stability of asphaltene, and at the same time, to the wax in heavy oil with a long ethylene chain. Also has the effect of co-crystallizing and finely dispersing. The effect of the present invention cannot be exhibited by only one of the polymers, and the polymer (1) and the polymer (2)
The effect of stabilizing heavy oil at low temperature becomes remarkable only when used together.

Polymer (1) The polymer (1) is a polymer having a> C = N ⁺ <bond in the molecule (in the molecular chain and / or at the terminal of the molecular chain). It is introduced into the molecule by the polymer reaction described, but it can also be introduced by copolymerization using a monomer having these bonds.

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

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 (same as above), styrene-piperylene copolymer, vinylnaphthalene-butadiene copolymer, styrene-isobutylene block copolymer. , Styrene-butadiene graft copolymer (including comb type), acenaphthylene-
Examples thereof include butadiene copolymers, butadiene-isoprene copolymers, polybutadienes, and diene polymers such as polyisoprene. For these starting polymer, usually, first, the molecular chain terminal> C = N + ^<introducing bond, then in the molecular chain> C = N + ^<introducing binding.

(1) As a method for introducing> C = N ⁺ <bond at the end of the molecular chain, the following methods can be mentioned. A polymer having a polymerization active terminal, that is, a polymer having an alkali metal or an alkaline earth metal bonded thereto,

[0031]

[Chemical 1] Is hydrolyzed by reacting with 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. Can be produced (JP-A-58-162604, JP-A-60-137).
913, etc.).

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.

The amount of the metal-based catalyst used is 100 g of the monomer.
It is usually in the range of 0.1 to 200 mmol. Also,
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.

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. Further, 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 having an alkali metal or alkaline earth metal bonded are as follows. Examples of the compound having the atomic group represented by the general formula [I] include N-methyl-β-propiolactam, N-methyl-2-pyrrolidone and Nt-butyl-2.
-Piperidone, N-methyl-ε-captralactam, N-
N-Substituted lactams such as phenyl-ω-laurylolactam and thiolactams corresponding thereto; N-substituted cyclic ureas such as 1,3-dimethyl-2-imidazolidinone and 1,3-dimethylethyleneurea , And N-substituted cyclic thioureas corresponding thereto;
0-137913).

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 Aminothioaldehydes; and the like (JP-A-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 over a wide range, but it is generally room temperature to 100 ° C. and several seconds to several hours. After completion of the reaction, by hydrolyzing the reaction product, specifically, for example, a method of adding an alcohol such as methanol or isopropyl alcohol to the reaction mixture as a coagulant, a method of subjecting the reaction mixture to steam stripping, etc. > C = N ^{+ at the} end of the molecular chain
<A polymer having an atomic group having a bond 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 its molecular chain, in the presence of a Lewis acid, a compound represented by the general formula R ¹ —CH═N—R ² (wherein R ¹ and R ² are organic atoms Group) and an organic acid halide are reacted with each other (JP-A-61-225).
No. 202).

Examples of the organic compound (II) include benzylideneaniline, benzylidenebutylamine and benzylideneoctylamine. Examples of organic acid halides include acetyl chloride and benzoyl chloride. Examples of the Lewis acid include BF ₃ , BF ₃ O (C ₂ H ₅ ) ₂ , AlCl ₃ , and TiC.
l ₄ , SnCl ₄ , SbCl ₅ , AgBF _{4 and the} like.

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, cyclohexane at 20 to 80 ° C. for about 1 to 2 hours. The organic compound (II) and the organic acid halide are usually about 0.1 to 30 parts by weight per 100 parts by weight of the polymer.

(Ii) In a polymer having a carbon-carbon unsaturated bond in the molecular chain in the presence of a Friedel-Crafts catalyst,
N-hydroxymethylamide compound (N-methylol compound) is reacted, and if necessary, further reacted with alkyl halide, methyl p-toluenesulfonate, etc. to give N-
There is a method for achieving alkylation [C. 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, methyl p-toluenesulfonate and the like 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, there is a method of reacting with an alkyl halide or dimethylsulfate to carry out N-alkylation [Huisgen Angew. C
hem. , 75 , 604 (163)]. Regarding the introduction reaction of the isoxazoline ring by nitroxide, the reference by Tada, Numata et al. (Journal of Japan Rubber Association, 43 , 996 (1
70)).

(Iv) A polymer having a carbon-carbon unsaturated bond in the molecular chain is reacted with a halohydroxyimino compound such as α-chlorohydroxyiminopropanal in the presence of a dehydrochlorinating agent such as anhydrous carbon sodium. Excuse me. Furthermore, there is a method of reacting with an alkyl halide or dimethylsulfate to measure N-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).

[0050] Polymer (2) Polymer (2) is a polymer soluble in heavy oil having at least five ethylene chain in the molecular chain. As noted above, at least 5 ethylene units in the chain are preferred for co-crystallizing with the wax in the heavy oil. If the polymer (2) is soluble in heavy oil, the upper limit of the number of ethylene units in the chain is not particularly limited.

As the polymer (2), a styrene-butadiene copolymer, a styrene-butadiene-isoprene copolymer, a vinylnaphthalene-butadiene copolymer, a styrene-piperylene-bundiene copolymer, an acenaphthylene-butadiene copolymer. And complete hydrides and partial hydrides. Further, a copolymer with ethylene having a structure in which the ethylene chain is 5 or more (for example, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester-unsaturated acid copolymer, ethylene-propylene copolymer, etc.) A copolymer of ethylene and a long-chain α-olefin (C10 or more) and the like are also included in the present invention.

Particularly preferred as the polymer (2) is A
A complete hydride and a partial hydride of a block copolymer of styrene (A) and butadiene (B) such as -B type, ABA type and BAB type.

In the low temperature stability improver of the present invention, the use ratio (weight ratio) of the polymer (1) to the polymer (2) may be slightly different depending on the kind of each polymer used, but it is usually 1/10 to 10/1, preferably 1/5 to 5/1,
More preferably, it is 1/4 to 3/1.

The addition amount of the low temperature stability improver of the present invention is usually 100 ppm or more, preferably 100 ppm to 5.0% by weight, more preferably 300 p, based on heavy oil.
It is a ratio of pm to 2.0% by weight.

The low temperature stability improver of the present invention includes other additives such as hindered phenols such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butylphenol. N, N'-diisopropyl-p-phenylenediamine, N, N'-dibutyl-p-
Amine-based antioxidants such as 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; calcium oxide, magnesium oxide, calcium carbonate, Ash content improvers such as magnesium carbonate and alumina; colorants such as azo dyes; pour point depressants such as polybutene, polymethacrylate, potystyrene, polyvinyl acetate, ethylene-vinyl acetate copolymers; polyoxyalkylene amines, polyoxyalkylenes It can be used in combination with a surfactant type additive such as Solmitan.

When the low temperature stability improver of the present invention is added to heavy oil, it is dissolved in a diluting solvent such as xylene, kerosene, a light lubricating base material, heavy aromatic naphtha, etc., and then added to the heavy oil. Can be mixed. Further, the reaction solution at the time of producing the polymer may be concentrated or diluted and then mixed with the heavy oil.

[0057]

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. <Low temperature stability of heavy oil> 1 heavy oil in a test tube with an internal volume of 15 ml
0 ml was added, then a predetermined amount of the additive was added, and the mixture was shaken well and then allowed to stand in a low temperature constant temperature bath at 0 ° C. afterwards,
The presence or absence of phase separation was observed every 24 hours for up to 5 days, and the number of days until phase separation was recorded.

<Low Temperature Fluidity> The low temperature fluidity of the sample oil is J
The clogging point (CFPP; Col) according to the clogging point test method for light oil specified in IS K-2288.
d Filter Plugging Point).

[Synthesis Experiment 1] A polymerization reactor made of stainless steel having an internal volume of 2 liters was washed, dried, and purged with dry nitrogen, and then 98.4 g of 1,3-butadiene, 820 g of benzene and n- Butyl lithium (n-hexane solution) (14.04 mmol) was charged, and the content was stirred and a polymerization reaction was performed at 40 ° C. for 1 hour. After confirming that the polymerization of butadiene was substantially completed, 21.4 g of styrene was added to the reaction system. After the completion of styrene polymerization, 14.04 mmol of N-methyl-2-pyrrolidone was added, and 1
The reaction was allowed for 0 minutes. Then, the content in the reactor was poured into a methanol solution containing 2% of 2,6-di-tert-butyl-p-cresol to coagulate the produced polymer. The polymer (A) was obtained by drying for one day in a vacuum dryer. The amount of bound styrene of the polymer (A) (a polymer having> C = N ⁺ <bond at the polymer chain end) is 18%, and the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) is 14. It was 1,000.

[Synthesis Experimental Example 2] By the method of Synthesis Experimental Example 1,
Polymerization was performed under the same conditions except that N-methyl-2-pyrrolidone was not reacted to obtain a polymer (a). Using this polymer (a),> C = N ^{+ in the} molecular chain by the following reaction.
<Introduction of binding. 100 g of polymer (a) was added to toluene 5
Dissolved in 00 ml and placed in a glass reactor equipped with stirrer, internal heating, steam condenser, and liquid-solid feed inlet. Heat to 50 ° C. with stirring. Then, 0.1 mol of each modifier shown in Table 1 was added,
The reaction was performed for about 2 hours. After the reaction was stopped by adding a small amount of methanol, the mixture was poured into 3 liters of methanol to coagulate. The obtained product was dried in a vacuum drier to obtain a polymer B and a polymer C.

[0062]

[Table 1]

[Preparation of low-temperature stability improver] Using the polymers obtained in the above synthesis experiments and the copolymers having ethylene chains shown in Table 2, low-temperature stability of the composition ratio shown in Table 2 was used. A sex improving agent (additives 1 to 7) was prepared. These additives were used after being dissolved in light oil at a solid concentration of 40%.

[0064]

[Table 2] (* 1) SEBS: Hydrogenated styrene-butadiene-styrene block copolymer (H-1052 manufactured by Asahi Kasei) (* 2) SEBS: Hydrogenated styrene-butadiene-styrene block copolymer (G manufactured by Shell Chemical Co., Ltd. -165
2) (* 3) EPR: ethylene-propylene copolymer; ethylene / propylene = 45/55, weight average molecular weight = 50
000 (X-4010 manufactured by Mitsui Petrochemical Industry Co., Ltd.) (* 4) SAO: styrene-α-olefin copolymer product; weight average molecular weight = 1860, styrene / α-olefin (C _{14 to} C ₁₈ ) = 1/3

[Preparation of Sample Heavy Oil] Atmospheric pressure distilled light oil (LGO) having the properties shown in Table 3, cracked light oil (light cycle oil; LCO), and four types of residual oils A to D were used. Sample heavy oils A to H were prepared according to the formulation shown.

[0066]

[Table 3] * 1: Measurement temperature 75 ℃

[0067]

[Table 4] * The blending ratio is shown on a volume basis.

[Example 1] 10 ml of each of the sample heavy oils shown in Table 4 was added to each test tube having an internal volume of 15 ml, a predetermined amount of the additives 1 to 7 prepared as shown in Table 2 was added, and the mixture was shaken well. It was left to stand in a low temperature constant temperature bath of 0 ° C. Then, every 24 hours, the presence or absence of phase separation was observed for up to 5 days, and the number of days until phase separation was recorded. For comparison, in the case of no addition,
Also, the same test was performed when each of Polymer A, Polymer B, SEBS (* 1), and SAO was added alone. The results of this low temperature stability test are shown in Table 5. Table 5
The middle circle indicates that there was no phase separation after 5 days, and each numerical value indicates the number of days until phase separation occurred.

[0069]

[Table 5] (Note) Addition amount is as it is (light oil 40% solution).

From Table 5, it can be seen that the use of the low temperature stability improver of the present invention markedly improves the stability of heavy oil at low temperatures.

[Example 2] As shown in Tables 6 to 7, the low temperature plugging point (CFPP) was measured for each of the heavy oils A to H containing various additives at a concentration of 300 ppm.
Was measured. Furthermore, after storing each sample at 0 degreeC for 5 days, the low temperature clogging point (CFPP) was measured. The measurement results are shown in Tables 6 to 7.

[0072]

[Table 6]

[0073]

[Table 7]

Additives 1 to 7 of the present invention have a low temperature fluidity effect even after storage at low temperature. It is considered that this is because the precipitation of residual oil, which has an effect as a pour point depressant, was suppressed. On the other hand, when no additives are added or when each additive is added alone, the CFPP after storage at low temperature is increased.

[0075]

INDUSTRIAL APPLICABILITY The low temperature stability improver for heavy oil of the present invention remarkably improves the oil permeability and storage stability of heavy oil. The low-temperature stability improver of the present invention is a straight-distillation base oil having a high wax content, which has been difficult in the past, or a cracked oil base oil such as a thermal cracked oil of a heavy oil or a catalytic cracked oil, and a base oil. It is possible to prevent precipitation of vacuum distillation residual oil from the base oil, and improve low temperature fluidity and long-term stability, for heavy oils containing vacuum distillation residual oil such as bisbroken residual oil whose compatibility with it can.

That is, additives such as known ethylene / vinyl acetate copolymers and α-olefin copolymers having a long side chain of 3 or more carbon atoms are generated at a low temperature of 0 ° C. or less and segregation is generated and coagulated and precipitated. Even for heavy oil A which cannot prevent the above, by adding the low temperature stability improver of the present invention, excellent long-term stability and low temperature fluidity can be realized.

Therefore, by simply adding the low temperature stability improver of the present invention to heavy oil such as A heavy oil, B heavy oil and C heavy oil, it is possible to prevent troubles such as pipe clogging during transportation or storage at low temperature. You can Further, it is possible to prevent the trouble of oil permeability when heavy oil is used for power generation and as fuel for ships and vehicles in cold regions.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiromoto Inoura 3-66-7 Nishigahara, Kita-ku, Tokyo (72) Inventor Shigeru Kinomoto 2-1-30 Kamata, Ota-ku, Tokyo

Claims (2)

[Claims] 1. It is soluble in heavy oil and has> C = N in the molecule.
Improve the low temperature stability of heavy oil, characterized by comprising a polymer (1) having a < ⁺ bond and a polymer (2) soluble in heavy oil and having at least 5 ethylene chains in the molecular chain. Agent. 2. A heavy oil composition obtained by adding the low temperature stability improver according to claim 1 to heavy oil.