JP3725347B2 - Fuel oil low temperature fluidity improver and fuel oil composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an additive for improving fluidity and oil permeability for a fuel oil and a fuel oil containing the same.
[0002]
[Prior art]
Petroleum middle distillate, such as diesel fuel oil, heavy fuel oil A, etc., when exposed to low temperatures in winter or in cold regions, the paraffin wax and wax-like substances contained in it precipitate, and the filter in the fuel piping system can be seen. Clogging or solidification of the fuel in the piping system causes problems such as being unable to start the engine and combustion device, and stopping the engine.
[0003]
In order to solve these problems related to fluidity at low temperatures, many methods for adding a vinyl ester copolymer of ethylene-saturated carboxylic acid to fuel oil have been proposed. For example, it is described in JP-B-39-20069, JP-B-48-23165, JP-A-59-136391, and the like.
Also, an unsaturated dicarboxylic ester graft adduct of ethylene-vinyl carboxylate copolymer and a method of adding these adducts together with ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, etc. [ JP-B-58-39472], complete esters of polyoxyalkylene ethers of alkanetriols and linear saturated fatty acids, and their esters with ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, long-chain alkyl groups A method of adding a (meth) acrylic acid copolymer or the like containing a mixture [Japanese Patent Publication No. 2-51477], a fatty acid ester of polyoxyalkylene glycol, and these esters and an ethylene-vinyl acetate copolymer Method of adding in combination [Japanese Patent Laid-Open No. 57-177702] Trivalent or less Polyhydric alcohol or a method of adding an incomplete ester of an alkylene oxide adduct and a fatty acid of the partial ester of [JP 61-181892] have been proposed.
[0004]
[Problems to be solved by the invention]
However, the ethylene-vinyl acetate copolymer has been developed because the ability to improve low-temperature fluidity of fuel oil differs depending on its structure (ethylene-vinyl carboxylate copolymerization ratio, molecular weight, molecular weight distribution, methyl branching degree, etc.) The agent has insufficient performance, and further, the dispersibility of the precipitated wax is poor in the fuel oil to which the improver is added. Further, even at the wax precipitation temperature (CP), the filter is clogged, and the oil permeability of the filter is not good.
[0005]
[Means for Solving the Problems]
However, in recent years, the demand for middle distillate oil has increased, and as a result of responding to this demand, the distillation properties of diesel fuel oil and heavy fuel oil A have narrow distillation boiling range, that is, narrow cut middle distillate oil. It has become. Moreover, when hydrodesulfurization is performed in order to reduce the sulfur content in light oil, it tends to become a narrow distillation property. In order to improve the fluidity of these middle distillates at low temperatures, the conventional method of adding ethylene-vinyl acetate ester copolymer is insufficient to improve fluidity and the precipitated wax settles. However, problems such as clogging of the filter may occur. Also, a method of adding a triester of a polyoxyalkylene ether of alkanetriol and a linear saturated fatty acid; and a (meth) acrylic acid copolymer containing a long-chain alkyl group in combination, and ethylene- In the method of adding an unsaturated dicarboxylic acid ester adduct of a vinyl carboxylate copolymer, precipitation of the precipitated wax is small, but the effect of improving fluidity at low temperatures is small.
[0006]
That is, the present invention provides a copolymer (A) comprising ethylene and a carboxylic acid vinyl ester and / or a modification (B) of a copolymer comprising ethylene and a carboxylic acid vinyl ester, and an aliphatic group having 12 to 30 carbon atoms. It comprises an oil permeability improver (C) made of carboxylic acid, and the mixing weight ratio of [(A) component + (B) component] :( C) component is 95: 5-70: 30, and the solubility of (C) It is a fuel oil low temperature fluidity improver with a parameter (SP value) of 8.0 to 9.6, an HLB value of 0.5 to 8.7, and a molecular weight of 200 to 700, and a sulfur content of 0.05% by weight. The present invention provides a fuel oil composition comprising the following low-sulfur fuel oil and a low-temperature fluidity improver for the fuel oil, and containing 0.002 to 0.50% by weight of the additive. Further, by using (A) and / or (B) and (C) in combination, not only the oil permeability is improved, but also the improver capable of synergistically improving PP and CFPP, and the fuel oil A composition is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the copolymer (A) used in the present invention, the carboxylic acid vinyl ester may be a C1-C4 short chain fatty acid vinyl (vinyl acetate, vinyl propionate, vinyl butyrate, etc.), C5 or more, preferably C5-C20 long. Chain fatty acid vinyl (vinyl laurate, vinyl myristate, vinyl stearate, vinyl palmitate, etc.), aromatic nucleus-substituted fatty acid vinyl (vinyl phenyl acetate, etc.), aromatic monocarboxylate vinyl (vinyl benzoate, etc.) and these 2 A mixture of seeds or more can be mentioned. Of these, preferred are short chain vinyl fatty acids in view of physical properties and performance, and particularly preferred is vinyl acetate.
[0008]
In the copolymer (A), the carboxylic acid vinyl ester content is 15 to 40%, preferably 20 to 30%, based on the weight of the copolymer (A). If the carboxylic acid vinyl ester content is less than 15% or more than 40%, the fluidity improving performance is insufficient. The ethylene content is usually 85-60%, preferably 80-55%.
In addition to the methyl group of the ester group of the copolymer (A), it has 4.5 to 6.5, preferably 5 to 6, methyl terminal side chains per 100 methylene groups of the ethylene chain. When the number of methyl terminal side chains is less than 1 and more than 10, the fluidity-improving performance is insufficient.
The number average molecular weight of the copolymer (A) is 500 to 8000, preferably 1000 to 3000.
When the number average molecular weight is less than 500 or more than 8000, the fluidity improving performance is insufficient.
The above carboxylic acid vinyl ester content and methyl terminal side chain can be measured by NMR (nuclear magnetic resonance method). The number average molecular weight can be measured by a vapor pressure infiltration method.
[0009]
Examples of the modified product (B) of a copolymer comprising ethylene and a carboxylic acid vinyl ester include an unsaturated carboxylic acid ester adduct of a copolymer comprising ethylene and a carboxylic acid vinyl ester. The carboxylic acid vinyl ester constituting the ethylene-carboxylic acid vinyl ester copolymer is the same as the component (A), and preferred ones are also the same. The number average molecular weight of a copolymer is 1000-10000 normally, Preferably it is 2000-5000. The carboxylic acid vinyl ester content is usually 5 to 25%, preferably 10 to 20%, based on the weight of the copolymer. Examples of the unsaturated carboxylic acid ester to be added include unsaturated dicarboxylic acid esters having at least one carbon-carbon unsaturated bond and at least two carboxylic acid groups in the molecule.
Preferable unsaturated dicarboxylic acids include unsaturated dicarboxylic acids having 4 to 40 carbon atoms. Examples of the unsaturated dicarboxylic acid having 4 to 40 carbon atoms include fumaric acid, maleic acid, itaconic acid, and citraconic acid.
Examples of the alcohol constituting the unsaturated carboxylic acid ester include linear and / or branched saturated or unsaturated alcohols and their alkylene oxide adducts, and alkylene oxide adducts of alkylphenols. It is done.
Examples of the linear and / or branched saturated alcohol include natural higher aliphatic alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol, Examples thereof include synthetic alcohols based on a graph catalyst, and mixtures thereof.
Examples of the linear and / or branched unsaturated alcohol include oleyl alcohol, linoleyl alcohol, and elenostearyl alcohol.
In the alkylene oxide adduct of a linear and / or branched saturated or unsaturated alcohol, examples of the alkylene oxide include alkylene oxides having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide, preferably Propylene oxide. The added mole number is usually 1 to 20 moles.
Examples of the alkylphenol in the alkylene oxide adduct of alkylphenols include t-butylphenol, nonylphenol, and dodecylphenol. The detailed added mole number of alkylene oxide is the same as described above.
Of the above alcohols, preferred are linear and / or branched saturated alcohols.
The amount of unsaturated carboxylic acid ester added to the copolymer of ethylene and carboxylic acid vinyl ester is usually 50 to 500 parts, preferably 100 to 100 parts of the copolymer of ethylene and carboxylic acid vinyl ester on a weight basis. 100 to 300 parts.
The unsaturated carboxylic acid ester is prepared by mixing the unsaturated carboxylic acid and alcohol described above so that the COOH / OH ratio is usually 1.5 to 3.0, preferably 1.8 to 2.5, and usually at room temperature. It can obtain by making it react at -200 degreeC, Preferably it is 70-250 degreeC.
In the reaction, a catalyst such as p-toluenesulfonic acid is usually used. The reaction product is subjected to the addition reaction of the fluidity improver as it is or after purification.
The reaction proceeds without using a solvent, but an appropriate solvent that does not react with the raw material carboxylic acid and alcohol can also be used. Suitable solvents include aliphatic hydrocarbons such as paraffin, olefin and cycloparaffin, aromatic hydrocarbons such as toluene and xylene, and petroleum solvents such as kerosene, light oil and solvent naphtha. The produced ester is usually solid to paste at room temperature.
An unsaturated carboxylic acid ester adduct of a copolymer composed of ethylene and a carboxylic acid vinyl ester can be prepared by various methods. For example, a method of mixing and heating a copolymer of ethylene and a carboxylic acid vinyl ester and an unsaturated carboxylic acid ester, or a copolymer of ethylene and a carboxylic acid vinyl ester previously with an unsaturated carboxylic acid or polyvalent carboxylic acid anhydride Followed by esterification with a suitable alcohol. The addition reaction can usually be carried out at 200 ° C. or higher. However, if a small amount of a radical generating catalyst (organic or inorganic peroxide, azo compound, etc.) is used or irradiation with radiation such as ultraviolet rays is performed, the addition reaction can be carried out at room temperature. It can be performed at a relatively low temperature of 200 ° C or lower. The reaction can also be carried out in the absence of a solvent or in the presence of a suitable solvent (hydrocarbon solvent, halogen solvent, etc.).
The thus obtained modified copolymer of ethylene and carboxylic acid vinyl ester may contain a small amount of unreacted material or a homopolymer of unsaturated carboxylic acid ester, but can be used without any trouble. .
[0010]
In the present invention, the HLB value is a value calculated by Griffin's HLB (“Introduction to New Surfactant”, Sanyo Chemical Industries, Ltd., P128), and the solubility parameter (SP value) is the Fedors method [Polym. Eng. Sci. 14 (2) 152, (1974)].
[0011]
The SP value of the oil permeability improver (C) is usually 8.0 to 9.6, preferably 8.5 to 9.2. The HLB value is usually 0.5 to 8.7, preferably 0.6 to 7.8. Mw is usually 200 to 700, preferably 200 to 500. If all of these physical property values are not satisfied, problems such as poor solubility in fuel and deterioration of demulsibility against condensed water in the fuel occur.
Examples of the oil permeability improver (C) include aliphatic carboxylic acids having 12 to 30 carbon atoms. Examples of the aliphatic carboxylic acid include linear saturated fatty acids having 12 to 30 carbon atoms (for example, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, etc.), carbon. A linear unsaturated fatty acid having a number of 12 to 30 (for example, palmitoleic acid, oleic acid, eicosenoic acid, erucic acid, linoleic acid, linolenic acid, etc.), a branched aliphatic having 12 to 30 carbon atoms Examples thereof include carboxylic acid.
[0012]
The mixing weight ratio of {(A) component + (B) component} :( C) component of the improver of the present invention is usually 95: 5-70: 30, preferably 90: 10-75: 25, Particularly good performance is shown in this range.
The fuel oil from which the fuel oil composition is obtained by adding the improver of the present invention to the fuel oil is mainly a distillate fuel oil. Specific examples include kerosene and light oil, with light oil being preferred. When the improver of the present invention is added to the fuel oil, the amount added is usually 0.002 to 0.50%, preferably 0.005 to 0.1%, based on the weight of the fuel oil.
[0013]
The method for adding the improver of the present invention to the fuel oil is not particularly limited. In the case of an improver comprising the component (A) or / and the component (B) and the component (C), for example, the component (A) or / and the component (B) and the component (C) are mixed in advance and used as a fuel. (A) component or / and (B) component, and (C) component are separately added to fuel oil, and (A) component or / and (B) component in fuel oil, and ( Examples thereof include a method for forming an additive comprising component C). When mixing in advance, (A) component and / or (B) component, and (C) component are heated and mixed uniformly, (A) component and / or (B) component, and (C) component Among them, there is a method in which two or more components are dissolved in a solvent and then mixed. Further, as a method of forming an improver in the above fuel oil, the component (A) or / and the component (B) and the component (C) are used as they are, or the component (A) or / and the component (B), There is a method in which two or more components among the component C) are dissolved in a solvent and added simultaneously or sequentially to the fuel oil.
[0014]
The following may be added to the fuel oil composition of the present invention according to each function. For example, when further imparting corrosion protection, a corrosion inhibitor (for example, alkenyl succinic acid-based rust preventive, alkenyl succinic acid ester-based rust preventive), and when imparting rust preventive (for example, An ethylene oxide adduct of dodecylamine, octylamine) may be added. When imparting cleanliness, a detergent (eg, dibutylamine ethylene oxide adduct or butanol ethylene oxide adduct), when imparting lubricity, a lubricity improver (eg, higher fatty acid mixture, sorbitan monoacetate) Oleate, glycerol monooleate) may be added.
[0015]
Specific examples of the low-sulfurized fuel oil having a sulfur content of 0.05% by weight or less in the present invention include JIS No. 1 gas oil obtained by ordinary distillation of low-sulfur crude oil (for example, Southern crude oil such as Minas crude oil), JIS 2 No. diesel oil, JIS No.3 diesel oil, JIS No.3 diesel oil; desulfurized diesel oil produced from ordinary crude oil through hydrodesulfurization treatment process; blending this desulfurized diesel oil and straight run diesel oil (light oil before hydrodesulfurization process) Examples include JIS No. 1 diesel oil, JIS No. 2 diesel oil, JIS No. 3 diesel oil, and JIS No. 3 diesel oil produced from the obtained diesel oil fraction. Particularly preferred are JIS No. 1 diesel oil, JIS No. 2 diesel oil, JIS No. 3 diesel oil, and JIS No. 3 diesel oil produced by using 50% by weight or more of the desulfurized diesel oil produced through the hydrodesulfurization treatment step.
[0016]
The low temperature fluidity improver of the present invention contained in 0.05% by weight or less of the low sulfur fuel oil is usually 20 to 5000 ppm, preferably 30 to 1000 ppm, more preferably 50 to 600 ppm. If it is less than 20 ppm, the low temperature fluidity is insufficient, and if it exceeds 5000 ppm, the addition efficiency is deteriorated and the economical efficiency is impaired.
[0017]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In the following, “parts” and “%” indicate the methyl branching degree of methyl terminal side chain per 100 methylene groups of ethylene chain in addition to parts by weight and weight% and methyl group of ester group, respectively.
[0018]
Example 1
(A) vinyl acetate content as component; 26%, number average molecular weight; 1900, methyl branching degree: 5.2 ethylene-vinyl acetate copolymer and (B) component modified with ethylene-vinyl acetate synthesized under the following conditions As a component (C), a higher fatty acid mixture having a weight percentage of oleic acid: linoleic acid: linolenic acid of 35: 60: 5 was blended in a weight ratio of 68:12:20 to obtain the improver of the present invention. (B) Component production conditions: number average molecular weight in a flask equipped with a stirrer, a thermometer, a nitrogen blower, and an exhaust pipe; 3000, vinyl acetate content; 100 parts of 12% ethylene-vinyl acetate copolymer, dioctyl male 100 parts of ate and 3 parts of dicumyl peroxide as a catalyst were charged, and after the flask was sufficiently substituted with nitrogen, the temperature was gradually raised. It was made to react at 140-150 degreeC for 8 hours. The obtained reaction product was light yellow solid.
Comparative Example 1
An ethylene-vinyl acetate copolymer having a vinyl acetate content of 25%, a number average molecular weight of 1,700, and a methyl branching degree of 7.9 was used as an improver.
Comparative Example 2
Vinyl acetate content: 25%, number average molecular weight: 1700, methyl branching degree: 7.9 ethylene-vinyl acetate copolymer and ethylene-vinyl acetate modified product prepared in Example 1 in a weight ratio of 80:20 Things were improved.
Example 2 and Comparative Examples 3-4
The improver of the present invention obtained in Example 1 and the improvers of Comparative Examples 1 and 2 were added to light oil having the properties shown in Table 1 to obtain a fuel oil composition. The effect of improving fluidity was evaluated by measuring PP (pour point) and CFPP (clogging point of low temperature filter). The dispersibility and filter oil permeability of the wax were evaluated by the methods shown below. The results are shown in Tables 2, 3, 4, and 5.
[0019]
<Evaluation method of wax dispersibility>
A light oil to which 0.05 wt% of a fluidity improver is added to a 100 ml graduated cylinder is stored in an air-cooled low temperature thermostatic bath at a temperature lower than the cloud point, and the state of wax settling is observed. Larger values indicate better wax dispersibility.
<Filter-oil permeability evaluation method>
1000 ml of light oil to which 0.03 wt% of the fluidity improver was added was allowed to stand in an air-cooled low-temperature thermostatic bath at 5 ° C for 5 hours to 10 hours, and then filtered under the following conditions, and the filtration time was determined. A short filtration time indicates a good filter-oil permeability.
Filter: Advantech 25mm filter holder
Fifter; membrane filter (made of cellulose ester)
Pore size: 0.8μm
Effective filtration area: 2.1cm2
Funnel capacity: 300ml
[0020]
[Table 1]
[0021]
[Table 2]
[0022]
[Table 3]
[0023]
[Table 4]
[0024]
[Table 5]
[0025]
【The invention's effect】
The improver of the present invention provides a low-temperature fluidity improver that further improves the low-temperature fluidity characteristics of the fuel oil as compared with the conventional one, and at the same time has good wax dispersibility and filter-oil permeability of the fuel oil. I can do it. In addition, improvement in the lubrication performance of the fuel oil in the engine can be expected.

Claims (3)

 A copolymer (A) composed of ethylene and a carboxylic acid vinyl ester and / or a modified product (B) of a copolymer composed of ethylene and a carboxylic acid vinyl ester, and an aliphatic carboxylic acid having 12 to 30 carbon atoms. It comprises an oiliness improver (C), and the mixing weight ratio of [(A) component + (B) component] :( C) component is 95: 5-70: 30, and the solubility parameter (SP value) of (C) Is a fuel oil low-temperature fluidity improver having a HLB value of 0.5 to 8.7 and a molecular weight of 200 to 700.  The component (B) is an unsaturated carboxylic acid ester adduct of an ethylene-carboxylic acid vinyl ester copolymer (number average molecular weight; 1000 to 10,000, vinyl carboxylate content: 5 to 25% by weight). Improver.  A fuel oil composition comprising 0.002 to 0.50% by weight of the improver according to claim 1 or 2 with respect to a low sulfur fuel oil having a sulfur content of 0.05% by weight or less.