JPH0252679B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a petroleum middle distillate fuel oil composition with improved cold flow properties that includes a novel fuel oil cold flow property improver. Low-temperature flow characteristics are important when using petroleum middle distillate fuel oils such as diesel fuel oil and A heavy oil in cold regions. In other words, when these fuel oils are used at low temperatures in cold regions, waxy substances precipitate and become semi-solid or gel-like, causing problems such as clogging of oil pipes and stopping the supply of fuel to internal combustion engines. arise. When a filter is installed in a pipeline, the filter is clogged with precipitated waxy substances, so the low-temperature fluidity of the fuel oil becomes even more important. In recent years, as the composition of crude oil has become heavier and the demand for light oil and kerosene has increased, the wax content in middle distillate fuel oil has increased, causing the above-mentioned problems to occur more frequently. I'm getting angry. Therefore, in order to improve the low temperature flow properties of petroleum middle distillate fuel oil and solve the above-mentioned problems, low temperature flow property improvers are being used. These additives have the function of improving the low-temperature flow characteristics of fuel oil by changing the size, shape, surface condition, etc. of wax crystals in fuel oil at low temperatures. Known cold flow property improvers commonly used to date include alkylnaphthalene polymers, polyacrylate derivatives, ethylene-vinyl acetate copolymers, chlorinated polyethylenes, alkenylsuccinic acid amides or imides, and mixtures thereof. There is.
In particular, as prior art related to the present invention,
No. 50-15005 and Japanese Unexamined Patent Publication No. 155204/1984 are known. In other words, in the former case, α- with carbon number 20 or more
A hydrocarbon fuel or hydrocarbon oil composition comprising a compound obtained by esterifying a copolymer of an olefin and an ethylenically unsaturated dicarboxylic acid with an alcohol having 16 or more carbon atoms is described. In the latter,
A distillate fluidity improver composition such as a compound obtained by esterifying a copolymer of an α-olefin having 8 to 32 carbon atoms and an ethylenically unsaturated dicarboxylic acid with an alcohol having 1 to 3 carbon atoms, and chlorinated polyethylene. and
A combination of polar compounds represented by RX is described. While searching for a low-temperature fluidity improver for the purpose of improving the low-temperature fluidity properties of fuel oil as described above, the present inventors esterified a copolymer of olefin and maleic anhydride with a long-chain alcohol. In the resulting esterified product, a compound or composition with a specific ratio of monoester moieties and diester moieties,
We discovered that excellent low-temperature flow properties can be obtained.
The present invention has now been completed. That is, the petroleum middle distillate fuel oil composition of the present invention has a C ₈ to C ₁₉ α-
Olefin/maleic anhydride copolymer from _C16 to _C30
The molar ratio (m/n) of the following repeating structural units A and B contained in the esterified product obtained by esterification with a linear alcohol or a mixture thereof is
0.25 to 4 cold flow property improver to 0.001 to 5
% by weight. (Here, m and n are integers, and R ₁ , R ₂ , R ₄
or R ₅ is hydrogen or an alkyl group, R ₃ ,
(R ₆ or R ₇ are the same or different alkyl groups) Single monoester and diester of the olefin/maleic anhydride copolymer constituting the low temperature flow property improver according to the present invention, that is, the above repeating structural unit A It is said that copolymer esterified products having only B or copolymer esterified products having only repeating structural unit B have no ability to improve the low temperature fluidity properties of fuel oil (for example, Japanese Patent Publication No. 50-15005 See Example 3).
Furthermore, in JP-A-54-155204, considering that these monoesterified products or diesterized products exhibit their improvement ability only when used in combination with other additives, it is said that these monoesterified products or diesterized products have no ability to improve low-temperature flow characteristics. Furthermore, it was completely unexpected that a composition prepared by mixing two structurally similar compounds at a certain ratio would have the ability to improve low-temperature flow characteristics. It was also found that the fuel oil containing the additive according to the present invention has excellent low-temperature storage stability and excellent separability of mixed water such as seawater. What is petroleum middle distillate fuel oil used in the present invention?
A wax-containing distillate fuel oil having a boiling point in the range from 120 to 500°C, such as diesel fuel oil or light heating oil. Next, a method for producing the copolymer and its derivative used in the present invention will be explained. First, a copolymer of olefin and maleic anhydride is produced. Ethylene, propylene, etc. are also used as olefins, but preferred olefins are C8-C19
Among these olefins, α-olefin is more preferable. Among these C8 to C19 α-olefins such as octene-1, decene-1 and hexadecene-1, C10 to C18 olefins are more preferred. Although these olefins may be used alone, it is preferable to use a mixed olefin because of its excellent solubility in fuel oil and low cost. In the present invention, as described above, α-olefin is preferred as the olefin. Therefore, in the following explanation, the copolymer of α-olefin and maleic anhydride will be described as an example, but the copolymer of α-olefin and maleic anhydride can be obtained by a conventional method. In other words, the reaction temperature can be controlled without a catalyst or with a radical initiator such as activated clay, acid clay, Lewis acid such as aluminum chloride, silica/alumina solid acid, azo compound, hydroperoxide, etc.
A copolymer can be obtained by copolymerizing these monomers at 50 to 250°C in the presence or absence of a solvent. Suitable solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and trimethylbenzene, and aliphatic ketones such as acetone, methyl ethyl ketone, and diethyl ketone.
Any solvent may be used as long as it dissolves these monomers and/or the produced copolymer and does not participate in the reaction. The molar ratio of α-olefin and maleic anhydride used in the reaction is 1:0.5 to 1:2, preferably 1:0.6 to 1:1.5. The molecular weight of the copolymer thus obtained depends on the reaction temperature, amount of solvent used,
Although it can be controlled by the amount of catalyst used,
The copolymer of the present invention has an average molecular weight of 500 to
50,000, more preferably between 800 and 5,000. In the present invention, an esterified product obtained by esterifying the above-obtained copolymer with a long-chain alcohol is used. The long chain alcohol used is
It is a C16-C30, preferably C18-C28 linear primary alcohol. Also, although single alcohol may be used, it is better to use mixed alcohol because it is cheaper. The types of esterified products obtained are three types represented by the repeating structural units of the following formulas () to (). (However, R1 and R2 are hydrogen or an alkyl group, and R3 or R4 are the same or different alkyl groups. Also, p, q, r, and s are integers.) That is, a monoester of maleic acid as a structural unit. The esterified product of formula () is a mixture of diester and diester, and the esterified product of formula () is a diester and a monoester is the esterified product of formula (). The low-temperature fluidity improver used in the present invention may be the esterified product of the formula () alone, or a mixture of the diester of the formula () and the monoester of the formula (). The ratio (m/n) of the repeating structural units represented by (A) and (B) contained in the flow property improver is 0.25 to 4.
It is important that the value be within the range of . In addition, to adjust the m/n ratio by mixing, ()
A monoester and/or diester may be mixed with the esterified product of the formula. Here, as a method for producing the esterified product of the above formula (), the copolymer obtained as described above and 1.2 to 1.8 moles of linear primary alcohol based on the maleic anhydride group are mixed together. The reaction is carried out in a solvent or an inert solvent without a catalyst or with an acid or alkali catalyst at a reaction temperature of 90 to 200°C. At this time, it is preferable to carry out the reaction while removing generated water. As the acid catalyst, sulfuric acid, p-toluenesulfonic acid, etc. are used, and as the alkali catalyst, sodium hydroxide, potassium hydroxide, etc. are used. Furthermore, when a solvent is used, it is preferable from an economic point of view to use the solvent used in the copolymerization reaction as is. The esterified product thus obtained is found to have an m/n ratio of 0.25 to 4 by measurement of its infrared absorption spectrum and acid value. In addition, the diester of the formula () and ()
The monoester of the formula is a linear primary alcohol with a ratio of 0.8 to the maleic anhydride group in the copolymer, respectively.
It can be obtained by adding ~1.1 mol or 1.8 to 2.1 mol and carrying out an esterification reaction. The conditions for the esterification product reaction can be the same as those for the production of esterification of formula (). The monoesters and diesters obtained in this way were measured for external absorption spectra and acid values, and the m/n ratio contained in the low temperature fluidity improver was determined to be 0.25 to 4.
The low temperature fluidity improver according to the present invention can be obtained by mixing them so that the following is achieved. The thus obtained low-temperature fluidity improver is preferably 0.01 to 5% by weight based on the fuel oil.
By adding 1% by weight, the low temperature flow characteristics of petroleum middle distillate fuel oil can be significantly improved. At this time, other known low-temperature flow characteristic improvers and known additives, such as antioxidants, combustion improvers, water separating agents, pour point depressants, etc., may also be used. In addition, when adding the low-temperature fluidity improver used in the present invention to fuel oil, it is necessary to use a diluting solvent,
For example, it can be dissolved in kerosene, light lubricating base material, heavy aromatic naphtha, etc. and then mixed into the fuel oil. In the present invention, the α-olefin, the carbon number of the alcohol, the molecular weight of the copolymer, and the monoester and diester of maleic anhydride groups are adjusted depending on the paraffin content in the fuel oil to be added and its carbon number distribution. By appropriately changing the ratio etc., an excellent effect of improving low temperature flow characteristics can be obtained. Cloud point and pour point are conventionally known methods for evaluating the low-temperature fluidity of petroleum middle distillate fuel oil, but low-temperature fluidity characteristics such as filter clogging as mentioned above cannot be evaluated using these methods. It is not possible to accurately understand the law alone, and for this reason, in recent years CFPPDIN
An evaluation method called -51428 was developed in Europe and is becoming widely used. This test method requires a 45ml sample of the oil to be tested.
This is done by cooling the liquid in a bath maintained at -34°C. Starting from a temperature 5°C higher than the cloud point, oil is sucked up through a 45μ screen under a reduced pressure of 200mmH ₂ O every time the temperature drops by 1°C, and the time until the amount of sucked up reaches 20ml is measured. this time
If it takes less than 60 seconds, return the sample to the sample chamber and repeat the same operation. Measure the temperature of the sample when the suction time is 60 seconds or more, and
(°C). Production examples and examples of the present invention are shown below. Production Example 1 250 g of C16-18 α-olefin (manufactured by Mitsubishi Kasei Co., Ltd., Dialene 168), 103 g of maleic anhydride, and 250 g of xylene were placed in a flask equipped with a condenser, thermometer, and stirrer, maintained at 130°C, and stirred vigorously. . Initiator tertiarybutyl-cumyl-peroxide (manufactured by NOF Corporation, Perbutyl C)
0.5g was gradually added and reacted for 3 hours. After the reaction was completed, xylene, unreacted α-olefin, and unreacted maleic anhydride were removed by vacuum distillation to obtain 331 g of a copolymer. The number average molecular weight of this copolymer (gel permeation method, hereinafter the same) is 5000,
The acid value was 172. Production Example 2 280 g of Decene-1, 215 g of maleic anhydride, and 500 g of Hysol #150 (manufactured by Nippon Petrochemical Co., Ltd., C10 aromatic solvent) were placed in a flask equipped with a condenser, thermometer, and stirrer, maintained at 150°C, and stirred vigorously. . 0.5 g of initiator ditertiary butyl peroxide (Perbutyl D, manufactured by NOF Corporation) was gradually added, and the mixture was reacted for 10 hours. After the reaction was completed, unreacted decene-1 and unreacted maleic anhydride were removed by vacuum distillation to obtain 447 g of a copolymer. This copolymer had a number average molecular weight of 3,500 and an acid value of 228. Production Example 3 50 g of the copolymer obtained in Production Example 1 (0.15 mol of maleic acid group), 60 g of stearyl alcohol (manufactured by Kao Soap Co., Ltd., Calcol 86), 73 g of xylene, and 1 g of p-toluenesulfonic acid as a catalyst were added to a condenser, A flask equipped with a thermometer and a stirrer was placed and the reaction was continued at 130°C for 24 hours while removing water.
After the reaction was completed, p-toluenesulfonic acid was removed with an aqueous solution of NaHCO ₃ and xylene was removed by distillation under reduced pressure to obtain 105 g of an esterified copolymer. According to infrared absorption spectrum, esterification had progressed completely and the acid value was 40. This shows that the ratio of monoester to diester maleic acid groups in the esterified product is 1. Production Example 4 50g of copolymer obtained in Production Example 2 (0.2 mol of maleic acid group) behenyl alcohol (C16 14%, C8
25%, C20 31%, C22 30%) 80g, xylene 150
g, further p-toluenesulfonic acid 1 as a catalyst
g was placed in a flask equipped with a condenser, a thermometer, and a stirrer, and the reaction was continued at 130°C for 20 hours while removing water. After the reaction was completed, the catalyst was removed by washing with an aqueous NaHCO ₃ solution, and then xylene was removed by distillation under reduced pressure to obtain 128 g of an esterified product. According to the infrared absorption spectrum, the ester had completely progressed, and its acid value was 58. This means that the ratio of maleic acid group monoester to diester in the esterified product is 2.3.
It means that. Production Example 5 50 g of the copolymer obtained in Production Example 1 (0.15 mol of maleic acid group), 40 g of stearyl alcohol (Calcol 86, manufactured by Kao Soap Co., Ltd.), 60 g of xylene, p
- Pour 1.4 g of toluenesulfonic acid into a flask equipped with a condenser, thermometer, and stirrer and heat at 130℃ for 15 minutes.
Time reacted. After the reaction was completed, the catalyst was removed by washing with an aqueous NaHCO ₃ solution, and then xylene was removed by distillation under reduced pressure to obtain 88 g of an esterified product. From the infrared absorption spectrum and oxidation of 96, it was confirmed that it was monoesterified. Production Example 6 50 g of the copolymer obtained in Production Example 1 (0.15 mol of maleic acid group), 85 g of stearyl alcohol (Calcol 86, manufactured by Kao Soap Co., Ltd.), 150 g of xylene, p
- Pour 1.5 g of toluenesulfonic acid into a flask equipped with a condenser, thermometer, and stirrer and heat at 130℃ for 15 minutes.
Time reacted. After the reaction was completed, the catalyst was removed by washing with an aqueous NaHCO ₃ solution, and then xylene was removed by distillation under reduced pressure to obtain 132 g of an esterified product. When the acid value of this product was measured, it was approximately 0, confirming that it was a diester. Production Example 7 An esterified product was obtained in the same manner as Production Example 4 except that the amount of behenyl alcohol charged was 120 g. The acid value of this esterified product was approximately 0, and a diesterified product was obtained. Example In this example, the additives produced in Production Examples 3 to 7 and their mixtures were evaluated for improving the fluidity of petroleum middle distillate fuel oil. Evaluation was performed by pour point and CFPP. The following two types of fuel oil were used. Oil A: 10% boiling point 237°C, 90% boiling point 389°C, dry point 450°C; Oil B: 10% boiling point 253°C, 90% boiling point 348°C, dry point 383°C. The results are shown in Table 1.

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Claims (1)

[Claims] 1. α- of C ₈ to C ₁₉ having an average molecular weight of 500 to 50,000.
Olefin/maleic anhydride copolymer from _C16 to _C30
The molar ratio (m/n) of the following repeating structural units A and B contained in the esterified product obtained by esterification with a linear alcohol or a mixture thereof is
0.25 to 4 cold flow property improver to 0.001 to 5
% by weight of a petroleum middle distillate fuel oil composition. (Here, m and n are integers, and R ₁ , R ₂ , R ₄
or R ₅ is hydrogen or an alkyl group, R ₃ ,
R ₆ or R ₇ are the same or different alkyl groups)