KR950014390B1 - Improved pour point lower and the fuel oil having thereof - Google Patents

Abstract

The pour point depressant having 1000-5000 numerical ave. molecular wt. is composed of 50-90 wt.% ester of C1-24 monoalcohol and C4 ethylene dicarboxylic acid, 5-45 wt.% C3-6 ethylenic unsaturated aliphatic, and 5-45 wt.% C3-24 ethylenic unsaturated ether, The ethylene dicarboxylic acid is pref. fumaric acid, and the ethylenic unsatd. ether is pref. methyl, ethyl, propyl or n-butyl vinyl ether. The fuel oil contains 10-1000ppm pour point depressant, C8-10 aromatic naphtha as an organic solvent, nonyl phenol as an antioxidant, etc.

Description

Improved Pour Point Reducing Agent and Fuel Oils Comprising the Same

The present invention relates to an improved pour point depressant and a fuel oil containing the same, more specifically, an ester of ethylene dicarboxylic acid having 1 to 24 carbon atoms and 4 carbon atoms, and an ethylenically unsaturated aliphatic having 3 to 6 carbon atoms. It is composed of a monoester and a terpolymer of ethylenically unsaturated ether having 3 to 24 carbon atoms, and relates to a pour point lowering agent capable of improving low temperature fluidity by being added to a petroleum spilled fuel at 120 to 500 ° C and a fuel oil including the same. Here, the terpolymer is the same material as the pour point lowering agent of the present invention, hereinafter the terpolymer means the pour point lowering agent of the present invention.

In order to obtain as much fuel oil as possible by fractional distillation from heavy crude oil containing a large amount of high molecular weight paraffin, it is necessary to take the effluent to a high boiling point fraction. As a result, the high molecular weight paraffin content in the effluent fuel oil increased. Such fuel oils are characterized in that fluidity decreases as the temperature of the fuel oil decreases. This is because paraffin crystals precipitate and grow inside the fuel oil to block the filter in the fuel supply pipe and the piping in the diesel engine, thereby preventing the flow of the fuel oil.

In order to solve this problem, various pour point depressants or fluidity enhancers have been described in various literatures and are also sold commercially.

For example, Korean Patent Publication No. 91-4942 (hereinafter referred to as 罕 942 Patent) contains vinyl esters of 32 to 35% by weight and has a number average molecular weight of 1,000 to 6,000 with carboxylic acid of 1 to 4 carbon atoms. Copolymers composed of vinyl esters are described.

U.S. Patent No. 4,7l3,088 (hereinafter '088 Patent) describes a fuel oil having a distillation range of 120 to 500 DEG C to which a copolymer of di-n-alkyl fumarate and vinyl acetate is added.

European Patent No. 360,419 (hereinafter '419 Patent) also discloses homopolymers of alkyl vinyl ethers having 1 to 17 carbon atoms, mixtures of homopolymers, polymers of alkylvinyl ethers of different alkyl chain lengths, one or more alkylvinyl ethers, and Copolymers with polymerizable monomers are described.

However, the '942 patent is widely used to increase the low-temperature fluidity of the intermediate effluent fuel copolymer of ethylene and vinyl ester has a disadvantage that is not effective when the distillation range is narrow.

The '088 patent has a problem that is not effective in lowering the pour point (fuel point) of fuel oil.

In addition, the '419 patent was able to improve the pour point by producing a polymer containing 50 mol% more expensive vinyl ether than vinyl acetate, but there was a problem that is not economical.

In order to solve this problem, the present inventors have conducted extensive research, and have been able to develop a pour point depressant capable of solving the problems shown in the patent, and the present invention has been completed based on the pour point depressant.

Accordingly, an object of the present invention is to provide a pour point lowering agent capable of improving the fluidity of petroleum spilled fuel oil cut at 120 ~ 500 ℃.

Another object of the present invention to provide a fuel oil containing the pour point depressant.

The present invention for achieving the above object is 50 to 90% by weight of esters of monoalcohol having 1 to 24 carbon atoms and dicarboxylic acid having 4 carbon atoms, 5 to 45% by weight of ethylenically unsaturated esters having 3 to 6 carbon atoms and carbon atoms 3 to 24 ethylenically unsaturated ethers of 5 to 45% by weight of a terpolymer.

The terpolymer in the present invention is 50 to 90% by weight, preferably 80 to 90% by weight of an alkyl ester of dicarboxylic acid containing an alkyl group having 1 to 24 carbon atoms, preferably 4 to 18 carbon atoms. %, A vinyl ester containing 5 to 45% by weight, preferably 5 to 15% by weight, and an alkylvinyl ether containing 5 to 45% by weight, preferably 5 to 15% by weight. Especially preferred are tripolymers consisting of 50 mol% di-n-alkyl fumarate, 12.5-37.5 mol% vinyl acetate and 12.5-37.5 mol% n-butyl ether.

The terpolymer used in the present invention has a number average molecular weight in the range of 1,000 to 10,000, preferably 1,000 to 5,000, as measured by gel permeation chromatography.

The alkyl ester of ethylene dicarboxylic acid, which is the first component useful for preparing a preferred terpolymer in the present invention, is represented by the following formula (l).

Herein, when R ₁ is hydrogen, R ₂ is COOR ₄ , when R ₂ is hydrogen, R ₁ is COOR ₄ , and R ₃ or R ₄ is hydrogen or a linear alkyl group having 1 to 24 carbon atoms, which may be the same or different. However, the case where both R ₃ and R ₄ are hydrogen are excluded from the scope of the present invention.

The alkyl ester of ethylene dicarboxylic acid represented by the formula (1) can be prepared by esterifying a specific dicarboxylic acid with a suitable alcohol or alcohol mixture. R ₃ in formula (1) is particularly preferably an alkyl group having ₄ to 18 carbon atoms, which relates to the solubility characteristics of the terpolymer in the fuel.

In addition, the alkyl ester of the dicarboxylic acid represented by the formula (1) may be mono or dialkyl ester, but dialkyl ester is preferred for the purpose of the present invention.

Examples of preferred dicarboxylic acid esters used in the present invention include di-n-butyl fumarate, di-n-hexyl fumarate, di-n-decyl fumarate, di-n-dodecyl fumarate, di-n-tetra Decyl fumarate, di-n-hexadecyl fumarate, di-n-octadecyl fumarate, di-n- tetradecyl fumarate, di-n- tetradecyl maleate, or di-n-hexadecyl maleate, and the like. Can be mentioned. The amount of dialkyl fumarate or dialkyl maleate in the terpolymer is 50 to 90% by weight, preferably 70 to 90% by weight and more preferably 86% by weight.

The dicarboxylic acid ester monomer of the said Formula (1) is various, for example, 5-45 weight% of ethylenically unsaturated aliphatic monoester monomers of following formula (2), and ethylenically unsaturated ether monomers of following formula (3) Tripolymerized by weight.

Wherein R ₅ is hydrogen or a branched or unbranched alkyl group having 1 to 4 carbon atoms, and R ₅ is a branched or unbranched alkyl group having 1 to 22 carbon atoms.

In the present invention, examples of the ester represented by the formula (2) include vinyl acetate, vinyl propionate and isoprenphenyl acetate. The amount of the vinyl ester of the formula (2) present in the terpolymer of the present invention is 5 to 45% by weight, preferably 5 to 15% by weight, more preferably 7% by weight.

In addition, examples of the preferred alkylvinyl ether represented by Formula (3) include methylvinyl ether, ethylvinyl ether, propylvinyl ether or butylvinyl ether. The amount of the alkylvinyl ether of formula (3) present in the terpolymer of the present invention is 5 to 45% by weight, preferably 5 to 15% by weight, more preferably 7% by weight.

The polymerization process used to prepare the pour point depressant of the present invention generally uses a hydrocarbon-based polymerization solvent such as hexane, cyclohexane, n-heptane, n-octane, benzene, toluene or xylene and the like. In addition, the initiator used in the polymerization process may be a compound such as a common peroxide or azobis-iso-butyronitrile such as benzoyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide or cumene peroxide. Can be mentioned. In particular, azobis-iso-butyronitrile is a preferred initiator for preparing a terpolymer having a molecular weight distribution excellent in fluidity improving effect among the initiators. The temperature of the polymerization reaction is in the range of 50 to 150 캜, preferably 60 to 80 캜. The reaction pressure is 1 to 5 atmospheres, preferably at 1 atmosphere. For example, the solvent, initiator, di-n-tetradecyl fumarate, vinyl acetate, and n-butylvinyl ether are obtained by distillation under reduced pressure in an atmospheric pressure reactor.

The monomer content in the terpolymer can be analyzed by measuring infrared spectroscopy, nuclear magnetic resonance apparatus, gel permeation chromatography, saponification value.

In order to achieve the other object of the present invention, the present invention comprises a fuel oil containing about 10 to 1000ppm of the pour point lowering agent of the present invention.

The pour point depressant of the present invention is compatible with other additives and can be easily mixed with petroleum based fuels containing viscosity index enhancers, corrosion inhibitors or antioxidants.

Pour point lowering agent of the present invention may be added to the fuel oil as it is, but may be added in a concentrated form using an inert, stable organic solvent of 80 ~ 400 ℃. As the organic solvent, aromatic naphtha having 8 to 10 carbon atoms is particularly preferable, and in order to increase the long-term storage stability of the concentrate, it is preferable to add an antioxidant such as nonyl phenol and the like.

As described above, the terpolymer is used for petroleum spilled fuel in the boiling range of 120 to 500 ° C., preferably diesel and heating flow, and the appropriate concentration of the terpolymer used to achieve the desired pour point drop effect is used. Although it may vary depending on the type of fuel oil, 10 to 1000 ppm is added to the normal fuel oil, and preferably 100 to 500 ppm is used. At this time, if the 10ppm or less, there is almost no fluidity strengthening effect, if more than 1000ppm the fluidity enhancing effect is rather reduced.

Hereinafter, the configuration and effects of the present invention will be described in detail by way of examples, but the scope of the present invention is not limited to the following examples.

Example 1

5.09 g (50 mol%) of di-n-tedradecyl fumarate, 0.46 ml (25 mol%) of vinyl acetate, 0.65 ml (25 mol%) of n-butylvinyl ether, 17.4 m1 of azobis-iso-butyronitrile A terpolymer 1 having a number average molecular weight of 2,400 (gel permeation chromatography) was obtained by heating under a nitrogen stream of the mixture of to obtain a polymerization reaction at a temperature of 65 to 70 ° C. for 18.5 hours.

Example 2

5.09 g (50 mol%) of di-n-tetradecyl fumarate, 0.69 ml (37.5 mol%) of vinyl acetate, 0.33 ml (12.5 mol%) of n-butylvinyl ether, 98.5 m 1 of azobis-iso-butyronitrile The mixture was prepared in the same manner as the preparation of terpolymer l, terpolymer 2 having a number average molecular weight of 3,000.

Example 3

5.09 g (50 mol%) of di-n-tetradecyl fumarate, 0.23 ml (12.5 mol%) of vinyl acetate, 0.99 ml (37.5 mol%) of n-butylvinyl ether, 98.5 m 1 of azobis-iso-butyronitrile The mixture was prepared in the same manner as the preparation of the terpolymer 1, the terpolymer 3 having a number average molecular weight of 3,500.

Comparative Example 1

US Pat. No. 4,713,088, which is a copolymer of di-n-tetradecyl fumarate-vinyl acetate having a number average molecular weight of 2,600 (hereafter additive A).

Comparative Example 2

It is a copolymer of di-n-tetradecyl fumarate-butylvinyl ether of number average molecular weight 2,000 of European Patent No. 360,419 (hereinafter additive B).

Example 4

The characteristics of the fuel I for sample for testing the low temperature flow performance of the terpolymer and the additive of the comparative example are shown in Table I below.

TABLE 1

The boiling point range of the said fuel I was measured by ASTM D86 method. In addition, the pour point of fuel I was determined by the ASTM D97 method, and the fluid I sample was checked by tilting or inverting the fuel I sample every 2.5 ° C interval. The difference between the pour point of the fuel without additives and the pour point of the same fuel containing the additive was recorded as the pour point drop by the additive. More effective pour point depressants show greater pour point drops with equal concentrations of additives. In addition, wax crystal size at the fast cooling rate of fuel I was measured by cold filter plugging point (CFPP) test. The test was carried out by the process described in "Journal of the Institute of Petroleum", Vol. 52, No. 510, June 1966, pages 173-185.

The oil located in the ASIM C1oud point jar was cooled in a broiler tank maintained at about 130 ^° F. Every 2 degrees drop at temperatures starting from 4 ^o F above the cloud point, the oil was forced into the marked pits at a volume of 20 m1 upon inhalation of 8 inches of water through a filter section equipped with a 350 mesh screen. At this time, the oil flows back to the cooling room by gravity. The test is repeated until the oil fails to fill the pitch within 60 seconds until the above indication. The results of the test are recorded as cold filter plugging points, which is the highest temperature at which the oil will not fill the pipette. The difference between the CFPP of the fuel without additives and the CFPP of the same fuel containing the additive is recorded as the CFPP drop by the additive. More effective rheology modifiers show greater CFPP drops with equal concentrations of additives.

In the present invention, the wax sedimentation test was carried out as follows to determine the effectiveness of another fluidity improver.

500 ml of the fuel oil composition mixed with the additive is immersed in a 45 ° C. thermostat for at least 20 minutes, then taken out, and 45 ml is placed in an ASTM cloud bottle. The prepared sample is slowly cooled at a rate of 1 to 6 ° C. per hour and finally maintained at a temperature of −15 to 20 ° C. for 24 to 48 hours. The size of the sedimentation bed is measured visually by measuring the volume of turbid fuel and as a percentage of the total fuel to obtain the "wax dispersion". Thus, in the case of severe wax settling, small numbers are indicated and 100% represent the fluid phase fuel which has not settled. Care should be taken when the gelled fuel sample is always at a high value due to the large expansion crystals, so these results are reported as "gels". If two wax layers are found, for example, expressed as "95/5". In addition, the cooled sample is left at room temperature, and the size of the crystal is observed in the process of gradually raising the temperature, and classified into "large", "medium", and "small". The time until all the waxes of the sample melt and the fuel becomes a homogeneous solution is recorded and recorded as "wax remelting time".

In Table 2 below, the result of comparing the pour point drop effect of the terpolymer according to the present invention with the additives of Comparative Example 1 and Comparative Example 2 was described.

TABLE 2

As described in Table 2 above, it can be seen that the terpolymers of di-n-tetradecyl fumarate, vinylacetate and n-butylvinyl ether of the present invention are very effective pour point depressants.

Table 3 below shows the effect of increasing the fluidity drop and the wax dispersion when the terpolymer of the present invention and an ethylene-vinyl acetate copolymer, which is a conventional fluidity improver, are added together.

TABLE 3

Additive C Co., Ltd .: AC-430 (product of US-Alide Chemical Co., Ltd., number average molecular weight 3,000, ratio of vinyl acetate to 23-30% by weight) and AC-400 (Product of US-Alide Chemical Co., Ltd.) And a 3: 1 (weight ratio) mixture of the number average molecular weight 6,500 and the ratio of vinyl acetate of 13 weight%).

As shown in Table 3, it can be seen that the core polymer of the present invention is more effective in improving wax dispersion performance than the additive A of Comparative Example 1 and the additive B of Comparative Example 2.

Claims (8)

50 to 90% by weight ester of ethylene dicarboxylic acid having 1 to 24 carbon atoms and 4 to 4 carbon atoms, ethylenically unsaturated aliphatic monoester having 5 to 6 carbon atoms selected from the group consisting of vinyl acetate and vinyl propionate It consists of 45 weight% and 5-45 weight% of ethylenically unsaturated ethers of 3 to 24 carbon atoms, and the number average molecular weight is 1,000 to 10,000, Pour point depressant. The pour point depressant according to claim 1, wherein the ethylene dicarboxylic acid is furic acid. The pour point lowering agent of claim 1, wherein the ethylenically unsaturated aliphatic monoester is vinyl acetate. The pour point lowering agent of claim 1, wherein the ethylenically unsaturated ether is methylvinyl ether, ethylvinyl ether, propylvinyl ether or n-butylvinyl ether. The pour point according to claim 1, wherein the ester of the monoalcohol and the ethylene dicarboxylic acid is 70 to 90% by weight, the ethylenically unsaturated monoester is composed of 5 to 15% by weight and the methylene unsaturated ether to 5 to 5% by weight. Lowering agent. The number according to claim 1, wherein the ethylene dicarboxylic acid is fumaric acid, the ethylenically unsaturated aliphatic monoester is vinyl acetate, and the ethylenically unsaturated ether is methylvinyl ether, ethylvinyl ether, propylvinyl ether or n-butylvinyl ether. Pour point depressant, characterized in that the average molecular weight is 1,000 to 5,000. A fuel oil comprising 10 to 1,000 ppm of the fluid lowering agent of claim 1. 8. The fuel oil according to claim 7, comprising 100 to 500 ppm of the fluid lowering agent.