JPH01103698A - Fuel oil composition - Google Patents

Abstract

PURPOSE:To obtain a fuel oil compsn. having excellent low-temp. fluidity, by adding a particular ethylene-satd. carboxylic acid vinyl ester to a fuel base oil. CONSTITUTION:A fuel base oil (A) (e.g., light gas oil) comprising medium and/or heavy fractions of oil mainly composed of hydrocarbons having a b.p. of 150-450 deg.C and having a 25C or higher n-paraffin content of 0.1-0.6wt.% and a content of wax precipitated at a temp. by 10 deg.C lower than the clouding temp. of less than 4wt.% is mixed with 30-1,500ppm of an ethylene-satd. carboxylic acid vinyl ester copolymer (B) (e.g., ethylene-vinyl acetate copolymer) having an ethylene content of 60-80% and a number-average MW of 1,000-5,000.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fuel oil composition with good low-temperature fluidity prepared from a heavy fraction of petroleum and a low-temperature fluidity improver.

As is well known, among the fractions obtained by distilling crude oil, those with a boiling point of approximately 150 to 450°C, called medium and heavy fractions, are used as various fuel sources such as melt oil, light oil, and Affi oil. Used in large quantities.

Among these, especially light oil and oil oil, under low temperatures such as winter IU, due to precipitation of wax contained in the oil, fluidity may be significantly deteriorated and serious problems may occur.

For example, due to the precipitation of wax contained in diesel fuel under cold conditions in winter, it is installed in a filter to prevent contaminants installed in the line that supplies diesel fuel from the diesel fuel tank to the engine. There are cases where the fine screens clogged, making it impossible to supply light oil and causing the engine to stop, and cases where the entire light oil turns into a gelatinous state and loses fluidity at extremely low temperatures.

Similarly, in the case of heavy oil used to drive the engines of fishing boats, heating machines for greenhouse cultivation, heating of buildings, etc., poor combustion can occur due to wax precipitation, which can have a serious impact on human life and plants. .

[Conventional technology]

Conventionally, various measures have been taken to maintain the fluidity of fuel oil at low temperatures.

For example, there are methods such as heating the fuel oil with hot water or an electric heater to keep it warm so that the drop in temperature does not directly cause a drop in the temperature of the fuel oil, but this requires equipment improvements and new energy costs. It is hard to say that this is an advantageous method.

It also has excellent cold fluidity even at relatively low temperatures.
For example, there is a method of diluting with kerosene distillate to reduce the amount of wax deposited, but this is not the preferred method because relatively light fuel oil such as kerosene distillate is in high demand and has high added value. hard.

Another known method for improving the low-temperature fluidity of fuel oil is to add a low-temperature fluidity improver.

The action of the low-temperature fluidity improver is to affect the precipitation of wax from fuel oil, to prevent the wax from growing to a gigantic size, and to stabilize it with microcrystals.

Various chemically synthesized products have been proposed as low-temperature fluidity improvers, but their effectiveness varies dramatically depending on the properties of the target fuel oil, and there has been an urgent need to understand the properties of fuel oil to ensure stable quality control. This was extremely difficult due to factors such as the large number of types of crude oil and the complicated operating conditions of the distillation equipment.

In order to effectively express the effect of adding a low-temperature fluidity improver, several studies have been made on the properties of target fuel oil.

For example, in JP-A-58-134188 @, low-temperature It improves fluidity.

However, this method requires the addition of both ethylene copolymer and n-paraffin to the fuel oil, which not only complicates the equipment and operations, but also causes the deterioration of low-temperature fluidity due to wax precipitation. Since n-paraffin is actively added, the amount of wax precipitated at low temperatures increases. As a result, the fluidity improver often does not work effectively.

When used as day-sale automobile fuel, which is a typical application, a strainer is installed in the middle of the fuel supply line, but due to the large amount of wax deposited, the wax saturation time in the strainer is shortened, and the strainer is quickly drained. This method is not preferred as it may cause occlusion.

Furthermore, JP-A No. 61-58116 discloses a composition using a pour point depressant in a gas oil whose amount of paraffin wax precipitated at -20 DEG C. is adjusted to 5.5 to 12%.

However, even for light oils in which the amount of paraffin wax that precipitates at -20'C is specified to be in the range of 5.5 to 12% by weight, the CFPP (cold filtration plugging temperature) may not be lowered at all by the addition of pour point depressants; In some cases, only a specific type of pour point depressant can lower the pour point, so it cannot be said to be sufficient.

(Problem to be Solved by the Invention 9) As mentioned above, in the conventional technology, there are additives that can only improve low-temperature fluidity for fuel oils with specific properties,
Furthermore, in order to facilitate the expression of the effects of additives, it is necessary to add a large amount of specific substances other than additives, making it extremely difficult to provide fuel oil with stably improved low-temperature fluidity.

An object of the present invention is to provide a fuel oil with improved low-temperature fluidity that uses medium and/or heavy distillate oil of crude oil as a base oil in a large proportion. The aim is to optimize the amount of n-paraffin contained in the medium and/or heavy distillate of crude oil so that the effect of the property improver can be fully exhibited.

(Means for Solving the Problems) The present inventors have made extensive studies to solve the problems, and as a result, have arrived at the present invention.

That is, the present invention comprises: 1) consisting of a large proportion of medium and/or heavy distillate oil of petroleum, containing 0.1% by weight or more and less than 0.6% by weight of "]-paraffins having 25 or more carbon atoms; and 10' from the cloud point
C. A vinyl ester of ethylene and a saturated carboxylic acid with an ethylene content of 60 to 80% by weight and a number average molecular xi of ooo to 5,000 is added to a fuel base oil in which the amount of wax precipitated at low temperatures is less than 4% by weight. 2) a fuel oil composition containing 30 to 1.500 ppm of a copolymer of 2) 0.2% by weight or more of n-paraffin having 25 or more carbon atoms contained in the fuel base oil; 3) The fuel oil composition of 1) above, wherein the vinyl ester of a saturated carboxylic acid is vinyl acetate; 4) A copolymer of ethylene and vinyl acetate. has an ethylene content of 60 to 75% by weight, a number average molecular weight of 1.000 to 4,000, and a molecular weight of 1 minute.54. The following describes the fuel oil composition of 4) above, which has 6 or less methyl-terminated side chains per 100 methylene groups in the main chain in addition to the methyl groups of the acetyl group.

The medium and/or heavy distillate oil of petroleum used as a large proportion of the base oil in the present invention is a distillate oil obtained by distilling crude oil, and has a boiling point in the range of about 150 to 450°C. It is a mixture of many components, mainly hydrocarbons.

Fractions obtained from general petroleum distillation equipment include light nose oil obtained from atmospheric distillation equipment, l\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ gas oil / \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ gas oil, ``, or these are removed by dehydration such as a unifier.
There are vacuum gas oils obtained by hydrogenation in Unit A, vacuum distillation of residual oil from lδ pressure distillation unit under reduced pressure in vacuum distillation equipment, and hydrogenated products thereof, and these may be blended as appropriate depending on the purpose. There is also.

If necessary, a small amount of heavy oil generated from petroleum refining equipment, such as oil processed in catalytic cracking equipment or hydrocracking equipment, or residual oil dewaxed during lubricating oil production, may be mixed. No problem.

Furthermore, a small amount of atmospheric residual oil or vacuum residual oil, which is commonly used as a method for preparing heavy oil, or extract oil produced in a lubricating oil refining process may be mixed.

In the present invention, the amount of n-paraffins having 25 or more carbon atoms contained in the medium and/or heavy distillate of petroleum as the base oil is analyzed by a conventional method using a temperature-programmed gas chromatograph. It is something.

That is, using a column packed with a packing material consisting of a weakly polar distributing agent and a porous carrier, a trace amount of sample is analyzed using a flame ionization detector, and n-paraffin is determined from the chromatogram of each separated component. This is to find the content.

For example, a column packing material (silicon GE 5E-30.2%, 80/80 mesh, Uniport HP carrier) commercially available from Wako Tsumugi Pharmaceutical Co., Ltd. was made of stainless steel, 3 m in diameter, and 4000 mm in length. Sample oil was injected using a column packed in a tube, and the sample oil was injected at a rate of 5°C/min from 70°C for 2 hours.
The temperature is raised to 70'C and detection is performed using a hydrogen flame ionization method.

The detected electrical signal is processed as an external output by a recorder or a data processor, and the n-paraffin peak is obtained.

In the present invention, the amount of n-paraffins having 25 or more carbon atoms contained in the medium and/or heavy distillate of petroleum, which is the base oil, is 0.1% by weight or more and less than 0.6% by weight. A range is preferred.

If the amount of n-paraffin having a carbon number of 25 or more is less than 0.1% by weight, the effect of improving the low-temperature filtration clogging temperature by the low-temperature fluidity improver will be poor, and if it is more than 0.6%, the amount will be extremely large. For example, it may be possible to improve the clogging temperature of low-temperature filtration by adding 2,000 ppm or more of a low-temperature fluidity improver, but this increases the total amount of precipitated wax, resulting in a fuel oil that cannot be put to practical use. There are many.

The preferred amount of n-paraffin having 25 or more carbon atoms is 0.2% by weight or more and less than 0.5% by weight to further exhibit the effect of adding the low-temperature fluidity improver.

Within this range, the low temperature filtration clogging temperature can be sufficiently lowered by adding a relatively small amount of the low temperature fluidity improver.

As an example of the low-temperature fluidity improver used in the present invention, the substances described on pages 192 to 195 of "New Edition Petroleum Product Additives" (edited and written by Toshio Sakurai, published by Koshobo in July 1986) may be referred to. However, more specifically, the
No. 3165, Special Publication No. 33480, Special Publication No. 1983-
Examples include ethylene copolymers disclosed in JP-A-59-136391 and the like.

Examples of ethylene copolymers include those using one or more vinyl esters of saturated fatty acids such as vinyl acetate, vinyl propionate, and vinyl acetate as comonomers, and these can be used as high molecular weight ethylene copolymers. It may also be a low-molecular-weight product that is produced and decomposed by oxygen, peroxide, heat, or the like.

Especially in ethylene copolymers, the ethylene content is 6
Those having a number average molecular weight of 0 to 80% by weight and a number average molecular weight of 1,000 to 5,000 as measured by vapor pressure equilibrium method are preferred.

Ethylene content is less than 60% by weight or 80% by weight or more, number average molecular weight is less than 1,000 or s, ooo
If it is more than that, the effect of improving the clogging temperature of the low-temperature filtration becomes somewhat poor, and a large amount of addition is required, so it cannot be said that it is economically advantageous.

One type of ethylene copolymer may be used, or a mixture of two or more types may be used. Although it is possible to mix and dissolve the ethylene copolymer in fuel oil as it is, industrially it is convenient to dissolve it in a hydrocarbon solvent and use it as a 10 to 90% by weight solution.

Among the above-mentioned ethylene copolymers, ethylene-
Particularly preferred are vinyl acetate copolymers.

It is roughly preferred that the ethylene-vinyl acetate copolymer has an ethylene content of 60 to 75% by weight, a number average molecular weight of 1000 to 4000, a molecular weight distribution of 4.0 or less, and acetyl groups other than methyl groups. It has 6 or less methyl-terminated side chains per 100 methylene groups in the main chain, and can further reduce the clogging temperature of low-temperature filtration.

The molecular weight distribution was determined by gel permeation chromatography (G
PC) method [“Polymer measurement methods, structure and physical properties (Part 1)” edited by the Society of Polymer Science and Technology, published by Baifukan in 1972.

The method described on pages 76 to 89 serves as a reference. ] is determined from the ratio of weight average molecular weight (Mw)/number average molecular Li (Mn) in terms of standard polystyrene.

Roughly speaking, in the present invention, the degree of branching is expressed as "the number of methyl terminal side chains per 100 methylene groups in the main chain other than the methyl group of the acetoxy group", and is expressed by the nuclear magnetic resonance (1HNMR) method ("Journal of the Chemical Society of Japan J 1980 .

The method described in No. 1, Nos. 74 to 78 may serve as a reference. )
It is calculated using the result obtained by .

That is, it is calculated by determining the peak ratio based on methyl groups and methylene groups in the proton nuclear magnetic resonance spectrum, and using the vinyl acetate content determined by the saponification method and the number average molecular weight determined by the vapor pressure osmotic pressure method. It is. Note that both ends of the main chain methylene group are methyl groups, and all side chains are ethyl groups, and the value is determined by subtracting the terminal methyl groups.

The amount of the low temperature fluidity improver used in the present invention is preferably in the range of 30 to 1,500 ppm by weight, more preferably 50 to 1,500 ppm, based on the base oil consisting of medium and/or heavy fractions of petroleum. It is in the range of 1,000 ppm.

If the amount added is less than 30 ppm, almost no reduction in the clogging temperature of the low-temperature filtration can be expected, and the amount added is less than 1.5001) l.
) m is not preferable because it is economically disadvantageous compared to the effect obtained.

The fuel oil composition according to the present invention may contain a rust inhibitor, an antioxidant, an antistatic agent, a cetane number improver, an anticorrosion agent, or the like.

[Examples] Hereinafter, the fuel oil composition of the present invention will be specifically explained using Examples, but the present invention is not limited by these descriptions.

The various analyzes and measurements of the sample oil used were performed using the following methods.

■Specific gravity JIS K2249 (198
6 years) ■Kinematic viscosity JIS K2283 (
1986) ■ Distillation test JIS K2254
(1986) ■Cloud point JIS K2
269 (1986)■Pour point JIS
K2269 (1986) ■CFPP (cold filtration clogging temperature) CO shown in IP-309 (1976 UK)! dFilter Plugging P
Measured using an automatic low-temperature filtration clogging point tester [Furukawa Kagaku Kiki (Model 111A4F2)] manufactured in accordance with o1nt of DistillateFLIelS ■Amount of wax precipitation sample oil 5 (L) Sex improver “Stabinol (registered trademark) Fl-18J
Dissolve 200 ppm of the solution in a 100ml graduated cylinder and heat at a rate of 1°C/hr from the lowest temperature to -5°C1-10'C.
Cool to 1 or 10'C below cloud point. The oil content other than the wax content precipitated from the cooled sample oil was discharged under reduced pressure through a filter fitting equipped with a 5 μm membrane filter, and 50 d of cold ethanol/ethyl ether (2/1 volume ratio) was added to the remaining wax content. After stirring gently, the oil is again discharged under reduced pressure.

Furthermore, 50 d of cold methanol was added to the remaining wax, the entire amount was poured into a 11G4 glass filter, the oil was discharged under reduced pressure, the wax remaining in the glass filter was air-dried for a day and night, and the weight of the wax was measured to determine the amount of wax precipitated. shall be.

(2) Contains n-paraffin The n-paraffin content in the sample oil was determined using a gas chromatograph GC-9A model manufactured by Shimadzu Corporation and a Chromatopack C-R2AX data processor.

Note that n-triacontane was used as an internal standard substance for quantitative determination. The main operating conditions are shown below.

Column: Stainless steel inner diameter 3#.

Length 4m Column packing material: Silicone GE 5E-30゜2% manufactured by Wako Tsumugi ■, 60/80 mesh (Uniport HP carrier) Injection temperature: 270℃ Carrier gas: Helium Detector: Flame ionization (FID) column Temperature increase rate: 5°C/m1n (70→270°C) Example 1 Diesel light oil sample N whose properties are shown in Tables 1 and 2
CFPP was measured by adding 500 ppm of a low-temperature fluidity improver containing various low-temperature fluidity improving substances shown in Table 3 as a 50% by weight solution in xylene to Nos. o, 1 to No. 4.

Table 3 shows the results of examining the effectiveness of the effect based on the temperature drop from CFPP of the sample oil itself (ΔCFPP).

Table 1 * CP-10°C; 2nd temperature 10°C lower than cloud point
Table: N-paraffin content (unit: wt%) Table 3
:ΔCPPP (unit: °C) *VA-Vinyl acetate **Mn-Number average molecular weight table The molecular weight distribution of No. 1 substance is 2.2. The number of methyl terminal side chains is 3.6/100 methylene number 2 substances.
2.8. /I 7.2 No. 3 substances
u 4,4. // 3,1
1 number 4 substances n 2.4. 〃
5.9 Example 2 The diesel gas oil samples Nα5 and Nα9 shown in Tables 4 and 5 were mixed in a volume ratio of 75/25 (sample N06), 50
150 (sample Nα7) and 25/75 (sample N08). The properties of the mixed sample oils are also shown in Tables 4 and 5.

A 60% by weight xylene solution of an ethylene-vinyl acetate copolymer (additive A ) to 300 or 500 ppm
and CFPP was measured.

Table 6 and FIG. 2 show the results of examining the effectiveness of the effect based on the temperature drop (ΔCFPP) from the sample oil itself.

Table 4 Table 5: N-paraffin content (unit: wt%) *N
A gas chromatogram of sample oil No. 05 is shown in FIG.

Table 6: ΔCFPP (unit: °C) Example 3 The additive A used in Example 2 was added to the fuel oil sample shown in Table 7.
was added at 500 ppm, and CFPP was measured.

Temperature drop from CFPP of sample oil itself (ΔCFPP)
The results of examining the effectiveness of the effects are listed in Table 7 and shown in Figure 2.

For comparison, the results using Additive B and Additive C are also listed in Table 7, and are shown in FIGS. 3 and 4, respectively.

[Effect of the invention 1] As is clear from the above examples, the content of r)-paraffins having 25 or more carbon atoms is less than 0.1% or 0.
．． 4 small amounts of wax that contains more than 6% by weight and precipitates at a temperature 10°C lower than the cloud point? For sample oils with a
Whether it was possible to obtain a reduction in FPP or not, the n-paraffin content was 0.1% by weight or more and less than 0.6% by weight, and the amount of wax that precipitated at a temperature close to 10'C above the cloud point was For sample oils with a concentration of less than 4% by weight, the reduction was possible, and in particular, a remarkable effect was obtained for sample oils with a concentration of 2% by weight or more and less than 0.5% by weight.

Furthermore, when an ethylene-vinyl acetate copolymer having an ethylene content of 0 to 60 to 75% by weight and a number average molecular weight of 1 to 4000 is used as a low-temperature fluidity improver, the CFPP is significantly lowered. (1+4
, 0 or less, and 6 methyl-terminated side chains/100 methylene or less, more remarkable effects were obtained.

[Brief explanation of the drawing]

FIG. 1 is a gas chromatogram of sample oil No. 5 obtained by the gas chromatography n-paraffin analysis method shown in the example, and the portion calculated as n-paraffin is shown with diagonal lines. Figure 2 shows the content of n-paraffins having 25 or more carbon atoms in various sample oils and the xylene 60% solution of ethylene-vinyl acetate copolymer with a vinyl acetate content of 36.5% and a number average molecular weight of 11,690. Decrease temperature of low temperature filtration clogging temperature (ΔCFPP) when adding 500 ppm (to additive)
). Figure 3 shows the content of n-paraffins having 25 or more carbon atoms in each sample oil, the content of fi 16.5% by weight containing vinyl acetate, and the addition of a 60% by weight xylene solution of ethylene-vinyl acetate copolymer with a number average molecular weight of 12,200. Agent B) The temperature at which the low-temperature filtration clogging temperature drops when 500 ppm is added (ΔCFPP
). Figure 4 shows the content of n-paraffins having 25 or more carbon atoms in each sample oil, the content of n-paraffins with a carbon number of 25 or more, and the xylene 60fflffi% solution of edylene-vinyl acetate copolymer with a vinyl acetate content of 44.6% by weight and a number average molecular fit of 1820 (additives). C) 500p
Decreasing temperature of low temperature filtration clogging temperature when pm is added (
ΔCFPP). Patent applicant Sumitomo Chemical Co., Ltd.

Claims (1)

[Claims] 1) Consisting of a large proportion of medium and/or heavy distillate oil of petroleum, containing 0.1% by weight of n-paraffin having 25 or more carbon atoms;
The fuel base oil contains less than 0.6% by weight and the amount of wax that precipitates at a temperature 10°C lower than the cloud point is less than 4% by weight, and the ethylene content is 60 to 80% by weight.
, a copolymer of ethylene and vinyl ester of saturated carboxylic acid with a number average molecular weight of 1,000 to 5,000.
A fuel oil composition characterized in that the fuel oil composition is added in an amount of 1 to 1,500 ppm. 2) The fuel oil composition according to claim 1, wherein the fuel base oil contains 0.2% by weight or more and less than 0.5% by weight of n-paraffins having 25 or more carbon atoms. 3) The fuel oil composition according to claim 1, wherein the vinyl ester of a saturated carboxylic acid is vinyl acetate. 4) The copolymer of ethylene and vinyl acetate has an ethylene content of 60 to 75% by weight, a number average molecular weight of 1,000 to 4,000, and a copolymer of 6 or less per 100 methylene groups in the main chain other than the methyl group of the acetyl group. The fuel oil composition of claim 3 having methyl-terminated side chains.