JPS60260691A - Dehydrating agent for diesel gas oil - Google Patents

Abstract

PURPOSE:The titled dehydrating agent excellent in dehydration and metal corrosion prevention effects and not reducing the flash point of diesel gas oil, prepd. by incorporating a specified nonionic surfactant obtd. by esterification between sorbitan and a fatty acid. CONSTITUTION:At least one nonionic surfactant such as sorbitan monoolerate of HLB 3-7 prepd. by esterification between sorbitan and a fatty acid and, if necessary, a metal corrosion inhibitor and hydrocarbon oil and/or an O2-contg. compd. are incorporated to obtain the titled dehydrating agent. The dehydrating agent in an amt. equivalent to an effective component to 0.01pt.vol. of the surfactant is added to 100pts.wt. diesel gas oil, and water is emulsified and withdrawn out of the system without varying general properties of the diesel gas oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water removal agent for fuel oil for diesel engines. More specifically, it prevents rust from accumulating in fuel supply systems such as diesel engine fuel tanks, fuel oil piping, filters, and injection pumps.
This invention relates to a water removal agent for efficiently dispersing and dissolving fuel oil.

Hydrocarbon oils such as fuel oil for diesel engines have a low water solubility of several tens to iooppm, and the saturated solubility increases or decreases depending on the temperature. Diesel gas oil often comes into contact with water during its production, transportation, storage, etc., and generally dissolves water close to its saturated solubility.

Even after it is refueled into the fuel tank of a diesel engine, its solubility differs due to temperature changes between day and night, causing water to separate, settle, and accumulate at the bottom of the fuel tank.

In addition, the air layer in the fuel tank changes depending on the fuel usage conditions, and especially during humid periods such as the rainy season, the moisture in the air in the fuel oil tank condenses into water droplets due to changes in outside air temperature between day and night, causing the fuel oil to If it does not dissolve, it will settle and accumulate at the bottom of the fuel tank.

It is difficult for the water accumulated in this way to completely dissolve into the fuel oil as it is, and if the water is drawn up from the fuel tank with the suction pipe and supplied, the fuel supply system The rust may corrode, the rust may peel off and block the filter, or in extreme cases, separated water may reach the injection pump, causing engine malfunction.

Conventionally, in order to prevent such troubles caused by water, it is well known that a water solubilizing agent for diesel light oil containing isopropyl alcohol as a main component is used.

However, conventional water-soluble agents mainly composed of alcohols such as isopropyl alcohol have the following disadvantages in practice.

That is, the first problem is that it lowers the flash point of fuel oil.

The flash point of isopropyl alcohol alone is 11. (It is as low as 2°C, for example, and even if it is added in just 1% by volume to G diesel light oil with a flash point of 65°C, the flash point will be extremely low to about 25°C.

Therefore, an explosive mixture will exist in the fuel tank.

Since the fuel tank of a typical diesel engine has an electrical contact point as an oil gauge, there is a drawback that there is a risk of explosion due to sparks.

The second problem lies in both the drainage effect and economic efficiency.

The water solubilization performance of a water solubilizer mainly composed of isopropyl alcohol is very small when added at a level of about 1% by volume to light oil, and it is not possible to satisfy both a sufficient water removal effect and economical efficiency. .

A third problem is that alcohol-based water-soluble agents, such as isopropyl alcohol, do not have corrosion-preventing properties.

The fuel system from the fuel tank to the injection nozzle includes metal parts made of iron, aluminum alloy, etc., and these parts corrode when they come into contact with moisture.

As described above, conventional alcohol-based water solubilizers have various drawbacks and cannot be put to practical use.

In addition, as a water solubilizer for fuel oil, (A) a monohydric alcohol having 3 to 6 carbon atoms and/or glycol ethers, and (B) a polyoxyethylene alkyl ether and/or
Alternatively, a mixture containing polyoxyethylene alkylphenyl ether and a nonionic surfactant has been proposed (Japanese Patent Application Laid-Open No. 8788/1988).

However, the above-mentioned method is not necessarily satisfactory.

In other words, it is considered that it is characterized by containing polyoxyethylene alkyl ether or polyoxyethylene alkyl phenyl ether as a nonionic surfactant, but as long as a low molecular weight alcohol is used as a mixing solvent. The same drawbacks as those of the water-soluble agents mainly composed of alcohols mentioned above are exposed.

In view of the actual situation of the conventional method described above, the present invention aims to provide a safe and effective water removal agent for diesel light oil.

For the above-mentioned purpose, the present inventor has worked hard to develop a product that does not lower the flash point of diesel light oil, can exhibit an extremely superior water removal effect than conventional products, and has the effect of preventing metal corrosion. As a result of repeated studies, we found that among nonionic surfactants consisting of ester bonds between sorbitan and fatty acids, those with a specific H113 value are not only safe, but also have extremely poor water handling properties and are highly resistant to metal corrosion. It was also found that it has preventive properties.

That is, the present invention is fundamentally different from conventionally known water solubilizing agents that dissolve water, and
The purpose of this method is to efficiently and economically remove water by trapping water in diesel light oil by utilizing the emulsifying effect of a nonionic ρ surfactant with a B value. In practical terms, the product according to the present invention is stable in a mixed state, has no danger of ignition or explosion, has excellent metal corrosion prevention performance, and has been completed with new effects that are economically beneficial. It is a water removing agent.

The nonionic surfactant referred to in the present invention generally includes several hydroxyl groups (OH-) and an ether bond (-0-).
Because it contains in the molecule, the hydrophobic group becomes water-soluble,
Moreover, since the active molecules do not contain any ionizable atoms or atomic groups, the aqueous solution is completely ionically unrelated and exhibits surface-active properties.

Nonionic surfactants that are generally widely used and relatively inexpensive include (A) aliphatic higher alcohols, alkylphenols, and fl, i', y
t″If-1't'emi&i!L, , , tSurfactant having ester bond, (B) [Polymer with polypropylene glycol group as hydrophobic group and 7-polyethylene glycol group as hydrophilic group] Examples include surfactants, (C) surfactants formed by ester bonds between sorbitan and various fatty acids, and the like.

The performance of many of these nonionic surfactants can be estimated based on the HLB value.

That is, those with an HL octavalence of 1.5 to 3 are antifoaming agents;
~7 is W10 type emulsifier, 8~18 is 0/W
It is said to be highly effective as a type emulsifier.

In the present invention, the HLB value refers to HLB (Hydrophile-L), which indicates the balance between hydrophilicity and hydrophobicity of a surfactant.
ipophile Ba1ance) and Journal of the Society of Cosmetic φ
Chemistry (J, Soc, Co51+etic, Ch
eiaistry), page 419, December 1948. In the present invention, nonionic surfactants having both lipophilicity and hydrophilicity and having an HLB value in the range of 3 to 7 are suitable.

When the HLB value is 3 or less, the ability of the surfactant to dissolve in the diesel fuel oil is high, but the ability to trap moisture, that is, the emulsification ability, tends to be poor. When the HLB value is 7 or more, the surfactant has a high solubility in water, but on the contrary tends to have poor oil solubility, and is not preferable alone in the present invention.

Therefore, in the present invention, in order to maximize the water removal effect, that is, the performance of trapping separated water into oil and emulsifying it, a nonionic surfactant with an l-I L 8 valence of 3 to 7 is essential. Becomes the property of

The present inventors used various nonionic surfactants with HLB values in the range of 3 to 7, and as a result of a detailed study of their solubility in diesel light oil and water emulsification, that is, water removal effect, they found that sorbitan and various nonionic surfactants Nonionic surfactants consisting of an ester bond with a fatty acid and having an HL octavalence in the range of 3 to 7 also have metal corrosion prevention properties and have extremely excellent water removal performance. discovered.

In particular, sorbitan monooleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan sesquioleate, and sorbitan distearate have very good compatibility with diesel light oil, and have a superior water removal effect compared to the above-mentioned invention. is outstanding.

Above) -118 Although nonionic surfactants with a valence of 3 to 7 have been mentioned, in the present invention, the above surfactants may be used alone or in combination of two or more types. It is possible.

That is, two or more types of nonionic surfactants other than those with a valency of 818 of 3 to 7 are mixed in appropriate amounts, and the 818 valence after mixing is
It has been found that if the valence of 18 falls within the range of 3 to 7, it can also be used.

For example, sorbitan trioleate (HLBli!
il, 8> After uniformly mixing and stirring 70% by volume and 30% by volume of polyoxyethylene (4) sorbitan trioleate (Hl-8 value 11.0), the FILB value was measured and found to be 4.6. .

As a result of carrying out this method in the same manner as in the example shown later,
It was confirmed that it has an excellent water removal effect.

Therefore, the nonionic surfactant that can be used in the present invention is (A) one or two or more surfactants that are composed of an ester bond between sorbitan and a fatty acid and have an 818 valency of 3 to 7. mixture, (B) a nonionic surfactant consisting of an ester bond between sorbitan and fatty acid 818
(C) A mixture of two or more types of substances other than those with a valency of 3 to 7 and whose 818 valence after mixing is adjusted to a range of 3 to 7.
Any mixture of the above (A) and (B) with an 818 value adjusted to a range of 3 to 7 can be used.5. (
It is possible to use it. 1. The surfactant used in the present invention can be used by being dissolved in a hydrocarbon-based solvent and/or an oxygen-containing compound-based solvent.

In that case, sufficient consideration must be given to the selection of a solvent and the amount used within a range that does not affect the flash point and other practical performance of diesel light oil.

In the diesel light oil water removal agent according to the present invention, the amount of the surfactant as an active ingredient added to the diesel light oil is at least 0.00 parts by volume per 100 parts by volume of the diesel light oil.
0.01 part by volume is required, preferably at least 0.05 part by volume.

If the amount added is 0.01 parts by volume or less, it will be related to the water content in the fuel tank, but if there is a lot of water, it will be difficult to achieve a sufficient water removal effect.

Conversely, the upper limit of the amount added depends on the balance between the water content in the fuel tank and the economic cost of the water removal agent to be added.

For example, if a large amount of separated water accidentally enters the fuel tank, it can be removed by a method such as letting it stand and then draining the tank. The upper limit of the amount added when removing moisture generated in the tank under normal conditions or moisture mixed in during the transportation process, etc., will slightly affect the cetane number of diesel light oil if it is dissolved with the above-mentioned solvent. Therefore, it must not lead to a decrease in the cetane number.

Therefore, if the surfactant is used alone, it is preferably 1.0 parts by volume or less per 100 parts by volume of diesel light oil.

As described above, the nonionic surfactant of the present invention having a valence of 118 of 3 to 7 is oil-soluble and has an emulsifying effect to entrap moisture if present.

Looking at this phenomenon from the perspective of its working structure, water on the metal surface is replaced by the polar groups of the surfactant, and the polar groups are adsorbed to the metal, forming a protective film that prevents corrosion. On the other hand, water is surrounded by polar groups and becomes emulsified in oil.

In this way, surfactants not only have the effect of entrapping water but also have the effect of preventing metal corrosion. In particular, sorbitan-based nonionic surfactants have excellent anti-corrosion properties.

Conventional alcohol-based water-based dissections, mainly made of isopropyl alcohol, do not have this corrosion-preventing ability, and will lead to corrosion or rust unless some measure is taken.

As mentioned above, the surfactant according to the present invention has superior corrosion prevention performance compared to alcohol-type surfactants. It is also possible to add an inhibitor, and a synergistic effect can be exerted by using this together.

Note that many of the corrosion inhibitors generally used in petroleum products are oil-soluble, such as organic acid-based and amine-based ones.

The surfactant to be used according to the present invention and the above-mentioned metal corrosion inhibitor generally exhibit a viscous liquid state, and when these are mixed into diesel light oil as a water removal agent, their handling and compatibility should be improved. It is convenient to use hydrocarbon oils or oxygenated compounds as solvents for this purpose.

Examples of the solvent include kerosene and aromatic solvents, but in actual use, it is preferable to use a solvent with a relatively high flash point.

These uses are not intended to limit the scope of the invention.

When actually using the product of the present invention, it is preferable to add and mix 0.05% by volume or more, that is, 20IRf1 or more, to diesel light oil filled with 401, for example.

Immediately after addition and mixing, it traps moisture at the bottom of the fuel tank and emulsifies it.

Particularly when the diesel engine is a self-propelled type such as an automobile, it is even more advantageous that the product of the present invention is sufficiently stirred with the diesel light oil, so that the effect of entrapping moisture is increased.

Diesel light oil that incorporates water is a fuel..., IG
・It passes through the filter paper, where the water is sent to the injection pump without being separated. Since the water is not separated until it is burned, it will not have any negative effect on the metal parts of the fuel system.

As mentioned above, it is a nonionic surfactant composed of an ester bond between sorbitan and a fatty acid, and has a valence of 3 to 818.
By using a water removal agent mainly composed of surfactants within the range of 7, it is possible to emulsify water generated or mixed in the fuel tank and remove water from the system without changing the general properties of diesel light oil. It can be carried out.

Furthermore, the metal parts within the fuel system are protected by the polar groups of the surfactant and the corrosion inhibitor, thereby providing long-term corrosion prevention performance.

As explained in detail above, the present invention is a nonionic surfactant composed of an ester bond between sorbitan and a fatty acid,
This relates to a water removal agent for diesel light oil characterized by containing an 818 value in the range of 3 to 7, and is suitable for use in all fields where water removal agents are used, especially diesel passenger cars, diesel trucks, and diesel oil. It can be used in engine-equipped agricultural tractors, agricultural machinery, construction machinery, and all industrial machinery that uses diesel light oil as fuel.

Next, typical examples of diesel light oil according to the present invention and comparative examples with conventional products will be described, but the present invention is not limited thereto.

Examples and Comparative Examples (1) Diesel light oil 100 in the right column measuring cylinder with water drainage rating of 100-
-, and add this to the 7 types of water removal agents listed in Table 1. 0.
After adding 5m and 2.0ae, shaking and mixing, adding water 3- and shaking vigorously, the mixture was left in the apparatus overnight, and the water content of each oil layer was measured by the Karl Fischer method. The results are shown in Table 1. .

A similar method was used to prepare diesel light oil, and the water content was found to be 11,611)I. Comparison of each sample was shown with this quantity set as 1.0.

These results show that the water removal effect is from slightly less than 2 times to more than 12 times that of conventional water removal agents containing alcohol as the main ingredient.

19- (2) Evaluation of rust prevention when using kerosene as a solvent Place a mild steel plate (50 x 25 x 1 m) at the bottom of a 200 mfl beaker, and add diesel light oil 10 (
7, and add 0.5 each of the 10 types of water removal agents shown in Table 2.
1d! , and after shaking and mixing, add 0.2-10.5 of water.
d was added and shaken vigorously, and this was placed in a beaker containing the test piece in A C-1 and allowed to stand at room temperature.

The appearance of the specimens was observed for two months, and the change in the amount of M in the specimens was measured after two months. The results are shown in Table 2.

The same method was used for diesel oil alone, and the results after the test were shown.

These results show that the alcohol-type conventional product shows a tendency for the occurrence of red spots to increase as water is added, whereas the product of the present invention shows no change in appearance and no change in the weight of the mild steel plate. .

21- (3) Rust prevention evaluation when aromatic hydrocarbon oil is used as a solvent Light steel plate (50 x 25 x 1 nm) is
! Place it at the bottom of the beaker and add 100mf of Deepil diesel oil to the graduated cylinder! , add 0.5 d of each of the 6 types of draining agents shown in Table 3, mix by shaking, and then add 0.5 d of water.
The test piece was added to the test piece, shaken vigorously, and poured into a beaker containing the test piece, and allowed to stand at room temperature.

The appearance was observed for 50 days, and
Table 3 shows the results of measuring changes in the test piece's fingertips after a day.

The same method was used for diesel light oil alone and aromatic solvents, and the results after the tests were shown.

Compared to the conventional alcohol type, the combination of an aromatic solvent with a slightly lower boiling point than kerosene and various rust preventives does not change the appearance and does not cause any change in the appearance of the mild steel plate.

23- (4) Water draining old actual vehicle test In order to evaluate the water draining performance using a method close to actual usage conditions, 13 fuel tanks (156J capacity) for 1 to 1 rack were fixed to the loading platform of 1 rack. We investigated the effect of water removal due to mixing and stirring during refueling, vibration during running, etc.

Each fuel tank was filled with IOJ oil as bottom oil, and 6 sets each of 50 m of water and 15 (7 m) were prepared, and the water removal agent according to the present invention and the conventional product were added.

Sorbitan monooleate according to the invention-1-20d (Example 8), Sorbitan monostearate 20m! (Example 9) and as a comparative example, polyethylene glycol decylphenyl ether 20m! ! (Comparative Example 4), Isopropyl Alcohol 200d (Comparative Example 6), Polypropylene,
Polyethylene glycol conyter 20ai! (Comparative Example 7), polycordylene glycol oleyl ether 20- (Comparative Example 8), etc., immediately after refueling with 35J of gas oil at gas station C (step 1).
), still in stock fH45j! After a short trip of about 1.5 hours (
In step 2), the amount in the tank was reduced to 201, and the gas oil was collected after about 2 hours of constant flow (step 3), and the water content was measured by the Karl Fischer method.

The unity is not shown in Table 4.

As is clear from Table 1, diesel light oil to which sorbitan monooleate and sorbitan monostearate 1 to 1, which are products of the present invention, have been added has a water content that significantly increases with the passage of time. After quantitative determination, polyethylene glyco1-rudodecyl phenyl ether, polyethylene glycol oleyl ether,
It has been found that it contains about 1.5 to 4 times more water than polypropylene glycol polyethylene glycol ether, making it an excellent water remover for diesel light oil.7
．． It has been revealed that it has a performance of 1. 'The properties of Example 8 are shown in Table 5.

Table 5 　28　-

Claims (6)

[Claims] (1) A water removal agent for diesel light oil, characterized in that it contains a nonionic surfactant formed by an ester bond between sorbitan and a fatty acid, and whose valence of 818 is in the range of 3 to 7. (2) Claim 1, wherein the nonionic surfactant is sorbitan monooleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan sesquioleate, or sorbitan distearate. Water removal agent for diesel light oil. (3) A water removal agent for diesel light oil whose valence of 818 is as set forth in claim (1) by mixing two or more types of nonionic surfactants with different valences of 818. (4) The diesel light oil according to claims (1) to (3), wherein the water removal agent also contains a metal corrosion inhibitor used in general petroleum products. Water removal agent. (5) Claims (1) to (3) characterized in that the water removal agent also contains a hydrocarbon oil and/or an oxygen-containing compound as a solvent for the nonionic surfactant. A water removal agent for diesel light oil as described in section. (6) Claim (1) characterized in that the water removal agent contains a nonionic surfactant and a hydrocarbon oil and/or an oxygen-containing compound as a solvent for a metal corrosion inhibitor. - A water removal agent for diesel light oil as described in item (4).