JP3388725B2 - Solid aggregate and its use as oil absorbent, method for producing the same, and method for recovering oil spilled at sea - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid aggregate which efficiently adsorbs oils in seawater or on the surface of seawater, a method for producing the same, its use as an oil absorbent, and oil spilled at sea as the absorbent. The present invention relates to a method of recovering by using.

[0002]

2. Description of the Related Art As the scale of the petrochemical industry has expanded year by year and the mass production and consumption of organic compounds has led to marine pollution, fires, and explosions due to accidents at petrochemical complexes and tankers. Pollution and accidents that threaten the survival of human beings and living things are occurring frequently all over the world, and safe handling and transportation of organic compounds such as petrochemicals,
Storage and proper processing after an accident has become a major issue. One of the fundamental measures against these pollutions and accidents is to prevent the accident itself by designing a device that can react, store or transport safely. On the other hand, it is the second best measure. It is necessary to take appropriate measures promptly when an accident occurs. When the sea surface is contaminated due to an accident in a petrochemical complex or tanker, in most cases, it has been left alone as it is to wait for it to naturally evaporate, dilute, or decompose, or to spray a large amount of a surfactant or the like. Although either method of forcibly diluting has been adopted, it is hard to say that any of them is effective. Enclose the spilled oil using an oil fence, pump up with seawater in an oil recovery ship, separate by density difference,
There is also a method of returning seawater to the sea, but it is inefficient and, as a result, most of the spilled oil diffuses and cannot be recovered, and is left as it is. Attempts have been made to decompose oil spills using microorganisms that live in seawater, but it is still in the experimental stage and far from practical use.

[0003] In consideration of such a current situation, it is desired to develop a method for quickly adsorbing and recovering oil spilled on the sea in the same form as it is. Considering the characteristics of oil that easily diffuses over a wide area at sea and in the sea, mechanical and physical recovery seems to be extremely difficult. In addition, it seems that desirable chemical treatment is possible by causing some chemical reaction in the ocean to change the oil spill into other safe substances, but in the wide ocean, a large amount of unknown new substances are accumulated. It is highly likely to produce and disperse it, so methods involving chemical reactions should be avoided. From this point of view, the method of adsorbing and recovering the physicochemical means as it is, using the physicochemical means, is considered most preferable.

The conditions that the adsorbent for oil that has flowed out to the sea surface should be provided are that salt in seawater acts without impairing its function, the adsorbent can be easily recovered along with the oil, and the recovered adsorbent must be recycled. As it is possible, chemically stable, and expected to be used in large quantities, it is a safe and harmless substance, and should it leak to the ocean, it will be difficult to collect it. However, there is little danger that it itself has a harmful effect on living organisms and the environment living in the ocean. Such a physicochemical adsorbent has not yet been put to practical use, and has hardly been proposed even in the experimental stage.

[0005]

Therefore, the present invention is
It is an object of the present invention to provide a solid aggregate which can be used as an oil absorbent that satisfies the above conditions. Another object of the present invention is to provide a method for solidifying a hydrocarbon to produce the solid aggregate. Another object of the present invention is to provide a method capable of efficiently recovering oils spilled over the sea by physicochemical adsorption.

[0006]

DISCLOSURE OF THE INVENTION In the course of studying the interaction of n-paraffin with a surfactant having a long-chain alkyl group in water based on van der Waals force, the surfactant was used. Easily form macroscopic aggregates with short-chain n-paraffins, and further formation of such macroscopic aggregates can be sufficiently realized even in seawater or so-called hard water containing various metal ions. It was also found that this aggregate adsorbs oils such as heavy oil. The present invention has been made through repeated studies based on this finding.

That is, the present invention provides (1) an aliphatic carboxylic acid metal salt and a hydrocarbon liquid at room temperature in seawater or artificial seawater or water containing metal ions ,
The carboxylic acid metal salt / liquid hydrocarbon molar ratio 1/1 to
Heated addition 1/1000, dissolved, emulsified or suspended
After, to stand and solidify at room temperature, solid aggregate formed separately from the water, (2), characterized in that a oils absorber (1) solid aggregate according to claim, ( 3) Add the solid-state aggregate described in (1) or (2) to seawater.
The method for collecting marine spilled oil, characterized in that the spilled heavy oil, crude oil or hydrocarbons discharged to the sea is adsorbed and collected, and the spilled oil described in (4) and (3) is included. A sea spill characterized by heating and decomposing the solid aggregate to separate it into the original aliphatic carboxylic acid metal salt, the hydrocarbon used to form the solid aggregate, and the oil spilled at sea. Oil recovery method, and (5) in seawater or artificial seawater or water containing metal ions
Carboxylic acid metal salt / liquid hydrocarbon molar ratio 1/1 to 1 /
After the aliphatic carboxylic acid metal salt suspended at 1000 and the liquid hydrocarbon at room temperature are brought into contact , heated and dissolved,
The present invention provides a method for producing a solid aggregate, which is characterized by allowing it to stand at room temperature to solidify, and separating it from water . The solid aggregate that acts as the oil absorbent of the present invention is a macroscopic aggregate consisting of an aliphatic carboxylic acid metal salt and a liquid hydrocarbon at room temperature (20 to 25 ° C.). It is a molecular assembly assembled by van der Waals force between the alkyl chain and the hydrocarbon of. This aggregate is strongly formed in seawater or artificial seawater or water containing metal ions, but does not contain water in the formed aggregate. In addition, this aggregate usually maintains a solid state stably at room temperature or lower for a long period of time.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The aliphatic carboxylic acid metal salt used in the present invention (hereinafter referred to as carboxylic acid metal salt) is not particularly limited, but is preferably linear or branched, or unsaturated in the middle of the carbon chain. It is a metal salt of a carboxylic acid having a bond. The carbon number of the carboxylic acid metal salt is preferably 4 to
22 and particularly preferably 13 to 20. The type of metal is preferably sodium, potassium or lithium. As the carboxylic acid metal salt that can be used in the present invention, specifically, for example, sodium tetradecanoate, sodium pentadecanoate, sodium hexadecanoate,
Examples thereof include sodium heptadecanoate, sodium octadecanoate, potassium hexadecanoate, potassium octadecanoate, potassium arachidonic acid, potassium behenate, and lithium octadecanoate. Sodium aliphatic carboxylate has long been used as a soap in the world and its safety has been proven. Aliphatic potassium carboxylates are also widely used as medicated soaps, and their safety has also been proved. Lithium aliphatic carboxylates are also widely accepted to be harmless. Furthermore, sodium and potassium are originally contained in seawater in large amounts,
It is known that lithium is also contained in a small amount, and even if it leaks into the ocean and remains, it does not adversely affect the environment.

The hydrocarbon liquid at room temperature used in the present invention is
Any compound that is liquid at room temperature and composed only of carbon and hydrogen may be used, and preferably does not contain oxygen atom, nitrogen atom, sulfur atom and the like. When an aliphatic hydrocarbon is used, it preferably has 5 to 18 carbon atoms, and more preferably 6 to 10 carbon atoms. When an aromatic hydrocarbon is used, it preferably has 6 to 9 carbon atoms. Specifically, for example, linear paraffins such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane, branched paraffins such as 2,2,4-trimethylpentane, 1 -Olefin such as decene, benzene, toluene, xylene, ethylbenzene,
Examples include aromatic hydrocarbons such as cumene. However, linear paraffins are most desirable in view of the slight possibility that the recovered material itself remains as a pollution source in the ocean. Usually, regarding hydrocarbons that are liquid at room temperature, it is easier to form solid aggregates with a smaller number of carbons, but after forming solid aggregates, it is easier to handle them for long-term storage. Considering it, the one with more carbon number is more stable, and the oils to be adsorbed and recovered are
The composition of the solid aggregate effective as an oil absorbent also differs depending on whether it is crude oil, heavy oil, refined hydrocarbon, or the like. Practically, a hydrocarbon in an appropriate combination is appropriately selected and used according to the type of oil to be recovered.

In the present invention, the carboxylic acid metal salt and the hydrocarbon that is liquid at room temperature are dissolved, emulsified or suspended in seawater, artificial seawater, or metal ion-containing water to give a solid form. As seawater, actual seawater can be used as it is, or suspended solids can be removed by filtration and used. Further, various commercially available artificial seawater may be used, or an aqueous solution adjusted to have a metal salt composition similar to that of seawater may be used. Further, an aqueous solution containing a single metal ion can also be used, and the types of metal ions contained in seawater include alkali metal ions such as sodium and potassium, and alkaline earth metal ions such as magnesium and calcium. Can be given. Further, an aqueous solution containing metal ions such as lithium, aluminum, zinc, strontium, barium, copper and iron can be used in addition to those containing metal ions contained in seawater. Considering the slight possibility that the recovered material itself remains as a pollution source in the ocean, it is an aqueous solution containing alkali metal or alkaline earth metal ions known to be contained in large amounts in seawater. Is desirable. The concentration of metal ions is preferably 0.1 mmol / liter
0.5 mol / l, more preferably 1 mmol / l
It is from liter to 0.5 mol / liter. When using artificial seawater or the like, the total concentration of metal ions contained may be within the above range, and may not be exactly the same as the seawater concentration or seawater composition. Further, the optimum concentration varies greatly depending on the type of metal ion.

In the method for producing a solid aggregate of the present invention, the metal carboxylate and the hydrocarbon liquid at room temperature are dissolved, emulsified or suspended in the seawater, artificial seawater or water containing metal ions, Although it is in a solid state, it is particularly important to form a solid aggregate in an aqueous solution containing a metal ion anyway. This makes it possible to form a macroscopic aggregate of hydrocarbons that is strong and efficiently adsorbs oils. It is considered that this is because the aggregate formed by fixing hydrocarbons to the alkyl chain of the carboxylic acid metal salt by Van der Waals force is reinforced by metal ions in water to make it more stable. This aggregate is formed in seawater, artificial seawater or metal ion-containing water, but it is formed completely separated from water,
Water is not included in the aggregate.

In the method of the present invention, an embodiment of producing an oil absorbent by forming a macroscopic aggregate is particularly preferable except that the hydrocarbon and the metal carboxylate are contacted in seawater or artificial seawater or water containing metal ions. There is no limit. To seawater or artificial seawater or metal ion-containing water in which a carboxylic acid metal salt is dispersed, under stirring, a liquid hydrocarbon is added, and a method of standing still at room temperature after heating carboxylic acid metal salt, liquid hydrocarbon, seawater or Artificial seawater or metal ion-containing water is added at the same time, and the mixture is heated and stirred and then allowed to stand at room temperature. A carboxylic acid metal salt is added to a liquid hydrocarbon, and after heating and dissolution, seawater or artificial seawater or metal ion-containing water is added. In addition, there are methods such as stirring and standing. In addition, oil-contaminated seawater was previously introduced into the container, carboxylic acid metal salt and liquid hydrocarbon were added, and after heating and stirring,
By allowing the mixture to stand at room temperature and forming an aggregate that takes in oils from the beginning, the oils are collected at the same time as the production of the oil absorbent,
You can also get clean seawater immediately. However, this method is practically suitable for restoring a relatively small amount of seawater.

The molar ratio of carboxylic acid metal salt / liquid hydrocarbon in the present invention is 1/1 to 1/1000, more preferably 1/10 to 1/500 . The amount of seawater or artificial seawater or metal ion-containing water used for forming the solid aggregate is preferably 1/50 to 1 / 50,000, more preferably 1 in terms of a carboxylic acid metal salt / water molar ratio. / 100 to 1/5000. In the present invention, in order to form a solid aggregate, the above-mentioned dissolved, emulsified or suspended aqueous solution is heated as necessary. The heating temperature varies depending on the type of the carboxylic acid metal salt and the type of the liquid hydrocarbon used, but in the case of sodium carboxylate or potassium carboxylate, for example, the heating temperature is preferably in the range of room temperature to 95 ° C., under a sealed condition of 5 to 30. Heat for a minute. When using a hydrocarbon with high volatility and when heating to 90 ° C. or higher, a pressure container is used. Further, in the case of lithium carboxylate, it is preferably heated at 350 to 400 ° C. for 10 to 60 minutes and a pressure resistant container is used. In any case, after the metal carboxylate is dissolved or melted by heating, the mixture is shaken and stirred for 3 to 30 minutes,
Let stand at room temperature. By doing so, the total amount of the carboxylic acid metal salt and the liquid hydrocarbon in the seawater or the artificial seawater or the metal ion-containing water can be practically converted into a solid macroscopic aggregate. The formed macroscopic aggregate can be separated from seawater or the like by ordinary means such as filtration or centrifugation, or by scooping the aggregate from seawater or artificial seawater or water containing metal ions. This solid aggregate is extremely stable after being formed, and is usually stable even if it is formed by heating or holding it at room temperature for a long period of time or even at high temperature. It
For example, an aggregate of sodium octadecanoate and n-octane is usually extremely stable up to about 60 ° C.

The solid aggregate formed by the above-mentioned method of the present invention selectively adsorbs heavy oil only by throwing it into seawater contaminated with heavy oil. As long as the ratio of heavy oil to the solid aggregate is not too large, substantially all of the heavy oil is adsorbed and floats on the purified seawater. The aggregate after adsorbing the heavy oil also remains solid and can be separated from seawater by ordinary means such as filtration and centrifugation, or by scooping from seawater. Oils that can be adsorbed and collected by the solid aggregate of the present invention include A heavy oil, C heavy oil, crude oil,
Examples include various refined hydrocarbons, that is, n-paraffins, olefins, branched paraffins, aromatic hydrocarbons, and the like. Depending on the kind of oils to be collected, it is usually 0.1 to 1 with respect to 1 g of the solid aggregate of the present invention.
g of oils can be adsorbed. In order to adsorb oils to the solid aggregate of the present invention, it is preferable to contact the oil with the solid aggregate for 1 minute or more, and it is more preferable to stir for 5 minutes or more.

The solid aggregate after adsorbing oils is separated from seawater, and then pure water is added and heated to separate into metal carboxylic acid salt, liquid hydrocarbon and recovered oils. be able to. The carboxylic acid metal salt separates and moves to the water side, and the oils and liquid hydrocarbons can be separated into the original hydrocarbons and oils by means of ordinary petroleum refining, using means such as distillation, Marine spilled oil can be recovered in its original state. Further, most of the carboxylic acid metal salts and liquid hydrocarbons in the solid aggregate collected by adsorbing oils can be used again for producing a solid aggregate that can be used as an oil absorbent. It can be used repeatedly. At this time, the metal salt of carboxylic acid is mixed with the metal in seawater, but there is no problem as long as it is used repeatedly for the purpose of the present invention. The heating for decomposition and separation is usually 80 ° C. or higher.

[0016]

EXAMPLES Next, the present invention will be described in more detail based on examples. Example 1 High-purity (99% or more) sodium octadecanoate 10
0 mg, 1 ml of n-octane and 10 ml of seawater were weighed, placed in a glass container 1, sealed, heated to 85 ° C., and stirred with a Vortex Mixer until a uniform emulsion was obtained. When this was left at room temperature for a day,
A white macroscopic aggregate (oil absorbent) was formed and floated on the seawater. When a glass container 2 containing 0.1 g of C heavy oil in 10 ml of seawater was newly prepared and stirred with a vortex mixer, the C heavy oil adhered to the inner wall of the glass container, and the glass container 2 was contaminated in brown. Glass container 1
0.5 g of the oil absorbing material was separated from the above, placed in the glass container 2 and stirred lightly for 1 minute with a vortex mixer. As a result, all C heavy oil was adsorbed by the oil absorbing material within the range visually observed. The inner wall of the building returned to almost transparent.
Although the oil absorbent that was white turned into a uniform light brown color,
It remained solid. When 0.1 g of C heavy oil was further added to the glass container 2 and lightly stirred for 1 minute with a vortex mixer, all the C heavy oil including the C heavy oil attached to the inner wall when added was found to be visually observed. Adsorbed by the oil absorbing material, the inner wall of the glass container 2 returned to be almost transparent. The oil absorbing material turns a uniform dark brown color,
It softened, but remained solid.

Example 2 Except that 1 ml of n-hexane was used in place of n-octane, the same procedure as in Example 1 was carried out, except that the oil absorbent was formed after standing for about half a day. We got exactly the same results.

Example 3 High-purity (99% or more) sodium octadecanoate 10
Instead of 0 mg, octadecanoic acid of low purity and easily available (purity of about 60%, the rest is hexadecanoic acid, sodium salts of other carboxylic acids, and free acid) 100
In exactly the same manner as in Example 1 except that mg was used,
It took about 2 days to obtain an oil absorber, and C heavy oil 0.2 g
The same results as in Example 1 were obtained, except that the oil absorbent that adsorbed was even softer.

Examples 4 to 6 High-purity (99% or more) sodium octadecanoate 10
Instead of 0 mg, hexadecanoic acid of low purity and usually easily available (purity about 60%, the rest is sodium salt of octadecanoic acid and other carboxylic acids, and free acid) 100
mg, n-hexane, n-, instead of n-octane
Except for using 1 ml each of heptane or n-nonane, the same procedure as in Example 1 was carried out. It took about 2 days to initially obtain the oil absorbent, and the oil absorbent adsorbed 0.2 g of C heavy oil was The same result as in Example 1 was obtained except that the result was softer.

Examples 7 to 12 High-purity (99% or more) sodium octadecanoate 10
Instead of 0 mg, high purity potassium hexadecanoate, potassium octadecanoate, potassium arachidonic acid, potassium behenate or lithium octadecanoate 10 each
Exactly the same as in Example 1 except that 0 mg was used, except that when lithium octadecanoate was used, it was necessary to first heat at 380 ° C. for 30 minutes to obtain an oil absorbent. The same result as in Example 1 was obtained.

[0021] The oil absorbent in which the C heavy oil was adsorbed in Example 1 was separated from the seawater purified by filtration, and all could be recovered. In addition, add pure water 1
0 ml was added, the mixture was heated to 90 ° C. to transfer sodium octadecanoate into water, and the oil was distilled to obtain 0.4 g of C heavy oil (including octane), 0.05 g of sodium octadecanoate, and n-octane 0. It was possible to separate and take out to 0.3 g.

[0022]

INDUSTRIAL APPLICABILITY The solid-state aggregate formed from the aliphatic carboxylic acid metal salt and the hydrocarbon which is liquid at room temperature according to the present invention can be used as an oil absorbent, and can be contacted in seawater or seawater. The oils thus made can be selectively and efficiently adsorbed. Since the solid aggregate of the present invention maintains a solid state even when adsorbing oils and can be easily recovered from seawater after adsorption, contamination of seawater by the absorbent itself can be prevented.
Further, the solid aggregate of the present invention is easy to handle because it maintains a stable solid state for a long period of time at room temperature, and after absorption of oils, it is heated to form carboxylic acid metal salts, liquid hydrocarbons and recovered oils. It can be separated, the spilled oil can be recovered in its original state, and the carboxylic acid metal salt and the liquid hydrocarbon can be reused in the production of an unused solid aggregate. The method for recovering spilled oils of the present invention using such a solid aggregate is suitable for industrial implementation.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C02F 1/40 C02F 1/40 Z C09K 3/00 103 C09K 3/00 103M E02B 15/10 E02B 15/10 B (72) Invention Person Sakaguchi 豁 1-1-1, Higashi Tsukuba-shi, Ibaraki Institute of Industrial Science and Technology, Institute of Materials Engineering (72) Inventor Rajab Ali Tishezan Iran Ahwaz, Ministry of Petroleum, Karoon Industrial Area Technical Training Center (72) Inventor Kamao Yasuo, Tsukuba-shi, Ibaraki Prefecture 1-chome No. 1 Industrial Technology, Institute for Materials Engineering (56) Reference JP 2000-86541 (JP, A) JP 9-253656 (JP, A) JP 63-223083 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09K 3/32 B01J 20/26 C02F 1/40 C09K 3/00 E02B 15/10

Claims (5)

(57) [Claims] 1. An aliphatic carboxylic acid metal salt and a hydrocarbon which is liquid at room temperature in seawater or artificial seawater or water containing metal ions, and a molar ratio of the carboxylic acid metal salt / liquid hydrocarbon.
1 / 1-1 / 1000 was added and heated, dissolved, after emulsifying or suspending, solidified to stand at room temperature, water and separated to form <br/> been solid aggregate. 2. The solid aggregate according to claim 1, which is an oil absorbent. 3. A sea solid aggregate of claim 1 or 2, wherein
A method for collecting oil spilled at sea, which comprises throwing in heavy water, crude oil or hydrocarbons that have flowed out into the sea to be adsorbed and collected. 4. The solid aggregate containing spilled oil according to claim 3, which is decomposed by heating, the original aliphatic carboxylic acid metal salt, the hydrocarbon used for forming the solid aggregate, and A method for collecting marine oil spills, which comprises separating the oil into marine oil spills and collecting the oil. 5. A molar ratio of metal carboxylate / liquid hydrocarbon in seawater or artificial seawater or water containing metal ions is 1 /
The aliphatic carboxylic acid metal salt suspended at 1 to 1/1000 and the liquid hydrocarbon at room temperature are brought into contact with each other , heated and dissolved.
A method for producing a solid aggregate, which comprises allowing the mixture to stand and then solidifying at room temperature to separate it from water .