JPS6146033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating and recovering high-boiling point polluted oil, and more specifically, the present invention relates to a method for regenerating and recovering high-boiling point polluted oil, and more specifically, to remove pollutant components and nonionic interfaces obtained by washing used oil-impregnated cleaning fiber products with a dust-adsorbing oil agent as a cleaning liquid. The following formula is applied to a high boiling point dirty oil containing an activator in the substantial absence of phase-separated water. In the formula, each of R ₁ , R ₂ , and R ₃ is an alkyl group having 2 to 5 carbon atoms, and R ₄ is an alkyl group having 2 to 5 carbon atoms or an aralkyl group whose alkyl moiety has 2 or more carbon atoms. A quaternary ammonium salt represented by X is a nonion is added in an amount of 0.5 to 10% by weight, heated and stirred at a temperature of 50 to 95°C, and left to coagulate and precipitate the pollutants. This invention relates to a method for recycling and recovering high-boiling point dirty oil, which is characterized by separating clear oil. Used oil-impregnated fiber cleaning materials contain a combination of cationic, nonionic, or amphoteric surfactants as dust adsorbents and nonvolatile mineral oils or synthetic oils, and also contain large amounts of dirt, dust, Other inorganic or organic dirt, mold, bacteria, etc. are attached. Thus, the wastewater discharged during the recycling and cleaning of cleaning materials contains an extremely high concentration of emulsified oil, and also contains pollutants such as COD and SS at a high concentration, making it difficult to treat the wastewater. Wastewater treatment requires many steps such as primary treatment and secondary treatment, and the cost of the treatment is also quite high. In order to eliminate these drawbacks, after cleaning used dirty cleaning oil-impregnated fiber products using the dust-absorbing oil agent itself, which is used to adsorb dust to the fibers, the amount of the remaining oil agent is removed to an appropriate level. It has already been proposed to perform both the cleaning and oil impregnation processes consistently by adjusting the adjustment within a certain range (Japanese Patent Publication No. 53).
-37471). As mentioned above, this method is superior in that both the cleaning and oil impregnation steps are performed consistently and does not require wastewater treatment after cleaning, but as the cleaning operation is repeated, it becomes contaminated. A problem arises in that components accumulate in the oil agent and it is difficult to remove these contaminating components. The oil agent for dust adsorption has a high boiling point, as is clear from the fact that it is non-volatile under normal conditions, and is difficult to purify by distillation using simple means such as the case with ordinary dry cleaning solvents. Furthermore, this oil has a high viscosity and is relatively difficult to purify by filtration, and even if it were to be filtrated, it is virtually impossible to sufficiently remove the contaminant components contained therein. Furthermore, even if a method of decolorizing the contaminated oil by adding an adsorbent polymer substance or activated carbon is applied to this contaminated oil, in addition to the above-mentioned problem of difficulty in filtration, it is easy to regenerate the adsorbed polymer substance or activated carbon. However, there are disadvantages in terms of economic efficiency. The present inventors added and mixed a specific quaternary ammonium salt to high-boiling point oil containing polluting components and surfactants, such as contaminated oil obtained by washing used oil-impregnated cleaning textile products, Add this mixture to 50 to 95
It has been found that when heated to a temperature of 0.degree. C., polluted components are very effectively coagulated and precipitated and separated, and the purified oil component is effectively recovered as a supernatant. The present invention shows that when a short-chain alkyl group-containing quaternary ammonium salt is added to high-boiling point foul oil containing polluting components and nonionic surfactants and the mixture is heated and stirred, even in the absence of water, the high-boiling point foul oil can be dissolved. This is based on the novel idea that pollutant components selectively coagulate and precipitate. Oil-impregnated fibers for cleaning contain water in proportion to the moisture absorption rate of the fibers, and even if this water were to migrate into the oil, this water would remain dissolved in the oil. It does not exist in a phase-separated form from the oil. This water content is at most 5%
within In the present invention, although the reason why contaminant components coagulate and settle in oil is not fully clear, the above-mentioned short-chain alkyl group-containing quaternary ammonium salt combines with negatively charged contaminant components in oil. It is thought that the oil coagulates and settles due to the action of the nonionic surfactant present in the oil. This estimation is based on high boiling point oil that does not contain nonionic surfactants.
This agrees well with the fact that even when a short-chain alkyl group-containing quaternary ammonium salt is added, no flocculation and sedimentation of pollutant components occurs. According to the present invention, the fourth
Grade ammonium salt is extracted by extracting the sedimentary pollutant components with water.
If necessary, it can be easily recovered in a reusable form by applying a concentration method known per se. The high-boiling point oil targeted in the present invention includes mineral oil, synthetic lubricating oil, or a mixture thereof, and any oil that is suitable as an oil agent for dust adsorption can be used. These oils can be used under normal conditions (20℃, 1
It is non-volatile (non-drying) at atmospheric pressure) and has a viscosity of 8 to 100 cP, preferably 10 to 90 cP, measured at 100 m. Suitably, the oil has an aniline point of 20 to 80, preferably 40 to 60, an ignition point of at least 130°C, a boiling point of at least 280°C, and a temperature of less than 15 mmHg measured at 70°C. It also has a low vapor pressure. The mineral oil may consist of paraffinic hydrocarbons, naphthenic hydrocarbons, aromatic hydrocarbons or mixtures thereof, suitable examples of which are liquid paraffin, spindle oil, machine oil, refrigeration oil and others. It is a petroleum-based lubricant. Synthetic lubricating oils include polyolefin oil (α-olefin oil), polyglycol oil, polybutene oil,
Examples include alkylbenzene oil, diester oil, polyol ester oil, polyphenyl ether oil, and isoparaffin oil. In the case of oil-impregnated fiber products for cleaning, in addition to the above-mentioned oil agents, a cationic surfactant may be added to the oil agent for the purpose of imparting dust adsorption properties or further imparting self-emulsifying and self-exhausting properties. A combination with a nonionic surfactant, or an amphoteric surfactant having a cationic active group such as a quaternary ammonium group or an amino group and an anionic active group such as a carboxylic acid or sulfonic acid group, or the above cation. Amphoteric surfactants containing active groups and nonionic active groups such as polyethylene oxide groups are included. Furthermore, oil-impregnated fiber products for cleaning contain antioxidants to prevent deterioration of the oil agent, antifungal agents to prevent the growth of mold and bacteria, and antibacterial agents. During the cleaning and deoiling treatment described later, a portion of the oil is transferred into the oil agent which is the cleaning medium. Dirt on used oil-impregnated fibers is a complex mixture of the various types of stains mentioned above that adhere to or are adsorbed to the fibers, and even become stuck to the fibers after long-term use or neglect. There are some. Therefore, when cleaning oil-impregnated fiber products for cleaning using the oil itself as a cleaning medium, it is necessary to use a nonionic surfactant, especially a nonionic surfactant made of an ethylene oxide adduct of nonylphenol or a higher alcohol, to enhance the cleaning power. The average added mole of ionic surfactant, especially ethylene oxide is 1 to 1.
Add 10 moles. The amount added is preferably in the range of 3 to 20% by weight based on the oil agent as the cleaning medium. As the washing machine, a commercially available rotary washer may be used, but a washer capable of washing and deoiling (adjusting the amount of oil retained), such as Floatair manufactured by Washex, USA, is preferred. Cleaning is preferably carried out at room temperature, but in some cases it may be heated at 60 to 80°C.
It can be done for 30 minutes to 1 hour. The amount of oil left on the fibers varies depending on the type of fiber base material, but
12 to 30% by weight, especially 18 to 23% based on the fiber weight
A range of weight percent is suitable. After washing, the recovered oil is first separated through a wire mesh to remove coarse fiber waste and dirt, and then, if necessary, is filtered using a supercharging agent such as acid clay or diatomaceous earth, and then subjected to the recycling treatment of the present invention. do. In the present invention, adding a quaternary ammonium salt of general formula () to the above-mentioned contaminated oil in an amount of 0.5 to 10% by weight, particularly preferably 1 to 3% by weight, effectively coagulates and sediments the pollutant components. It is important to do so. First, the alkyl group in the molecule of the quaternary ammonium salt used must have 2 to 5 carbon atoms. Quaternary surfactants with long chain alkyl groups commonly used as cationic surfactants
Class ammonium salts such as cetylpyridium chloride, trioctylmethylammonium chloride, dimethyldimyristylbenzylammonium chloride, dimethyldistearylammonium chloride, dimethylalkylbenzylammonium chloride, and dimethyldialkyl ammonium chloride are all pollutant components in contaminated oil. It does not have the ability to coagulate and precipitate. That is, contaminated oil obtained by washing used oil-impregnated fiber products is stained brown to black, and its absorbance is generally 2.0 or more. When a quaternary ammonium salt having a long-chain alkyl group as exemplified above is added to this contaminated oil, no sedimentation of these contaminating components occurs, and the absorbance of the treated liquid remains that of the contaminated oil. On the other hand, according to the present invention, when a quaternary ammonium salt whose alkyl group has carbon atoms in the range of 2 to 5 is added, the contaminant components are significantly flocculated and sedimented, and this fact is clear from the examples described below. Probably. In the quaternary ammonium salt used in the present invention, only one of the four alkyl groups may be substituted with an aralkyl group such as a benzyl group. The anion of the quaternary ammonium salt is preferably a halide ion, particularly a chloride ion.
Suitable examples thereof are tetraethylammonium chloride, tetra-n-propylammonium chloride, tetra-n-butylammonium chloride, tetra-n-pentylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium iodide, These include benzyltri-n-butylammonium chloride, and these may be used alone or in combination of two or more. Most preferred is tetra-n-butylammonium chloride. The mixture with the addition of quaternary ammonium salt is 50
Heating and stirring at a temperature of 60 to 80°C, particularly 60 to 80°C,
Uniformly disperse the quaternary ammonium salt. When this liquid is then allowed to stand and cool, the polluted components coagulate and settle, and a clear, almost transparent oil component is separated in the upper layer. This separation is completed within an hour, especially within 30 minutes. However, it is of course also possible to perform a centrifugation operation to facilitate separation. Further, according to the present invention, the quaternary ammonium salt used as a flocculant and sedimentation agent is prepared by diluting the pollutant layer separated by flocculation and sedimentation with water 5 to 10 times.
Heat to 95℃ and leave for a while, or 5 to 10 minutes.
After dilution, a clear aqueous solution of the quaternary ammonium salt is obtained by adding an inorganic salt such as common salt or mirabilite to a concentration of 2 to 10% based on the amount of diluted water. This aqueous solution can be reused by extracting it with an organic solvent or by evaporating and concentrating it. The present invention will be explained below with reference to FIG. 1, which shows one embodiment of the method of the present invention. Contaminated oil A and flocculant precipitant B in an amount of 1.5 to 10% by weight based on contaminated oil A are heated at 50 to 95°C in stirring tank 1.
Heat and stir at a temperature of . Next, this mixed liquid C is transferred to the flocculation sedimentation tank 3, where it is left to cool and stand. After standing for a while, a clear, almost colorless oil layer D from which contaminant components have been removed is obtained as the upper layer. Transfer this recycled oil layer D to the stirring layer 4, add activated clay G, mix and stir,
This is subjected to a pre-coating process to obtain recycled oil. Further, the contaminant component (tar component) E condensed and precipitated in the condensation sedimentation tank is diluted 5 to 10 times with water F, and mixed and stirred in the stirring tank 6 at 50 to 90°C. If necessary, add inorganic salts such as table salt or mirabilite.
By adding 3 to 10% by weight to the amount of diluted water, mixing and leaving it for a while in the next settling tank 7, an oil layer containing pollutant components (tar content) and an aqueous layer containing the quaternary ammonium salt are formed. Separate into Next, the quaternary ammonium salt can be recovered and reused by subjecting the aqueous layer to operations such as reverse osmosis and evaporation. The present invention will be explained below using examples. Example 1 A used cleaning oil-impregnated fiber product (dust control product) was collected after cleaning with industrial paraffin oil, and the cleaning oil filtered through diatomaceous earth was used as a dirty oil sample. This cleaning oil is mainly made of industrial paraffin.
Nonionic surfactant 7% by weight, antioxidant 0.35
% by weight, 1.0% by weight of antifungal agent, 0.15% by weight of antibacterial agent, and several % of animal and vegetable oils, wax, grease, fine earth and sand, etc. 3% by weight of tetra-n-butylammonium chloride was added as a flocculant to the contaminated liquid, and the mixture was heated and stirred at 80°C. After the flocculant was uniformly dispersed, the heating and stirring was stopped, and the mixture was allowed to stand for about 1 hour to cool. The evaluation of the supernatant liquid is shown in Table 1. 【table】

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the process of the regeneration and recovery method of the present invention, where reference number 1 is a stirring layer, 2 is a coagulation sedimentation layer, 4 is a
and 5 is a stirring layer, 6 is a sedimentation layer, A is contaminated oil, B is a coagulation sedimentation agent, D is a recycled oil layer, H is a pre-coat filter, I is a recycled oil, J is an operation such as reverse osmosis or evaporation, K indicate regenerated flocculation and sedimentation agents, respectively.

Claims (1)

[Scope of Claims] 1. A high boiling point dirty oil containing polluting components and nonionic surfactants obtained by washing used oil-impregnated cleaning fiber products with a dust adsorption oil agent as a cleaning liquid is mixed with substantially non-containing phase-separated water. In the presence of the following formula In the formula, each of R ₁ , R ₂ , and R ₃ is an alkyl group having 2 to 5 carbon atoms, and R ₄ is an alkyl group having 2 to 5 carbon atoms or an aralkyl group whose alkyl moiety has 2 or less carbon atoms. 0.5 to 10 of the quaternary ammonium salt represented by
A method for regenerating and recovering high-boiling point dirty oil, which is characterized in that it is added in an amount of % by weight, heated and stirred at a temperature of 50 to 95°C, allowed to stand to coagulate and precipitate the pollutants, and then separate the supernatant clean oil. . 2. The regeneration and recovery method according to claim 1, wherein the quaternary ammonium salt represented by the formula () is tetra-n-butylammonium chloride. 3. Regeneration according to claim 1, in which the coagulated and precipitated pollutants are subjected to an extraction operation using an aqueous medium to recover quaternary ammonium salts, and the recovered quaternary ammonium salts are reused as a flocculant. Collection method.