JPS5895527A - Treatment for hydrous waste petroleum oil - Google Patents

Abstract

PURPOSE:To separate oils from waste oils effectively by adding specific ratios of arom. oils contg. specific contents of arom. hydrocarbons and anionic surfactants to hydrous petroleum waste oils of water-in-oil type emulsions. CONSTITUTION:About 1vol%, more preferably 1-50vol% arom. oils contg. >=50wt% arom. hydrocarbons, for example, naphthalene and 100-5,000ppm, more preferably 500-2,000ppm anionic or nonionic surfactants are added to hydrous waste petroleum oils of water-in-oil type emulsions consisting of oils, water, sludge, etc. and these are mixed at 50-70 deg.C. Such hydrous waste oils are controlled to 4-8, more preferably 6-7pH, and are removed of sludge by utilizing >=1,000G centrifugal force then the oils are allowed to stand still, whereby oils and water are separated. The arom. oils consisting essentially of fractions of 130-275 deg.C b.p. are used.

Description

[Detailed Description of the Invention] More specifically, the present invention relates to a method for treating petroleum-based water-containing waste oil, which forms an emulsion consisting of petroleum-derived oil, moisture, and sludge.

Conventionally, rolling processes and pipe manufacturing processes in steel mills, coke oven gas cleaning processes that use petroleum-based absorbing oil, rolling waste oil, lubricating waste oil, and cleaning waste oil from Oji Factory, etc., crude oil tanks in oil refineries and petrochemical plants, Crude oil waste oil, heavy oil waste oil, tank residual oil, mixed oil, etc. from the cleaning process of heavy oil tanks, etc., lubricating oil manufacturing process, etc., lubricating waste oil from automobile factories, machine manufacturing factories, shipyards, etc., automobile engine oil waste oil, cutting oil. A large amount of petroleum-based water-containing waste oil, such as , rust preventive oil, etc., is generated.

These petroleum-based water-containing waste oils have slightly different properties depending on where they are generated, but they usually contain not only oil and water but also solid sludge and other additives such as emulsifiers. This forms an extremely stable emulsion. For example, waste oil generated from rolling processes in steel plants, coke oven gas cleaning processes, Oya Factory, etc. is mixed oil mainly composed of petroleum oils such as rolling oil, lubricating oil, machine oil, cleaning oil, etc. and a water-in-oil type (hereinafter referred to as W2O type) emulsion consisting of finely powdered solids such as iron oxide, carbon, etc. It also occurs during the cleaning process of crude oil tanks, heavy oil tanks, etc. at oil refineries. The waste oil, mixed oil, etc. produced in the manufacturing process, as well as the waste oil generated from machine manufacturing factories and other places, are almost similar water-containing waste oils in the form of W10 emulsion.

The composition of these water-containing waste oils is usually a petroleum oil content of 50% by weight or more, a solid content (in terms of dry content) of 01 to 10% by weight, and the balance being water. Petroleum-based oil refers to oil mainly consisting of non-aromatic oil. The solid content includes metal powder such as iron powder, iron compounds such as iron oxide, carbon, dust, sand, and the like. The solid content exists as sludge with oil or water attached.

Even if these water-containing waste oils are forcibly separated using a centrifuge, the oil, emulsion, and
The process is extremely difficult because the water and solids proportions change little over the course of 2 hours. Also,
This water-containing waste oil has poor flammability, so it is less efficient as a fuel, and the sludge can clog the burner tip.

As a method for treating such emulsion-type petroleum-based water-containing waste oil, the waste oil is heated and pressurized, then cooled, separated into three layers of oil, water, and solids, and each layer is centrifuged. 47722), a method of heating waste oil to destroy the emulsion, and separating each layer after cooling (Japanese Patent Publication No. 1973-
No. 43305), waste oil is centrifuged under heating to
A method of centrifuging water and sludge and then further centrifuging the obtained oil and water (Japanese Patent Laid-Open No. 52-123403)
No. 2) has been proposed. However, these methods not only require a large amount of energy for heating, pressurization, centrifugation, etc., but also are insufficient in separating sludge and oil. Another method is to add a light petroleum fraction to a mixed oil to extract the oil, and then heat or treat the resulting deoiled mixed oil with a coagulant and centrifuge it to separate water and solids.
-15025 Publication), by adding and mixing a hydrocarbon solvent mainly composed of hydrocarbons from propane to light oil to waste oil,
Method for separating oil and sludge (JP-A-49-39
No. 601) has been proposed. However, these methods also have the disadvantage that the separation of sludge and oil is insufficient.

The present invention was made in order to eliminate the various disadvantages of the conventional methods as described above. A method for treating petroleum-based water-containing waste oil, which comprises adding 100 to soooppm of an oil component containing 50% by weight or more of group hydrocarbons and an anionic or cationic surfactant to the water-containing waste oil, and then separating the oil component. .

That is, according to the findings of the present inventors, if a specific solvent consisting of an oil containing 50% by weight or more of aromatic hydrocarbons and a specific surfactant are added to and mixed with petroleum-based water-containing waste oil, the above-mentioned The highly stable W10 type emulsion is broken, resulting in good sludge settling properties and good separation from water. The oil can be separated by allowing the mixture to stand still. In addition, it was found that centrifugation can quickly remove the sludge, and after the sludge has been removed, the oil-water mixture is left to stand, making the interface between the layers clearer, resulting in better oil-water separation. did.

However, when comparing various types of solvents to be added, it was found that the separation effect of aliphatic hydrocarbon oils, including naphtha, kerosene, light oil, and heavy oil, was unsatisfactory.

Therefore, as the solvent used for breaking the emulsion in the present invention, any aromatic oil containing aromatic hydrocarbons in an amount of 50% by weight or more, preferably 70% by weight or more can be used. - For example, light oil obtained by absorbing coke oven gas into absorption oil, light oil obtained by fractional distillation of coal tar, or reformed oil obtained by aromatizing petroleum-based soot. , crude to purified benzene obtained by these fractional distillations, toluene, solvent naphtha, naphthalene oil obtained from coal tar,
Examples include absorption oil, anthracene oil, creosote oil, and mixtures thereof. Among them, the boiling point is 130-27
Aromatic oils containing mainly a 5°C fraction are effective, and aromatic oils containing 20 to 60 units of naphthalene are particularly effective.

Such aromatic oils include residual oils obtained by distilling the fractions from tar gas oil to xylene. The amount of these aromatic oils to be added is selected depending on the oil content in the water-containing waste oil, the amount of sludge, the treatment conditions, and the processing equipment, but generally speaking, it is preferably at least ■volume relative to the oil content in the water-containing waste oil. has a capacity of 1 to 50. Although the upper limit of the amount added is not regulated from the separation effect, using too much is disadvantageous from an economic point of view. Furthermore, when an anionic or nonionic surfactant is used together with the above solvent, the amount of solvent added can be reduced by about 1%.
It can be reduced to about 1/0. As anionic surfactants, fatty acid salt R, CH2C00M
(However, R1 is an alkyl group or alkenyl group having 11 to 17 carbon atoms, M is Na or K.) Triethanolamine sulfonate or sodium sulfonate R25o3Na (However, R2 is the number of carbon atoms (
However, Rs is an alkyl group having 1 to 4 alkyl atoms having 11 to 15 carbon atoms. ) R, ClIC0OH (however, R3 has 11 to 11 carbon atoms)
1703Na is an alkyl group. ), R6C00H2SO3Na
(Tft: LR6 is an alkyl group having 11 to 17 carbon atoms.), C R7C0NHCH,, CH, 803Na (However, R
7 is the number of carbon atoms (however, the total number of carbon atoms of R6 and Rt is an alkyl group of 10 to 20), lignin sulfonate, etc., higher alcohol sulfate acid R,08
0, Na (wherein, Ro is an alkyl group having 12 to 18 carbon atoms, and IO is an alkyl group having 12 to 18 carbon atoms), polyoxyethylene alkyl ether sulfate R
1, (CH20)ns03Na (However, R11 is an alkyl group having 8 to 18 carbon atoms, and n is an integer of 1 to 2o.), RI 200 (CH2CH2O)mSO3
Anionic surfactants such as Na (Tata L/, Rr2 is an alkyl group having 8 to 18 carbon atoms, m is an integer of 1 to 2°) and alkyl succinate, poly(
oxyethylene) glycol alkyl ether pv R,
3 (CH2CH20), H (wherein R13 is an alkyl group having 6 to 3 carbon atoms, n is an integer of 3 to 120), poly(oxyethylene) alkylaryl ether R14-○-0 (CH2CH20) nH (However, R
14 is a furkyl group having 6 to 12 carbon atoms (7), and n is 3 to
It is an integer of 120. ), poly(oxyethylene) alkyl ester R-Sumi5 Coo(C)I2CH20)nHt TahaR,,-CO
O(CH,CH2)-,-CH2CI(,,-C0OR
,, (However, R15 is an alkyl group having 6 to 24 carbon atoms, n is an integer of 3 to 120.), poly(oxyethylene)alkyluane R,6-NH(CH2C) (20
) nl (also an alkyl group with 6 to 30 children, n and n'
is an integer from 3 to 120. ), poly(oxyethylene)alamide R,7-C0NH(CH2CH20) n
H or alkyl group of R17-6 to 30, n and n'
is an integer from 3 to 120. ), fatty acid ester of poly(oxyethylene) sorbitan 1H(OCH2CH,,)nO)IC-CHo(CH2C
l, 0)nHHO(CH2CH20)nH (However, R18 is an alkyl group having 6 to 24 carbon atoms,
n is an integer from 3 to 60. ), Pluronic poly(oxyethylene)-poly(oxypropylene) cocondensate HO(CH2Cl,,O)a (CI, CH2H20
)b (CH2Cl,.

0) cH (where a, b and c) at 1 (a -
4-b-1-c)=20-400. ), said cocondensate of tetronic type (where x −x“′ and y−y“′〉1, x +
x' -1-1+ x"+ y + y'+ y"+
y'''-20 to 800).

The amount of these surfactants added is usually 100 to 5000 PI 1 m, preferably 500 PI 1 m to water-containing waste oil.
~20001]111n. If the surfactant is water-soluble, it can be added as a 1-10% aqueous solution, or if it is oil-soluble, it can be added as a undiluted solution or dissolved in a tar-based solvent.

Particularly good results can be obtained when such treatment of water-containing waste oil with a solvent is carried out at a pH of 4 to 8, preferably p1]6 to 7.

After adding the aromatic oil and, if necessary, a surfactant to the water-containing waste oil, it is necessary to sufficiently stir and mix them to improve contact mixing, and it is preferable to heat them during this mixing. As a mixing method, any suitable method may be used, such as circulating the mixture in a tank using a pump or using a line mixer.

It is preferable to heat the waste oil to a high temperature within a range where vaporization of the oil and solvent in the waste oil does not become a problem, and for practical purposes it is from room temperature to 90°C.
, preferably 50 to 70°C.

After such aromatic oil is added and mixed, if it is left to stand, the oil will separate. Further, after adding and mixing such an aromatic oil, if sludge is removed by centrifugation or the like, the oil/water separation effect is further improved. Centrifugation is suitable as a method for removing sludge. The higher the centrifugal force, the better the separation effect, but it is usually 1000G or more, and from an economical point of view, preferably 2000G.
~4000G. It is preferable to separate the sludge when applying this centrifugal force.

Various types of centrifugal separation can be used as devices to perform sludge separation at the same time. It is difficult to completely separate the sludge. Therefore, it is preferable to use a centrifugal sedimentation type.

If the R-liquid from which sludge has been removed by a centrifugal separator is allowed to stand, almost no emulsion layer will remain at the interface, and it will separate into two layers: an oil layer at the top and a water layer at the bottom, and the oil and water will be separated easily. It can be collected and separated.

The oil thus recovered can be used at least as fuel oil, and depending on the source of the waste oil, it can be used for more valuable applications. On the other hand, since the amount of oil mixed in with water is only the dissolved amount, it can be purified by activated sludge treatment without any special pretreatment.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 and Comparative Examples 1 to 2 Specific gravity at 4°C is 0842, elemental analysis value C85
Mixed waste oil mainly composed of petroleum oil such as rolling oil and machine oil, which has an oil content of 73% by weight and a HI of 37%, a water content of 26% by weight, and a solid content such as iron oxide (dry state equivalent) of 12% by weight. A predetermined amount of steel mill waste oil and additives forming a W10 emulsion were charged into a 50 cc centrifugal sedimentation tube, and heated in a water bath at 60°C for 30 minutes with occasional stirring.
Heated for minutes. Then, in a hanging centrifuge, 1250
Centrifugal sedimentation was performed at 0 for 15 minutes. The centrifugal sedimentation tube was taken out, and the volumes and weights of the oil layer, the intermediate layer between the oil layer and the water layer (emulsion), the water layer, and the sedimentation layer (solid matter dry water) were read.

The results of experiments conducted with different types of additives are shown in Table 1.

(Left below) Examples 2 to 6 and Comparative Examples 3 to 4 Specific gravity at 4°C is 0835, elemental analysis value C85
5%, oil content with HI 3.2%, water content 55% by weight, water content 44%.
Weight% and solid content such as carbon (converted to dry state) 1
The mixed waste oil is a mixed waste oil mainly composed of petroleum oil such as lubricating oil and coke f' gas cleaning oil consisting of 5% by weight, forming an emulsion.

(The following is a blank space) - 157 Example 7 A liquid obtained by adding 20 volume jL% of the tar-based mixed oil ■ in Example 1 and 200 degrees of sodium dioctyl sulfosuccinate to steel mill waste oil having the same composition as in Example 2 was heated at 70°C. The mixture was heated on a heating stand for 30 minutes. Next, add 1 portion of this liquid.
250-300 m with 103 glass filter) If
When vacuum filtration was carried out under the pressure of
It was 3m1. This liquid f easily separated into oil and water.

Examples 8 to 14 and Comparative Examples 5 to 6 Regarding steel mill waste oil similar to Example 1, fractions from tar light oil to xylene were distilled off, resulting in residual oil (boiling point 140~
230°C) was added to the waste oil, 30 g and a surfactant were mixed, heated at 70°C for 30 minutes, and then heated at 1250G for 1
A 5 minute centrifugation test was performed. The results are shown in Table 3.

(Leaving space below) Example 15 For 1 part of automobile engine oil waste oil (composition determined by centrifugation method: oil content: 91.7 volumes, moisture: 3.8 volumes, sediment: 45% by weight), from tar diesel oil to Residual oil (boiling point 140-230°G) from distillation of up to 0.02
After adding 200011flfi of sodium dodecylbenzenesulfonic acid triethanolamine salt, heating and stirring, a centrifugation test was conducted.

As a result, 0.91 parts of oil, 0.04 parts of water, and 0.007 parts of sediment were recovered.

After addition and mixing, a heating and standing test was conducted at 80° C. for 2 hours, and a clean oil layer of 0.7 vol. was formed in the upper layer. Furthermore, when it was left to stand at room temperature for 24 hours, the oil layer became over 0.8 vol.

When only the waste oil was heated and left at 80°C, no change occurred even after 2 hours.

Patent Applicant: Nippon Steel Chemical Industry Co., Ltd., Nippon Steel & Chemical Industry Co., Ltd., Nippon Steel & Chemical Industry Co., Ltd., Agent, Patent Attorney, Nippon Kaenkyo Engineering Co., Ltd., Patent Attorney 8 1) Mikio Procedural Amendment (released) 1. Indication of the case 1980 Patent Application No. 86,410 2. Invention Name of Petroleum-based water-containing waste oil treatment method 3, relationship with the case of the person making the amendment Patent applicant's address Kaoru, Chuo-ku, Tokyo! ! 6-17-2 Name
Name (664) Zan Nippon Steel Chemical Industry Co., Ltd. (and 1 other person) Representative Joint venture Landlord September 9, 1982 (Shipping date: September 28, 1980)
6. Subject of amendment (1) Application [Patent applicant (Zan Nikka Environmental Engineering Co., Ltd.) 7. Contents of amendment (1) Application [Patent applicant (Zan Nikka Environmental Engineering Co., Ltd.] 8. Reason: The address of the patent applicant (Shin Nikka Environmental Engineering Co., Ltd.) is ``46-51, Nakaharasaki-no-hama, Tobata-ku, Kitakyushu City,'' as stated in the power of attorney attached at the time of application, but the address of this patent applicant is At the time, the name of the town was written incorrectly as ``Daigaku Nakahara Saki-no-hama'' by Mehara, so I have attached an excerpt from the register here and amended it as stated in the correction application.

9. Attachment - List of Classes (3) Registry Extract 1 copy Lukenyl group, MFiNa or K. ) Triethanolamine sulfonate or sodium sulfonate R1801Nm (However, R1 is the number of carbon atoms (However, R itself is the number of alkyl atoms having 11-15 carbon atoms.
~4 alkyl group. ) R, CHCOOI-1 (however, %"l is the number of carbon atoms 1
1 to 1780, an alkyl group of Na. ), R, C0OH, 80, Na
(Tata LR6 is an alkyl group having 11 to 17 carbon atoms.), CH.

R,C0NHCH,CH,80,Na (However, R'
r d number of carbon atoms (however, the total number of carbon atoms of R and R- is an alkyl group of 10 to 20), lignin sulfonate, higher alcohol 6Il acid ester acid R
@ 080 B N a (However, Ro is the number of charcoal Xi atoms 1
The alkyl group of 2 to 1B and R1. is an alkyl group having 12 to 18 carbon atoms. ), polyoxyethylene alkyl ether sulfate R,, (CH,0)n80. Na (However, R11 is an alkyl group having 8 to 18 atoms on carbon 3, n is an integer of 1 to 20.), R, @ -01-0(CH
ICH, O) m801Nm (wherein R1° is an alkyl group having 8 to 18 carbon atoms, mFi is an integer of 1 to 20) and anionic surfactant of alkyl succinic ester, poly(oxyethylene) glycol alkyl Ether R1, (CH,OH,0)nH (however, “
1m is an alkyl group having 6 to 30 carbon atoms, n is 3 to 12
It is an integer of 0. ), poly(oxyethylene)alkylaryl ether R14a-〇 (CH,CH,0)n
H (However, R14 is [[alkyl group having 6 to 12 children,
n is an integer from 3 to 12'0. ), poly(oxyethylene)alkylnyester R1,-〇〇〇(CH,C)
1,0)nHitiR,, -COO(CH,CH,)
70H, CH, -COORIm (However, R111 is alkyl A4 having 6 to 24 carbon atoms, and fl is an integer of 3 to 120.), poly(oxyethylene) alkyl y
R,6-NH(CH,CH,0)nH and number of children 6 to 3
0 alkyl group, n and n' are integers of 3 to 120; ), poly(oxyethylene)alamide R,, -C
0NH(CH,CH,0) nH or R,, = 6~3
The alkyl group of 0, n and n' are integers from 3 to 120. ), fatty acid ester of poly(oxyethylene) sorbitan h O (CH, CH, 0) nH (however, R88 is an alkyl group having 6424 carbon atoms,
n is an integer from 3 to 60. ), Pluronic type poly(oxyethylene)-poly(oxypropylene) cocondensate) 10(CH,CH,0)a(CHCHCH,0)
b(CH,CH.

0) cH (where a, b and c) are 1 (a ten su ten () wz 20 to 400), and the above co-condensate of tetronic type (however, X-?' and y=y" )t, x+x'+1
10N=10'j+'! '+I+Y''-20 to 800.) Go's nonionic surfactants, etc.

The amount of these surfactants added is usually ioo to 5000P, preferably 500 to 20
It is 004. For water-soluble surfactants, 1 to 1
As a 0% aqueous solution, or as a undiluted solution for oil-soluble ones,
It can be added by dissolving it in a tar-based solvent or by dissolving it in a tar-based solvent.

Particularly good results are obtained when such treatment of water-containing waste oil with a solvent is carried out at a pH of 4 to 8, preferably 6 to 7.

Claims (1)

[Scope of Claims] 1. Aromatic hydrocarbons containing 50% by weight or more of aromatic hydrocarbons in petroleum-based water-containing waste oil that forms a water-in-oil emulsion consisting of solid components such as oil, moisture, and sludge derived from petroleum. based oil and anionic or nonionic surfactant,
A method for treating petroleum-based water-containing waste oil, which comprises adding 100 to 5,000 ppl to the water-containing waste oil and separating the oil. 2. The method according to claim 1, wherein after adding the aromatic oil, sludge is removed using centrifugal force, and then separated into oil and water by a static separation method. 3. The method according to claim 1, wherein the amount of the aromatic oil added is 1 volume or more based on the oil content in the water-containing waste oil. 4. The method according to any one of claims 1 to 3, wherein the addition amount is carried out at a temperature of room temperature to 90°C. 5. The method according to any one of claims 1 to 3, wherein the addition and mixing is carried out at a temperature of 50 to 70°C. 6. The method according to any one of claims 1 to 5, wherein the pH is adjusted to 4 to 8 after addition and mixing. 6. The method according to any one of claims 1 to 5, wherein the pH is adjusted to 6 to 7 after the addition amount is 7. 8. The method according to any one of claims 1 to 8, wherein the centrifugal force is 100 OG or more. 9. The method according to any one of claims 1 to 8, wherein the aromatic oil is mainly a fraction having a boiling point of 130 to 275°C. 10. The method according to claim 9, wherein the aromatic oil contains 20 to 60 units of naphthalene. 11. The aromatic oil is a residual oil obtained by distilling a fraction obtained by distilling tar or a fraction from light oil collected from coke oven gas to xylene, according to claim 9. Method.